WO2014128905A1 - Lithium ion secondary battery - Google Patents
Lithium ion secondary battery Download PDFInfo
- Publication number
- WO2014128905A1 WO2014128905A1 PCT/JP2013/054448 JP2013054448W WO2014128905A1 WO 2014128905 A1 WO2014128905 A1 WO 2014128905A1 JP 2013054448 W JP2013054448 W JP 2013054448W WO 2014128905 A1 WO2014128905 A1 WO 2014128905A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- electrode
- diode
- positive electrode
- negative electrode
- battery
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4242—Regeneration of electrolyte or reactants
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Definitions
- the present invention relates to a non-aqueous secondary battery, and more particularly, to a high energy density lithium ion secondary battery suitable for use in portable equipment, electric vehicles, power storage, and the like, and a battery module thereof.
- a coating can be formed on the surface of the negative electrode due to a side reaction accompanying a negative electrode charging reaction at the first charge after the battery is manufactured.
- this coating grows during storage in a relatively high temperature environment or as the negative electrode surface side reaction proceeds with charge / discharge cycles.
- This side reaction is accompanied by lithium ion desorption in the negative electrode, so that battery characteristics such as capacity deterioration due to the potential of the positive electrode and the negative electrode shifting to a higher potential side and resistance increase due to an increase in the film thickness of the negative electrode surface coating are included. It has been a problem to cause the deterioration. In order to suppress capacity deterioration due to lithium ion desorption in the negative electrode, it is necessary to cause a discharge reaction with the positive electrode alone or a charge reaction with the single negative electrode.
- Patent Document 1 discloses an ion supply source that elutes ions of the same type as ions used for charging and discharging in an electrolyte solution inside a battery, and a mesh electrode that is in contact with part of the surface of the negative electrode or part of the surface of the positive electrode And the technique which provides the diode which connects an ion supply source and a mesh electrode, and is arrange
- an object of the present invention is to suppress unintended battery deterioration by appropriately controlling a current flowing through a diode portion.
- Another object of the present invention is to provide a non-aqueous secondary battery and a battery module in which the positive electrode and / or the negative electrode are maintained in a preferable charged state by the current control.
- a non-aqueous secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution, and repeats a reaction of releasing or occluding ions from the positive electrode or the negative electrode into the electrolytic solution.
- An ion supply source that charges and discharges and elutes ions of the same type as the ions in the electrolyte; and a first mesh electrode that is in contact with a part of the surface of the negative electrode; and the ion supply source and the A first diode and a first resistor are provided between the first mesh electrode and the first mesh electrode.
- FIG. 1 is a configuration inside a lithium ion secondary battery in the present invention, (a) a diagram showing a first embodiment, (b) a diagram showing a third embodiment, (c) a diagram showing a fourth embodiment, (D) It is a figure which shows 5th embodiment. It is the schematic of the lithium ion secondary battery in this invention.
- FIG. 3 is a cross-sectional view of the lithium ion secondary battery of FIG. 2 along AA. It is the schematic of the electrode part of the lithium ion secondary battery in this invention. It is a block diagram of the lithium ion secondary battery in 2nd embodiment.
- FIG. 1 shows a simplified configuration diagram of a lithium ion secondary battery according to an embodiment of the present invention.
- a positive electrode 200, a negative electrode 300, and a third electrode 401 are provided inside the battery can 100, and each electrode and the third electrode 401 are connected in series with a diode 402 and a resistance component 403.
- the basic configuration of the present invention is divided into three types (a), (b), (c), and (d) in FIG. Each configuration is shown below.
- the positive electrode 200, the negative electrode 300, and the third electrode 401 are connected via two or more diodes 402 and a resistance component 403.
- the anode side of each diode 402 is connected to the electrode (the positive electrode 200 and the negative electrode 300 are collectively referred to as such) side
- the cathode side of each diode 402 is connected to the third electrode 401 side via a resistor. It becomes the structure connected.
- the cathode and anode terminals of the diodes 402a and 402b are connected in a direction in which a current can flow from the electrode side to the third electrode 401 side.
- the positive electrode 200, the negative electrode 300, and the third electrode 401 are connected via two or more diodes 402 and a resistance component 403, respectively.
- the cathode side of the diode 402e on one side and the electrode (for example, the negative electrode 300) on one side are connected, and the anode side of the diode 402e on one side and the third electrode 401 are connected.
- the anode side of the other side diode 402f and the other side electrode (for example, the positive electrode 200) are connected, and the cathode side of the other side diode 402a and the third electrode 401 are connected.
- the diodes 402e and 402f are connected in a direction in which a current can flow from the electrode side to the third electrode 401 side and a direction in which a current can flow from the third electrode 401 side to the electrode side, respectively.
- a direction in which a current can flow from the electrode side to the third electrode 401 side and a direction in which a current can flow from the third electrode 401 side to the electrode side, respectively.
- FIG. 2 shows a schematic view of a lithium ion secondary battery
- FIG. 3 shows a cross-sectional view taken along the line AA ′ of FIG.
- an electrode group 101 is inserted inside the battery can 100, and the electrode group 101 has a positive electrode 200 and a negative electrode 300, and a separator 350 alternately stacked between the positive electrode and the negative electrode.
- the electrode group 101 has a positive electrode 200 and a negative electrode 300, and a separator 350 alternately stacked between the positive electrode and the negative electrode.
- the mesh electrode 400 is disposed on the surface of the negative electrode 300, and the diode 402 and the resistance component 403 are connected in series with the mesh electrode 400 and the third electrode 401 as the anode side. .
- the mesh electrode 400 to which the diode 402 is connected is preferably the mesh electrode 400 disposed at the center of the electrode group 101.
- the negative electrode 300, the diode 402, and the resistance component 403 are connected in series.
- the mesh electrode 400 is formed on the surface of the positive electrode 200.
- the diode 402 and the resistance component 403 are connected in series with the third electrode 401 as the cathode side.
- the third electrode 401 has a third electrode 401, a diode 402, and a resistance component 403 arranged in a gap on the central axis of the electrode group 101, and plays a role as a lithium ion supply source. .
- the third electrode 401 may be installed anywhere inside the battery can 100. However, as described above, since the third electrode 401 is preferably connected to the positive electrode and the negative electrode in the center of the cell, the center of the electrode group 101 is used. It is desirable to insert it into the gap in the shaft. Thus, by arranging the third electrode 401 on the central axis of the electrode group 101, the wiring distance to the mesh electrode 400 can be shortened. Therefore, it becomes possible to reduce wiring resistance and cost.
- FIG. 4 shows the structure of the positive electrode foil 201 and the negative electrode foil 301.
- the positive electrode material 202 is applied to both surfaces of the positive electrode foil 201
- the negative electrode material 302 is applied to both surfaces of the negative electrode foil 301.
- a mesh electrode 400 is disposed on the surface of the negative electrode material 302. In this embodiment, the mesh electrode 400 is disposed on the negative electrode. However, in the embodiment described later, the mesh electrode may be disposed on the positive electrode material 202 side.
- the positive electrode 200 and the negative electrode 300 are arranged via a separator 350.
- LiCoO2 as a positive electrode active material of a battery, 7 wt% of acetylene black as a conductive agent, and 5 wt% of polyvinylidene fluoride (PVDF) as a binder are added, and N-methyl-2-pyrrolidone is added thereto and mixed.
- PVDF polyvinylidene fluoride
- a positive electrode mixture slurry was prepared.
- the positive electrode mixture slurry is applied and dried on both surfaces of a positive electrode foil 201 (see FIG. 4), which is an aluminum foil having a thickness of 25 ⁇ m, and then pressed and cut.
- the positive electrode 200 was obtained by binding.
- non-graphitizable carbon was used as the negative electrode active material
- 8 wt% of PVDF was added as a binder
- N-methyl-2-pyrrolidone was added thereto and mixed to prepare a slurry of the negative electrode mixture.
- the negative electrode mixture slurry is applied to both surfaces of a negative electrode foil 301 (see FIG. 4), which is a copper foil having a thickness of 10 ⁇ m, and pressed and cut to bind the negative electrode material 302 (see FIG. 4) to both surfaces of the negative electrode foil 301.
- a negative electrode 300 was formed.
- metallic lithium is used for the third electrode 401.
- the diode 402 has a characteristic that current passes only when the potential difference between the positive electrode 200 or the negative electrode 300 and the third electrode 401 is a specific value or more as a threshold value, and the resistance component 403 is the amount of current that flows when the diode 402 is activated. It is installed for the purpose of controlling. In addition, when a diode that operates at a high potential is used, there is a risk of ignition due to generation of a high current and heat generation, but safety is improved by connecting the resistance component 403 to control the current. There are also benefits.
- the mesh electrode 400 is attached to the electrode surface, and a metal foil having a hole so that lithium ions can pass therethrough is used.
- the metal foils 201 and 301 are preferably made of aluminum foil on the positive electrode 200 side and copper foil on the negative electrode 300 side, but any material may be used as long as it is chemically stable in the charge / discharge reaction of the lithium ion battery. .
- LiCoO2 lithium nickel oxide LiNiO 2 or lithium manganese oxide LiMn 2 O 4
- other active materials can be utilized.
- non-graphitizable carbon is used as the negative electrode active material, but other carbon materials such as graphite may be used.
- the contents relating to the cylindrical battery are applicable, but the applicable battery is not limited to the cylindrical battery, but can be applied to a square battery and a laminated cell battery with the same structure.
- FIG. 1A is a simplified diagram of FIG.
- the negative electrode 300 is connected to the third electrode 401 via the diode 402 and the resistance component 403, the negative electrode 300 is connected to the anode side of the diode 402, and the third electrode 401 is connected to the cathode side.
- FIG. 6A shows the initial charge / discharge state of the cell.
- the battery cell used in the experiment is a cylindrical cell having an electric capacity of 1.0 Ah when charged and discharged in the range of the operating potential of the cell battery from 4.1 V to 2.7 V.
- the negative electrode 300 is designed so that the potential of the metallic lithium as the third electrode 401 changes to about 0.1 V during charging and to about 0.8 V during discharging.
- Lithium-ion batteries are cycled over a long period of time, so that side reactions on the surface of the negative electrode proceed, the amount of lithium that functions substantially decreases, the charge / discharge capacity decreases, and the positive electrode potential during operation, the negative electrode Deterioration is further promoted by shifting the potential to the higher potential side. That is, when the charge / discharge state of FIG. 6 (a) goes through a long-term cycle, the positive electrode potential and the negative electrode potential during operation shift to the high potential side as shown in FIG. Capacity is reduced.
- the present embodiment alleviates this shift in the charge / discharge range, and will be described below.
- the threshold value of the diode 402 is set to 0.8 V, and when the potential difference between the negative electrode 300 and the lithium metal that is the third electrode becomes 0.8 V or more, the negative electrode 300 moves toward the lithium metal. A current flows and the negative electrode 300 is charged.
- FIG. 7 simply shows the behavior. That is, the negative electrode potential shifts to the high potential side as shown in FIG. 6 (b) due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 1 (a), the potential of the negative electrode 300 is reduced during discharge. When the voltage exceeds 0.8 V, a current flows from the negative electrode 300 toward the lithium metal, and lithium is supplied to the negative electrode 300.
- the negative electrode potential is lowered to 0.8V.
- the charge / discharge capacity is recovered, and the operating potential of the negative electrode 300 is shifted to the low potential side as shown in FIGS. 7A and 7B (from the circle position (a) to the square position (b). Change in potential) can also reduce potential shift in the charge / discharge range.
- the threshold value of the diode 402 used in this example was set to 0.8V. This threshold value is a value set from the negative electrode maximum potential at the time of initial charge / discharge, and diodes having different threshold values may be used depending on the intended use.
- a diode having a small threshold value of about 0.5 V may be used.
- the charge / discharge range may shift to a lower potential side, and metal lithium may deposit on the negative electrode surface during charging. Therefore, about 0.8V is preferable.
- the threshold is preferably set to the maximum potential in the battery usage range in the initial battery state.
- the resistance component value of the resistance component 403 used in this embodiment is a resistance component corresponding to 0.1 ⁇ .
- the resistance component value of the resistance component 403 is not limited to this value, and is desirably used in the following range. If the resistance value of the resistance component 403 is small, the amount of current flowing through the negative electrode is large and the battery generates heat, which is a safety problem. For example, when the threshold value of the diode 402 is 0.8 V and the potential difference between the negative electrode and the third electrode is 1.0 V, if the resistance value of the resistance component 403 is 0.04 ⁇ , the amount of current flowing through the negative electrode corresponds to 5 C or less. Because there is no problem in safety because it can be controlled.
- the resistance value of the resistance component 403 when the resistance value of the resistance component 403 is large, when the amount of current flowing through the negative electrode is small and the charge / discharge cycle span is short, the recovery of the charge / discharge capacity may not be sufficiently completed. Therefore, when the threshold voltage of the diode 402 is 0.8 V and the potential difference between the negative electrode and the third electrode is 1.0 V, for example, if 0.4 ⁇ , the amount of current flowing through the negative electrode is equivalent to 0.5 C or more. The recovery of the discharge capacity can be completed sufficiently. From the above, the range of 0.04 ⁇ to 0.4 ⁇ can be used appropriately.
- the diode portion Since the flowing current becomes an appropriate C rate, unintended battery deterioration can be suppressed. Moreover, since the negative electrode 300 is maintained in a preferable charged state by using the current control described above and this embodiment is used, the capacity deterioration of the lithium ion battery can be mitigated.
- this embodiment is effective particularly when the capacity deterioration at the negative electrode is large because lithium ions are supplied from the third electrode 401 to the negative electrode 300.
- This example is an example based on the configuration of FIG. 1A as in the first embodiment, and is the same as that of the first embodiment except that the diode 402 is connected to the positive electrode 200 side. It is the same.
- FIG. 5 A simplified diagram of the battery cell configuration in this example is shown in FIG.
- the positive electrode 200 is connected to the third electrode 401 via the diode 402 and the resistance component 403, and the positive electrode 200 is connected to the anode side of the diode 402 and the third electrode 401 is connected to the cathode side.
- the operating potential of the cell battery in the charge / discharge state in the initial state of the cell, is in the usage range of 4.1V to 2.7V, and the positive electrode 200 is the third electrode 401. It is designed to change the potential to about 4.2 V during charging and about 3.5 V during discharging with respect to metallic lithium.
- FIG. 10 simply shows the behavior. In other words, the positive electrode potential shifts to the high potential side as shown in FIG. 6B due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG.
- the potential of the positive electrode 200 is 4.2 V during charging.
- a current flows from the positive electrode 200 toward the lithium metal and lithium is supplied to the positive electrode 200, so that the charge / discharge capacity is recovered and the operating potential of the positive electrode 200 is shifted to the low potential side ((c) (Change from the position of the circle to the square position of (d)), the potential shift in the charge / discharge range can be alleviated.
- the threshold value of the diode 402 used in this embodiment is set to 4.2 V, a diode having a different threshold value may be used depending on the application.
- a diode having a small threshold of about 3.8 V may be used when only a narrow charge / discharge range is used and the potential change of the positive electrode 200 can be expected to be small as in HEV applications.
- a diode having a small threshold of about 3.8 V may shift to a lower potential side, and the positive electrode may be overdischarged during discharge. Therefore, care must be taken in setting the threshold depending on the intended use.
- the threshold is preferably set to the maximum potential in the battery usage range in the initial battery state.
- the resistance component value of the resistance component 403 used in this embodiment is a resistance component corresponding to 0.1 ⁇ .
- the resistance component value of the resistance component 403 is not limited to this value, and is desirably used in the following range. If the resistance value of the resistance component 403 is small, the amount of current flowing through the positive electrode is large, and the battery generates heat, which causes a safety problem.
- the threshold value of the diode 402 is 4.2V and the potential difference between the positive electrode and the third electrode is 4.4V
- the resistance value of the resistance component 403 is 0.04 ⁇
- the amount of current flowing through the positive electrode is 5C.
- the resistance value of the resistance component 403 is large, the amount of current flowing from the positive electrode is small, and if the charge / discharge cycle span is short, the recovery of the charge / discharge capacity may not be sufficiently completed.
- the threshold voltage of the diode 402 is 4.2 V and the potential difference between the positive electrode and the third electrode is 4.4 V, for example, if 0.4 ⁇ , the amount of current flowing through the negative electrode is equivalent to 0.5 C or more.
- the recovery of the discharge capacity can be completed sufficiently. From the above, the range of 0.04 ⁇ to 0.4 ⁇ can be used appropriately.
- the diode portion Since the flowing current becomes an appropriate C rate, unintended battery deterioration can be suppressed.
- the positive electrode is maintained in a preferable charged state by the current control described above, the capacity deterioration of the lithium ion battery can be alleviated.
- this embodiment is effective particularly when the capacity deterioration in the positive electrode 200 is large.
- lithium ions are supplied from the third electrode 401 to the positive electrode 200, which is particularly effective when deterioration at the positive electrode 200 is large.
- This embodiment is an example based on the configuration of FIG. 1B, and is the same as the first embodiment except for the following points.
- FIG.1 (b) the battery cell structure in this embodiment is demonstrated using FIG.1 (b).
- the positive electrode 200 and the negative electrode 300 are connected to the third electrode 401 via the diode 402 (402a, 402b) and the resistance component 403 (403a, 403b), as shown in FIG.
- the positive electrode 200 is connected to the anode side
- the third electrode 401 is connected to the cathode side of the diode 402b.
- two diodes and a resistance component are connected. More specifically, the present embodiment has a configuration in which the configurations of the first embodiment and the second embodiment are combined. Also in the present embodiment, as shown in FIG.
- the positive electrode 200 in the charge / discharge state in the initial state of the cell, is the third electrode 401 in the operating range of the cell battery operating voltage of 4.1V to 2.7V.
- the negative electrode 300 is designed to change in potential from about 4.2 V to about 3.5 V with respect to metallic lithium, and from about 0.1 V to about 0.8 V.
- a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle over a long period of time.
- it is possible to alleviate a shift in the charge / discharge range. is there.
- the threshold value of the diode 402b connected to the positive electrode 200 side is set to 4.2V
- the threshold value of the diode 402a connected to the negative electrode 300 side is set to 0.8V.
- both the positive electrode 200 and the negative electrode 300 have the merit of preventing overcharge and overdischarge, respectively, and a safe lithium ion secondary battery can be provided.
- 4.2V and 0.8V which are the threshold values of the set diodes 402a and 402b, can be used depending on the application. good.
- the capacity deterioration of the lithium ion secondary battery can be alleviated, and a safer lithium ion secondary battery can be provided.
- This embodiment is an example based on the configuration of FIG. 1C, and is the same as the second embodiment except for the following points.
- FIG. 1C A simplified diagram of the battery cell configuration in this example is shown in FIG.
- the configuration is such that the positive electrode 200 is connected to the third electrode 401 via two diodes 402 (402c and 403d) and a resistance component 403 (403c and 403d), and the diodes 402c and 402d.
- the positive electrode 200 is connected to the anode side, and the third electrode 401 is connected to the cathode side of the diodes 402c and 402d.
- the positive electrode 200 in the charge / discharge state in the initial state of the cell, the positive electrode 200 is about 4 when the operating potential of the cell battery is 4.1V to 2.7V.
- the threshold value of the diode 402c connected to the positive electrode 200 side is set to 4.2V
- the threshold value of the diode 402d is set to 4.5V
- the positive electrode 200 and the lithium metal that is the third electrode 401 are connected.
- the threshold voltage of the diode 402d is larger than the threshold voltage of the diode 402c.
- the resistance value of the resistance component 403c connected in series with the diode 402c having a threshold value of 4.2V is the same as that of the second embodiment, but is connected in series with the diode 402d whose threshold value is set to 4.5V.
- the resistance value of the resistance component 403d is 0.01 m ⁇ . This component is not limited to this value, but it is desirable that the component be relatively small and have a value that does not cause abnormal battery heat generation. Further, the resistance value of the resistance component 403d is configured to be smaller than the resistance of the resistance component 403c.
- the threshold value of the potential that should not be exceeded is set to 4.5V.
- each is configured to prevent overcharging of the positive electrode, but a sudden abnormality occurs in the battery system, and a large current flows to cause the positive electrode to be overcharged.
- a relatively large resistance value is connected between the positive electrode 200 and the third electrode 401, there is a possibility that a large current does not flow and the overcharge state cannot be resolved. Therefore, as in this embodiment, by using a diode having a threshold value larger than the threshold voltage of the diode 402c as the diode 402d and further using a resistance component 403d having a resistance value lower than that of the resistance component 403c, the battery system is abnormal.
- the battery When the potential of the positive electrode 200 does not occur and operates at a potential lower than 4.5V, the battery operates with the same effect as in the second embodiment. If the battery system malfunctions, the potential of the positive electrode 200 becomes 4.5V. When exceeding, it is possible to eliminate the overcharged state of the positive electrode.
- the threshold value of the potential that should not be exceeded is set to 4.5 V, but the value varies depending on the material of the positive electrode.
- the negative electrode 300 may be connected to the third electrode 401 via the diodes 402c and 402d and the resistance components 403c and 403d.
- the negative electrode 200 is connected to the anode side of the diode 402 and the third electrode 401 is connected to the cathode side.
- the threshold value of the diode at that time is considered to be about 0.8V and 1.4V.
- the resistance connected in series with the diode is the same as in the case of the positive electrode, and the resistance value of the resistance component connected in series with the diode whose threshold is set to 0.8 V is as in the first embodiment.
- the resistance value of the resistance component connected in series with the diode whose threshold value is set to 1.4 V is relatively small, such as 0.01 m ⁇ , and is a value that does not cause abnormal battery heat generation. Is considered desirable.
- both the positive electrode 200 and the negative electrode 300 may be connected to the third electrode 401 via two diodes 402c and 402d and resistance components 403c and 403d. Even when it flows, it is possible to prevent the overcharge state of the positive electrode and the overdischarge state of the negative electrode. As described above, by using this embodiment, it is possible to alleviate the capacity deterioration of the lithium ion secondary battery and provide a safer lithium ion secondary battery.
- the present embodiment is an example based on the configuration of FIG. 1D, and is the same as the third embodiment except for the following points.
- FIG. 1D A simplified diagram of the battery cell configuration in the present embodiment is shown in FIG.
- the positive electrode 200 and the negative electrode 300 are connected to the third electrode 501 via the diode 402 (402e, 402f) and the resistance component 403 (403e, 403f).
- the positive electrode 200 is connected to the anode side of the diode 402f
- the third electrode 501 is connected to the cathode side of the diode 402e.
- the third electrode 501 is connected to the anode side of the diode 403e, the negative electrode 300 is connected to the cathode side of the diode 403e, and the direction of the diode connected to the negative electrode side is reversed. It has become.
- lithium titanate hereinafter referred to as LTO
- LTO lithium titanate
- LiSi, LiSn, and the like are also considered as candidates for the third electrode 501, and possesses a standard potential that is intermediate between the positive electrode operating potential and the negative electrode operating potential. It is a condition to be a material to be used.
- the positive electrode 200 in the charge / discharge state in the initial state of the cell, has the potential of metallic lithium in the operating range of the cell battery of 4.1V to 2.7V.
- the negative electrode 300 is designed to change in potential from about 4.2 V to about 3.5 V with respect to the level, from about 0.1 V to about 0.8 V.
- the potential level of the LTO used as the third electrode 501 in the present embodiment was about 1.5 V with respect to the potential level of metallic lithium.
- the case where the battery is used in the range of 4.1V to 2.7V will be described.
- the threshold value of the diode 402f connected to the positive electrode 200 is set to 2.3V
- the threshold value of the diode 402e connected to the negative electrode 300 is set to 1.1V.
- Each electrode and the third electrode 501 When the potential difference between a certain LTO becomes more than each threshold, a current flows from the positive electrode 200 to the LTO direction, a current flows from the LTO to the negative electrode 300, the positive electrode 200 is charged, and the negative electrode 300 is charged.
- the threshold values 2.3 V and 1.1 V of the diodes set above are potential differences between the potentials of the positive electrode 200 and the negative electrode 300 and the LTO which is the third electrode 510 in the initial 50% SOC state of the lithium ion battery.
- FIG. 12 simply shows the behavior.
- the potential of the negative electrode shifts to the high potential side due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 1D, the potential difference between the positive electrode 200 and the LTO during charging.
- each diode used in this example was set by the potential difference between the potential of the positive electrode 200 and the negative electrode 300 and the LTO which is the third electrode 510 in the SOC 50% state of the initial lithium ion battery.
- a diode having a threshold value that is a potential difference between a different SOC state potential and the LTO that is the third electrode 510 may be used.
- the configuration in which each electrode performs voltage balancing with a potential of SOC 50% as in the present embodiment is such that the SOC is about 50% at the center of the working potential range as in HEV applications, and the charging / discharging range to be used is small.
- the potential of the initial 80% SOC state of the lithium ion battery and the third potential You may use the diode which has a potential difference with LTO which is an electrode as a threshold value.
- the resistance value of the resistance component 403f connected to the positive electrode 200 is about 500 ⁇
- the resistance value of the resistance component 403e connected to the negative electrode 200 is about 250 ⁇ . It was.
- the resistance values of the resistance components 403e and 403f are not limited to this value, and depending on the application, it is desirable to use resistance components in the range of 1 k ⁇ to 500 ⁇ and 500 ⁇ to 250 ⁇ , respectively.
- the reason why the resistance component having a relatively high resistance value is used is that each electrode is stabilized at the initial SOC 50% potential as in this example. This is because, when the diode is set, the electrodes are discharged in a short time and the energy efficiency is poor if the resistance value of the resistance component 403 is small even when charged in a high SOC state.
- the battery control system 600 includes a battery group 31 in which batteries of at least two cells or more are connected in series, a charge / discharge control device 30 that collects battery information of the battery group 31, and the battery group from the charge / discharge control device. And a controller 36 that receives control information for controlling the battery 31 and controls the battery group 31.
- the charge / discharge control device 30 includes a battery information acquisition unit 32 that acquires battery information of the battery group 31, a battery variation determination unit 33 that determines variations in the state of charge of each battery based on information of the battery information acquisition unit 32, and a battery The charge state control unit 34 that calculates a charge state control instruction based on the information of the variation determination unit 34, the control signal transmission unit 35 that outputs the instruction of the charge state control unit 34 to the controller 36, and the charge state control unit 34. It comprises a display unit 37 for displaying the information. As more specific control, the battery information acquisition unit 32 acquires voltage information of each battery, and the voltage variation determination unit 33 determines whether or not the voltage balancing function needs to be operated.
- the charge state control unit 34 instructs the controller 36 through the control signal transmission unit 35 about the charge state of the battery group.
- the battery information acquisition unit 32 acquires temperature information, current information, and voltage information of the battery group 31.
- the battery variation determination unit 34 determines the battery variation based on the battery information acquired by the battery information acquisition unit 32. More specifically, it is determined whether or not each battery is equal to or higher than a voltage value that activates the voltage balancing function.
- the voltage difference of each battery that operates the voltage balancing function is not particularly limited.
- step S3 the process proceeds to step S3, where the charge state control unit 34 calculates the charge state in which the variation is suppressed, and the charge state varies depending on the embodiment. An instruction is output to the controller 36 and the control is terminated. On the other hand, if the voltage is equal to or lower than the predetermined voltage value in step S2, the control is terminated without particularly instructing the state of charge.
- the battery group controlled to the charged state operates the voltage balancing function in each embodiment described above inside each battery, the positive electrode and the negative electrode shift to a predetermined charged state, and each battery The state of charge converges to a predetermined value.
- the charge state of each battery does not converge to a predetermined value due to, for example, a case where deterioration accelerates in some batteries due to variations in battery temperature.
- an algorithm that provides a loop that returns from step S3 to step S1 and raises the state of charge indicated by the state of charge control unit by a predetermined value to finally converge is preferable.
- the lithium ion secondary battery is controlled so as not to be overcharged.
- the display unit 37 notifies the host system or the user of the number of loops, for example, together with the signal of completion.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Secondary Cells (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
An objective of the present invention is to provide a secondary battery and a battery module, each of which is suppressed in unintended battery deterioration by adequately controlling the electric current flowing through a diode portion.
Another objective of the present invention is to provide a nonaqueous secondary battery and a battery module, in each of which the positive electrode and/or the negative electrode is held in a desirably charged state by the above-described electric current control.
A nonaqueous secondary battery of the present invention comprises a positive electrode (200), a negative electrode (300) and an electrolyte solution, and is charged and discharged by repeating a reaction wherein ions are desorbed from the positive electrode (200) or the negative electrode (300) into the electrolyte solution or absorbed from the electrolyte solution. This nonaqueous secondary battery is characterized by being provided with an ion supply source (401) which dissolves ions of the same kind as the above-described ions into the electrolyte solution, and a first mesh electrode (400) which is in contact with a part of the surface of the negative electrode (300). This nonaqueous secondary battery is also characterized in that a first diode (402) and a first resistor (403) are provided between the ion supply source (401) and the first mesh electrode (400).
Description
本発明は、非水系二次電池に係り、特に、ポータブル機器,電気自動車,電力貯蔵等に
用いるに好適な、高エネルギー密度リチウムイオン二次電池及びその電池モジュールに関
する。 The present invention relates to a non-aqueous secondary battery, and more particularly, to a high energy density lithium ion secondary battery suitable for use in portable equipment, electric vehicles, power storage, and the like, and a battery module thereof.
用いるに好適な、高エネルギー密度リチウムイオン二次電池及びその電池モジュールに関
する。 The present invention relates to a non-aqueous secondary battery, and more particularly, to a high energy density lithium ion secondary battery suitable for use in portable equipment, electric vehicles, power storage, and the like, and a battery module thereof.
炭素材料を負極活物質として用いるリチウムイオン二次電池においては、電池を製造した後の初回充電時の負極充電反応に伴う副反応により、負極表面に被膜ができることが知られている。
In a lithium ion secondary battery using a carbon material as a negative electrode active material, it is known that a coating can be formed on the surface of the negative electrode due to a side reaction accompanying a negative electrode charging reaction at the first charge after the battery is manufactured.
この被膜は、比較的高温環境下での保存時や、充放電サイクルに伴う負極表面副反応の進行に伴い成長することが知られている。そしてこの副反応は、負極内のリチウムイオン脱離を伴うため、正極や負極の電位が高電位側にシフトすることによる容量劣化や、負極表面被膜の膜厚増加に伴う抵抗上昇などの電池特性の劣化を発生させてしまうことが課題となっている。前記負極内のリチウムイオン脱離に起因した容量劣化を抑制するためには、正極単独での放電反応か、負極単体での充電反応を起こす必要がある。
特許文献1には電池内部の電解液中に充放電に使われるイオンと同種のイオンを溶出するイオン供給源と、負極の表面の一部にまたは正極の表面の一部に接しているメッシュ電極と、イオン供給源とメッシュ電極を接続してメッシュ電極側を+極性として配置されるダイオードを設ける技術が開示されている。
特許文献1に開示されている技術によれば、充放電時の副反応によるセル内部の局所的な電位分布を解消し、容量劣化を抑制することが可能になる。 It is known that this coating grows during storage in a relatively high temperature environment or as the negative electrode surface side reaction proceeds with charge / discharge cycles. This side reaction is accompanied by lithium ion desorption in the negative electrode, so that battery characteristics such as capacity deterioration due to the potential of the positive electrode and the negative electrode shifting to a higher potential side and resistance increase due to an increase in the film thickness of the negative electrode surface coating are included. It has been a problem to cause the deterioration. In order to suppress capacity deterioration due to lithium ion desorption in the negative electrode, it is necessary to cause a discharge reaction with the positive electrode alone or a charge reaction with the single negative electrode.
Patent Document 1 discloses an ion supply source that elutes ions of the same type as ions used for charging and discharging in an electrolyte solution inside a battery, and a mesh electrode that is in contact with part of the surface of the negative electrode or part of the surface of the positive electrode And the technique which provides the diode which connects an ion supply source and a mesh electrode, and is arrange | positioned by making the mesh electrode side into + polarity is disclosed.
According to the technique disclosed inPatent Document 1, it is possible to eliminate local potential distribution inside the cell due to side reactions during charge and discharge, and to suppress capacity deterioration.
特許文献1には電池内部の電解液中に充放電に使われるイオンと同種のイオンを溶出するイオン供給源と、負極の表面の一部にまたは正極の表面の一部に接しているメッシュ電極と、イオン供給源とメッシュ電極を接続してメッシュ電極側を+極性として配置されるダイオードを設ける技術が開示されている。
特許文献1に開示されている技術によれば、充放電時の副反応によるセル内部の局所的な電位分布を解消し、容量劣化を抑制することが可能になる。 It is known that this coating grows during storage in a relatively high temperature environment or as the negative electrode surface side reaction proceeds with charge / discharge cycles. This side reaction is accompanied by lithium ion desorption in the negative electrode, so that battery characteristics such as capacity deterioration due to the potential of the positive electrode and the negative electrode shifting to a higher potential side and resistance increase due to an increase in the film thickness of the negative electrode surface coating are included. It has been a problem to cause the deterioration. In order to suppress capacity deterioration due to lithium ion desorption in the negative electrode, it is necessary to cause a discharge reaction with the positive electrode alone or a charge reaction with the single negative electrode.
According to the technique disclosed in
しかしながら、特許文献1に記載発明では、イオン供給の速度を制御し回路を流れる電流を制御しないことには、ダイオード部分を大電流が流れることにより発熱し、電池の劣化を促進してしまうといった課題がある。
また、負極の一部で副反応が加速され、局所的な電位分布が発生する結果として、負極の一部が他の部分より過放電状態に至ることを防止できるが、正極および/または負極が、標準的な充放電範囲の内で好ましい状態に移行する機能を付加することはできない。
本発明の目的は、上記課題を鑑み、ダイオード部分を流れる電流を適切に制御することで、意図せぬ電池劣化を抑制することにある。
また、前記電流制御により、正極および/または負極が好ましい充電状態に保持された非水系二次電池及び電池モジュールを提供することにある。 However, in the invention described inPatent Document 1, in order to control the ion supply speed and not to control the current flowing through the circuit, a problem arises in that heat is generated due to a large current flowing through the diode portion and the deterioration of the battery is promoted. There is.
Further, as a result of the side reaction being accelerated in a part of the negative electrode and the generation of a local potential distribution, it is possible to prevent a part of the negative electrode from reaching an overdischarged state than the other part. The function of shifting to a preferable state within the standard charge / discharge range cannot be added.
In view of the above problems, an object of the present invention is to suppress unintended battery deterioration by appropriately controlling a current flowing through a diode portion.
Another object of the present invention is to provide a non-aqueous secondary battery and a battery module in which the positive electrode and / or the negative electrode are maintained in a preferable charged state by the current control.
また、負極の一部で副反応が加速され、局所的な電位分布が発生する結果として、負極の一部が他の部分より過放電状態に至ることを防止できるが、正極および/または負極が、標準的な充放電範囲の内で好ましい状態に移行する機能を付加することはできない。
本発明の目的は、上記課題を鑑み、ダイオード部分を流れる電流を適切に制御することで、意図せぬ電池劣化を抑制することにある。
また、前記電流制御により、正極および/または負極が好ましい充電状態に保持された非水系二次電池及び電池モジュールを提供することにある。 However, in the invention described in
Further, as a result of the side reaction being accelerated in a part of the negative electrode and the generation of a local potential distribution, it is possible to prevent a part of the negative electrode from reaching an overdischarged state than the other part. The function of shifting to a preferable state within the standard charge / discharge range cannot be added.
In view of the above problems, an object of the present invention is to suppress unintended battery deterioration by appropriately controlling a current flowing through a diode portion.
Another object of the present invention is to provide a non-aqueous secondary battery and a battery module in which the positive electrode and / or the negative electrode are maintained in a preferable charged state by the current control.
上記課題に鑑み、本発明にかかる非水系二次電池は、正極と負極と電解液とを含み、前記正極または前記負極から前記電解液中へイオンを放出する、あるいは、吸蔵する反応を繰り返して充放電し、前記電解液中に前記イオンと同種のイオンを溶出するイオン供給源と、前記負極の表面の一部に接している第一のメッシュ電極とを有し、前記イオン供給源と前記第一のメッシュ電極との間に第一のダイオードと第一の抵抗を設けたことを特徴とする。
In view of the above problems, a non-aqueous secondary battery according to the present invention includes a positive electrode, a negative electrode, and an electrolytic solution, and repeats a reaction of releasing or occluding ions from the positive electrode or the negative electrode into the electrolytic solution. An ion supply source that charges and discharges and elutes ions of the same type as the ions in the electrolyte; and a first mesh electrode that is in contact with a part of the surface of the negative electrode; and the ion supply source and the A first diode and a first resistor are provided between the first mesh electrode and the first mesh electrode.
本発明によれば、ダイオード部分を流れる電流を適切に制御することで意図せぬ電池劣化を抑制し、さらには、正極および/または負極が好ましい充電状態に保持された非水系二次電池及び電池モジュールを提供することができる。
上記した以外の課題、構成及び効果は以下の実施形態の説明により明らかにされる。 According to the present invention, undesired battery deterioration is suppressed by appropriately controlling the current flowing through the diode portion, and further, the nonaqueous secondary battery and the battery in which the positive electrode and / or the negative electrode are maintained in a preferable charged state. Modules can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.
上記した以外の課題、構成及び効果は以下の実施形態の説明により明らかにされる。 According to the present invention, undesired battery deterioration is suppressed by appropriately controlling the current flowing through the diode portion, and further, the nonaqueous secondary battery and the battery in which the positive electrode and / or the negative electrode are maintained in a preferable charged state. Modules can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.
以下、図面等を用いて、本発明の実施形態について説明する。以下の説明は本発明の内容の具体例を示すものであり、本発明がこれらの説明に限定されるものではなく、本明細書に開示される技術的思想の範囲内において当業者による様々な変更および修正が可能である。また、本発明を説明するための全図において、同一の機能を有するものは、同一の符号を付け、その繰り返しの説明は省略する場合がある。
図1は、本発明の実施形態におけるリチウムイオン二次電池の簡略的な構成図を示している。電池缶100内部に正極200、負極300、第3電極401が設けられており、各電極と第3電極401は、ダイオード402と抵抗成分403と直列的に接続している。本発明の基本的な構成は、図1における(a)、(b)及び(c)、(d)の3種類に分けられる。各構成を下記で示す。
(a):正極200、負極300のどちらか一方が第3電極401とダイオード402と抵抗成分403を介して接続されている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Changes and modifications are possible. In all the drawings for explaining the present invention, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted.
FIG. 1 shows a simplified configuration diagram of a lithium ion secondary battery according to an embodiment of the present invention. Apositive electrode 200, a negative electrode 300, and a third electrode 401 are provided inside the battery can 100, and each electrode and the third electrode 401 are connected in series with a diode 402 and a resistance component 403. The basic configuration of the present invention is divided into three types (a), (b), (c), and (d) in FIG. Each configuration is shown below.
(A): Either thepositive electrode 200 or the negative electrode 300 is connected to the third electrode 401, the diode 402, and the resistance component 403.
図1は、本発明の実施形態におけるリチウムイオン二次電池の簡略的な構成図を示している。電池缶100内部に正極200、負極300、第3電極401が設けられており、各電極と第3電極401は、ダイオード402と抵抗成分403と直列的に接続している。本発明の基本的な構成は、図1における(a)、(b)及び(c)、(d)の3種類に分けられる。各構成を下記で示す。
(a):正極200、負極300のどちらか一方が第3電極401とダイオード402と抵抗成分403を介して接続されている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Changes and modifications are possible. In all the drawings for explaining the present invention, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted.
FIG. 1 shows a simplified configuration diagram of a lithium ion secondary battery according to an embodiment of the present invention. A
(A): Either the
(b)及び(c):正極200、負極300と第3電極401間が2つ以上のダイオード402と抵抗成分403を介して接続されている。この時、各ダイオード402のアノード側が電極(正極200、負極300を総称してこのように呼ぶこととする。)側と接続され、各ダイオード402のカソード側が抵抗を介して第3電極401側と接続される構成となる。言い換えると、各ダイオード402a、402bのカソード、アノードの端子が、電極側から第3電極401側に電流を流せる方向で接続される。
(d):正極200、負極300と第3電極401間がそれぞれ2つ以上のダイオード402と抵抗成分403を介して接続されている。この時、一方側のダイオード402eのカソード側と一方側の電極(例えば負極300)が接続され、一方側のダイオード402eのアノード側と第3電極401が接続される。さらに、他方側のダイオード402fのアノード側と他方側の電極(例えば正極200)が接続され、他方側のダイオード402aのカソード側と第3電極401が接続される。言い換えると、ダイオード402eと402fで、それぞれ電極側から第3電極401側に電流を流せる方向、第3電極401側から電極側に電流を流せる方向で接続されている。
以下、実施例を用いて、各構成の詳細について説明する。 (B) and (c): Thepositive electrode 200, the negative electrode 300, and the third electrode 401 are connected via two or more diodes 402 and a resistance component 403. At this time, the anode side of each diode 402 is connected to the electrode (the positive electrode 200 and the negative electrode 300 are collectively referred to as such) side, and the cathode side of each diode 402 is connected to the third electrode 401 side via a resistor. It becomes the structure connected. In other words, the cathode and anode terminals of the diodes 402a and 402b are connected in a direction in which a current can flow from the electrode side to the third electrode 401 side.
(D): Thepositive electrode 200, the negative electrode 300, and the third electrode 401 are connected via two or more diodes 402 and a resistance component 403, respectively. At this time, the cathode side of the diode 402e on one side and the electrode (for example, the negative electrode 300) on one side are connected, and the anode side of the diode 402e on one side and the third electrode 401 are connected. Furthermore, the anode side of the other side diode 402f and the other side electrode (for example, the positive electrode 200) are connected, and the cathode side of the other side diode 402a and the third electrode 401 are connected. In other words, the diodes 402e and 402f are connected in a direction in which a current can flow from the electrode side to the third electrode 401 side and a direction in which a current can flow from the third electrode 401 side to the electrode side, respectively.
Hereinafter, details of each configuration will be described using an embodiment.
(d):正極200、負極300と第3電極401間がそれぞれ2つ以上のダイオード402と抵抗成分403を介して接続されている。この時、一方側のダイオード402eのカソード側と一方側の電極(例えば負極300)が接続され、一方側のダイオード402eのアノード側と第3電極401が接続される。さらに、他方側のダイオード402fのアノード側と他方側の電極(例えば正極200)が接続され、他方側のダイオード402aのカソード側と第3電極401が接続される。言い換えると、ダイオード402eと402fで、それぞれ電極側から第3電極401側に電流を流せる方向、第3電極401側から電極側に電流を流せる方向で接続されている。
以下、実施例を用いて、各構成の詳細について説明する。 (B) and (c): The
(D): The
Hereinafter, details of each configuration will be described using an embodiment.
《第一の実施形態》
本実施形態は、図1の(a)の構成に基づいている。まず、図2に、リチウムイオン二次電池の概略図を、図3に、図2のA-A′の断面図を示す。 First embodiment
This embodiment is based on the configuration shown in FIG. First, FIG. 2 shows a schematic view of a lithium ion secondary battery, and FIG. 3 shows a cross-sectional view taken along the line AA ′ of FIG.
本実施形態は、図1の(a)の構成に基づいている。まず、図2に、リチウムイオン二次電池の概略図を、図3に、図2のA-A′の断面図を示す。 First embodiment
This embodiment is based on the configuration shown in FIG. First, FIG. 2 shows a schematic view of a lithium ion secondary battery, and FIG. 3 shows a cross-sectional view taken along the line AA ′ of FIG.
図2および図3に示すように、電池缶100の内部には電極群101が挿入されており、電極群101は、正極200と負極300、及びセパレータ350を正極と負極の間に交互に重ねて円筒形に捲回したものである。
As shown in FIGS. 2 and 3, an electrode group 101 is inserted inside the battery can 100, and the electrode group 101 has a positive electrode 200 and a negative electrode 300, and a separator 350 alternately stacked between the positive electrode and the negative electrode. Rolled into a cylindrical shape.
図2では、負極300の表面上にメッシュ電極400を配置し、そのメッシュ電極400と第3電極401とを、メッシュ電極400をアノード側として、ダイオード402と抵抗成分403を直列に接続されている。なお、ダイオード402が接続されるメッシュ電極400は電極群101の最も中心部に配置されているメッシュ電極400が好ましい。電池反応が進行してセルが発熱する際、最も温度が高くなる位置である中心部付近で最も被膜生成の副反応が進行する。そのため、ダイオード402と電極群101の最も中心部に配置されているメッシュ電極400を接続することにより、いち早く電池の劣化に対応することが可能となる。
また、図2では、負極300とダイオード402、抵抗成分403が直列に接続している図を示しているが、後述する正極200と接続させる場合も同様、正極200の表面上にメッシュ電極400を配置し、第3電極401をカソード側として、ダイオード402と抵抗成分403を直列に接続させる。なお、この場合も電極群101の最も中心部に配置されているメッシュ電極400にダイオード402を接続することが好ましい。理由については、上述したように電池反応が進行してセルが発熱する際、最も温度が高くなる位置である中心部付近で最も被膜生成の副反応が進行するためである。 In FIG. 2, themesh electrode 400 is disposed on the surface of the negative electrode 300, and the diode 402 and the resistance component 403 are connected in series with the mesh electrode 400 and the third electrode 401 as the anode side. . The mesh electrode 400 to which the diode 402 is connected is preferably the mesh electrode 400 disposed at the center of the electrode group 101. When the battery reaction proceeds and the cell generates heat, the side reaction for forming the film proceeds most in the vicinity of the central portion where the temperature is highest. Therefore, by connecting the diode 402 and the mesh electrode 400 disposed at the most central portion of the electrode group 101, it becomes possible to quickly cope with the deterioration of the battery.
2 shows a diagram in which thenegative electrode 300, the diode 402, and the resistance component 403 are connected in series. Similarly, when the positive electrode 200 described later is connected, the mesh electrode 400 is formed on the surface of the positive electrode 200. The diode 402 and the resistance component 403 are connected in series with the third electrode 401 as the cathode side. In this case also, it is preferable to connect the diode 402 to the mesh electrode 400 arranged at the most central portion of the electrode group 101. The reason is that, as described above, when the battery reaction proceeds and the cell generates heat, the side reaction for forming the film proceeds most in the vicinity of the central portion where the temperature is highest.
また、図2では、負極300とダイオード402、抵抗成分403が直列に接続している図を示しているが、後述する正極200と接続させる場合も同様、正極200の表面上にメッシュ電極400を配置し、第3電極401をカソード側として、ダイオード402と抵抗成分403を直列に接続させる。なお、この場合も電極群101の最も中心部に配置されているメッシュ電極400にダイオード402を接続することが好ましい。理由については、上述したように電池反応が進行してセルが発熱する際、最も温度が高くなる位置である中心部付近で最も被膜生成の副反応が進行するためである。 In FIG. 2, the
2 shows a diagram in which the
第3極401は、図3に示す通り、第3電極401、ダイオード402、抵抗成分403が電極群101の中心軸にある隙間に配置されており、リチウムイオン供給源としての役割を担っている。第3極401は、電池缶100の内部のどこに設置しても良いが、上記のように、第3極401はセル中心部の正極、負極と接続するのが望ましいため、電極群101の中心軸にある隙間に挿入するのが望ましい。このように電極群101の中心軸に第3電極401を配置することによって、メッシュ電極400までの配線距離を短くすることが出来る。そのため、配線抵抗の低減やコストを下げることが可能となる。
As shown in FIG. 3, the third electrode 401 has a third electrode 401, a diode 402, and a resistance component 403 arranged in a gap on the central axis of the electrode group 101, and plays a role as a lithium ion supply source. . The third electrode 401 may be installed anywhere inside the battery can 100. However, as described above, since the third electrode 401 is preferably connected to the positive electrode and the negative electrode in the center of the cell, the center of the electrode group 101 is used. It is desirable to insert it into the gap in the shaft. Thus, by arranging the third electrode 401 on the central axis of the electrode group 101, the wiring distance to the mesh electrode 400 can be shortened. Therefore, it becomes possible to reduce wiring resistance and cost.
電池缶100には電解液360が注入され、正極蓋102とガスケット103とで封止されている。
電極群101の詳細を図4を用いて説明する。図4は正極箔201、負極箔301の構造を示すものである。図4に示すように正極箔201の両面には正極材202が塗布され、負極箔301の両面には負極材302が塗布されている。そして、負極材302の表面にメッシュ電極400が配置されている。なお、本実施形態では負極にメッシュ電極400を配置しているが、後述する実施形態では正極材202側にメッシュ電極を配置する場合もある。正極200と負極300はセパレータ350を介して配置される構造となっている。 Anelectrolytic solution 360 is injected into the battery can 100 and sealed with a positive electrode lid 102 and a gasket 103.
Details of theelectrode group 101 will be described with reference to FIG. FIG. 4 shows the structure of the positive electrode foil 201 and the negative electrode foil 301. As shown in FIG. 4, the positive electrode material 202 is applied to both surfaces of the positive electrode foil 201, and the negative electrode material 302 is applied to both surfaces of the negative electrode foil 301. A mesh electrode 400 is disposed on the surface of the negative electrode material 302. In this embodiment, the mesh electrode 400 is disposed on the negative electrode. However, in the embodiment described later, the mesh electrode may be disposed on the positive electrode material 202 side. The positive electrode 200 and the negative electrode 300 are arranged via a separator 350.
電極群101の詳細を図4を用いて説明する。図4は正極箔201、負極箔301の構造を示すものである。図4に示すように正極箔201の両面には正極材202が塗布され、負極箔301の両面には負極材302が塗布されている。そして、負極材302の表面にメッシュ電極400が配置されている。なお、本実施形態では負極にメッシュ電極400を配置しているが、後述する実施形態では正極材202側にメッシュ電極を配置する場合もある。正極200と負極300はセパレータ350を介して配置される構造となっている。 An
Details of the
続いて、本実施形態で用いられる正極材202や負極材302の具体的な材料について説明する。本実施形態では電池の正極活物質としてLiCoO2、導電剤としてアセチレンブラックを7wt%、結着剤としてポリフッ化ビニリデン(PVDF)を5wt%添加して、これにN-メチル-2-ピロリドンを加え混合して正極合剤のスラリーを調製した。 この正極合剤スラリーを厚み25μmのアルミニウム箔である正極箔201(図4参照)の両面に塗布乾燥後、プレス,裁断することで、正極箔201の両面に正極材202(図4参照)を結着させ、正極200とした。
Subsequently, specific materials of the positive electrode material 202 and the negative electrode material 302 used in the present embodiment will be described. In this embodiment, LiCoO2 as a positive electrode active material of a battery, 7 wt% of acetylene black as a conductive agent, and 5 wt% of polyvinylidene fluoride (PVDF) as a binder are added, and N-methyl-2-pyrrolidone is added thereto and mixed. Thus, a positive electrode mixture slurry was prepared. The positive electrode mixture slurry is applied and dried on both surfaces of a positive electrode foil 201 (see FIG. 4), which is an aluminum foil having a thickness of 25 μm, and then pressed and cut. The positive electrode 200 was obtained by binding.
同様に負極活物質としては難黒鉛化炭素を使用し、結着剤としてPVDFを8wt%添加して、これにN-メチル-2-ピロリドンを加え混合して負極合剤のスラリーを調製した。
Similarly, non-graphitizable carbon was used as the negative electrode active material, 8 wt% of PVDF was added as a binder, and N-methyl-2-pyrrolidone was added thereto and mixed to prepare a slurry of the negative electrode mixture.
この負極合剤スラリーを厚み10μmの銅箔である負極箔301(図4参照)の両面に塗布し、プレス,裁断することで、負極箔301の両面に負極材302(図4参照)を結着させ、負極300とした。本実施形態では、第3電極401に、金属リチウムを用いている。ダイオード402は正極200もしくは負極300と第3電極401の電位差が、閾値として特定の値以上となった場合のみ電流が通過する特性を持ち、抵抗成分403はダイオード402が起動した際に流れる電流量を制御する目的で設置している。また、高電位で作動するダイオードを用いた際、高電流が発生して発熱することにより発火する危険性があるが、抵抗成分403を接続して電流を制御することで、安全性が向上するメリットもある。
The negative electrode mixture slurry is applied to both surfaces of a negative electrode foil 301 (see FIG. 4), which is a copper foil having a thickness of 10 μm, and pressed and cut to bind the negative electrode material 302 (see FIG. 4) to both surfaces of the negative electrode foil 301. A negative electrode 300 was formed. In the present embodiment, metallic lithium is used for the third electrode 401. The diode 402 has a characteristic that current passes only when the potential difference between the positive electrode 200 or the negative electrode 300 and the third electrode 401 is a specific value or more as a threshold value, and the resistance component 403 is the amount of current that flows when the diode 402 is activated. It is installed for the purpose of controlling. In addition, when a diode that operates at a high potential is used, there is a risk of ignition due to generation of a high current and heat generation, but safety is improved by connecting the resistance component 403 to control the current. There are also benefits.
正極200もしくは負極300の電位を検出するために、メッシュ電極400は電極表面に張り付けてあり、リチウムイオンが通過できるように穴が開いた金属箔を使用している。
金属箔201、301は、正極200側ではアルミ箔、負極300側では銅箔を用いるのが望ましいが、リチウムイオン電池の充放電反応において、化学的に安定であればどの材料を用いても良い。
また、正極活物質にLiCoO2を用いているが、ニッケル酸リチウムLiNiO2やマンガン酸リチウムLiMn2O4など、他の活物質を用いても活用できる。
同様に、本実施形態において、負極活物質には難黒鉛化炭素を用いているが、黒鉛などの他の炭素材料を用いても良い。
また、本実施形態において、円筒型電池に関する内容だが、適用できる電池は円筒型電池に限らず、角型電池、ラミネートセル電池でも同様な構造で適用できる。 In order to detect the potential of thepositive electrode 200 or the negative electrode 300, the mesh electrode 400 is attached to the electrode surface, and a metal foil having a hole so that lithium ions can pass therethrough is used.
The metal foils 201 and 301 are preferably made of aluminum foil on thepositive electrode 200 side and copper foil on the negative electrode 300 side, but any material may be used as long as it is chemically stable in the charge / discharge reaction of the lithium ion battery. .
Further, although using LiCoO2 as the positive electrode active material, lithium nickel oxide LiNiO 2 or lithium manganese oxide LiMn 2 O 4, also using other active materials can be utilized.
Similarly, in the present embodiment, non-graphitizable carbon is used as the negative electrode active material, but other carbon materials such as graphite may be used.
Further, in the present embodiment, the contents relating to the cylindrical battery are applicable, but the applicable battery is not limited to the cylindrical battery, but can be applied to a square battery and a laminated cell battery with the same structure.
金属箔201、301は、正極200側ではアルミ箔、負極300側では銅箔を用いるのが望ましいが、リチウムイオン電池の充放電反応において、化学的に安定であればどの材料を用いても良い。
また、正極活物質にLiCoO2を用いているが、ニッケル酸リチウムLiNiO2やマンガン酸リチウムLiMn2O4など、他の活物質を用いても活用できる。
同様に、本実施形態において、負極活物質には難黒鉛化炭素を用いているが、黒鉛などの他の炭素材料を用いても良い。
また、本実施形態において、円筒型電池に関する内容だが、適用できる電池は円筒型電池に限らず、角型電池、ラミネートセル電池でも同様な構造で適用できる。 In order to detect the potential of the
The metal foils 201 and 301 are preferably made of aluminum foil on the
Further, although using LiCoO2 as the positive electrode active material, lithium nickel oxide LiNiO 2 or lithium manganese oxide LiMn 2 O 4, also using other active materials can be utilized.
Similarly, in the present embodiment, non-graphitizable carbon is used as the negative electrode active material, but other carbon materials such as graphite may be used.
Further, in the present embodiment, the contents relating to the cylindrical battery are applicable, but the applicable battery is not limited to the cylindrical battery, but can be applied to a square battery and a laminated cell battery with the same structure.
上述したように図1(a)は図2の簡略図である。図1(a)では、負極300がダイオード402と抵抗成分403を介して第3電極401と接続しており、ダイオード402のアノード側に負極300、カソード側に第3電極401が接続している。
セルの初期状態の充放電状態を図6(a)に示す。本実施形態において、実験に用いた電池セルは、セル電池の作動電位は4.1V~2.7Vの範囲で充放電した際の電気容量が1.0Ahの円筒型セルであり、通常使用範囲において負極300は、第3電極401である金属リチウムに対して充電時には約0.1V,放電時には約0.8Vまで電位変化するように設計してある。本実施例では、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池は長期的にサイクルを繰り返すことで、負極表面の副反応が進行し、実質的に機能するリチウム量が減少することにより充放電容量が減少し、かつ、作動時の正極電位、負極電位がそれぞれ高電位側にシフトすることでさらに劣化が促進する。
すなわち、図6(a)の充放電状態が、長期的なサイクルを経ると、図6(b)に示すように作動時の正極電位、及び負極電位がそれぞれ高電位側にシフトし、充放電容量が減少する。本実施形態は、この充放電範囲のずれを緩和するものであり、以下で説明する。 As described above, FIG. 1A is a simplified diagram of FIG. In FIG. 1A, thenegative electrode 300 is connected to the third electrode 401 via the diode 402 and the resistance component 403, the negative electrode 300 is connected to the anode side of the diode 402, and the third electrode 401 is connected to the cathode side. .
FIG. 6A shows the initial charge / discharge state of the cell. In this embodiment, the battery cell used in the experiment is a cylindrical cell having an electric capacity of 1.0 Ah when charged and discharged in the range of the operating potential of the cell battery from 4.1 V to 2.7 V. Thenegative electrode 300 is designed so that the potential of the metallic lithium as the third electrode 401 changes to about 0.1 V during charging and to about 0.8 V during discharging. In this embodiment, a case where a battery is used in the range of 4.1 V to 2.7 V will be described.
Lithium-ion batteries are cycled over a long period of time, so that side reactions on the surface of the negative electrode proceed, the amount of lithium that functions substantially decreases, the charge / discharge capacity decreases, and the positive electrode potential during operation, the negative electrode Deterioration is further promoted by shifting the potential to the higher potential side.
That is, when the charge / discharge state of FIG. 6 (a) goes through a long-term cycle, the positive electrode potential and the negative electrode potential during operation shift to the high potential side as shown in FIG. Capacity is reduced. The present embodiment alleviates this shift in the charge / discharge range, and will be described below.
セルの初期状態の充放電状態を図6(a)に示す。本実施形態において、実験に用いた電池セルは、セル電池の作動電位は4.1V~2.7Vの範囲で充放電した際の電気容量が1.0Ahの円筒型セルであり、通常使用範囲において負極300は、第3電極401である金属リチウムに対して充電時には約0.1V,放電時には約0.8Vまで電位変化するように設計してある。本実施例では、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池は長期的にサイクルを繰り返すことで、負極表面の副反応が進行し、実質的に機能するリチウム量が減少することにより充放電容量が減少し、かつ、作動時の正極電位、負極電位がそれぞれ高電位側にシフトすることでさらに劣化が促進する。
すなわち、図6(a)の充放電状態が、長期的なサイクルを経ると、図6(b)に示すように作動時の正極電位、及び負極電位がそれぞれ高電位側にシフトし、充放電容量が減少する。本実施形態は、この充放電範囲のずれを緩和するものであり、以下で説明する。 As described above, FIG. 1A is a simplified diagram of FIG. In FIG. 1A, the
FIG. 6A shows the initial charge / discharge state of the cell. In this embodiment, the battery cell used in the experiment is a cylindrical cell having an electric capacity of 1.0 Ah when charged and discharged in the range of the operating potential of the cell battery from 4.1 V to 2.7 V. The
Lithium-ion batteries are cycled over a long period of time, so that side reactions on the surface of the negative electrode proceed, the amount of lithium that functions substantially decreases, the charge / discharge capacity decreases, and the positive electrode potential during operation, the negative electrode Deterioration is further promoted by shifting the potential to the higher potential side.
That is, when the charge / discharge state of FIG. 6 (a) goes through a long-term cycle, the positive electrode potential and the negative electrode potential during operation shift to the high potential side as shown in FIG. Capacity is reduced. The present embodiment alleviates this shift in the charge / discharge range, and will be described below.
本実施例において、ダイオード402の閾値を0.8Vと設定しており、負極300と第3電極であるリチウム金属間の電位差が0.8V以上になることで、負極300からリチウム金属の方向へ電流が流れ、負極300が充電される仕組みとなっている。
図7は、その挙動を簡易的に示している。すなわち、劣化による充放電範囲のずれによって、図6(b)に示すように負極電位が高電位側にシフトするが、図1(a)の構成を用いることで、放電時に負極300の電位が0.8Vを超えた際に、負極300からリチウム金属の方向へ電流が流れて負極300にリチウムが供給される。本実施形態のように電位をダイオードの閾値を0.8Vと設定した場合には、負極電位は0.8Vまで低下することとなる。そのため充放電容量が回復し、図7内の(a)及び(b)に示すように負極300の作動電位を低電位側へシフト((a)の丸の位置から (b)の四角の位置へ変化)させることで、充放電範囲の電位ずれも緩和できる。また、負極の過放電を防止できるメリットもある。
本実施例で用いたダイオード402の閾値は0.8Vと設定した。この閾値は、初期充放電時の負極最大電位から設定した値であり、使用用途によって、異なる閾値のダイオードを用いても良い。例えば、HEV用途のように狭い充放電範囲しか使用せず、負極材302の電位変化が小さいと見込める場合は、0.5V程度の閾値が小さいダイオードを使用してもよい。
ただし、広い充放電範囲を使用するにもかかわらず、0.5V程度の閾値が小さいダイオードを使用すると充放電範囲がより低電位側にシフトし、充電時には負極表面に金属リチウムが析出する可能性があるため0.8V程度が好ましい。なお、閾値の設定は、初期の電池状態における電池使用範囲の最大電位が望ましい。
また、本実施形態で用いた抵抗成分403の抵抗成分値は0.1Ω相当の抵抗成分を用いた。抵抗成分403の抵抗成分値はこの値限定ではなく、以下のような範囲で使用するのが望ましい。
抵抗成分403の抵抗値が小さいと負極に流れる電流量が大きく、電池が発熱するため安全上問題がある。例えば、ダイオード402の閾値が0.8Vで、負極と第3電極間の電位差が1.0Vの時、抵抗成分403の抵抗値が0.04Ωであれば、負極に流れる電流量を5C以下相当に制御できるため安全上問題無い。
また、抵抗成分403の抵抗値が大きいと負極に流れる電流量が少なく、充放電サイクルスパンが短い場合、充放電容量の回復が十分に完了しない可能性がある。そのため、ダイオード402の閾値が0.8Vで、負極と第3電極間の電位差が1.0Vの場合、例えば0.4Ωであれば負極に流れる電流量は0.5C以上相当であるため、充放電容量の回復が十分に完了できる。以上より、0.04Ω~0.4Ωの範囲であれば適切に利用できる。
以上、本実施形態のように、ダイオード402と第3電極401の間に抵抗成分403を直列に接続することによって、第3電極と負極300との間に電位差が発生したとしても、ダイオード部分に流れる電流が適切なCレートとなるため、意図しない電池劣化を抑制することが可能となる。
また、上述した電流制御により、負極300が好ましい充電状態に保持され本実施を用いることにより、るため、リチウムイオン電池の容量劣化を緩和させることができる。 In this embodiment, the threshold value of thediode 402 is set to 0.8 V, and when the potential difference between the negative electrode 300 and the lithium metal that is the third electrode becomes 0.8 V or more, the negative electrode 300 moves toward the lithium metal. A current flows and the negative electrode 300 is charged.
FIG. 7 simply shows the behavior. That is, the negative electrode potential shifts to the high potential side as shown in FIG. 6 (b) due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 1 (a), the potential of thenegative electrode 300 is reduced during discharge. When the voltage exceeds 0.8 V, a current flows from the negative electrode 300 toward the lithium metal, and lithium is supplied to the negative electrode 300. When the potential of the diode is set to 0.8V as in the present embodiment, the negative electrode potential is lowered to 0.8V. As a result, the charge / discharge capacity is recovered, and the operating potential of the negative electrode 300 is shifted to the low potential side as shown in FIGS. 7A and 7B (from the circle position (a) to the square position (b). Change in potential) can also reduce potential shift in the charge / discharge range. In addition, there is an advantage that overdischarge of the negative electrode can be prevented.
The threshold value of thediode 402 used in this example was set to 0.8V. This threshold value is a value set from the negative electrode maximum potential at the time of initial charge / discharge, and diodes having different threshold values may be used depending on the intended use. For example, when only a narrow charge / discharge range is used as in the HEV application and the potential change of the negative electrode material 302 is expected to be small, a diode having a small threshold value of about 0.5 V may be used.
However, even if a wide charge / discharge range is used, if a diode with a small threshold of about 0.5 V is used, the charge / discharge range may shift to a lower potential side, and metal lithium may deposit on the negative electrode surface during charging. Therefore, about 0.8V is preferable. The threshold is preferably set to the maximum potential in the battery usage range in the initial battery state.
The resistance component value of theresistance component 403 used in this embodiment is a resistance component corresponding to 0.1Ω. The resistance component value of the resistance component 403 is not limited to this value, and is desirably used in the following range.
If the resistance value of theresistance component 403 is small, the amount of current flowing through the negative electrode is large and the battery generates heat, which is a safety problem. For example, when the threshold value of the diode 402 is 0.8 V and the potential difference between the negative electrode and the third electrode is 1.0 V, if the resistance value of the resistance component 403 is 0.04Ω, the amount of current flowing through the negative electrode corresponds to 5 C or less. Because there is no problem in safety because it can be controlled.
Further, when the resistance value of theresistance component 403 is large, when the amount of current flowing through the negative electrode is small and the charge / discharge cycle span is short, the recovery of the charge / discharge capacity may not be sufficiently completed. Therefore, when the threshold voltage of the diode 402 is 0.8 V and the potential difference between the negative electrode and the third electrode is 1.0 V, for example, if 0.4Ω, the amount of current flowing through the negative electrode is equivalent to 0.5 C or more. The recovery of the discharge capacity can be completed sufficiently. From the above, the range of 0.04Ω to 0.4Ω can be used appropriately.
As described above, even if a potential difference is generated between the third electrode and thenegative electrode 300 by connecting the resistance component 403 in series between the diode 402 and the third electrode 401 as in this embodiment, the diode portion Since the flowing current becomes an appropriate C rate, unintended battery deterioration can be suppressed.
Moreover, since thenegative electrode 300 is maintained in a preferable charged state by using the current control described above and this embodiment is used, the capacity deterioration of the lithium ion battery can be mitigated.
図7は、その挙動を簡易的に示している。すなわち、劣化による充放電範囲のずれによって、図6(b)に示すように負極電位が高電位側にシフトするが、図1(a)の構成を用いることで、放電時に負極300の電位が0.8Vを超えた際に、負極300からリチウム金属の方向へ電流が流れて負極300にリチウムが供給される。本実施形態のように電位をダイオードの閾値を0.8Vと設定した場合には、負極電位は0.8Vまで低下することとなる。そのため充放電容量が回復し、図7内の(a)及び(b)に示すように負極300の作動電位を低電位側へシフト((a)の丸の位置から (b)の四角の位置へ変化)させることで、充放電範囲の電位ずれも緩和できる。また、負極の過放電を防止できるメリットもある。
本実施例で用いたダイオード402の閾値は0.8Vと設定した。この閾値は、初期充放電時の負極最大電位から設定した値であり、使用用途によって、異なる閾値のダイオードを用いても良い。例えば、HEV用途のように狭い充放電範囲しか使用せず、負極材302の電位変化が小さいと見込める場合は、0.5V程度の閾値が小さいダイオードを使用してもよい。
ただし、広い充放電範囲を使用するにもかかわらず、0.5V程度の閾値が小さいダイオードを使用すると充放電範囲がより低電位側にシフトし、充電時には負極表面に金属リチウムが析出する可能性があるため0.8V程度が好ましい。なお、閾値の設定は、初期の電池状態における電池使用範囲の最大電位が望ましい。
また、本実施形態で用いた抵抗成分403の抵抗成分値は0.1Ω相当の抵抗成分を用いた。抵抗成分403の抵抗成分値はこの値限定ではなく、以下のような範囲で使用するのが望ましい。
抵抗成分403の抵抗値が小さいと負極に流れる電流量が大きく、電池が発熱するため安全上問題がある。例えば、ダイオード402の閾値が0.8Vで、負極と第3電極間の電位差が1.0Vの時、抵抗成分403の抵抗値が0.04Ωであれば、負極に流れる電流量を5C以下相当に制御できるため安全上問題無い。
また、抵抗成分403の抵抗値が大きいと負極に流れる電流量が少なく、充放電サイクルスパンが短い場合、充放電容量の回復が十分に完了しない可能性がある。そのため、ダイオード402の閾値が0.8Vで、負極と第3電極間の電位差が1.0Vの場合、例えば0.4Ωであれば負極に流れる電流量は0.5C以上相当であるため、充放電容量の回復が十分に完了できる。以上より、0.04Ω~0.4Ωの範囲であれば適切に利用できる。
以上、本実施形態のように、ダイオード402と第3電極401の間に抵抗成分403を直列に接続することによって、第3電極と負極300との間に電位差が発生したとしても、ダイオード部分に流れる電流が適切なCレートとなるため、意図しない電池劣化を抑制することが可能となる。
また、上述した電流制御により、負極300が好ましい充電状態に保持され本実施を用いることにより、るため、リチウムイオン電池の容量劣化を緩和させることができる。 In this embodiment, the threshold value of the
FIG. 7 simply shows the behavior. That is, the negative electrode potential shifts to the high potential side as shown in FIG. 6 (b) due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 1 (a), the potential of the
The threshold value of the
However, even if a wide charge / discharge range is used, if a diode with a small threshold of about 0.5 V is used, the charge / discharge range may shift to a lower potential side, and metal lithium may deposit on the negative electrode surface during charging. Therefore, about 0.8V is preferable. The threshold is preferably set to the maximum potential in the battery usage range in the initial battery state.
The resistance component value of the
If the resistance value of the
Further, when the resistance value of the
As described above, even if a potential difference is generated between the third electrode and the
Moreover, since the
また、本実施形態は、第3電極401から負極300にリチウムイオンが供給されるため、特に負極での容量劣化が大きい場合に効果がある。
Further, this embodiment is effective particularly when the capacity deterioration at the negative electrode is large because lithium ions are supplied from the third electrode 401 to the negative electrode 300.
《第二の実施形態》
本実施例は、第一の実施形態と同様、図1(a)の構成に基づいている例であり、ダイオード402が正極200側に接続されている点を除けば、第一の実施形態と同様である。 << Second Embodiment >>
This example is an example based on the configuration of FIG. 1A as in the first embodiment, and is the same as that of the first embodiment except that thediode 402 is connected to the positive electrode 200 side. It is the same.
本実施例は、第一の実施形態と同様、図1(a)の構成に基づいている例であり、ダイオード402が正極200側に接続されている点を除けば、第一の実施形態と同様である。 << Second Embodiment >>
This example is an example based on the configuration of FIG. 1A as in the first embodiment, and is the same as that of the first embodiment except that the
本実施例における電池セル構成の簡略図を図5に示す。図5のように、正極200がダイオード402と抵抗成分403を介して第3電極401と接続しており、ダイオード402のアノード側に正極200、カソード側に第3電極401が接続している。
本実施形態においても図6(a)に示すように、セルの初期状態の充放電状態において、セル電池の作動電位は4.1V~2.7Vの使用範囲で正極200は、第3電極401である金属リチウムに対して充電時には約4.2V、放電時には約3.5Vまで電位変化するように設計してある。本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
第一の実施形態でも説明したが、リチウムイオン電池を長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施例を用いて、充放電範囲のずれを緩和することが可能である。 A simplified diagram of the battery cell configuration in this example is shown in FIG. As shown in FIG. 5, thepositive electrode 200 is connected to the third electrode 401 via the diode 402 and the resistance component 403, and the positive electrode 200 is connected to the anode side of the diode 402 and the third electrode 401 is connected to the cathode side.
Also in the present embodiment, as shown in FIG. 6A, in the charge / discharge state in the initial state of the cell, the operating potential of the cell battery is in the usage range of 4.1V to 2.7V, and thepositive electrode 200 is the third electrode 401. It is designed to change the potential to about 4.2 V during charging and about 3.5 V during discharging with respect to metallic lithium. In this embodiment, the case where the battery is used in the range of 4.1V to 2.7V will be described.
As described in the first embodiment, it is considered that a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle of the lithium ion battery for a long time. It is possible to reduce the deviation.
本実施形態においても図6(a)に示すように、セルの初期状態の充放電状態において、セル電池の作動電位は4.1V~2.7Vの使用範囲で正極200は、第3電極401である金属リチウムに対して充電時には約4.2V、放電時には約3.5Vまで電位変化するように設計してある。本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
第一の実施形態でも説明したが、リチウムイオン電池を長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施例を用いて、充放電範囲のずれを緩和することが可能である。 A simplified diagram of the battery cell configuration in this example is shown in FIG. As shown in FIG. 5, the
Also in the present embodiment, as shown in FIG. 6A, in the charge / discharge state in the initial state of the cell, the operating potential of the cell battery is in the usage range of 4.1V to 2.7V, and the
As described in the first embodiment, it is considered that a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle of the lithium ion battery for a long time. It is possible to reduce the deviation.
本実施例において、閾値が2.1V相当のダイオード402を2個直列に接続し、閾値を4.2Vと設定した。この閾値は、初期充放電時の正極最大電位から設定した値であり、使用用途によって、異なる閾値のダイオードを用いても良い。ここでは、正極200と第3電極401であるリチウム金属間の電位差が4.2V以上になることで、正極200からリチウム金属の方向へ電流が流れ、正極200が放電される仕組みとなっている。
図10は、その挙動を簡易的に示したものである。すなわち、劣化による充放電範囲のずれによって、図6(b)に示すように正極電位が高電位側にシフトするが、図5の構成を用いることで、充電時に正極200の電位が4.2Vを超えた際に、正極200からリチウム金属の方向へ電流が流れて正極200にリチウムが供給されるため、充放電容量が回復し、正極200の作動電位を低電位側へシフト((c)の丸の位置から(d)の四角の位置に変化)させることで、充放電範囲の電位ずれも緩和できる。また、正極200の過充電を防止するメリットもある。
本実施例で用いたダイオード402の閾値は4.2Vと設定したが、使用用途によって、異なる閾値のダイオードを用いても良い。例えば、HEV用途のように狭い充放電範囲しか使用せず、正極200の電位変化が小さいと見込める場合は、3.8V程度の閾値が小さいダイオードを使用してもよい。ただ、広い充放電範囲を使用するにもかかわらず、3.8V程度の閾値が小さいダイオードを使用すると充放電範囲がより低電位側にシフトし、放電時には正極が過放電状態になる可能性があるので、使用用途によって閾値の設定は注意が必要である。閾値の設定は、初期の電池状態における電池使用範囲の最大電位が望ましい。
なお、ダイオード402の閾値を4.2Vとする場合には、閾値0.8Vのダイオードを4個直列に接続させるなどの構成とすることが考えられる。
また、本実施形態で用いた抵抗成分403の抵抗成分値は0.1Ω相当の抵抗成分を用いた。抵抗成分403の抵抗成分値はこの値限定ではなく、以下のような範囲で使用するのが望ましい。抵抗成分403の抵抗値が小さいと正極に流れる電流量が大きく、電池が発熱するため安全上問題がある。
例えば、ダイオード402の閾値が4.2Vで、正極と第3電極間の電位差が4.4Vになった時、抵抗成分403の抵抗値が0.04Ωであれば、正極に流れる電流量を5C以下相当に制御できるため安全上問題無い。また、抵抗成分403の抵抗値が大きいと正極から流れる電流量が少なく、充放電サイクルスパンが短い場合、充放電容量の回復が十分に完了しない可能性がある。そのため、ダイオード402の閾値が4.2Vで、正極と第3電極間の電位差が4.4Vの場合、例えば0.4Ωであれば負極に流れる電流量は0.5C以上相当であるため、充放電容量の回復が十分に完了できる。以上より、0.04Ω~0.4Ωの範囲であれば適切に利用できる。
以上、本実施形態のように、ダイオード402と第3電極401の間に抵抗成分403を直列に接続することによって、第3電極と正極200との間に電位差が発生したとしても、ダイオード部分に流れる電流が適切なCレートとなるため、意図しない電池劣化を抑制することが可能となる。
また、上述した電流制御により、正極が好ましい充電状態に保持されるため、リチウムイオン電池の容量劣化を緩和させることができる。
また、本実施形態は、第3電極401から正極200にリチウムイオンが供給されるため、特に正極200での容量劣化が大きい場合に効果がある。 In this example, twodiodes 402 having a threshold value equivalent to 2.1V were connected in series, and the threshold value was set to 4.2V. This threshold value is a value set from the positive electrode maximum potential at the time of initial charge / discharge, and diodes having different threshold values may be used depending on the intended use. Here, when the potential difference between the positive electrode 200 and the lithium metal that is the third electrode 401 is 4.2 V or more, a current flows from the positive electrode 200 toward the lithium metal, and the positive electrode 200 is discharged. .
FIG. 10 simply shows the behavior. In other words, the positive electrode potential shifts to the high potential side as shown in FIG. 6B due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 5, the potential of thepositive electrode 200 is 4.2 V during charging. When the current exceeds the value, a current flows from the positive electrode 200 toward the lithium metal and lithium is supplied to the positive electrode 200, so that the charge / discharge capacity is recovered and the operating potential of the positive electrode 200 is shifted to the low potential side ((c) (Change from the position of the circle to the square position of (d)), the potential shift in the charge / discharge range can be alleviated. In addition, there is an advantage of preventing overcharge of the positive electrode 200.
Although the threshold value of thediode 402 used in this embodiment is set to 4.2 V, a diode having a different threshold value may be used depending on the application. For example, a diode having a small threshold of about 3.8 V may be used when only a narrow charge / discharge range is used and the potential change of the positive electrode 200 can be expected to be small as in HEV applications. However, even if a wide charge / discharge range is used, if a diode having a small threshold of about 3.8 V is used, the charge / discharge range may shift to a lower potential side, and the positive electrode may be overdischarged during discharge. Therefore, care must be taken in setting the threshold depending on the intended use. The threshold is preferably set to the maximum potential in the battery usage range in the initial battery state.
Note that when the threshold value of thediode 402 is 4.2 V, a configuration in which four diodes having a threshold value of 0.8 V are connected in series is conceivable.
The resistance component value of theresistance component 403 used in this embodiment is a resistance component corresponding to 0.1Ω. The resistance component value of the resistance component 403 is not limited to this value, and is desirably used in the following range. If the resistance value of the resistance component 403 is small, the amount of current flowing through the positive electrode is large, and the battery generates heat, which causes a safety problem.
For example, when the threshold value of thediode 402 is 4.2V and the potential difference between the positive electrode and the third electrode is 4.4V, if the resistance value of the resistance component 403 is 0.04Ω, the amount of current flowing through the positive electrode is 5C. There is no safety problem because it can be controlled considerably below. Further, if the resistance value of the resistance component 403 is large, the amount of current flowing from the positive electrode is small, and if the charge / discharge cycle span is short, the recovery of the charge / discharge capacity may not be sufficiently completed. Therefore, when the threshold voltage of the diode 402 is 4.2 V and the potential difference between the positive electrode and the third electrode is 4.4 V, for example, if 0.4Ω, the amount of current flowing through the negative electrode is equivalent to 0.5 C or more. The recovery of the discharge capacity can be completed sufficiently. From the above, the range of 0.04Ω to 0.4Ω can be used appropriately.
As described above, even if a potential difference is generated between the third electrode and thepositive electrode 200 by connecting the resistance component 403 in series between the diode 402 and the third electrode 401 as in the present embodiment, the diode portion Since the flowing current becomes an appropriate C rate, unintended battery deterioration can be suppressed.
Moreover, since the positive electrode is maintained in a preferable charged state by the current control described above, the capacity deterioration of the lithium ion battery can be alleviated.
In addition, since the lithium ion is supplied from thethird electrode 401 to the positive electrode 200, this embodiment is effective particularly when the capacity deterioration in the positive electrode 200 is large.
図10は、その挙動を簡易的に示したものである。すなわち、劣化による充放電範囲のずれによって、図6(b)に示すように正極電位が高電位側にシフトするが、図5の構成を用いることで、充電時に正極200の電位が4.2Vを超えた際に、正極200からリチウム金属の方向へ電流が流れて正極200にリチウムが供給されるため、充放電容量が回復し、正極200の作動電位を低電位側へシフト((c)の丸の位置から(d)の四角の位置に変化)させることで、充放電範囲の電位ずれも緩和できる。また、正極200の過充電を防止するメリットもある。
本実施例で用いたダイオード402の閾値は4.2Vと設定したが、使用用途によって、異なる閾値のダイオードを用いても良い。例えば、HEV用途のように狭い充放電範囲しか使用せず、正極200の電位変化が小さいと見込める場合は、3.8V程度の閾値が小さいダイオードを使用してもよい。ただ、広い充放電範囲を使用するにもかかわらず、3.8V程度の閾値が小さいダイオードを使用すると充放電範囲がより低電位側にシフトし、放電時には正極が過放電状態になる可能性があるので、使用用途によって閾値の設定は注意が必要である。閾値の設定は、初期の電池状態における電池使用範囲の最大電位が望ましい。
なお、ダイオード402の閾値を4.2Vとする場合には、閾値0.8Vのダイオードを4個直列に接続させるなどの構成とすることが考えられる。
また、本実施形態で用いた抵抗成分403の抵抗成分値は0.1Ω相当の抵抗成分を用いた。抵抗成分403の抵抗成分値はこの値限定ではなく、以下のような範囲で使用するのが望ましい。抵抗成分403の抵抗値が小さいと正極に流れる電流量が大きく、電池が発熱するため安全上問題がある。
例えば、ダイオード402の閾値が4.2Vで、正極と第3電極間の電位差が4.4Vになった時、抵抗成分403の抵抗値が0.04Ωであれば、正極に流れる電流量を5C以下相当に制御できるため安全上問題無い。また、抵抗成分403の抵抗値が大きいと正極から流れる電流量が少なく、充放電サイクルスパンが短い場合、充放電容量の回復が十分に完了しない可能性がある。そのため、ダイオード402の閾値が4.2Vで、正極と第3電極間の電位差が4.4Vの場合、例えば0.4Ωであれば負極に流れる電流量は0.5C以上相当であるため、充放電容量の回復が十分に完了できる。以上より、0.04Ω~0.4Ωの範囲であれば適切に利用できる。
以上、本実施形態のように、ダイオード402と第3電極401の間に抵抗成分403を直列に接続することによって、第3電極と正極200との間に電位差が発生したとしても、ダイオード部分に流れる電流が適切なCレートとなるため、意図しない電池劣化を抑制することが可能となる。
また、上述した電流制御により、正極が好ましい充電状態に保持されるため、リチウムイオン電池の容量劣化を緩和させることができる。
また、本実施形態は、第3電極401から正極200にリチウムイオンが供給されるため、特に正極200での容量劣化が大きい場合に効果がある。 In this example, two
FIG. 10 simply shows the behavior. In other words, the positive electrode potential shifts to the high potential side as shown in FIG. 6B due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 5, the potential of the
Although the threshold value of the
Note that when the threshold value of the
The resistance component value of the
For example, when the threshold value of the
As described above, even if a potential difference is generated between the third electrode and the
Moreover, since the positive electrode is maintained in a preferable charged state by the current control described above, the capacity deterioration of the lithium ion battery can be alleviated.
In addition, since the lithium ion is supplied from the
また、本実施形態を用いた場合には、第3電極401より正極200にリチウムイオンが供給されるため、特に正極200での劣化が大きい場合に効果がある。
Further, when this embodiment is used, lithium ions are supplied from the third electrode 401 to the positive electrode 200, which is particularly effective when deterioration at the positive electrode 200 is large.
《第三の実施形態》
本実施形態は、図1(b)の構成に基づいている例であり、以下の点を除けば、第一の実施形態と同様である。 << Third embodiment >>
This embodiment is an example based on the configuration of FIG. 1B, and is the same as the first embodiment except for the following points.
本実施形態は、図1(b)の構成に基づいている例であり、以下の点を除けば、第一の実施形態と同様である。 << Third embodiment >>
This embodiment is an example based on the configuration of FIG. 1B, and is the same as the first embodiment except for the following points.
まず、本実施形態における電池セル構成を図1(b)を用いて説明する。構成は、図1(b)のように、正極200と負極300がダイオード402(402a、402b)、抵抗成分403(403a、403b)を介して第3電極401と接続しており、ダイオード402bのアノード側に正極200が接続、ダイオード402bのカソード側に第3電極401が接続している。本実施形態では第一の実施形態とは異なり、2つのダイオードと抵抗成分が接続されている。より具体的には、本実施形態は、第一の実施形態と第二の実施形態の構成を複合させた構成となっている。
本実施形態においても図6(a)に示すように、セルの初期状態の充放電状態において、セル電池の作動電位が4.1V~2.7Vの使用範囲で正極200は、第3電極401である金属リチウムに対して約4.2V~約3.5Vまで、負極300は、約0.1V~約0.8Vまで電位変化するように設計してある。本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池において、長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施形態を用いて、充放電範囲のずれを緩和することが可能である。 First, the battery cell structure in this embodiment is demonstrated using FIG.1 (b). As shown in FIG. 1B, thepositive electrode 200 and the negative electrode 300 are connected to the third electrode 401 via the diode 402 (402a, 402b) and the resistance component 403 (403a, 403b), as shown in FIG. The positive electrode 200 is connected to the anode side, and the third electrode 401 is connected to the cathode side of the diode 402b. In the present embodiment, unlike the first embodiment, two diodes and a resistance component are connected. More specifically, the present embodiment has a configuration in which the configurations of the first embodiment and the second embodiment are combined.
Also in the present embodiment, as shown in FIG. 6A, in the charge / discharge state in the initial state of the cell, thepositive electrode 200 is the third electrode 401 in the operating range of the cell battery operating voltage of 4.1V to 2.7V. The negative electrode 300 is designed to change in potential from about 4.2 V to about 3.5 V with respect to metallic lithium, and from about 0.1 V to about 0.8 V. In this embodiment, the case where the battery is used in the range of 4.1V to 2.7V will be described.
In a lithium ion battery, it is considered that a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle over a long period of time. However, using this embodiment, it is possible to alleviate a shift in the charge / discharge range. is there.
本実施形態においても図6(a)に示すように、セルの初期状態の充放電状態において、セル電池の作動電位が4.1V~2.7Vの使用範囲で正極200は、第3電極401である金属リチウムに対して約4.2V~約3.5Vまで、負極300は、約0.1V~約0.8Vまで電位変化するように設計してある。本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池において、長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施形態を用いて、充放電範囲のずれを緩和することが可能である。 First, the battery cell structure in this embodiment is demonstrated using FIG.1 (b). As shown in FIG. 1B, the
Also in the present embodiment, as shown in FIG. 6A, in the charge / discharge state in the initial state of the cell, the
In a lithium ion battery, it is considered that a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle over a long period of time. However, using this embodiment, it is possible to alleviate a shift in the charge / discharge range. is there.
本実施形態において、正極200側に接続されているダイオード402bの閾値を4.2V、負極300側に接続されているダイオード402aの閾値を0.8Vと設定しており、各電極と第3電極401であるリチウム金属間の電位差がそれぞれの閾値以上になることで、各電極からリチウム金属の方向へ電流が流れ、正極200は放電、負極300は充電される仕組みとなっている。
図11は、その挙動を簡易的に示したものである。第一の実施形態の効果と第二の実施形態の効果を複合させることで、リチウムイオン二次電池の充電側、放電側のどちらにおいても、劣化したリチウムイオン二次電池において、充放電容量が回復し、充放電範囲の電位ずれも緩和できる。
また、正極200、負極300において両極共に、それぞれ過充電防止、過放電防止できるメリットがあり、安全なリチウムイオン二次電池を提供できる。
第一の実施形態、及び第二の実施形態2でも記述した通り、設定したダイオード402a、402bの閾値である、4.2V、0.8Vは、使用用途によって、異なる閾値のダイオードを用いても良い。また、抵抗成分403a、及び403bの抵抗値においても同様である。
以上、本実施例を用いることにより、リチウムイオン二次電池の容量劣化を緩和させることができ、また、より安全なリチウムイオン二次電池を提供できる。 In the present embodiment, the threshold value of thediode 402b connected to the positive electrode 200 side is set to 4.2V, and the threshold value of the diode 402a connected to the negative electrode 300 side is set to 0.8V. When the potential difference between the lithium metals 401, which is equal to or greater than each threshold value, current flows from each electrode in the direction of the lithium metal, the positive electrode 200 is discharged and the negative electrode 300 is charged.
FIG. 11 simply shows the behavior. By combining the effect of the first embodiment and the effect of the second embodiment, the charge / discharge capacity of the deteriorated lithium ion secondary battery is reduced on both the charge side and the discharge side of the lithium ion secondary battery. It recovers and the potential shift in the charge / discharge range can be reduced.
Further, both thepositive electrode 200 and the negative electrode 300 have the merit of preventing overcharge and overdischarge, respectively, and a safe lithium ion secondary battery can be provided.
As described in the first embodiment and thesecond embodiment 2, 4.2V and 0.8V, which are the threshold values of the set diodes 402a and 402b, can be used depending on the application. good. The same applies to the resistance values of the resistance components 403a and 403b.
As described above, by using this embodiment, the capacity deterioration of the lithium ion secondary battery can be alleviated, and a safer lithium ion secondary battery can be provided.
図11は、その挙動を簡易的に示したものである。第一の実施形態の効果と第二の実施形態の効果を複合させることで、リチウムイオン二次電池の充電側、放電側のどちらにおいても、劣化したリチウムイオン二次電池において、充放電容量が回復し、充放電範囲の電位ずれも緩和できる。
また、正極200、負極300において両極共に、それぞれ過充電防止、過放電防止できるメリットがあり、安全なリチウムイオン二次電池を提供できる。
第一の実施形態、及び第二の実施形態2でも記述した通り、設定したダイオード402a、402bの閾値である、4.2V、0.8Vは、使用用途によって、異なる閾値のダイオードを用いても良い。また、抵抗成分403a、及び403bの抵抗値においても同様である。
以上、本実施例を用いることにより、リチウムイオン二次電池の容量劣化を緩和させることができ、また、より安全なリチウムイオン二次電池を提供できる。 In the present embodiment, the threshold value of the
FIG. 11 simply shows the behavior. By combining the effect of the first embodiment and the effect of the second embodiment, the charge / discharge capacity of the deteriorated lithium ion secondary battery is reduced on both the charge side and the discharge side of the lithium ion secondary battery. It recovers and the potential shift in the charge / discharge range can be reduced.
Further, both the
As described in the first embodiment and the
As described above, by using this embodiment, the capacity deterioration of the lithium ion secondary battery can be alleviated, and a safer lithium ion secondary battery can be provided.
《第四の実施形態》
本実施形態は、図1(c)の構成に基づいている例であり、以下の点を除けば、第二の実施形態と同様である。 << Fourth Embodiment >>
This embodiment is an example based on the configuration of FIG. 1C, and is the same as the second embodiment except for the following points.
本実施形態は、図1(c)の構成に基づいている例であり、以下の点を除けば、第二の実施形態と同様である。 << Fourth Embodiment >>
This embodiment is an example based on the configuration of FIG. 1C, and is the same as the second embodiment except for the following points.
本実施例における電池セル構成の簡略図を図1(c)に示す。構成は、図1(c)のように、正極200に2つのダイオード402(402c、403d)、抵抗成分403(403c、403d)を介して第3電極401と接続しており、ダイオード402c及び402dのアノード側に正極200、ダイオード402c及び402dのカソード側に第3電極401が接続している。
本実施形態においても図6(a)に示しているように、セルの初期状態の充放電状態において、セル電池の作動電位が4.1V~2.7Vの使用範囲で正極200は、約4.2V~約3.5Vまで電位変化するように設計しており、本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池において、長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施例を用いて、充放電範囲のずれを緩和することが可能であり、より安全性を保証することができる。 A simplified diagram of the battery cell configuration in this example is shown in FIG. As shown in FIG. 1C, the configuration is such that thepositive electrode 200 is connected to the third electrode 401 via two diodes 402 (402c and 403d) and a resistance component 403 (403c and 403d), and the diodes 402c and 402d. The positive electrode 200 is connected to the anode side, and the third electrode 401 is connected to the cathode side of the diodes 402c and 402d.
Also in this embodiment, as shown in FIG. 6A, in the charge / discharge state in the initial state of the cell, thepositive electrode 200 is about 4 when the operating potential of the cell battery is 4.1V to 2.7V. It is designed to change the potential from 2 V to about 3.5 V, and this embodiment will also be described in the case where the battery is used in the range of 4.1 V to 2.7 V.
In a lithium ion battery, it is considered that charging / discharging states as shown in FIG. 6B are obtained by repeating the cycle over a long period of time. However, using this embodiment, it is possible to alleviate the deviation of the charging / discharging range. Yes, it can guarantee more safety.
本実施形態においても図6(a)に示しているように、セルの初期状態の充放電状態において、セル電池の作動電位が4.1V~2.7Vの使用範囲で正極200は、約4.2V~約3.5Vまで電位変化するように設計しており、本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池において、長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施例を用いて、充放電範囲のずれを緩和することが可能であり、より安全性を保証することができる。 A simplified diagram of the battery cell configuration in this example is shown in FIG. As shown in FIG. 1C, the configuration is such that the
Also in this embodiment, as shown in FIG. 6A, in the charge / discharge state in the initial state of the cell, the
In a lithium ion battery, it is considered that charging / discharging states as shown in FIG. 6B are obtained by repeating the cycle over a long period of time. However, using this embodiment, it is possible to alleviate the deviation of the charging / discharging range. Yes, it can guarantee more safety.
本実施形態において、正極200側に接続されているダイオード402cの閾値は4.2V、ダイオード402dの閾値は4.5 Vと設定しており、正極200と第3電極401であるリチウム金属間の電位差がそれぞれの閾値以上になることで、正極からリチウム金属の方向へ電流が流れるように構成されている。つまり、ダイオード402dの閾値電圧はダイオード402cの閾値電圧よりも大きなものとなっている。
また、閾値が4.2Vであるダイオード402cと直列接続している抵抗成分403cの抵抗値は第二の実施形態の通りだが、閾値が4.5 Vと設定しているダイオード402dと直列接続している抵抗成分403dの抵抗値は0.01mΩとした。この成分は、この値限定ではないが、比較的小さく、かつ、電池の発熱異常が生じない程度の値であることが望ましい。また、当該抵抗成分403dの抵抗値は、抵抗成分403cの抵抗よりも小さくなる構成となっている。
過充電によって正極200の電位が高電位となると、正極活物質であるLiCoO2の結晶崩壊や酸素脱離等の劣化原因となるため望ましくない。そのため、正極200の電位が少しの間でも高電位とならないことが望ましい。本実施形態では、超えるべきではない電位の閾値を4.5Vと設定した。第二の実施形態、第三の実施形態においては、それぞれ正極の過充電を防止する構成となっているが、電池システムに急激な異常が生じ、大電流が流れることによって正極が過充電状態になった場合、正極200と第3電極401間には比較的大きな抵抗値が接続されているために大電流が流れずに過充電状態を解消できない可能性があった。
そこで、本実施形態のように、ダイオード402dにダイオード402cの閾値電圧よりも大きな閾値を持つダイオードを用い、さらに抵抗成分403cよりも抵抗値の低い抵抗成分403dを用いることで、電池システムに異常が起きず、正極200の電位が4.5V未満で作動している場合、第二の実施形態と同様な効果で電池が稼働し、万が一、電池システムの異常により正極200の電位が4.5Vを超えた場合、正極の過充電状態を解消することが可能である。
なお、本実施形態において、超えるべきではない電位の閾値を4.5Vと設定しているが、正極の材料によりその値は変動する。
また、実施例では紹介しないが、ダイオード402c及び402d、抵抗成分403c及び403dを介して第3電極401と接続されているのは、正極200ではなく、負極300でもよい。
その際ダイオード402のアノード側に負極200、カソード側に第3電極401が接続する。また、その際のダイオードの閾値は0.8V、1.4V程度と考えられる。ダイオードと直列接続している抵抗については、正極の場合と同様で、閾値が0.8Vと設定しているダイオードと直列接続している抵抗成分の抵抗値は、第一の実施形態の通りだが、閾値が1.4 Vと設定しているダイオードと直列接続している抵抗成分の抵抗値は0.01mΩなどの、比較的小さく、かつ、電池の発熱異常が生じない程度の値であることが望ましい、と考えられる。これにより、万が一、電池システムの異常により大電流が流れた場合でも、負極の過放電状態をそれぞれ防止することが可能である。
また、正極200、負極300の両極共に、2つのダイオード402c及び402d、抵抗成分403c及び403dを介して第3電極401と接続しても良く、その時、万一、電池システムの異常により大電流が流れた場合でも、正極の過充電状態、負極の過放電状態をそれぞれ防止することが可能である。
以上、本実施例を用いることにより、リチウムイオン二次電池の容量劣化を緩和させることができ、かつ、より安全なリチウムイオン二次電池を提供できる。 In the present embodiment, the threshold value of thediode 402c connected to the positive electrode 200 side is set to 4.2V, the threshold value of the diode 402d is set to 4.5V, and the positive electrode 200 and the lithium metal that is the third electrode 401 are connected. When the potential difference is equal to or greater than each threshold value, the current flows from the positive electrode toward the lithium metal. That is, the threshold voltage of the diode 402d is larger than the threshold voltage of the diode 402c.
Further, the resistance value of theresistance component 403c connected in series with the diode 402c having a threshold value of 4.2V is the same as that of the second embodiment, but is connected in series with the diode 402d whose threshold value is set to 4.5V. The resistance value of the resistance component 403d is 0.01 mΩ. This component is not limited to this value, but it is desirable that the component be relatively small and have a value that does not cause abnormal battery heat generation. Further, the resistance value of the resistance component 403d is configured to be smaller than the resistance of the resistance component 403c.
When the potential of thepositive electrode 200 becomes high due to overcharging, it is not desirable because it causes deterioration such as crystal collapse and oxygen desorption of the LiCoO 2 that is the positive electrode active material. Therefore, it is desirable that the potential of the positive electrode 200 does not become a high potential even for a short time. In the present embodiment, the threshold value of the potential that should not be exceeded is set to 4.5V. In the second embodiment and the third embodiment, each is configured to prevent overcharging of the positive electrode, but a sudden abnormality occurs in the battery system, and a large current flows to cause the positive electrode to be overcharged. In this case, since a relatively large resistance value is connected between the positive electrode 200 and the third electrode 401, there is a possibility that a large current does not flow and the overcharge state cannot be resolved.
Therefore, as in this embodiment, by using a diode having a threshold value larger than the threshold voltage of thediode 402c as the diode 402d and further using a resistance component 403d having a resistance value lower than that of the resistance component 403c, the battery system is abnormal. When the potential of the positive electrode 200 does not occur and operates at a potential lower than 4.5V, the battery operates with the same effect as in the second embodiment. If the battery system malfunctions, the potential of the positive electrode 200 becomes 4.5V. When exceeding, it is possible to eliminate the overcharged state of the positive electrode.
In the present embodiment, the threshold value of the potential that should not be exceeded is set to 4.5 V, but the value varies depending on the material of the positive electrode.
Although not introduced in the embodiment, thenegative electrode 300 may be connected to the third electrode 401 via the diodes 402c and 402d and the resistance components 403c and 403d.
At that time, thenegative electrode 200 is connected to the anode side of the diode 402 and the third electrode 401 is connected to the cathode side. Further, the threshold value of the diode at that time is considered to be about 0.8V and 1.4V. The resistance connected in series with the diode is the same as in the case of the positive electrode, and the resistance value of the resistance component connected in series with the diode whose threshold is set to 0.8 V is as in the first embodiment. The resistance value of the resistance component connected in series with the diode whose threshold value is set to 1.4 V is relatively small, such as 0.01 mΩ, and is a value that does not cause abnormal battery heat generation. Is considered desirable. Thereby, even if a large current flows due to an abnormality in the battery system, it is possible to prevent the overdischarge state of the negative electrode.
In addition, both thepositive electrode 200 and the negative electrode 300 may be connected to the third electrode 401 via two diodes 402c and 402d and resistance components 403c and 403d. Even when it flows, it is possible to prevent the overcharge state of the positive electrode and the overdischarge state of the negative electrode.
As described above, by using this embodiment, it is possible to alleviate the capacity deterioration of the lithium ion secondary battery and provide a safer lithium ion secondary battery.
また、閾値が4.2Vであるダイオード402cと直列接続している抵抗成分403cの抵抗値は第二の実施形態の通りだが、閾値が4.5 Vと設定しているダイオード402dと直列接続している抵抗成分403dの抵抗値は0.01mΩとした。この成分は、この値限定ではないが、比較的小さく、かつ、電池の発熱異常が生じない程度の値であることが望ましい。また、当該抵抗成分403dの抵抗値は、抵抗成分403cの抵抗よりも小さくなる構成となっている。
過充電によって正極200の電位が高電位となると、正極活物質であるLiCoO2の結晶崩壊や酸素脱離等の劣化原因となるため望ましくない。そのため、正極200の電位が少しの間でも高電位とならないことが望ましい。本実施形態では、超えるべきではない電位の閾値を4.5Vと設定した。第二の実施形態、第三の実施形態においては、それぞれ正極の過充電を防止する構成となっているが、電池システムに急激な異常が生じ、大電流が流れることによって正極が過充電状態になった場合、正極200と第3電極401間には比較的大きな抵抗値が接続されているために大電流が流れずに過充電状態を解消できない可能性があった。
そこで、本実施形態のように、ダイオード402dにダイオード402cの閾値電圧よりも大きな閾値を持つダイオードを用い、さらに抵抗成分403cよりも抵抗値の低い抵抗成分403dを用いることで、電池システムに異常が起きず、正極200の電位が4.5V未満で作動している場合、第二の実施形態と同様な効果で電池が稼働し、万が一、電池システムの異常により正極200の電位が4.5Vを超えた場合、正極の過充電状態を解消することが可能である。
なお、本実施形態において、超えるべきではない電位の閾値を4.5Vと設定しているが、正極の材料によりその値は変動する。
また、実施例では紹介しないが、ダイオード402c及び402d、抵抗成分403c及び403dを介して第3電極401と接続されているのは、正極200ではなく、負極300でもよい。
その際ダイオード402のアノード側に負極200、カソード側に第3電極401が接続する。また、その際のダイオードの閾値は0.8V、1.4V程度と考えられる。ダイオードと直列接続している抵抗については、正極の場合と同様で、閾値が0.8Vと設定しているダイオードと直列接続している抵抗成分の抵抗値は、第一の実施形態の通りだが、閾値が1.4 Vと設定しているダイオードと直列接続している抵抗成分の抵抗値は0.01mΩなどの、比較的小さく、かつ、電池の発熱異常が生じない程度の値であることが望ましい、と考えられる。これにより、万が一、電池システムの異常により大電流が流れた場合でも、負極の過放電状態をそれぞれ防止することが可能である。
また、正極200、負極300の両極共に、2つのダイオード402c及び402d、抵抗成分403c及び403dを介して第3電極401と接続しても良く、その時、万一、電池システムの異常により大電流が流れた場合でも、正極の過充電状態、負極の過放電状態をそれぞれ防止することが可能である。
以上、本実施例を用いることにより、リチウムイオン二次電池の容量劣化を緩和させることができ、かつ、より安全なリチウムイオン二次電池を提供できる。 In the present embodiment, the threshold value of the
Further, the resistance value of the
When the potential of the
Therefore, as in this embodiment, by using a diode having a threshold value larger than the threshold voltage of the
In the present embodiment, the threshold value of the potential that should not be exceeded is set to 4.5 V, but the value varies depending on the material of the positive electrode.
Although not introduced in the embodiment, the
At that time, the
In addition, both the
As described above, by using this embodiment, it is possible to alleviate the capacity deterioration of the lithium ion secondary battery and provide a safer lithium ion secondary battery.
《第五の実施形態》
本実施形態は、図1(d)の構成に基づいている例であり、以下の点を除けば、第三の実施形態と同様である。 << Fifth Embodiment >>
The present embodiment is an example based on the configuration of FIG. 1D, and is the same as the third embodiment except for the following points.
本実施形態は、図1(d)の構成に基づいている例であり、以下の点を除けば、第三の実施形態と同様である。 << Fifth Embodiment >>
The present embodiment is an example based on the configuration of FIG. 1D, and is the same as the third embodiment except for the following points.
本実施形態における電池セル構成の簡略図を図1(d)に示す。構成は、図1(d)のように、正極200と負極300がダイオード402(402e、402f)、抵抗成分403(403e、403f)を介して第3電極501と接続している。ダイオード402fのアノード側に正極200が接続、ダイオード402eのカソード側に第3電極501が接続している。一方負極側は第三の実施形態と異なり、ダイオード403eのアノード側に第3電極501、ダイオード403eのカソード側に負極300が接続と、負極側に接続されているダイオードの向きが逆となる構成となっている。
また、本実施形態では、第3電極501にチタン酸リチウム(以下、LTOと表記)を用いている。なお本実施形態では、第3電極501にLTOを起用したが、第3電極501の候補としては、LiSiやLiSnなども考えられ、正極の作動電位と負極の作動電位の中間の標準電位を所有する材料であることが条件である。
以下、本実施形態の効果について説明する。
本実施形態においても図6(a)に示すように、セルの初期状態の充放電状態において、セル電池の作動電位が4.1V~2.7Vの使用範囲で正極200は、金属リチウムの電位水準に対して約4.2V~約3.5Vまで、負極300は、約0.1V~約0.8Vまで電位変化するように設計している。また本実施形態ではで第3電極501として用いたLTOの電位水準は、金属リチウムの電位水準に対して約1.5Vであった。本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池において、長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施形態を用いて、充放電範囲のずれを緩和することが可能である。 A simplified diagram of the battery cell configuration in the present embodiment is shown in FIG. As shown in FIG. 1D, thepositive electrode 200 and the negative electrode 300 are connected to the third electrode 501 via the diode 402 (402e, 402f) and the resistance component 403 (403e, 403f). The positive electrode 200 is connected to the anode side of the diode 402f, and the third electrode 501 is connected to the cathode side of the diode 402e. On the other hand, on the negative electrode side, unlike the third embodiment, the third electrode 501 is connected to the anode side of the diode 403e, the negative electrode 300 is connected to the cathode side of the diode 403e, and the direction of the diode connected to the negative electrode side is reversed. It has become.
In the present embodiment, lithium titanate (hereinafter referred to as LTO) is used for thethird electrode 501. In this embodiment, LTO is used for the third electrode 501, but LiSi, LiSn, and the like are also considered as candidates for the third electrode 501, and possesses a standard potential that is intermediate between the positive electrode operating potential and the negative electrode operating potential. It is a condition to be a material to be used.
Hereinafter, the effect of this embodiment will be described.
Also in this embodiment, as shown in FIG. 6 (a), in the charge / discharge state in the initial state of the cell, thepositive electrode 200 has the potential of metallic lithium in the operating range of the cell battery of 4.1V to 2.7V. The negative electrode 300 is designed to change in potential from about 4.2 V to about 3.5 V with respect to the level, from about 0.1 V to about 0.8 V. In this embodiment, the potential level of the LTO used as the third electrode 501 in the present embodiment was about 1.5 V with respect to the potential level of metallic lithium. In this embodiment, the case where the battery is used in the range of 4.1V to 2.7V will be described.
In a lithium ion battery, it is considered that a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle over a long period of time. However, using this embodiment, it is possible to alleviate a shift in the charge / discharge range. is there.
また、本実施形態では、第3電極501にチタン酸リチウム(以下、LTOと表記)を用いている。なお本実施形態では、第3電極501にLTOを起用したが、第3電極501の候補としては、LiSiやLiSnなども考えられ、正極の作動電位と負極の作動電位の中間の標準電位を所有する材料であることが条件である。
以下、本実施形態の効果について説明する。
本実施形態においても図6(a)に示すように、セルの初期状態の充放電状態において、セル電池の作動電位が4.1V~2.7Vの使用範囲で正極200は、金属リチウムの電位水準に対して約4.2V~約3.5Vまで、負極300は、約0.1V~約0.8Vまで電位変化するように設計している。また本実施形態ではで第3電極501として用いたLTOの電位水準は、金属リチウムの電位水準に対して約1.5Vであった。本実施例においても、4.1V~2.7Vの範囲で電池を使用した場合において説明する。
リチウムイオン電池において、長期的にサイクルを繰り返すことで、図6(b)のような充放電状態になると考えられるが、本実施形態を用いて、充放電範囲のずれを緩和することが可能である。 A simplified diagram of the battery cell configuration in the present embodiment is shown in FIG. As shown in FIG. 1D, the
In the present embodiment, lithium titanate (hereinafter referred to as LTO) is used for the
Hereinafter, the effect of this embodiment will be described.
Also in this embodiment, as shown in FIG. 6 (a), in the charge / discharge state in the initial state of the cell, the
In a lithium ion battery, it is considered that a charge / discharge state as shown in FIG. 6B is obtained by repeating the cycle over a long period of time. However, using this embodiment, it is possible to alleviate a shift in the charge / discharge range. is there.
本実施形態において、正極200と接続されているダイオード402fの閾値を2.3V、負極300と接続されているダイオード402eの閾値を1.1Vと設定しており、各電極と第3電極501であるLTO間の電位差が各閾値以上になることで、正極200からLTOの方向へ電流が流れ、LTOから負極300の方向へ電流が流れ、正極200は充電、負極300は充電される仕組みとなっている。
上記で設定した各ダイオードの閾値2.3V、1.1Vという値は、初期のリチウムイオン電池のSOC50%状態における正極200、負極300の電位と第3電極510であるLTO間の電位差であり、本実施形態では、充放電範囲のずれの緩和だけでなく、各電極のSOC状態を初期のSOC50%の状態に戻す効果も含んでいる。
図12は、その挙動を簡易的に示したものである。図6(b)で示した通り劣化による充放電範囲のずれによって、負極電位が高電位側にシフトするが、図1(d)の構成を用いることで、充電時に正極200とLTO間の電位差が2.3Vを超えた際に、また、負極300とLTO間の電位差が1.1Vを超えた際に、図12に示すように、正極200では正極200からLTOの方向へ電流が流れ((g)の三角から (h)の四角の方向にシフト)、LTOから負極300の方向へ電流が流れて((e)の三角から (f)の四角の方向にシフト)、差分のリチウム量の分、充放電容量が回復し、また、各電極のSOC状態が初期のSOC50%の状態へ戻る方向へ向かう。
すなわち、本実施形態を用いることによって充電後、長時間充放電を停止し保管することで、各電極のSOC状態を初期のSOC50%の電位に戻すことが可能になり、容量ズレによる電池容量劣化を解消することができる。
なお、本実施例で用いた各ダイオードの閾値は、初期のリチウムイオン電池のSOC50%状態における正極200、負極300の電位と第3電極510であるLTO間の電位差で設定したが、使用用途によって、異なるSOC状態の電位と第3電極510であるLTOとの電位差を閾値に持つダイオードを用いても良い。
また、本実施形態のように、各電極がSOC50%の電位で電圧バランシングを行う構成は、HEV用途のようにSOC50%程度が使用電位範囲の中心であり、使用する充放電範囲の小さい使用方法の場合に用いられる。
また、HEV用途の場合でも、使用範囲内においてSOCの高い状態で電圧バランシングを行う方が、より望ましいと考えられる。
一方、PHEV用途のように、より多くの充放電範囲を要し、かつ、保管時は比較的高SOCが望ましい用途の場合は、例えば、初期のリチウムイオン電池のSOC80%状態の電位と第3電極であるLTOとの電位差を閾値に持つダイオードを用いても良い。
本実施形態で用いた抵抗成分403e及び403fについて、正極200に接続されている抵抗成分403fの抵抗値は500Ω程度、負極200に接続されている抵抗成分403eの抵抗値は250Ω程度のものを用いた。各抵抗成分403e及び403fの抵抗値はこの値限定ではなく、用途にも依存するが、それぞれ1kΩ~500Ω、500Ω~250Ωの範囲の抵抗成分を使用するのが望ましい。
このように第一の実施形態から第四の実施形態と異なり抵抗値が比較的高い抵抗成分を用いているのは、本実施例のように各電極が初期のSOC50%の電位に安定するようにダイオードを設定した場合、高SOC状態に充電しても抵抗成分403の抵抗値が小さければ、各電極が短時間で放電し、エネルギー効率が悪いためである。
そのため、本実施形態では、1C程度の電流値で充放電する使用時において、電圧バランシングによる容量減少が1%程度に収めるために、上記の値に設定した。
また、電位バランシングが長くても一週間で完了するように計算した場合の抵抗値を上記で最大値としている。
以上より、本実施形態を用いることにより、エネルギー効率が十分に保障でき、電圧バランシング機能により充放電電位のずれによるリチウムイオン二次電池の容量劣化を解消できる電池を提供できる。
《第六の実施形態》
本実施形態では、第一の実施形態から第五の実施形態に示す電池を制御する電池制御システム600の例を示す。
図8は電池制御システム600のシステム構成を示す図である。当該電池制御システム600は、少なくとも2セル以上の電池が直列に接続された電池群31と、当該電池群31の電池情報を収集等する充放電制御装置30と、当該充放電制御装置から電池群31を制御する制御情報を受信し、電池群31の制御を行なうコントローラ36を有する。
充放電制御装置30は、電池群31の電池情報を取得する電池情報取得部32、当該電池情報取得部32の情報に基づいて各電池の充電状態のばらつきを判定する電池ばらつき判定部33、電池ばらつき判定部34の情報により充電状態の制御指示を演算する充電状態制御部34、当該充電状態制御部34の指示をコントローラ36に出力する制御信号送信部35、及び充電状態制御部34で演算された情報を表示する表示部37から構成される。
より具体的な制御としては、各電池の電圧情報を電池情報取得部32が取得し、電圧ばらつき判定部33において電圧バランシング機能の作動の要否を判定する。必要と判定された場合は、充電状態制御部34が制御信号送信部35を通してコントローラ36へと電池群の充電状態を指示する。
続いて図9を用いて充放電制御装置30内出の処理を説明する。まずステップS1で電池情報取得部32が電池群31の温度情報、電流情報、電圧情報を取得する。続いて、ステップS2では、電池ばらつき判定部34が電池情報取得部32で取得された電池情報に基づき電池ばらつきを判定する。より具体的には各電池が電圧バランシング機能を作動させる電圧値以上であるか否かが判断される。電圧バランシング機能を作動させる各電池の電圧差は、特に制限しないが、小さいとステップS3へ移行する回数が頻繁になるため電池システムの作動の妨げになり、大きいとステップS3へ移行せず電圧バランシング機能が作動しない。例えば、電圧差50mVは容量10%程度のずれに相当するため、適切な値である。
当該電圧値以上であった場合にはステップS3に進み、充電状態制御部34がばらつきが抑制される充電状態を演算する上記の充電状態は実施形態によって異なるそしてステップS4に進み、当該充電状態の指示をコントローラ36に出力して制御を終了する。
一方、ステップS2で所定電圧値以下であった場合には特に充電状態の指示はせず制御を終了する。
当該制御を行なうことによって、前記充電状態に制御された電池群は、各電池内部で上述した各実施形態での電圧バランシング機能が作動し、正極および負極が所定の充電状態に移行し、各電池の充電状態が所定の値に収束する。
また、例えば電池温度のばらつきなどに起因して、一部の電池で劣化が加速進行した場合などで、各電池の充電状態が所定の値に収束しない場合が考えられる。そのような場合に備えて、ステップS3からステップS1に戻るループを設けて、充電状態制御部が指示する充電状態を所定の値だけ上昇させて最終的に収束させるアルゴリズムが好ましい。この際、リチウムイオン二次電池が過充電状態にならないような制御をすることは自明である。
処理が終了したら、終了のシグナルと併せて、例えばループ回数などを表示部37により上位システムまたはユーザーに通知するとなお好ましい。
以上、本発明の実施形態について詳述したが、本発明は、前記の実施形態に限定されるものではなく、特許請求の範囲に記載された本発明の精神を逸脱しない範囲で、種々の設計変更を行うことができるものである。例えば、前記した実施の形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、ある実施形態の構成に他の実施形態の構成を加えることも可能である。さらに、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 In the present embodiment, the threshold value of thediode 402f connected to the positive electrode 200 is set to 2.3V, and the threshold value of the diode 402e connected to the negative electrode 300 is set to 1.1V. Each electrode and the third electrode 501 When the potential difference between a certain LTO becomes more than each threshold, a current flows from the positive electrode 200 to the LTO direction, a current flows from the LTO to the negative electrode 300, the positive electrode 200 is charged, and the negative electrode 300 is charged. ing.
The threshold values 2.3 V and 1.1 V of the diodes set above are potential differences between the potentials of thepositive electrode 200 and the negative electrode 300 and the LTO which is the third electrode 510 in the initial 50% SOC state of the lithium ion battery. In the present embodiment, not only mitigation of the deviation of the charge / discharge range but also the effect of returning the SOC state of each electrode to the initial SOC state of 50% is included.
FIG. 12 simply shows the behavior. As shown in FIG. 6B, the potential of the negative electrode shifts to the high potential side due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 1D, the potential difference between thepositive electrode 200 and the LTO during charging. When the voltage exceeds 2.3 V and when the potential difference between the negative electrode 300 and the LTO exceeds 1.1 V, current flows from the positive electrode 200 to the LTO in the positive electrode 200 as shown in FIG. (shift from the triangle of (g) to the square of (h)), current flows from the LTO to the negative electrode 300 (shift from the triangle of (e) to the square of (f)), and the difference in lithium content As a result, the charge / discharge capacity is recovered, and the SOC state of each electrode returns to the initial SOC state of 50%.
That is, by using this embodiment, charging and discharging are stopped and stored for a long time after charging, so that the SOC state of each electrode can be returned to the initial SOC 50% potential, and the battery capacity deteriorates due to capacity deviation. Can be eliminated.
The threshold value of each diode used in this example was set by the potential difference between the potential of thepositive electrode 200 and the negative electrode 300 and the LTO which is the third electrode 510 in the SOC 50% state of the initial lithium ion battery. Alternatively, a diode having a threshold value that is a potential difference between a different SOC state potential and the LTO that is the third electrode 510 may be used.
In addition, the configuration in which each electrode performs voltage balancing with a potential of SOC 50% as in the present embodiment is such that the SOC is about 50% at the center of the working potential range as in HEV applications, and the charging / discharging range to be used is small. Used in the case of
Even in the case of HEV applications, it is considered more desirable to perform voltage balancing with a high SOC within the usage range.
On the other hand, in a case where a higher charge / discharge range is required and a relatively high SOC is desirable at the time of storage, such as PHEV use, for example, the potential of the initial 80% SOC state of the lithium ion battery and the third potential You may use the diode which has a potential difference with LTO which is an electrode as a threshold value.
Regarding the resistance components 403e and 403f used in this embodiment, the resistance value of the resistance component 403f connected to the positive electrode 200 is about 500Ω, and the resistance value of the resistance component 403e connected to the negative electrode 200 is about 250Ω. It was. The resistance values of the resistance components 403e and 403f are not limited to this value, and depending on the application, it is desirable to use resistance components in the range of 1 kΩ to 500Ω and 500Ω to 250Ω, respectively.
Thus, unlike the first to fourth embodiments, the reason why the resistance component having a relatively high resistance value is used is that each electrode is stabilized at the initial SOC 50% potential as in this example. This is because, when the diode is set, the electrodes are discharged in a short time and the energy efficiency is poor if the resistance value of theresistance component 403 is small even when charged in a high SOC state.
For this reason, in the present embodiment, when charging / discharging with a current value of about 1 C, the above value is set so that the capacity reduction due to voltage balancing is about 1%.
In addition, the resistance value when the calculation is made so that the voltage balancing is completed in one week even if the potential balancing is long is set to the maximum value.
As described above, by using this embodiment, it is possible to provide a battery that can sufficiently ensure energy efficiency and can eliminate the capacity deterioration of the lithium ion secondary battery due to the charge / discharge potential shift by the voltage balancing function.
<< Sixth Embodiment >>
In this embodiment, an example of abattery control system 600 that controls the batteries shown in the first to fifth embodiments is shown.
FIG. 8 is a diagram showing a system configuration of thebattery control system 600. The battery control system 600 includes a battery group 31 in which batteries of at least two cells or more are connected in series, a charge / discharge control device 30 that collects battery information of the battery group 31, and the battery group from the charge / discharge control device. And a controller 36 that receives control information for controlling the battery 31 and controls the battery group 31.
The charge / discharge control device 30 includes a batteryinformation acquisition unit 32 that acquires battery information of the battery group 31, a battery variation determination unit 33 that determines variations in the state of charge of each battery based on information of the battery information acquisition unit 32, and a battery The charge state control unit 34 that calculates a charge state control instruction based on the information of the variation determination unit 34, the control signal transmission unit 35 that outputs the instruction of the charge state control unit 34 to the controller 36, and the charge state control unit 34. It comprises a display unit 37 for displaying the information.
As more specific control, the batteryinformation acquisition unit 32 acquires voltage information of each battery, and the voltage variation determination unit 33 determines whether or not the voltage balancing function needs to be operated. When it is determined that it is necessary, the charge state control unit 34 instructs the controller 36 through the control signal transmission unit 35 about the charge state of the battery group.
Next, the process inside the charge / discharge control device 30 will be described with reference to FIG. First, in step S1, the batteryinformation acquisition unit 32 acquires temperature information, current information, and voltage information of the battery group 31. Subsequently, in step S <b> 2, the battery variation determination unit 34 determines the battery variation based on the battery information acquired by the battery information acquisition unit 32. More specifically, it is determined whether or not each battery is equal to or higher than a voltage value that activates the voltage balancing function. The voltage difference of each battery that operates the voltage balancing function is not particularly limited. However, if the voltage difference is small, the number of times of shifting to step S3 becomes frequent, which hinders the operation of the battery system. The function does not work. For example, a voltage difference of 50 mV is an appropriate value because it corresponds to a deviation of about 10% of capacity.
If the voltage value is greater than or equal to the voltage value, the process proceeds to step S3, where the chargestate control unit 34 calculates the charge state in which the variation is suppressed, and the charge state varies depending on the embodiment. An instruction is output to the controller 36 and the control is terminated.
On the other hand, if the voltage is equal to or lower than the predetermined voltage value in step S2, the control is terminated without particularly instructing the state of charge.
By performing the control, the battery group controlled to the charged state operates the voltage balancing function in each embodiment described above inside each battery, the positive electrode and the negative electrode shift to a predetermined charged state, and each battery The state of charge converges to a predetermined value.
In addition, there may be a case where the charge state of each battery does not converge to a predetermined value due to, for example, a case where deterioration accelerates in some batteries due to variations in battery temperature. In preparation for such a case, an algorithm that provides a loop that returns from step S3 to step S1 and raises the state of charge indicated by the state of charge control unit by a predetermined value to finally converge is preferable. At this time, it is obvious that the lithium ion secondary battery is controlled so as not to be overcharged.
When the processing is completed, it is more preferable that thedisplay unit 37 notifies the host system or the user of the number of loops, for example, together with the signal of completion.
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
上記で設定した各ダイオードの閾値2.3V、1.1Vという値は、初期のリチウムイオン電池のSOC50%状態における正極200、負極300の電位と第3電極510であるLTO間の電位差であり、本実施形態では、充放電範囲のずれの緩和だけでなく、各電極のSOC状態を初期のSOC50%の状態に戻す効果も含んでいる。
図12は、その挙動を簡易的に示したものである。図6(b)で示した通り劣化による充放電範囲のずれによって、負極電位が高電位側にシフトするが、図1(d)の構成を用いることで、充電時に正極200とLTO間の電位差が2.3Vを超えた際に、また、負極300とLTO間の電位差が1.1Vを超えた際に、図12に示すように、正極200では正極200からLTOの方向へ電流が流れ((g)の三角から (h)の四角の方向にシフト)、LTOから負極300の方向へ電流が流れて((e)の三角から (f)の四角の方向にシフト)、差分のリチウム量の分、充放電容量が回復し、また、各電極のSOC状態が初期のSOC50%の状態へ戻る方向へ向かう。
すなわち、本実施形態を用いることによって充電後、長時間充放電を停止し保管することで、各電極のSOC状態を初期のSOC50%の電位に戻すことが可能になり、容量ズレによる電池容量劣化を解消することができる。
なお、本実施例で用いた各ダイオードの閾値は、初期のリチウムイオン電池のSOC50%状態における正極200、負極300の電位と第3電極510であるLTO間の電位差で設定したが、使用用途によって、異なるSOC状態の電位と第3電極510であるLTOとの電位差を閾値に持つダイオードを用いても良い。
また、本実施形態のように、各電極がSOC50%の電位で電圧バランシングを行う構成は、HEV用途のようにSOC50%程度が使用電位範囲の中心であり、使用する充放電範囲の小さい使用方法の場合に用いられる。
また、HEV用途の場合でも、使用範囲内においてSOCの高い状態で電圧バランシングを行う方が、より望ましいと考えられる。
一方、PHEV用途のように、より多くの充放電範囲を要し、かつ、保管時は比較的高SOCが望ましい用途の場合は、例えば、初期のリチウムイオン電池のSOC80%状態の電位と第3電極であるLTOとの電位差を閾値に持つダイオードを用いても良い。
本実施形態で用いた抵抗成分403e及び403fについて、正極200に接続されている抵抗成分403fの抵抗値は500Ω程度、負極200に接続されている抵抗成分403eの抵抗値は250Ω程度のものを用いた。各抵抗成分403e及び403fの抵抗値はこの値限定ではなく、用途にも依存するが、それぞれ1kΩ~500Ω、500Ω~250Ωの範囲の抵抗成分を使用するのが望ましい。
このように第一の実施形態から第四の実施形態と異なり抵抗値が比較的高い抵抗成分を用いているのは、本実施例のように各電極が初期のSOC50%の電位に安定するようにダイオードを設定した場合、高SOC状態に充電しても抵抗成分403の抵抗値が小さければ、各電極が短時間で放電し、エネルギー効率が悪いためである。
そのため、本実施形態では、1C程度の電流値で充放電する使用時において、電圧バランシングによる容量減少が1%程度に収めるために、上記の値に設定した。
また、電位バランシングが長くても一週間で完了するように計算した場合の抵抗値を上記で最大値としている。
以上より、本実施形態を用いることにより、エネルギー効率が十分に保障でき、電圧バランシング機能により充放電電位のずれによるリチウムイオン二次電池の容量劣化を解消できる電池を提供できる。
《第六の実施形態》
本実施形態では、第一の実施形態から第五の実施形態に示す電池を制御する電池制御システム600の例を示す。
図8は電池制御システム600のシステム構成を示す図である。当該電池制御システム600は、少なくとも2セル以上の電池が直列に接続された電池群31と、当該電池群31の電池情報を収集等する充放電制御装置30と、当該充放電制御装置から電池群31を制御する制御情報を受信し、電池群31の制御を行なうコントローラ36を有する。
充放電制御装置30は、電池群31の電池情報を取得する電池情報取得部32、当該電池情報取得部32の情報に基づいて各電池の充電状態のばらつきを判定する電池ばらつき判定部33、電池ばらつき判定部34の情報により充電状態の制御指示を演算する充電状態制御部34、当該充電状態制御部34の指示をコントローラ36に出力する制御信号送信部35、及び充電状態制御部34で演算された情報を表示する表示部37から構成される。
より具体的な制御としては、各電池の電圧情報を電池情報取得部32が取得し、電圧ばらつき判定部33において電圧バランシング機能の作動の要否を判定する。必要と判定された場合は、充電状態制御部34が制御信号送信部35を通してコントローラ36へと電池群の充電状態を指示する。
続いて図9を用いて充放電制御装置30内出の処理を説明する。まずステップS1で電池情報取得部32が電池群31の温度情報、電流情報、電圧情報を取得する。続いて、ステップS2では、電池ばらつき判定部34が電池情報取得部32で取得された電池情報に基づき電池ばらつきを判定する。より具体的には各電池が電圧バランシング機能を作動させる電圧値以上であるか否かが判断される。電圧バランシング機能を作動させる各電池の電圧差は、特に制限しないが、小さいとステップS3へ移行する回数が頻繁になるため電池システムの作動の妨げになり、大きいとステップS3へ移行せず電圧バランシング機能が作動しない。例えば、電圧差50mVは容量10%程度のずれに相当するため、適切な値である。
当該電圧値以上であった場合にはステップS3に進み、充電状態制御部34がばらつきが抑制される充電状態を演算する上記の充電状態は実施形態によって異なるそしてステップS4に進み、当該充電状態の指示をコントローラ36に出力して制御を終了する。
一方、ステップS2で所定電圧値以下であった場合には特に充電状態の指示はせず制御を終了する。
当該制御を行なうことによって、前記充電状態に制御された電池群は、各電池内部で上述した各実施形態での電圧バランシング機能が作動し、正極および負極が所定の充電状態に移行し、各電池の充電状態が所定の値に収束する。
また、例えば電池温度のばらつきなどに起因して、一部の電池で劣化が加速進行した場合などで、各電池の充電状態が所定の値に収束しない場合が考えられる。そのような場合に備えて、ステップS3からステップS1に戻るループを設けて、充電状態制御部が指示する充電状態を所定の値だけ上昇させて最終的に収束させるアルゴリズムが好ましい。この際、リチウムイオン二次電池が過充電状態にならないような制御をすることは自明である。
処理が終了したら、終了のシグナルと併せて、例えばループ回数などを表示部37により上位システムまたはユーザーに通知するとなお好ましい。
以上、本発明の実施形態について詳述したが、本発明は、前記の実施形態に限定されるものではなく、特許請求の範囲に記載された本発明の精神を逸脱しない範囲で、種々の設計変更を行うことができるものである。例えば、前記した実施の形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、ある実施形態の構成に他の実施形態の構成を加えることも可能である。さらに、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 In the present embodiment, the threshold value of the
The threshold values 2.3 V and 1.1 V of the diodes set above are potential differences between the potentials of the
FIG. 12 simply shows the behavior. As shown in FIG. 6B, the potential of the negative electrode shifts to the high potential side due to the shift of the charge / discharge range due to deterioration, but by using the configuration of FIG. 1D, the potential difference between the
That is, by using this embodiment, charging and discharging are stopped and stored for a long time after charging, so that the SOC state of each electrode can be returned to the initial SOC 50% potential, and the battery capacity deteriorates due to capacity deviation. Can be eliminated.
The threshold value of each diode used in this example was set by the potential difference between the potential of the
In addition, the configuration in which each electrode performs voltage balancing with a potential of SOC 50% as in the present embodiment is such that the SOC is about 50% at the center of the working potential range as in HEV applications, and the charging / discharging range to be used is small. Used in the case of
Even in the case of HEV applications, it is considered more desirable to perform voltage balancing with a high SOC within the usage range.
On the other hand, in a case where a higher charge / discharge range is required and a relatively high SOC is desirable at the time of storage, such as PHEV use, for example, the potential of the initial 80% SOC state of the lithium ion battery and the third potential You may use the diode which has a potential difference with LTO which is an electrode as a threshold value.
Regarding the
Thus, unlike the first to fourth embodiments, the reason why the resistance component having a relatively high resistance value is used is that each electrode is stabilized at the initial SOC 50% potential as in this example. This is because, when the diode is set, the electrodes are discharged in a short time and the energy efficiency is poor if the resistance value of the
For this reason, in the present embodiment, when charging / discharging with a current value of about 1 C, the above value is set so that the capacity reduction due to voltage balancing is about 1%.
In addition, the resistance value when the calculation is made so that the voltage balancing is completed in one week even if the potential balancing is long is set to the maximum value.
As described above, by using this embodiment, it is possible to provide a battery that can sufficiently ensure energy efficiency and can eliminate the capacity deterioration of the lithium ion secondary battery due to the charge / discharge potential shift by the voltage balancing function.
<< Sixth Embodiment >>
In this embodiment, an example of a
FIG. 8 is a diagram showing a system configuration of the
The charge / discharge control device 30 includes a battery
As more specific control, the battery
Next, the process inside the charge / discharge control device 30 will be described with reference to FIG. First, in step S1, the battery
If the voltage value is greater than or equal to the voltage value, the process proceeds to step S3, where the charge
On the other hand, if the voltage is equal to or lower than the predetermined voltage value in step S2, the control is terminated without particularly instructing the state of charge.
By performing the control, the battery group controlled to the charged state operates the voltage balancing function in each embodiment described above inside each battery, the positive electrode and the negative electrode shift to a predetermined charged state, and each battery The state of charge converges to a predetermined value.
In addition, there may be a case where the charge state of each battery does not converge to a predetermined value due to, for example, a case where deterioration accelerates in some batteries due to variations in battery temperature. In preparation for such a case, an algorithm that provides a loop that returns from step S3 to step S1 and raises the state of charge indicated by the state of charge control unit by a predetermined value to finally converge is preferable. At this time, it is obvious that the lithium ion secondary battery is controlled so as not to be overcharged.
When the processing is completed, it is more preferable that the
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
30 充放電制御装置
31 電池群
32 電池情報取得部
33 電池ばらつき判定部
34 充電状態制御部
35 制御信号送信部
36 コントローラ
37 表示部
100 電池缶
101 電極群
102 正極蓋
103 ガスケット
200 正極
201 正極箔
202 正極材
300 負極
301 負極箔
302 負極材
350 セパレータ
360 電解液
400 メッシュ電極
401 第3電極
402 ダイオード
403 抵抗成分 30 charge /discharge control device 31 battery group 32 battery information acquisition unit 33 battery variation determination unit 34 charge state control unit 35 control signal transmission unit 36 controller 37 display unit 100 battery can 101 electrode group 102 positive electrode lid 103 gasket 200 positive electrode 201 positive electrode foil 202 Positive electrode material 300 Negative electrode 301 Negative electrode foil 302 Negative electrode material 350 Separator 360 Electrolytic solution 400 Mesh electrode 401 Third electrode 402 Diode 403 Resistance component
31 電池群
32 電池情報取得部
33 電池ばらつき判定部
34 充電状態制御部
35 制御信号送信部
36 コントローラ
37 表示部
100 電池缶
101 電極群
102 正極蓋
103 ガスケット
200 正極
201 正極箔
202 正極材
300 負極
301 負極箔
302 負極材
350 セパレータ
360 電解液
400 メッシュ電極
401 第3電極
402 ダイオード
403 抵抗成分 30 charge /
Claims (8)
- 正極と負極と電解液とを含み、前記正極または前記負極から前記電解液中へイオンを放出する、あるいは、吸蔵する反応を繰り返して充放電する非水系二次電池において、
前記電解液中に前記イオンと同種のイオンを溶出するイオン供給源と、前記負極の表面の一部に接している第一のメッシュ電極とを有し、前記イオン供給源と前記第一のメッシュ電極との間に第一のダイオードと第一の抵抗を設けたことを特徴とする非水系二次電池。 In a non-aqueous secondary battery that includes a positive electrode, a negative electrode, and an electrolytic solution, and discharges ions from the positive electrode or the negative electrode into the electrolytic solution, or repeatedly charges and discharges,
An ion source that elutes ions of the same type as the ions in the electrolyte; and a first mesh electrode that is in contact with a part of the surface of the negative electrode; the ion source and the first mesh A non-aqueous secondary battery, wherein a first diode and a first resistor are provided between electrodes. - 請求項1に記載の非水系二次電池において、
前記第一のダイオードのアノード側は前記負極と電気的に接続され、
前記第一のダイオードのカソード側は前記イオン供給源と電気的に接続されることを特徴とする非水二次電池。 The non-aqueous secondary battery according to claim 1,
The anode side of the first diode is electrically connected to the negative electrode;
The non-aqueous secondary battery, wherein the cathode side of the first diode is electrically connected to the ion supply source. - 請求項2に記載の非水系二次電池において、
前記正極の表面の一部には第二のメッシュ電極が設けられ、
前記イオン供給源と前記第二のメッシュ電極との間に第二のダイオードと第二の抵抗を設けたことを特徴とする非水二次電池。 The non-aqueous secondary battery according to claim 2,
A part of the surface of the positive electrode is provided with a second mesh electrode,
A non-aqueous secondary battery, wherein a second diode and a second resistor are provided between the ion supply source and the second mesh electrode. - 請求項3に記載の非水系二次電池において、
前記第二のダイオードのアノード側は前記正極と電気的に接続され、
前記第二のダイオードのカソード側は前記イオン供給源と電気的に接続されることを特徴とする非水二次電池。 The non-aqueous secondary battery according to claim 3,
The anode side of the second diode is electrically connected to the positive electrode;
The non-aqueous secondary battery, wherein a cathode side of the second diode is electrically connected to the ion supply source. - 請求項1に記載の非水系二次電池において、
前記正極の表面の一部には第二のメッシュ電極が設けられ、
前記イオン供給源と前記第二のメッシュ電極との間に第二のダイオードと第二の抵抗が設けられ、
前記第一のダイオードのカソード側は前記負極と電気的に接続され、
前記第一のダイオードのアノード側は前記イオン供給源と電気的に接続され、
前記第二のダイオードのアノード側は前記正極と電気的に接続され、
前記第二のダイオードのカソード側は前記イオン供給源と電気的に接続されることを特徴とする非水二次電池。 The non-aqueous secondary battery according to claim 1,
A part of the surface of the positive electrode is provided with a second mesh electrode,
A second diode and a second resistor are provided between the ion source and the second mesh electrode;
The cathode side of the first diode is electrically connected to the negative electrode;
The anode side of the first diode is electrically connected to the ion source;
The anode side of the second diode is electrically connected to the positive electrode;
The non-aqueous secondary battery, wherein a cathode side of the second diode is electrically connected to the ion supply source. - 請求項2に記載の非水二次電池において、
前記第一のダイオードの閾値電圧は0.8Vであり、
前記第一の抵抗の抵抗値は0.04Ωから0.4Ωであることを特徴とする非水二次電池。 The nonaqueous secondary battery according to claim 2,
The threshold voltage of the first diode is 0.8V,
The non-aqueous secondary battery, wherein the resistance value of the first resistor is 0.04Ω to 0.4Ω. - 正極と負極と電解液とを含み、前記正極または前記負極から前記電解液中へイオンを放出する、あるいは、吸蔵する反応を繰り返して充放電する非水系二次電池において、
前記電解液中に前記イオンと同種のイオンを溶出するイオン供給源と、前記正極の表面の一部に接しているメッシュ電極とを有し、前記イオン供給源と前記メッシュ電極との間に第一のダイオードと第一の抵抗を設けたことを特徴とする非水系二次電池。 In a non-aqueous secondary battery that includes a positive electrode, a negative electrode, and an electrolytic solution, and discharges ions from the positive electrode or the negative electrode into the electrolytic solution, or repeatedly charges and discharges,
An ion supply source that elutes ions of the same type as the ions in the electrolytic solution; and a mesh electrode that is in contact with a part of the surface of the positive electrode; and a second electrode between the ion supply source and the mesh electrode. A non-aqueous secondary battery comprising a diode and a first resistor. - 請求項7に記載の非水二次電池において、
前記イオン供給源と前記メッシュ電極との間に第二のダイオードと第二の抵抗が設けられており、
前記第二のダイオードの閾値電圧は前記第一のダイオードの閾値電圧よりも大きく、
前記第二の抵抗の抵抗値は前記第一の抵抗の抵抗値よりも小さいことを特徴とする非水系二次電池。 The nonaqueous secondary battery according to claim 7,
A second diode and a second resistor are provided between the ion source and the mesh electrode;
The threshold voltage of the second diode is greater than the threshold voltage of the first diode;
The non-aqueous secondary battery, wherein a resistance value of the second resistor is smaller than a resistance value of the first resistor.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2013/054448 WO2014128905A1 (en) | 2013-02-22 | 2013-02-22 | Lithium ion secondary battery |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2013/054448 WO2014128905A1 (en) | 2013-02-22 | 2013-02-22 | Lithium ion secondary battery |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014128905A1 true WO2014128905A1 (en) | 2014-08-28 |
Family
ID=51390733
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/054448 WO2014128905A1 (en) | 2013-02-22 | 2013-02-22 | Lithium ion secondary battery |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2014128905A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110165306A (en) * | 2019-05-29 | 2019-08-23 | 珠海格力电器股份有限公司 | Storage battery and manufacturing method thereof |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007305475A (en) * | 2006-05-12 | 2007-11-22 | Fdk Corp | Storage device and storage cell |
JP2011103178A (en) * | 2009-11-10 | 2011-05-26 | Hitachi Ltd | Nonaqueous secondary battery and battery module |
-
2013
- 2013-02-22 WO PCT/JP2013/054448 patent/WO2014128905A1/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007305475A (en) * | 2006-05-12 | 2007-11-22 | Fdk Corp | Storage device and storage cell |
JP2011103178A (en) * | 2009-11-10 | 2011-05-26 | Hitachi Ltd | Nonaqueous secondary battery and battery module |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110165306A (en) * | 2019-05-29 | 2019-08-23 | 珠海格力电器股份有限公司 | Storage battery and manufacturing method thereof |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6081584B2 (en) | Apparatus and method for estimating voltage of secondary battery including mixed positive electrode material | |
JP6029251B2 (en) | Apparatus and method for estimating state of charge of secondary battery including mixed positive electrode material | |
WO2011114641A1 (en) | Electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery having same | |
KR101568110B1 (en) | Charging control method for secondary cell and charging control device for secondary cell | |
JP2008536272A (en) | Lithium-ion rocking chair rechargeable battery | |
JP5849234B2 (en) | Nonaqueous electrolyte secondary battery | |
WO2015049778A1 (en) | Lithium ion secondary battery, lithium ion secondary battery system, method for detecting potential in lithium ion secondary battery, and method for controlling lithium ion secondary battery | |
JP2007305475A (en) | Storage device and storage cell | |
JP2013178935A (en) | Lithium-ion secondary battery, and battery pack and power storage device using the same | |
JP2016076358A (en) | Lithium ion secondary battery and battery system | |
JP2009199929A (en) | Lithium secondary battery | |
JP2013517592A (en) | Lithium electrochemical generator with two separate electrochemical battery cells | |
JP5705046B2 (en) | Power system | |
JP5292260B2 (en) | Non-aqueous secondary battery and battery module | |
JP5703996B2 (en) | Battery capacity recovery device and battery capacity recovery method | |
JP5122899B2 (en) | Discharge control device | |
WO2014128905A1 (en) | Lithium ion secondary battery | |
KR20170019349A (en) | Sodium ion secondary battery | |
CN106605330B (en) | Method for controlling nonaqueous electrolyte secondary battery | |
WO2015040685A1 (en) | Lithium-ion secondary battery separator, lithium-ion secondary battery using lithium-ion secondary battery separator, and lithium-ion secondary battery module | |
US20180269473A1 (en) | Active material for a positive electrode of a battery cell, positive electrode, and battery cell | |
JP7380898B2 (en) | secondary battery | |
JP7581307B2 (en) | Rechargeable battery with internal current limiter and internal current interrupter | |
US10790502B2 (en) | Active material for a positive electrode of a battery cell, positive electrode, and battery cell | |
US10763502B2 (en) | Active material for a positive electrode of a battery cell, positive electrode, and battery cell |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13876022 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13876022 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: JP |