JP2001273884A - Sealed type battery and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a closed type battery and its manufacturing method, in which electrolyte can be injected easily into the battery, the gas in the package can be evacuated effectively, sealed surely, stable quality can be maintained without degradation, and is excellent in electric characteristics. SOLUTION: This is a sealed battery manufactured by injecting an electrolyte into a package 7 enclosing wound electrode groups 1. On the inside surface of the package facing an edge 4 of the wound electrode group 1, there is provided an inlet and exhaust port 9 through which the electrolyte can be injected and the gas in the package can be evacuated as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery and a method for manufacturing the same, and more particularly, to a sealed battery in which an electrolytic solution is injected into a package containing a wound electrode group, which is excellent in volumetric efficiency and electrical. The present invention relates to a sealed battery such as a polymer electrolyte battery having stable characteristics and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, with the great progress of electronic technology, the size and weight of electronic devices for general users have been dramatically reduced. Along with such technical innovations, there is a demand for a battery that is smaller and lighter and further improved in reliability. In particular, portable devices such as mobile phones, PHSs, and small personal computers have been significantly reduced in size and weight with the development of electronics technology, and the batteries used as power supplies for these devices have also been reduced in size and weight. Is required.

As one of batteries that are suitable for miniaturization and weight reduction and can be expected for applications such as portable equipment, there are square or flat nonaqueous electrolyte sealed batteries such as lithium ion batteries. This sealed battery has a smaller dead space when loaded into various devices compared to a cylindrical battery,
It is heavily used because it is advantageous in volumetric efficiency. In addition, from the viewpoint of the structure, this type of sealed battery is a type in which the electrolyte is gelled with a polymer, so that it is difficult to leak liquid and is excellent in safety. In.

[0004] A sealed battery having a built-in polymer electrolyte typified by, for example, a lithium ion battery will be described below. In this sealed battery, generally, an electrode group in which a positive electrode and a negative electrode are stacked via an electrolyte layer is hermetically sealed and housed in a package, and a positive electrode terminal and a negative electrode terminal respectively connected to the positive electrode and the negative electrode of this electrode group are provided. It is configured to be exposed outside the package.

[0005] In the conventional sealed type battery, for example, there are the following three production modes as follows. The first form is
A case in which a positive electrode containing a gel polymer electrolyte, a separator, and a negative electrode are laminated. In a second embodiment, a solution comprising a monomer or macromer having a polymerizable functional group and an electrolytic solution is sealed in a closed container as disclosed in, for example, US Pat. No. 5,837,015 and JP-A-9-330740. When gelling after injection into (package). In a third embodiment, as disclosed in, for example, Japanese Patent Application Laid-Open No. 9-320617, a package containing a polymer that absorbs an electrolytic solution and gels in an electrode group and contains the electrode group is contained in advance. In this case, a gel is formed by injecting an electrolytic solution.

In the case of the above-described second and third manufacturing modes, which are so-called electrolyte post-injection systems, the workability in battery manufacturing is higher than that of the first manufacturing mode. In addition, since the sealing can be performed immediately after the electrolyte is injected, the time during which the inside of the battery and the electrolyte are exposed to the atmosphere can be shortened. It is also advantageous in that the chance of intrusion of harmful substances can be reduced.

On the other hand, in the case of the electrolyte post-injection method, the electrolyte injected into the package quickly penetrates into the electrode group having a narrow gap, and the electrode group is injected at the end of the injection. The condition that no gas remains in the battery is a condition for maintaining good battery performance. For example, in the case of a lithium-ion battery, it is known that, during the first charging, a carbon dioxide gas, a decomposition product of an electrolytic solution, or a hydrocarbon gas such as ethylene or propylene is generated from the electrode surface during the first charging. It is desired that the gas generated by this charging be promptly removed from the system.

Japanese Utility Model Registration No. 2602648 discloses a battery in which a liquid injection hole is provided at a position facing a winding surface. However, in this structure, the flow of the electrolytic solution at the time of pouring cannot be aligned in a certain direction, and it is difficult to discharge gas simultaneously with pouring, and the gas remains inside the electrode group or the battery case. There was a problem that it would.

[0009]

As described above, in a sealed battery of the electrolyte post-injection type, if gas as a decomposition product of the electrolyte remains in the electrode group, the internal impedance of the battery is reduced. To make the current distribution on the electrode surface non-uniform. As a result, there is a problem that a voltage drop or a discharge capacity drop at a high rate discharge is caused and battery performance is significantly reduced. In particular, in the above-described second production mode, since the gel electrolyte forming material solution contains a monomer or a macromer, the solution viscosity is higher than that of a mere electrolytic solution containing neither of them. Therefore, there is a drawback that when the forming material solution is injected into the package, the permeation of the solution into the electrode group is slow and productivity does not increase. In addition, since the viscosity of the forming material solution is high, gas generated by the first charging is difficult to escape to the outside of the battery, and there is a problem in productivity and battery performance.

In the above-described third production mode, after the electrolyte is injected, the gelation of the electrolyte proceeds to increase the viscosity of the electrolyte. There is a problem that it is difficult for gas generated by the gas to escape to the outside of the battery. Therefore, also in this case, in the battery manufacturing process, gas is likely to remain in the electrode group, which causes a decrease in voltage and a decrease in discharge capacity at high-rate discharge as described above, which tends to cause a decrease in battery performance. there were.

In the battery manufacturing process, after the electrolyte is injected into the package, the injection port is sealed by bonding the portion facing the injection port. However, when the electrolytic solution is injected into the package, the electrolytic solution adheres to the liquid inlet of the package. If the electrolyte is attached to the injection port and the surface is contaminated, the injection port may be closed or a difficult interface may be formed when closing the injection port after injecting the electrolyte. May be incomplete. As described above, there is a problem that the performance of the battery is deteriorated in terms of long-term storability due to imperfect sealing. Particularly, in a sealed battery having a structure in which pole groups extremely densely packed in a wound state are housed in a package, it takes time to infiltrate the electrolyte into the inside of the pole group at the time of injecting the electrolyte. Since the gas generated by charging the gas must move through a narrow gap between the electrode groups and within the highly viscous electrolytic solution, it is extremely difficult to exhaust the gas.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object the purpose of packaging a highly viscous electrolytic solution or an electrolytic solution having a high viscosity after injection to produce a gel electrolyte in a package. In a sealed battery of the so-called electrolyte post-injection type in which the electrolyte is injected, the electrolyte can be easily injected, the gas in the package can be effectively discharged, and the package can be securely sealed after the electrolyte is injected, so that the quality is stable. It is an object of the present invention to provide a sealed battery which is excellent in electrical characteristics without deterioration in performance and excellent in performance, and a method for manufacturing the same.

[0013]

According to the present invention, there is provided a sealed battery in which an electrolytic solution is injected into a package accommodating a wound group of electrodes, according to the present invention. A sealed battery characterized in that an injection / exhaust port capable of injecting the electrolytic solution and exhausting gas in the package is arranged at a position on an inner wall surface of the package opposite to a winding end surface of the group. is there. With such a configuration, the above object can be achieved. That is, by injecting the electrolytic solution from a liquid injection / exhaust port arranged at a position facing the wound end face of the electrode group, the liquid pressure at the time of injection is directly applied to the wound end face having the gap between the electrode groups opened. be able to. Therefore, it is possible to quickly infiltrate the electrolyte into the electrode group, to effectively push out the gas in the electrode group, and to quickly and reliably replace the electrolyte with the gas. Also, when discharging the gas generated by charging after the injection of the electrolyte, most of the gas moves so as to exit from the winding end face of the electrode group (move in the electrode group winding axis direction). With respect to such a movement of the gas, since the liquid injection / exhaust port is located at a position facing the wound end surface, the gas can be easily discharged out of the package.

According to a second aspect of the present invention, there is provided a sealed battery wherein the liquid injection / exhaust port is provided at a position near an end of the inner wall surface of the package. In this way, the liquid injection / exhaust port is provided at a position near the end of the inner wall surface of the package, so that when the liquid is injected, the electrolyte permeates the electrode group from a position near one side of the wound end face. The gas in the electrode group can be effectively pushed out with the electrolytic solution, and the gas can be smoothly replaced with the injected electrolytic solution.

According to a third aspect of the present invention, an inclined portion is provided on the inner wall surface of the package, the inclined portion decreasing the wall interval from the inside of the package toward the outside of the package. A sealed battery characterized by being configured to be continuous with a liquid / exhaust port. That is,
Since the inclined portion that narrows the wall interval from the inside of the package toward the outside of the package is provided so as to be continuous with the injection / exhaust port, when the electrolyte is injected, the electrolyte is pushed out by the injection of the electrolyte. The gas can be effectively collected by the inclined portion at the injection / exhaust port. Further, when the gas generated during charging is to be removed, the function of guiding the generated gas to the liquid injection / exhaust port can be exhibited only by positioning the liquid injection / exhaust port above.

According to a fourth aspect of the present invention, there is provided a hermetically sealed container, wherein the liquid injection / exhaust port is provided at two locations on one side of the inner wall surface of the package opposed to the wound end surface. Battery. Therefore, the injection of the electrolytic solution and the discharge of the gas can be performed from a plurality of places, and the liquid injection and the gas exhaust can be performed more effectively. In addition, when performing the liquid injection with the liquid injection / exhaust port on the upper side, even if the package is unexpectedly inclined, the liquid injection / exhaust port located at a higher position can be effectively used as the exhaust port. . It is also possible to inject the liquid in a state where the package is tilted in advance and to use the liquid injection / exhaust port located at a slightly higher position for exhausting and to positively use the one located at a lower position for liquid injection. .

According to a fifth aspect of the present invention, the inner wall of the liquid injection / exhaust port is formed of a heat-fusible resin, and the liquid injection / exhaust port is heat-welded. It is a sealed battery characterized by the above. Therefore, the injection / exhaust port can be easily fused and sealed by heating, so that reliable sealing can be ensured.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a sealed battery including a step of injecting an electrolytic solution into a package accommodating the wound electrode group. The liquid injection / exhaust port provided near the end of the package inner wall surface facing the turning end face is positioned above, and simultaneously the liquid is injected from the liquid injection / exhaust port, and the gas in the package is injected by the liquid injection. A method for manufacturing a sealed battery, wherein the battery is discharged from an exhaust port. In this way, by injecting the electrolyte from the injection / exhaust port disposed at a position facing the winding end face of the electrode group, the liquid pressure at the time of injection is adjusted to the winding end face where the gap between the electrode groups is opened. It can be added directly, and by arranging the injection / exhaust port upward, the flow of injection and the flow of gas can not only be effectively separated by gravity, but also Since the exhaust port is provided at a position near the end of the inner wall surface of the package, at the time of injection, the electrolyte can penetrate the electrode group from a position near one side of the wound end surface, The gas in the electrode group can be effectively pushed out by the electrolytic solution, and the injected electrolytic solution can be replaced with the gas smoothly.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a first embodiment of a sealed battery according to the present invention, and is a schematic plan view showing the inside of the battery. FIG. 2 is a cross-sectional view of FIG.
It is sectional drawing of the part along A line. FIG. 3 shows a second embodiment of the sealed battery according to the present invention, and is a schematic plan view showing the inside of the battery. FIG. 4 shows a third embodiment of the sealed battery according to the present invention, and is a schematic plan view showing the inside of the battery. FIG. 5 is a cross-sectional view of a portion taken along line AA in FIG. FIG. 6 shows a fourth embodiment of the sealed battery according to the present invention, and is a schematic plan view showing the inside of the battery.

(First Embodiment) A battery 100 according to the present embodiment shown in FIGS.
Of the electrode group 1 in which a positive electrode, a negative electrode and a separator are wound, a positive electrode terminal 5 connected to the electrode group 1 as a positive electrode lead, and a negative electrode terminal 6 connected as a negative electrode lead And a structure in which an electrolytic solution is accommodated. The package 7 is appropriately fused at a fusion portion 8 at a peripheral portion thereof to form an internal space 11. And the characteristic configuration in this embodiment is:
Wall surface 10 facing winding end surface 4 of pole group 1 (see FIG. 2)
(In FIG. 1, since the package 7 of the sealed battery 100 has a flat structure in which a flexible material is bonded by a fusion bonding portion 8 in FIG. 1, the “side” constituting the rectangular internal space 11 is formed. ), And a liquid injection / exhaust port 9 capable of injecting an electrolytic solution and exhausting gas (including generated gas generated during charging) in the package 7 is arranged.

The package 7 is made of a relatively flexible material. For example, a metal foil and a resin film having a fusible resin layer on the inner surface which can be appropriately melted and bonded by heating. (Resin film is package 7
(Inner side). Therefore, the injection / exhaust port 9 can be fused and sealed by heating, and the package 7 can be hermetically sealed.

The electrode group 1 has a structure in which a strip-shaped electrode is spirally wound. That is, a strip-shaped laminate having a positive electrode, a separator, and a negative electrode is spirally and flatly wound around the winding axis 2, and one of the winding end surfaces 4 (upper side in the figure) From the positive terminal 5 and the negative terminal 6. Therefore, the wound peripheral surface 3 of the electrode group 1 is configured to be closed by the electrode itself, but the wound end surface 4 has a spiral shape (positive and negative electrode) as shown in FIG. In between, a gap is formed via a separator).

A description will be given of the electrolytic solution and the gas exhaust during charging in the manufacturing process of the sealed battery 100 configured as described above. First, an electrolytic solution is injected into the package 7 in which the wound electrode group 1 is stored from the injection / exhaust port 9 of the package 7 by appropriate means (injected in the direction of arrow S in FIG. 1). The package 7 at the time of injecting the electrolyte is
Is appropriately held so that the liquid injection / exhaust port 9 faces upward. Injection of this electrolyte (injection from the direction of arrow S)
As a result, the electrolyte that has entered the package 7 flows, for example, as shown by arrows S1, S2, and S3 in FIG. 1, and flows into the electrode group 1 along the separator on the winding end surface 4 and the interface between the separator and the positive electrode and the negative electrode. The gas that has penetrated into the package and has been filled from the lower side of the package and has been pushed out by the inflow of the electrolytic solution is discharged from the injection / exhaust port 9.

That is, when the electrolytic solution is injected from the injection / exhaust port 9 disposed at a position facing the wound end face 4 of the electrode group 1, the liquid pressure at the time of injection increases the gap (separator) of the electrode group 1. Is concentrated on one end 4a of the interface between the positive electrode and the positive electrode, so that it flows, for example, as shown by arrows S1, S2, and S3 in FIG. From the position), penetrates into the electrode group 1 along the separator and the interface between the separator and the positive electrode, and is filled from the lower side of the package. On the other hand, as shown by arrows H1, H2, and H3 in the figure, the gas pushed by the electrolytic solution flows smoothly from the opposite side to the above-mentioned one end 4a into the injection / exhaust port 9, and Since the electrolyte solution is exhausted from the exhaust port 9, the electrolyte solution can quickly penetrate into the electrode group 1. Also,
In the charging process after the injection of the electrolytic solution, carbon dioxide gas, hydrocarbon gas, and the like are generated from the electrode group 1. The generated gas is discharged from the injection / exhaust port 9 to the outside of the package 7. That is, most of the gas moves in the direction of the winding axis 2 from the entire wound end face 4 of the pole group 1 (arrows H1, H2, H in the figure).
3 and in the directions opposite to the S1, S2, and S3 directions) to exit the package 7 through the liquid injection / exhaust port 9.

Further, as in the present embodiment, in addition to the liquid injection / exhaust port 9 facing the wound end face 4 of the electrode group 1, the arrangement of the liquid injection / exhaust port 9 is not It is configured to be biased to one side of the wall surface 10 facing the end surface 4. With such a configuration, at the time of injecting the electrolyte, the injected electrolyte preferentially permeates from the injection / exhaust port 9 side of the electrode group 1 and the wound end face. Since the water permeates from one end 4a of the electrode group 4, the entire winding end face 4 is not wetted first, and a gas discharge path from the electrode group 1 is secured. That is, in the case where the liquid injection / exhaust port 9 is located near the center of the wall surface 10, only one side (upper part) of the electrode group 1 gets wet before the infiltration is completed. Although a state in which the retreat of the gas in the electrode group 1 is blocked may occur, the retreat and exhaust port 9 is biased to one side of the wall surface 10 as in the present embodiment. State can be avoided.

Also, in the present embodiment, when the electrolyte penetrates into electrode group 1, the capillary action of the electrolyte and the difference in density between the injected electrolyte and the gas contained in electrode group 1 are considered. Thereby, the replacement of the electrolyte with the gas proceeds smoothly.
Therefore, in the electrolyte solution injection step, when vacuum impregnation is required to speed up the injection, not only expensive equipment is required but also the process becomes complicated, but as in the present embodiment, With the configured sealed battery 100, extremely easy and effective injection is possible without using complicated and expensive equipment.

(Second Embodiment) FIG. 3 shows a sealed battery according to a second embodiment of the present invention. In FIG. 3, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Book second
In the embodiment, as shown in FIG. 3, inclined portions 31 and 32 are provided on the inner wall surface of the package 37 so as to narrow the wall interval from inside the package 37 to the outside of the package (upward in the figure). Have been. The inclined portions 31 and 32 are configured to be continuous with the liquid injection / exhaust port 9.

As described above, the inner wall surface facing the winding end surface 4 of the electrode group 1 is formed as the inclined portions 31 and 32 for narrowing the wall interval from the inside of the package toward the outside of the package, and is also used for injection and exhaust. By being continuous with the opening 9, even when the package 7 is held slightly inclined (either left or right in FIG. 3) during the injection of the electrolytic solution, for example, the inclined portion Gases 31 and 32 that are extruded by the injection of the electrolyte (including the gas that is replaced by the electrolyte and discharged from the electrode group 1) are smoothly guided to the injection / exhaust port 9 (the extruded gases H1 and H2). H
2, H3), and can be exhausted to the outside. On the other hand, at the time of charging after the injection of the electrolyte, the inclined portions 31 and 32 cause the gas generated in the electrode group 1 to be injected into the liquid injection / exhaust port 9 as shown by arrows H1, H2 and H3 in FIG. It can guide efficiently and exhaust gas effectively.

(Third Embodiment) FIGS. 4 and 5 show a sealed battery according to a third embodiment of the present invention. In addition,
4 and 5, the same elements as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The sealed battery 300 shown in FIG. 4 has a structure in which two injection / exhaust ports 9 are provided near both corners of the wall surface 10 of the package 47. In the case of such a configuration, since the liquid injection / exhaust port 9 is provided at two places, if the side where the liquid injection / exhaust port 9 is formed is placed at the upper side during the injection of the electrolytic solution and at the time of charging, the battery can be obtained. Even when the holding state of 300 is tilted, the gas discharged from the electrode group 1 smoothly moves to the liquid injection / exhaust port 9 which is located at one of the higher positions, and is exhausted out of the package. Injection and exhaust port 9
, The liquid injection port and the exhaust port can be properly used.

(Fourth Embodiment) FIG. 6 shows a sealed battery according to a fourth embodiment of the present invention. In FIG. 6, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Book 4
The embodiment has a configuration in which the above-described second embodiment and the third embodiment are combined. That is, as shown in FIG. 6, on the inner wall surface of the package 47, the space between the wall surfaces is set from the inside of the package 47 toward the outside of the package 47 (upward in the figure) toward the two liquid injection / exhaust ports 9. Narrowing inclined portions 61 and 62 and inclined portions 63 and 64 are provided. The operation of the present embodiment is the same as that of the above-described second and third embodiments.
1 and 62 and the inclined portions 63 and 64 have a synergistic effect.

Any of the sealed batteries 2 shown in the second, third and fourth embodiments.
Also in 00, 300 and 400, since the inner surface of the injection / exhaust port 9 is formed of a heat-fusible resin, the process of closing the injection / exhaust port 9 is extremely easy and complete sealing by heating. Is possible. That is, it is inevitable that the inner surface of the injection / exhaust port 9 is contaminated with the electrolytic solution or the gel-like electrolyte solution during the injection step and the gas exhaust process. If the inside of the injection port is made of metal, it is extremely difficult to completely hermetically seal the interface regardless of whether the sealing method is adhesion to resin or caulking, if it is contaminated with electrolyte. . But,
Since the inner surface of the package 7 is entirely made of a fusible resin as in each embodiment of the present invention, even if the inner surface of the injection / exhaust port 9 which is the fusion surface in the injection step is contaminated with the electrolytic solution, The fusion of the resins by heating is not affected by the contamination of the electrolyte at all, and is very easy and complete sealing is possible.

(Embodiments) The sealed batteries 100, 200, and 3 shown in the first, second, third, and fourth embodiments.
Using 00 and 400, the electrolyte was injected such that the injection / exhaust port 9 was positioned above. As a result, in any case, during the permeation of the electrolytic solution, the electrolytic solution and the gas in the electrode group are smoothly replaced, and the extruded gas is discharged from the injection / exhaust port 9 and quickly ( About one minute)
Liquid injection was completed. In addition, the sealed batteries 100, 200, 3
As a result of charging by using the electrodes 00 and 400, in each case, the gas generated from the electrode group was injected into the injection / exhaust port 9.
Could be discharged from When the injection and exhaust port 9 was heated by using a heating member so as to be pressed from the outer surface, the resin at the injection and exhaust port 9 was fused together, and complete sealing was achieved.

Comparative Example On the other hand, a sealed battery 70 as shown in FIG. 7 was prepared, and an electrolyte was injected and charged.
The sealed battery 70 used in this comparative example is a package 77
Except for the position where the liquid injection / exhaust port 9 is formed, the configuration is exactly the same as in each of the above embodiments. In the configuration shown in FIG. 7, the same components as those shown in FIG. 1 are denoted by the same reference numerals and the description thereof will be omitted. However, the sealed battery 70 shown in FIG. 79 is located substantially at the center of the side surface 80 of the pole group 1 parallel to the winding axis 2.

In this configuration, the electrolyte is injected from the injection / exhaust port 79 while the injection / exhaust port 79 is laid down (the positive electrode terminal 5 and the negative electrode terminal 6 are up as shown in FIG. 7). The injection was performed under exactly the same conditions as in the above example. As a result,
The injected electrolyte (injected from the direction shown by arrow S)
It hits the side face 3 of the pole group 1 and takes time to turn around to the winding end face 4 as shown by arrows S7 and S8.
In the case of the above embodiment, the permeation of the liquid into the electrode group does not proceed smoothly because the gas entering the inside of the electrode group does not proceed smoothly because the gas contained in the electrode group is not easily released and the gas contained in the electrode group is difficult to escape. In comparison with the case, the filling time of the electrolytic solution was required to be about 10 to 100 times longer. Further, the gas generated in the first charging was not easily transferred to the liquid injection / exhaust port 79, and remained in the electrode group 1 and the package 77. Furthermore, the sealed battery 7
In the configuration of No. 0, the electrolyte was injected from the injection / exhaust port 79 with the injection / exhaust port 79 turned upward (rotated 90 degrees to the left from the state shown in FIG. 7). Further, charging was performed in this state. Also in this case, the substitution between the electrolyte and the gas does not proceed smoothly, compared to the case of the above embodiment,
This required a long time to fill the electrolyte, and gas exhaust during charging was clearly insufficient.

[0035]

As described in detail above, claim 1 of the present invention
According to the configuration according to the above, the injection / exhaust port capable of injecting the electrolytic solution and exhausting the gas in the package is disposed at the position of the inner wall surface of the package facing the winding end surface of the electrode group. By injecting the electrolyte from the injection and exhaust port,
The liquid pressure at the time of injection can be directly applied to the wound end face of the electrode group, so that the penetration of the electrolyte into the electrode group can be accelerated, and the replacement of the electrolyte with the gas can be performed quickly and reliably. Can be. In addition, when discharging gas generated by charging, it is possible to easily and reliably discharge gas to the outside of the package by a liquid injection / exhaust port, and to provide a sealed battery excellent in productivity and excellent in electrical characteristics. it can.

According to the configuration of the second aspect of the present invention, the liquid injection / exhaust port is provided at a position near the end of the inner wall surface of the package. The liquid can penetrate from a position near one side of the wound end face, and the gas in the electrode group can be effectively pushed out with the electrolyte, and the gas can be quickly replaced with the injected electrolyte. A sealed battery having excellent productivity and excellent electrical characteristics can be provided.

According to the structure of the third aspect of the present invention, the inclined portion for reducing the wall interval from the inside of the package toward the outside of the package is provided so as to be continuous with the liquid injection / exhaust port. When the liquid is injected, the gas pushed out by the injection of the electrolytic solution can be effectively collected at the injection / exhaust port by the inclined portion. Also, when discharging the gas generated during charging, the function of guiding the generated gas to the liquid injection / exhaust port can be exhibited only by locating the liquid injection / exhaust port above. It is possible to provide a sealed battery that is excellent in productivity, good in degassing and the like, and excellent in electrical characteristics without having to increase the positioning accuracy.

According to the configuration of the fourth aspect of the present invention, since the liquid injection / exhaust port is provided at two locations on one side of the inner wall surface of the package opposed to the winding end surface, the injection of the electrolytic solution and the gas supply are performed. Can be discharged from two places, liquid injection and gas exhaust can be performed more effectively, and one of both liquid injection and exhaust ports can be appropriately used for exhaust or liquid injection,
In particular, a sealed battery excellent in productivity can be provided.

According to the fifth aspect of the present invention, the inner wall surface constituting the liquid injection / exhaust port is made of a heat-fusible resin, and the liquid injection / exhaust port can be thermally welded. Therefore, the injection / exhaust port can be easily fused and sealed by heating, so that it is possible to provide a sealed battery having excellent productivity and assured tight sealing, and having excellent electrical characteristics.

According to the manufacturing method of the sixth aspect of the present invention, by injecting the electrolyte from the injection / exhaust port disposed at the position facing the end face of the winding of the electrode group, the hydraulic pressure at the time of injection is reduced. ,
The gap between the pole groups can be added directly to the open winding end face, and the injection and exhaust port is located at the top, effectively using the gravity to flow the injection liquid and the gas flow. Not only can it be separated, but also the injection / exhaust port is provided near the end of the inner wall of the package. And the gas in the electrode group can be effectively pushed out by the electrolyte solution, and as a result, the replacement of the gas with the injected electrolyte solution can be performed quickly. And a method of manufacturing a sealed battery excellent in the above.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a sealed battery according to the present invention, and is a schematic plan view showing the inside of the battery.

FIG. 2 is a sectional view of a portion taken along line AA in FIG.

FIG. 3 is a schematic plan view showing the inside of the battery according to a second embodiment of the sealed battery according to the present invention.

FIG. 4 is a schematic plan view showing the inside of the battery according to a third embodiment of the sealed battery according to the present invention.

FIG. 5 is a sectional view of a portion taken along line AA in FIG. 4;

FIG. 6 is a schematic plan view showing the inside of the battery according to a fourth embodiment of the sealed battery according to the present invention.

FIG. 7 is a schematic plan view showing the inside of a comparative battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pole group 2 Pole group winding axis line 3 Pole group side face 4 Pole group winding end face 5 Positive electrode terminal 6 Negative terminal 7, 37, 47, 77 Package 8 Fused part 9 Injection and exhaust port 10 Inner wall surface 11 Internal space 31,32,61,62,63,64 Inclined part 100,200,300,400 Sealed battery

Continued on the front page (72) Inventor Kenji Yamauchi 2-3-1, Furube-cho, Takatsuki-shi, Osaka F-term in Yuasa Corporation 5H023 AA03 AS01 5H029 AJ14 BJ04 BJ14 CJ13 DJ02

Claims (6)

[Claims] 1. A sealed battery in which an electrolytic solution is injected into a package containing a wound electrode group, wherein the electrolytic solution is provided at a position on an inner wall surface of the package facing a wound end surface of the electrode group. A sealed battery comprising a liquid injection / exhaust port capable of injecting liquid and exhausting gas in a package. 2. The sealed battery according to claim 1, wherein the liquid injection / exhaust port is provided at a position near an end of the inner wall surface of the package. 3. An inner wall surface of the package is provided with an inclined portion for decreasing a wall interval from the inside of the package toward the outside of the package, and the inclined portion is configured to be continuous with the liquid injection / exhaust port. 3. The method according to claim 1, wherein
A sealed battery according to claim 1. 4. The hermetic seal according to claim 1, wherein the liquid injection / exhaust port is provided at two places on one side of an inner wall surface of the package opposed to the wound end surface. Shaped batteries. 5. The method according to claim 1, wherein an inner wall surface of the liquid injection / exhaust port is made of a heat-fusible resin, and the liquid injection / exhaust port is fusion-sealed. Claims 1 to 4
The sealed battery according to any one of the above. 6. A method for manufacturing a sealed battery, comprising a step of injecting an electrolytic solution into a package accommodating a wound electrode group, wherein the package inner wall surface facing the wound end surface of the electrode group is closer to the end. A liquid filling / exhaust port provided at the upper side is positioned upward, and simultaneously with the liquid pouring from the liquid pouring / exhaust port, the gas in the package is discharged from the liquid pouring / exhaust port by the liquid pouring. Battery manufacturing method.