JP2020017486A - Vehicle power storage device - Google Patents

Abstract

To provide a vehicle power storage device which includes a storage battery capable of uniformly heating and cooling a power storage body having a winding body pair.SOLUTION: The vehicle power storage device includes a plurality of square-shaped storage batteries, each including in a case: a power storage body 25; a heat insulation member 26 which covers the outer periphery of the power storage body; a sheet heater 28 which warms the power storage body 25; and a sheet heat pipe 27 which transfers the heat of the power storage body 25. The power storage body 25 has at least one winding body pair 32 composed of a pair of flat winding bodies 30. The pair of winding bodies 30 has a positive electrode foil and a negative electrode foil wound in flat shapes around a horizontal shaft center through a separator, and the outer periphery is covered with an insulating member. The winding body pair 32 makes the mutual planar parts of the winding bodies 30 which are placed in proximity to face each other. The heat pipe 27 includes: a heat absorption part 27a which contacts to the opposite planar part of the winding body pair 32 inside a heat insulation member 26; and a heat dissipation part 27b which extends from the heat absorption part 27a to the outside of the heat insulation member 26 to contact to the inner wall of the case. The heater 28 contacts to the planar part of the side to which the heat absorption part 27a of the winding body pair 32 is not in contact.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vehicle power storage device mounted on a vehicle.

  2. Description of the Related Art Conventionally, hybrid vehicles that run by driving drive wheels by an engine and an electric motor have been widely used. A hybrid vehicle mounts an engine and an electric motor in a limited space of the vehicle, and mainly runs on the engine. Therefore, the scene in which the electric motor is driven is limited, and a small power storage device having a small power storage capacity is used to store electric power for driving the electric motor to travel.

  On the other hand, there is also growing interest in electric vehicles (EVs) that do not emit carbon dioxide or the like during traveling. The EV is equipped with an electric motor and a power storage device that stores electric power for driving the electric motor to travel, and has a larger storage capacity than a hybrid vehicle in order to extend the distance that can be traveled by one charge. Has been adopted. The power storage device also supplies electric power for operating electrical components such as a braking device, a steering device, a headlight, and an air conditioner.

  A power storage device of a hybrid vehicle or an EV includes a plurality of storage batteries. As the storage battery, for example, a rectangular lithium ion secondary battery is used in which positive and negative electrode foils and an electrolyte are hermetically housed in a rectangular parallelepiped case made of an aluminum alloy. A plurality of prismatic lithium ion secondary batteries connected in series form a power storage device having a high output voltage for driving the electric motor. In an electric storage device of an EV, a plurality of lithium ion secondary batteries are connected in parallel and connected in series to realize a large storage capacity and a high output voltage.

  A lithium ion secondary battery constituting a power storage device has a use temperature range in which excellent performance can be exhibited, and charging and discharging outside this use temperature range may not only exert performance but also cause deterioration. Therefore, it is necessary to make the storage battery less susceptible to a low outside air temperature, and it is necessary to heat the storage battery so that it does not become lower than the lower limit temperature of the operating temperature range when it is cold. Further, since the storage battery generates heat during charge and discharge, it is necessary to cool the storage battery so as not to exceed the upper limit temperature of the operating temperature range.

  As a technique for warming a power storage device, for example, as disclosed in Patent Literature 1, a technique is known in which a heater disposed on the bottom side of an assembly of prismatic storage batteries is used. Also, as in Patent Document 2, there is known a technique in which a sheet-like heater is provided between a laminate type storage battery in which positive and negative electrode foils are alternately stacked via a separator and sealed with an insulating film. On the other hand, as a cooling technique of a power storage device, a technique is known in which cooling air is circulated around a storage battery by a blower fan or the like to promote heat radiation from the surface of the storage battery.

  When a power storage device formed of a rectangular storage battery is warmed, as in Patent Document 1, a heater is disposed so as to be close to or in contact with a case, and Joule heat of the heater generated by energization is transmitted to the case to transfer the storage battery. Since the heating is performed, it is difficult to efficiently heat the electrode foil as in Patent Literature 2. Specifically, since the heat capacity of the case or the like other than the electrode foil has heat capacity, the heat of the heater is used for purposes other than heating the positive and negative electrode foils.

  In order to prevent the heat of the heater from escaping and to reduce the effect of the outside air temperature, it is conceivable to cover the storage battery together with the heater with a heat insulating member.However, since the heater is heated from a predetermined surface of the case, the electrode foil must be covered. It is difficult to heat evenly. On the other hand, cooling of the storage battery promotes heat radiation from the surface of the storage battery case by the cooling air. Therefore, if the storage battery is covered with a heat insulating member together with the heater, the heat radiation is obstructed and cooling is not possible.

  Therefore, in the case, a power storage unit for storing electric power, a heat insulating member covering the outer periphery of the power storage unit, a sheet-shaped heater for heating the power storage unit, and a sheet-shaped unit for transferring heat of the power storage unit to the case. The present applicant has already proposed a power storage device for a vehicle having a rectangular storage battery provided with the heat pipe (Japanese Patent Application No. 2018-81169).

JP 2008-103207 A Japanese Patent No. 5609799

  As described above, a high output voltage and a large storage capacity are required for an electric storage device of an EV. The power storage device of the hybrid vehicle is required to have an output voltage as high as that of the EV power storage device, but has a smaller storage capacity than the EV power storage device. At present, the manufacturing cost of a storage battery is not inexpensive. Therefore, the storage battery used for the power storage device of the EV and the storage battery used for the power storage device of the hybrid vehicle are shared to some extent to reduce the manufacturing cost.

  For example, a wound body in which a positive electrode foil and a negative electrode foil are wound via a separator is formed, and a power storage unit of a rectangular storage battery is configured by at least one set of a wound body pair including a pair of wound bodies. The battery is housed in a case, and is separately formed into an EV storage battery and a hybrid vehicle storage battery depending on the connection mode of the plurality of winding bodies. If a plurality of windings are connected in parallel, a storage battery for an EV having a large storage capacity can be formed. If a plurality of windings are connected in series, a storage battery for a hybrid vehicle with a high output voltage can be formed.

  Even in a rectangular storage battery having a power storage unit formed of such a wound body pair, it is necessary to adjust the power storage unit to an appropriate temperature by heating and cooling. However, since a member for insulation is provided between the adjacent windings, it is difficult to conduct heat between the windings, and all the windings of the power storage unit can be uniformly heated and cooled. Did not.

  It is an object of the present invention to provide a power storage device for a vehicle including a storage battery capable of uniformly heating and cooling a power storage unit formed of a wound body pair.

  The invention according to claim 1 provides a power storage unit for storing electric power in a rectangular parallelepiped case, a heat insulating member covering an outer periphery of the power storage unit, a sheet-like heater for warming the power storage unit, and a heat storage unit. In the power storage device for a vehicle having a plurality of storage batteries provided with a sheet-like heat pipe for moving the storage battery to the case, the power storage body of the storage battery includes at least one set of a pair of flat wound bodies. It has a wound body pair, the wound body, the positive electrode foil and the negative electrode foil are wound flat around the horizontal axis via a separator and the outer periphery is covered with an insulating member, the wound body pair is The heat pipe is configured such that the flat portions of the winding body are opposed to each other in an opposing manner, and the heat pipe includes a heat absorbing portion that abuts on the facing flat portion of the winding body pair inside the heat insulating member; Extending out of the heat insulating member from the A heat dissipating portion that is in contact with the inner wall of the wound body, wherein the heater is disposed so as to be in contact with a flat portion on the side where the heat absorbing portion of the wound body pair is not in contact with the inside of the heat insulating member. Features.

  According to the above configuration, the power storage device for a vehicle has a plurality of storage batteries, and the storage battery has at least one pair of wound bodies forming a power storage unit in a case, and is provided with a heat insulating member that covers an outer periphery of the power storage unit. The effect of the temperature of The heat absorbing portion of the heat pipe in contact with the opposing flat portion of the wound body pair can absorb heat from the wound body pair and move to the heat radiating portion, and the heat radiating portion can transfer heat to the case to promote heat radiation. it can. Further, the heater is disposed so as to sandwich the wound body pair on the flat portion of the heat pipe where the heat absorbing portion is not in contact, and can uniformly heat the wound body pair from the wide flat portion. Therefore, it is possible to uniformly heat and cool the power storage unit including the wound body pair of the plurality of storage batteries included in the power storage device for a vehicle.

  The invention according to claim 2 is a power storage unit for storing electric power in a rectangular parallelepiped case, a heat insulating member covering an outer periphery of the power storage unit, a sheet-like heater for heating the power storage unit, and a heat storage unit. In the power storage device for a vehicle having a plurality of storage batteries provided with a sheet-like heat pipe for moving the storage battery to the case, the power storage body of the storage battery includes at least one set of a pair of flat wound bodies. It has a wound body pair, the wound body, the positive electrode foil and the negative electrode foil are wound flat around the horizontal axis via a separator and the outer periphery is covered with an insulating member, the wound body pair is The heater is arranged so that the flat portions of the wound body are opposed to each other in an opposing manner, and the heater is disposed so as to contact the opposed flat portions of the wound pair inside the heat insulating member, The heat pipe is wound inside the heat insulating member. A heat-absorbing portion disposed so as to be in contact with each of the plane portions on the side where the heater of the pair is not in contact, and a heat-radiating portion extending from the heat-absorbing portion to the outside of the heat insulating member and in contact with the inner wall of the case. It is characterized by that.

  According to the above configuration, the power storage device for a vehicle has a plurality of storage batteries, and the storage battery has at least one pair of winding bodies forming a power storage unit in a case, and is provided with a heat insulating member that covers an outer periphery of the power storage unit. The effect of outside temperature is reduced. The heater is disposed so as to abut on the opposed flat portions of the wound body pair, and can uniformly heat the wound body pair from a wide flat portion. In addition, a heat absorbing portion of the heat pipe is disposed so as to sandwich the wound body pair on the flat portion on the side where the heater does not contact, and the heat of the wound body pair absorbs heat from the flat portions that the heat absorbing portions respectively contact. To the heat dissipating portion, and the heat dissipating portion transfers heat to the case to promote heat dissipation. Therefore, it is possible to uniformly heat and cool the power storage unit including the wound body pair of the plurality of storage batteries included in the vehicle power storage device.

According to a third aspect of the present invention, in the first or second aspect, the heat pipe is provided for each of the wound body pairs.
According to the above configuration, it is possible to easily increase the capacity or output voltage of the storage battery by increasing the number of wound body pairs constituting the storage battery.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a plurality of the storage batteries are arranged at predetermined intervals and have a cooling air passage formed between the storage batteries. It is characterized by.
According to the configuration, the heat of the wound body pair moved by the heat pipe to the case is radiated to the outside by the cooling air flowing through the cooling air passage from the side surface of the case facing the cooling air passage. Therefore, heat dissipation of the power storage device for a vehicle can be promoted and cooling can be performed.

  ADVANTAGE OF THE INVENTION According to the electric power storage device for vehicles of this invention, the heating and cooling of the storage battery which has the electric storage body comprised by the winding body pair can be performed uniformly.

1 is a block diagram illustrating a configuration of a vehicle according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a main part of the power storage device according to the embodiment of the present invention. FIG. 2 is an exploded perspective view of a main part of the power storage module according to the embodiment of the present invention. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3. 1 is an exploded perspective view of a main part of a storage battery according to an embodiment of the present invention. FIG. 6 is a cross-sectional view taken along line VI-VI showing one example of the power storage unit of FIG. 5. FIG. 7 is a diagram illustrating the wound body of FIG. 6. FIG. 7 is a perspective view of the heat pipe of FIG. 6. FIG. 9 is a cross-sectional view taken along line IX-IX illustrating another example of the power storage unit of FIG. 5. It is a perspective view of the heat pipe of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described based on examples.

An example of a large-capacity power storage device for a vehicle that supplies electric power for driving an EV will be described.
As shown in FIG. 1, EV is a vehicle-side load 1, an electric motor 2 for driving the vehicle, a braking device 3, various sensors including a vehicle speed sensor 4, a temperature sensor 5, a cooling fan 6, and DC power supplied to these. And a DC-DC converter 7 for adjusting the voltage. Power storage device 10 (vehicle power storage device) for storing power for driving the vehicle supplied to vehicle-side load 1, and control unit (ECU 8) for controlling vehicle-side load 1 and power storage device 10 are provided.

  Temperature sensor 5 detects the temperature of power storage device 10. Cooling fan 6 sends cooling air for cooling power storage device 10. The ECU 8 is configured by a computer including a CPU, a memory for storing various programs, an input / output device, and the like. The ECU 8 processes signals periodically output from various sensors and outputs control signals for appropriately operating the power storage device 10, the electric motor 2, the braking device 3, the cooling fan 6, and the like. The ECU 8 manages the state of charge (SOC) of the power storage device 10 and notifies the driver of the current SOC, the possible travel distance, and the like. The electric storage device 10 is charged by electric power supplied from an external power supply during parking, and is also charged by electric power generated by rotating the electric motor 2 by the rotational force of the wheels by regenerative braking.

Next, the power storage device 10 will be described.
As shown in FIG. 2, the power storage device 10 includes a support panel member 12 and a cover for securing vibration resistance (rigidity) and water resistance (waterproofness) for disposing in the space below the floor panel of the EV cabin. It is housed in a power storage device case made of member 13. An arrow U in the figure indicates an upper side, an arrow F indicates a front side of the vehicle, and an arrow L indicates a left side of the vehicle. The heat generated from the power storage device 10 is generated by cooling air that is introduced into the power storage device case from the front side so as to flow along the support panel member 12 by operating the cooling fan 6 (not shown) and is discharged rearward. It is discharged outside the equipment case. Temperature sensor 5 detects the temperature of power storage device 10 and outputs temperature data to ECU 8, and ECU 8 adjusts the amount of air blown by cooling fan 6 to prevent the temperature of power storage device 10 from rising excessively.

  The power storage device 10 is configured to connect a plurality of (for example, 16) power storage modules 11 in series by a plurality of bus bars 14 and supply electric power for driving the EV vehicle. The number of power storage modules 11 constituting power storage device 10 is appropriately set according to the specification of an EV on which power storage device 10 is mounted.

Next, the power storage module 11 will be described.
As illustrated in FIG. 3, the power storage module 11 includes a plurality (for example, six) of storage batteries 20. The pair of support members 15 and the pair of end plates 16 are connected so as to maintain a state in which the plurality of storage batteries 20 are arranged in a row in a horizontal direction at a predetermined interval (for example, an interval of 10 mm). Fixed. Note that the power storage module 11 can be configured with a number of storage batteries 20 according to a required output voltage or the like.

  The pair of support members 15 are provided with a plurality of spacer members 15 a for maintaining the cooling air passage 17 while maintaining a predetermined interval between the storage batteries 20. Further, a cooling air passage 17 is provided between the end plate 16 and the storage battery 20. The plurality of storage batteries 20 are connected in series by a plurality of bus bars 18, and have a positive terminal 11 a and a negative terminal 11 b of the power storage module 11 at both ends. As shown in FIG. 4, a passage 19 for supplying cooling air to each cooling air passage 17 is provided between the storage battery 20 of the power storage module 11 and the support panel member 12.

Next, the storage battery 20 will be described with reference to FIGS.
The storage battery 20 has a rectangular parallelepiped case 22, and a positive electrode terminal 23 and a negative electrode terminal 24 of the storage battery 20 are disposed on an upper surface portion 22a serving as a lid member. The case 22 includes a first side face portion 22b and a second side face portion 22c facing the cooling air passage 17 and a third side face portion 22d orthogonal to the first and second side face portions 22b and 22c and parallel to each other. And a fourth side surface portion 22e and a bottom surface portion 22f facing the upper surface portion 22a, and their inner walls are insulated.

  The case 22 contains a power storage unit 25, a heat insulating member 26 covering the outer periphery of the power storage unit 25, a sheet-shaped heat pipe 27, a sheet-shaped heater 28, and an electrolyte (not shown). Sealed with members. The power storage unit 25 has at least one wound body pair 32 including a pair of wound bodies 30, and is configured by, for example, two wound body pairs 32. Note that the power storage unit 25 may be configured by three or more sets or one set of the wound body pairs 32.

  In the wound body 30, the positive electrode foil 30 a and the negative electrode foil 30 b are flatly wound around a horizontal axis via a porous sheet-shaped separator (not shown), and the outer periphery thereof is covered with an insulating member 31. And a pair of flat portions 30d. The insulating member 31 is formed in a sheet shape having flexibility from a synthetic resin material (for example, polypropylene or polyethylene), and has a bag-shaped housing portion for housing the heater 28 in contact with the flat portion 30 d of the wound body 30. (Not shown).

  The wound body pair 32 is configured by bringing the flat portions 30d of the pair of flat wound bodies 30 into close proximity to each other. The power storage unit 25 composed of the two wound body pairs 32 faces one of the outer flat parts 30d of the winding body pair 32 that is not opposed to the outer flat part 30d of the other wound body pair 32. The four winding bodies 30 are arranged in a line in the horizontal direction so as to be close to each other.

  Positive current collecting tabs 33 connected to the positive foils 30a of the four winding bodies 30 of the power storage unit 25 are provided on the third side surface part 22d side and connected to the positive terminal 23 of the storage battery 20. A negative electrode current collecting tab 34 connected to the negative electrode foil 30b is arranged on the fourth side surface 22e side and connected to the negative electrode terminal 24 of the storage battery 20. That is, the power storage unit 25 in which the four winding bodies 30 are connected in parallel is accommodated in the case 22, and the storage battery 20 having a large storage capacity for EV is formed. The wound body 30 constituting the power storage unit 25 is connected in series, the positive electrode current collecting tab 33 is connected to the positive electrode foil 30a at the positive electrode end of the serial connection, and the negative electrode collector 30b is connected to the negative electrode foil 30b at the negative electrode end. By connecting the power tab 34, for example, a storage battery 20 having a high output voltage for a hybrid vehicle can be formed.

  The power storage unit 25 has at least a majority of its outer peripheral area covered with a sheet-like heat insulating member 26. The heat insulating member 26 is formed, for example, of a silica airgel-based hollow structure in a sheet shape that can be bent so that the hollow structure is closed to the outside. The heat insulating member 26 has a higher effect of suppressing heat conduction between the winding body 30 and the case 22 than the insulating member 31, and has an insulating property without infiltration of the electrolytic solution.

  Each of the wound body pairs 32 of the power storage unit 25 are provided with a sheet-shaped heat pipe 27 for transferring heat of the wound body pair 32 to the case 22 and a sheet-shaped heater 28 for heating the wound body 30 from the flat surface 30d. Has been established. The heat absorbing portion 27a of the heat pipe 27 abuts on the opposing flat surface portion 30d of the wound body pair 32, and the heater 28 is accommodated in the housing portion of the insulating member 31 on the flat surface portion 30d on which the heat absorbing portion 27a is not in contact. Being in contact. In other words, the heat absorbing portion 27a is sandwiched between the opposed flat portions 30d of the pair of winding bodies 30, and the outer flat portion 30d is sandwiched between the pair of winding bodies 30, that is, the winding body pair 32, by the heater. 28 are provided. The heaters 28 of the flat portion 30d in which the wound body pairs 32 are close to each other share the heater 28 provided in any one of the wound body pairs 32 to reduce the number of heaters 28. You may equip the body pair 32 with it.

  The heat pipe 27 extends outside the heat insulating member 26 from the heat absorbing portion 27 a that contacts the flat portion 30 d of the wound body pair 32 inside the heat insulating member 26 that covers the power storage unit 25, and extends to the inner wall (the first side surface portion) of the case 22. 22b or an inner wall of the second side surface portion 22c). The heat pipe 27 can be easily bent, and although not shown, a working fluid and a wick for causing a capillary action of the working fluid are sealed therein, and a passage for the vaporized working fluid is formed. The surface of the heat pipe 27 is covered with an insulating protective film for protecting the heat pipe 27 from the electrolytic solution.

  The working fluid that has absorbed heat from the wound body 30 and vaporized in the heat absorbing portion 27a moves to the heat radiating portion 27b having a lower atmospheric pressure than the heat absorbing portion 27a. The working fluid that has radiated heat, condensed, and liquefied in the heat radiating portion 27b returns to the heat absorbing portion 27a through the wick by capillary action. The circulation of the hydraulic fluid causes the heat of the wound body pair 32 to move to the outside of the heat insulating member 26, and the power storage unit 25 is cooled.

  In order for the heat pipe 27 to function, a heat radiation area that is sufficiently large with respect to the area of the heat absorbing portion 27a is secured. It is preferable that the area of the heat radiating portion 27b be at least 10 times the area of the heat absorbing portion 27a. The heat radiating portion 27b may also be brought into contact with the bottom surface 22f of the case 22 to further increase the heat radiating area, and the heat radiation may be promoted by utilizing the cooling air passing near the lower side of the bottom surface 22f.

  The heat pipe 27 can be configured in various forms so as to have an area ratio between the heat absorbing section 27a and the heat radiating section 27b. For example, as shown in FIGS. 6 and 8, the heat pipe 27 extends from the heat absorbing portion 27 a contacting the flat portion 30 d to the outside of the lower heat insulating member 26 and is connected to the heat radiating portion 27 b outside the heat insulating member 26. . Each of the wound body pairs 32 has a heat pipe 27. Therefore, it is easy to increase the storage capacity or the output voltage by increasing the number of wound body pairs 32 constituting the storage battery 20. When the power storage unit 25 includes three or more wound body pairs 32, the heat radiating portions 27b of the wound body pairs 32 are appropriately disposed on the bottom surface 22f and the like so as not to overlap.

  Further, the heat pipe 27 may extend horizontally from the heat absorbing portion 27a to the outside of the heat insulating member 26 and may be connected to the heat radiating portion 27b. For example, as shown in FIGS. 9 and 10, the heater 28 accommodated in the accommodating portion of the insulating member 31 abuts against the opposed flat portion 30 d of the wound body pair 32, and the flat portion on the side where the heater 28 does not abut. The heat absorbing portion 37a of the heat pipe 37A or 37B contacts 30d. In other words, the heater 28 is sandwiched between the opposed flat portions 30d of the pair of winding bodies 30, and the heat pipe is connected to the outer flat portion 30d so as to sandwich the pair of winding bodies 30, ie, the winding body pair 32. A heat absorbing portion 37a of 37A or a heat pipe 37B is provided. Accordingly, the number of heaters 28 of the storage battery 20 can be reduced, and the heat absorbing portions 37a of the heat pipes 37A and 37B are disposed so as not to overlap the flat portion 30d where the wound body pairs 32 are close to each other. This promotes heat absorption in the flat portion 30d where the wound body pairs 32 are close to each other.

  The heat pipes 37A and 37B extend horizontally from the pair of heat absorbing portions 37a that come into contact with the flat portion 30d to the outside of the heat insulating member 26, and are connected to the heat radiating portion 37b outside the heat insulating member 26. Each of the two wound body pairs 32 has a heat pipe 37A or a heat pipe 37B. Similarly, in the case where the power storage unit 25 is configured by three or more wound body pairs 32, the heat absorbing portion of the heat pipe of each wound body pair 32 does not overlap the flat portion 30d where the wound body pairs 32 are close to each other. So that the heat radiating portions of the heat pipes of each wound body pair 32 do not overlap each other.

  The heat absorbing portion 27a (37a) is wound by the force of pressing the side surface portions (the first side surface portion 22b and the second side surface portion 22c) of the power storage unit 25 in the case 22 and the reaction force from the side surface portion. The heat dissipating portion 27b (37b) closely adheres to the inner wall of the first side surface portion 22b or the second side surface portion 22c of the case 22. Therefore, the heat of the wound body 30 is smoothly absorbed from the flat portion 30d to which the heat absorbing portion 27a (37a) is in close contact, and is transmitted to the first side portion 22b and the second side portion 22c to which the heat radiating portion 27b (37b) is in close contact. Heat is dissipated (heat transfer) smoothly. Since the heat absorbing portions 27 a (37 a) are in close contact with the respective winding bodies 30, heat is uniformly absorbed from the respective winding bodies 30.

  Further, since the heater 28 is in close contact with the flat portion 30d where the heat absorbing portion 27a (37a) is not in contact, the heat of the heater 28 is smoothly transmitted to the wound body 30. The heater 28 is configured to generate Joule heat when energized. Then, as shown in FIG. 5, for example, as shown in FIG. 5, a power switch 28a for switching the power supply line 28a of each heater 28 so that the power supply line 28a is energized at a temperature lower than the predetermined temperature. The power line 28 b is connected to the negative terminal 24 via the positive terminal 23. Although not shown, the heater 28 sealed with a synthetic resin insulating film is sandwiched between the flat portions 30d of the wound body 30 that is close to the facing shape, or the flat portion 30d and the heat insulating member 26 are used. It can also be pinched.

  The temperature switch 29 detects the temperature of the upper surface portion 22a or the temperature in the case 22 as the temperature of the storage battery 20, and energizes when the detected temperature is lower than a predetermined temperature. Thereby, the storage battery 20 operates the heater 28 with the electric power stored in the power storage unit 25 to maintain a predetermined temperature. The predetermined temperature is, for example, −20 ° C., and is appropriately set according to the specifications of the storage battery 20 (the lower limit of the operating temperature range).

  The resistance value of the heater 28 is set such that the power storage unit 25 covered with the heat insulating member 26 can maintain a predetermined temperature due to the Joule heat and the self-heating of the storage battery 20 that supplies electric power when the heater 28 operates. . Since the amount of heat radiation differs depending on the specifications of the storage battery 20, this resistance value is appropriately set according to the specifications of the storage battery 20 and the like. As a result, the power consumption of the heater 28 is minimized, and the decrease in the SOC is moderated.

  The ECU 8 controls cooling by the cooling fan 6 based on the temperature data of the temperature sensor 5 so that the power storage device 10 can exhibit its performance within a predetermined use temperature range. For example, if the temperature sensor 5 detects a temperature that is equal to or higher than the upper limit temperature (for example, 60 ° C.) of the operating temperature range, or if it is predicted that the detected temperature will exceed the upper limit temperature, the ECU 8 sets the upper limit of the operating temperature range. The air blowing amount of the cooling fan 6 is adjusted so as to maintain the temperature lower than the temperature. Thereby, the heat transferred to the case 22 of each storage battery 20 is discharged to the outside by the cooling air, and the power storage device 10 is cooled so as not to exceed the upper limit temperature of the use temperature range.

Next, the operation and effect of the present invention will be described.
Power storage device 10 has a plurality of storage batteries 20, and storage battery 20 has at least one wound body pair 32 constituting power storage unit 25 in case 22, and is insulated by heat insulating member 26 covering the outer periphery of power storage unit 25. The influence of the temperature outside the member 26 is reduced. Further, the wound body pair 32 can be heated from the wide flat portion 30 d by the heater 28 disposed on the wound body pair 32 inside the heat insulating member 26, and the heat of the heater 28 is prevented from being released by the heat insulating member 26. ing. In addition, when the power storage unit 25 becomes hot due to charging and discharging, the heat of the wound body pair 32 is transferred to the first side surface portion 22b and the second side surface portion 22c of the case 22 by the heat pipe 27 (37A, 37B). And can be discharged outside by the cooling air. Therefore, it is possible to uniformly heat and cool the power storage unit 25 including the wound body pairs 32 of the plurality of storage batteries 20 included in the power storage device 10.

  Further, since the heat pipes 27 (37A, 37B) are provided for each winding body pair 32, the number of winding body pairs 32 constituting the storage battery 20 can be easily increased, and the storage capacity or output of the storage battery 20 can be increased. The voltage can be easily increased.

  In addition, a plurality of storage batteries 20 are arranged at predetermined intervals and have a cooling air passage 17 formed between the storage batteries 20. Accordingly, the heat of the power storage unit 25 moved by the heat pipe 27 to the case 22 circulates through the cooling air passage 17 from the side surfaces (the first and second side surfaces 22 b and 22 c) of the case 22 facing the cooling air passage 17. Since the heat can be radiated to the outside by the cooling air, the power storage device 10 can be cooled by promoting heat radiation.

  The power storage unit 25 may be configured by arranging the wound bodies 30 in a line in the vertical direction. A heat pipe provided with a heat absorbing portion abutting on the flat portion 30d of each winding body 30 may be provided for each winding body 30. In addition, those skilled in the art can implement the above-described embodiment by adding various modifications without departing from the spirit of the present invention, and the present invention also includes such modifications.

2: Electric motor 5: Temperature sensor 6: Cooling fan 8: ECU
Reference numeral 10: power storage device 11: power storage module 15: support member 16: end plate 17: cooling air passage 20: storage battery 22: case 22 b: first side surface portion 22 c: second side surface portion 23: positive electrode terminal 24: negative electrode terminal 25: power storage Body 26: heat insulating members 27, 27A, 27B: heat pipe 27a: heat absorbing portion 27b: heat radiating portion 28: heater 29: temperature switch 30: wound body 30a: positive electrode foil 30b: negative electrode foil 30d: flat portion 31: insulating member 32 : Winding body pair 33: Positive current collecting tab 34: Negative current collecting tab

Claims (4)

In a rectangular parallelepiped case, a power storage unit for storing electric power, a heat insulating member covering the outer periphery of the power storage unit, a sheet-like heater for heating the power storage unit, and a device for transferring heat of the power storage unit to the case In a power storage device for a vehicle having a plurality of storage batteries provided with a sheet-shaped heat pipe,
The power storage unit of the storage battery has at least one pair of wound body pairs including a pair of flat wound bodies,
The wound body, the positive electrode foil and the negative electrode foil are wound flat around the horizontal axis via a separator and the outer periphery is covered with an insulating member,
The wound body pair is configured by bringing the flat portions of the wound body into close proximity to each other,
The heat pipe includes a heat absorbing portion that contacts the flat surface portion of the wound body pair inside the heat insulating member, and a heat dissipating portion that extends from the heat absorbing portion to the outside of the heat insulating member and contacts the inner wall of the case. With
The power storage device for a vehicle according to claim 1, wherein the heater is disposed so as to be in contact with a planar portion of the wound body pair on the side where the heat absorbing portion is not in contact with the inside of the heat insulating member. In a rectangular parallelepiped case, a power storage unit for storing electric power, a heat insulating member covering the outer periphery of the power storage unit, a sheet-like heater for heating the power storage unit, and a device for transferring heat of the power storage unit to the case In a power storage device for a vehicle having a plurality of storage batteries provided with a sheet-shaped heat pipe,
The power storage unit of the storage battery has at least one pair of wound body pairs including a pair of flat wound bodies,
The wound body, the positive electrode foil and the negative electrode foil are wound flat around the horizontal axis via a separator and the outer periphery is covered with an insulating member,
The wound body pair is configured by bringing the flat portions of the wound body into close proximity to each other,
The heater is disposed so as to abut on the opposed flat portion of the wound body pair inside the heat insulating member,
The heat pipe is provided with a heat absorbing portion disposed so as to be in contact with a plane portion of the wound body pair on the side where the heater is not in contact with the inside of the heat insulating member, and a heat absorbing portion of the heat insulating member from the heat absorbing portion. A power storage device for a vehicle, comprising: a heat radiating portion extending outward and in contact with an inner wall of the case.   The power storage device for a vehicle according to claim 1, wherein the heat pipe is provided for each of the wound body pairs.   The power storage device for a vehicle according to any one of claims 1 to 3, further comprising a cooling air passage formed between the storage batteries by arranging the plurality of storage batteries at predetermined intervals. .