JP2017107885A - Secondary battery, gas discharge device and gas discharge method of secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery which reduces capital investment, air conditioning cost, and the like, required for maintaining dry environment of a space for discharging gas generated from a battery while charging, and to provide a gas discharge device and a gas discharge method of the secondary battery.SOLUTION: A gas discharge device 100 of a secondary battery includes: a storage container 10 installed in an indoor space so as to store a secondary battery 20 where a power generation element 26 is covered with an exterior member 25, and having an internal space isolated from the indoor space; cutting means 40 stored in the storage container and forming an opening 23 for discharging gas generated by cutting some joints 22a to 22c in the exterior member sealing the power generation element and charging the secondary battery; sealing means 60 for sealing the opening; and an adjustment mechanism capable of adjusting the internal space of the storage container to dry environment by dehumidification.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a secondary battery, a gas discharge device for the secondary battery, and a gas discharge method.

  A lithium ion battery used for an electric vehicle or the like has a liquid or gel electrolyte, and the active material of the positive electrode or the negative electrode is composed of a polymer.

  When charging a lithium ion battery, lithium atoms become lithium ions and enter the carbon layer of the negative electrode, and when discharging, the lithium ions leave the carbon layer and move to the positive electrode, becoming the original lithium compound and the charge / discharge reaction proceeds. .

  In the secondary battery manufacturing process, particularly during initial charging, gas is generated from the battery by the charge / discharge reaction. Therefore, an opening is provided in the exterior member covering the power generation element of the lithium ion battery to discharge the gas. Yes.

  If the opening is formed in the exterior member that covers the power generation element of the battery, the liquid or gel electrolyte inside the lithium ion battery may leak out. Furthermore, in the state where the opening is formed, water vapor may enter from the outside, and if the moisture is present above a certain level, the battery performance will be degraded. Therefore, it is necessary to discharge the gas while paying attention to such points. . Therefore, the formation of the opening in the exterior member, the discharge of gas, and the sealing step must be performed in a dry environment with low humidity so that moisture does not enter the battery, and the vast room is maintained in a dry environment. Therefore, it becomes a considerable burden with capital investment and air conditioning costs.

  On the other hand, in Patent Document 1 below, an opening is provided in a part of the exterior member, the battery body is sealed in the exterior member, the opening is sandwiched between clips, temporarily closed, and the gas is discharged after the initial charge. A technique for sealing a portion is disclosed.

JP 2008-103240 A

  However, even in the technique in Patent Document 1, since the opening cannot be completely sealed in the temporarily closed state by the clip, the formation of the opening in the exterior member, the discharge of gas, and the sealing process are performed with moisture in the battery. It must be done in a room with low humidity so as not to enter.

  Furthermore, the use of the clip further requires labor for clip investment and clip attachment / detachment work.

  Accordingly, the present invention has been made to solve the above-described problems, and reduces the capital investment and air conditioning costs required for maintaining a dry environment in a space where the gas generated from the battery is discharged during charging. It is an object of the present invention to provide a gas discharge device and a gas discharge method for a battery and a secondary battery.

  The present invention that achieves the above object is to install a secondary battery in a storage container that is installed in a building space and forms an internal space isolated from the building space, and dehumidifies the storage container to adjust to a dry environment. To do. Next, a part of the joint for sealing the power generation element of the exterior member covering the power generation element in the containment vessel is cut by a cutting means to form an opening, and the gas generated from the charged secondary battery is opened. It is characterized by discharging from the part and sealing the opening.

  According to the gas discharge device and the gas discharge method of the secondary battery according to the present invention, the inside of the storage container installed in the space of the building and storing the secondary battery, the cutting means, and the sealing means is dried by the adjusting mechanism. The environment is adjusted, the opening is formed in the secondary battery by the cutting means, and the opening is sealed by the sealing means after the gas is discharged. The containment vessel is compact enough to be installed in a building space compared to the gas discharge chamber in the factory, so the equipment investment in the gas discharge chamber in the factory can be reduced by the equipment manufacturing costs and the air conditioning costs required to maintain a dry environment. Compared with the air conditioning cost, the productivity can be improved.

  Further, the gas generated from the secondary battery may be generated not only during initial charging in the manufacturing process but also during main charging and aging. On the other hand, the containment vessel according to the present invention can be installed in a building space in another process, unlike the gas discharge chamber in the factory. Therefore, the gas can be discharged using the gas discharge device according to the present invention even after the main charging or aging. As described above, since the gas discharge device according to the present invention can be used in various processes, the gas from the secondary battery can be sufficiently discharged, and the performance deterioration of the secondary battery can be effectively prevented.

  The secondary battery according to the present invention has an opening for discharging gas generated by charging by projecting outward from the first portion that always joins the exterior members to the joint and being cut off. A gas discharge part including a second part to be formed is provided. Therefore, gas discharge is performed by cutting only a portion necessary for gas discharge in the joint, and a secondary battery in which deterioration of battery performance is suppressed can be obtained.

  Further, when a plurality of gas discharge portions are formed side by side along one edge of the exterior member in the secondary battery, gas discharge can be performed in a plurality of steps, so that the gas generated by charging can be sufficiently discharged, It is possible to obtain a secondary battery in which a decrease in battery performance is further effectively suppressed.

It is a front view which shows the secondary battery which concerns on one Embodiment of this invention. It is a top view which shows an example of the gas discharge chamber of the secondary battery installed in the factory. It is sectional drawing which shows the inside of the gas discharge apparatus of the secondary battery which concerns on one Embodiment of this invention. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is sectional drawing with which it uses for description of the dry environment adjustment process in the position of FIG. It is sectional drawing with which it uses for description of the cutting process in the position of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. It is sectional drawing which follows the 8-8 line of FIG. It is sectional drawing with which it uses for description at the time of taking out a secondary battery from the inside of a storage container in the position of FIG. It is a figure where it uses for description of the gas discharge | emission method of the secondary battery which concerns on the modification of this embodiment. It is a figure where it uses for description of the gas discharge | emission method of the secondary battery which concerns on the modification of this embodiment. It is a figure where it uses for description of the gas discharge | emission method of the secondary battery which concerns on the modification of this embodiment. It is a figure where it uses for description of the gas discharge | emission method of the secondary battery which concerns on the modification of this embodiment. It is a figure where it uses for description of the gas discharge | emission method of the secondary battery which concerns on the modification of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the following description does not limit the technical scope and terms used in the claims. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from actual ratios.

  FIG. 1 is a front view showing a secondary battery according to an embodiment of the present invention, FIG. 2 is a plan view showing an example of a conventional gas discharge chamber for performing gas discharge, and FIG. 3 is a plan view showing an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3 and FIG.

  5 is a cross-sectional view for explaining the dry environment adjusting process at the position of FIG. 4, FIG. 6 is a cross-sectional view for explaining the cutting process at the position of FIG. 4, and FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 3, and FIG. 9 is a cross-sectional view for explaining the secondary battery taken out from the storage container at the position shown in FIG.

  The secondary battery 20 according to the present invention is used in a power section of an electric vehicle, etc., and as shown in FIGS. 1 and 5, a power generation element 26 in which positive electrodes, separators, and negative electrodes are alternately stacked, And an exterior member 25 that covers the power generation element 26. Further, the exterior member 25 of the secondary battery 20 includes joint portions 21 a, 21 b, 22 a to 22 c, and 25 b to 25 d that seal the power generation element 26. The joint portion of the exterior member 25 protrudes outward from the first portions 21a and 21b that always join the exterior members to each other in the exterior member 25 and is cut to have an opening that discharges gas generated by charging. A gas discharge portion 29 including second portions 22a to 22c to be formed is provided.

  The exterior member 25 is a rectangular member laminated with aluminum, polypropylene, or the like, and electrode tabs 27a and 27b are joined to the end sides 25b and 25d. In order to cover and seal the power generation element 26, the end sides 25 b to 25 d of the exterior member 25 are joined linearly to form a joined portion. On the other hand, in the end side 25a, joint portions 21a and 21b are formed at positions spaced apart from the end side 25a inward of the exterior member 25 by a predetermined distance, and joined from the joint portions 21a and 21b toward the exterior of the exterior member 25. Portions 22a to 22c are formed to protrude.

  The joints 22a to 22c are formed so as to protrude outward in the exterior member 25, so that the gas generated from the secondary battery 20 by charging as shown in FIGS. 5 to 7 inside the joints 22a to 22c. The gas retention part 28 in which the gas stays is formed.

  In this way, the joint portions 22a to 22c are formed so as to protrude outward from the joint portions 21a and 21b, so that an opening is not formed more than necessary when the gas is discharged, and moisture enters the exterior member. And leakage of electrolyte from the inside can be suppressed.

  Next, a method for manufacturing a secondary battery according to this embodiment will be described. To outline the manufacturing process of the secondary battery, first, a positive electrode active material constituting a positive electrode or a negative electrode active material constituting a negative electrode is prepared, and this is coated on a long metal foil sheet which is a material of a current collector. Apply by pressing and compress by pressing. Next, using a slitter or the like, the metal foil sheet is cut in the longitudinal direction, and further cut in the lateral direction to form a predetermined dimension. As a result, a positive electrode or negative electrode in which the current collector is coated with the positive electrode active material or the negative electrode active material is formed.

  Next, the molded positive electrode or negative electrode is laminated with a separator interposed therebetween, and the positive electrode or the negative electrode is covered with a rectangular exterior member welded with an electrode tab. Next, among the edges of the exterior member, sealing is performed leaving an opening, using a vacuum dryer or the like to remove moisture inside the battery, injecting an electrolyte solution inside, sealing the opening, Impregnate. When the impregnation is completed, the initial charge is performed, a part of the exterior member is cut and formed in the opening, the gas generated by the initial charge is discharged, the opening is sealed, the main charge is performed, and the aging is performed. Perform inspection and sorting.

  The present invention relates to a gas discharging process for discharging gas generated after initial charging, among the above processes. For example, as shown in FIG. 2, the gas discharge chamber B that discharges gas after charging the conventional secondary battery has lines L1 to L10 having a length of about 5 m and a width of about 3 m, and about 2 m between the lines and in the corner of the room. It is a vast space with a passage and a height of about 3m.

  The gas exhaust chamber B is dehumidified by air conditioning equipment so that moisture does not enter the secondary battery when the secondary battery is discharged. The gas discharge device 100 according to this embodiment can be installed in the building space of the gas discharge chamber B as shown by a two-dot chain line in the line L1 of FIG. It is an extremely compact space that is less than half the height and less than half the height of the gas exhaust chamber. As described above, the gas discharge device 100 is compact enough to be installed in the building space of the gas discharge chamber B, thereby greatly reducing the air conditioning costs required to maintain the room in a dry environment. Can do.

  With reference to FIG. 3, the gas discharge device 100 according to the present embodiment is installed in a building space, stores the secondary battery 20 in which the power generation element 26 is covered by the exterior member 25, and is isolated from the building space. It has a containment vessel 10 with an internal space. Storage doors 11a, 11b, and 11c for carrying the secondary battery 20 are attached to the storage container 10, and partition plates 13a and 13b are provided on the side surfaces inside the storage container 10. The secondary battery 20 is placed on the placement case 30 and stored in the gas discharge device 100.

  In addition to the secondary battery 20, the storage container 10 has an opening for discharging gas generated by charging the secondary battery 20 by cutting the joint portions 22 a to 22 c in the exterior member 25 as shown in FIG. 2. The cutting device 40 which forms 23 is stored. Moreover, the storage container 10 stores the sealing device 60 that seals the opening 23 formed by the cutting device 40 after gas is discharged.

  In addition, piping ducts 12a to 12c are connected to the storage container 10 in order to dehumidify the internal space of the storage container 10 and prepare it in a dry environment. Further, the storage container 10 has a transfer device 50 for transferring the secondary battery 20 from a position 20a for performing the cutting process to a position 20b for performing the gas discharging process and from a position 20b for performing the gas discharging process to a position 20c for performing the sealing process. Stored.

  As shown in FIG. 3, the gas exhaust device 100 uses a cutting area 20 a that cuts the joint portions 22 a to 22 c provided in the secondary battery 20 by the cutting device 40 to form an opening 23, and a piping duct 12 b. The gas discharge area 20b for discharging the gas generated from the opening 23 and the sealing area 20c for sealing the opening 23 by the sealing device 60 after gas discharge.

  In the gas discharge method according to the present embodiment, the secondary battery 20 is stored in a storage container, the inside of the storage container is dehumidified and adjusted to a dry environment (dry environment adjustment process), and the joint portions 22a to 22c in the exterior member 25 are stored. Is cut to form the opening 23 (cutting step). The dry environment adjustment process and the cutting process are performed in the cutting area 20 a of the secondary battery 20.

  Next, the secondary battery 20 is transported to the gas discharge area 20b, and the gas generated by charging the secondary battery 20 in the storage container is discharged from the opening 23 (gas discharge step). From there, the secondary battery 20 is further conveyed to the sealing area 20c, and the opening 23 is sealed (sealing step). After sealing, the secondary battery 20 is taken out from the storage container and transported to the next process. The sealing step is performed in the sealing area 20c where the secondary battery 20 is carried out. Details will be described below.

  In the present embodiment, the storage doors 11a to 11c are installed in an upper part of the storage container 10 in order to form the storage container in a closed space and allow the secondary battery 20 to be carried into the storage container. In this embodiment, the storage doors 11a to 11c are configured to open and close by sliding in the left-right direction in FIG. 4, and the storage doors are provided on the upper surface of the storage container 10 for each of the cutting area 20a, the gas discharge area 20b, and the sealing area 20c. 11a, 11b, and 11c are arranged. Therefore, since only a required part can be opened among the open / close doors 11a to 11c, water vapor or the like from the outside hardly enters, and the indoor dry environment can be easily maintained.

  The partition plates 13a and 13b are located at the boundary positions between the cutting area 20a, the gas discharge area 20b, and the sealing area 20c, 20a and 20b, and 20b and 20c, in order to suppress the entry of moisture and the like from the outside into the storage container. Formed. The partition plates 13a and 13b are formed so as to protrude from the inner surface of the storage container 10 into the room so as not to enter the transport path when the secondary battery 20 is transported to the next process.

  A vacuum pump (not shown) is connected to the pipe ducts 12a to 12c, and an adjustment mechanism for adjusting the inside of the storage container to a dry environment by the pipe ducts 12a to 12c and the vacuum pump is configured.

  By evacuating the piping ducts 12a to 12c using a vacuum pump, the containment vessel becomes a vacuum chamber and is adjusted to a dry environment with a dew point of about -40 ° C. The adjusting mechanism may adjust the inside of the storage container to a dry environment by using a dehumidifying device such as a compressor type or a desiccant type in addition to the vacuum pump.

  The placement case 30 sandwiches the secondary battery 20 in order to place the placement battery 31 on which the secondary battery 20 is placed and the secondary battery 20 perpendicular to the thickness direction (upward in FIG. 5). Two sandwiching plates 32 and 33 are attached to the mounting plate 31 substantially vertically. In the present embodiment, the sandwiching plate 32 can slide in the thickness direction of the secondary battery 20 (left and right direction in FIG. 5), and the sandwiching plate 33 is fixed to the mounting plate 31.

  In addition, springs 34 a to 34 d are attached to the opposing side surfaces of the sandwiching plates 32 and 33, whereby the sandwiching plate 32 is biased toward the sandwiching plate 33 and the secondary battery 20 is sandwiched. In the present embodiment, four springs 34a to 34d are provided at the four corners of the sandwiching plates 32 and 33, but the location and number of the springs 34a to 34d are not limited to the above as long as the secondary battery 20 can be placed.

  As shown in FIG. 6, the cutting device 40 cuts the joints 22 a to 22 c of the secondary battery 20 to form the opening 23, and guides the cutter 41 in the cutting direction, thereby connecting the joints 22 a to 22 c. And a cutter guide 42 for supporting cutting.

  The secondary battery 20 is stopped in the cutting area 20a by the cutter 41 and the cutter guide 42, and the joint portions 22a to 22c are cut in a state where the room is in a dry environment. In the present embodiment, the cutting device 40 employs a configuration that cuts the joint portions 22a to 22c, but is not limited to the above configuration as long as the exterior member 25 laminated with aluminum, polyethylene, or the like can be cut.

  The transport device 50 is installed on the bottom surface of the storage container 10 and includes a roller conveyor 51 that moves the secondary battery 20 from the cutting area 20a to the sealing area 20c. Further, the transport device 50 sandwiches the secondary battery 20 from the side, and moves the secondary battery 20 from the position 20b to the position 20c, and the side roller conveyors 55a and 55b that move the secondary battery 20 to the position 20b. Side roller conveyors 55c and 55d. The roller conveyor 51 includes rollers 52a to 52v (hereinafter referred to as 52) that convey the secondary battery 20, and support plates 53a and 53b that rotatably support the roller 52.

  The side roller conveyors 55a and 55b are composed of a back roller conveyor 55a and a front roller conveyor 55b, and sandwich the secondary battery 20 to convey the battery 20 from the cutting process position 20a to the gas discharge process position 20b. The back roller conveyor 55a includes rollers 56a to 56c, a support column 57a that rotatably holds the rollers 56a to 56c, and a guide rail 58a that moves the rollers 56a to 56c and the support column 57a close to and away from the secondary battery 20. Have.

  The near-side roller conveyor 55b includes rollers 56d to 56f, support pillars 57b, and guide rails 58b similarly to the back-side roller conveyor 55a.

  The rollers 56a to 56c are rotatably attached to the support column 57a, and the rollers 56d to 56f are rotatably attached to the support column 57b. The supporting column 57a is attached to the rails of the guide rail 58a together with the rollers 56a to 56c so as to be able to translate, and similarly the supporting column 57b is attached together with the rollers 56d to 56f to be able to translate on the rails of the guide rail 58b.

  The guide rail 58a forms a path along which the support column 57a slides, and the guide rail 58b forms a path along which the support column 57b slides. The support pillar 57a moves on the guide rail 58a, and the support pillar 57b moves on the guide rail 58b, so that the rollers 56a to 56c and the rollers 56d to 56f are sandwiched between the sandwiching plates 32 and 33 that sandwich the secondary battery 20. It moves from a position having an interval to a position in contact with the sandwiching plates 32 and 33.

  The back roller conveyor 55c and the front roller conveyor 55d convey the secondary battery 20 and the mounting case 30 from the gas discharge process position 20b to the sealing process position 20c, and have the same configuration as the roller conveyors 55a and 55b. The description is omitted.

  In the present embodiment, the sealing device 60 includes a clip-shaped heat seal that sandwiches the opening 23 of the secondary battery 20 from the outside of the opening 23 and performs heat fusion. If it can do, it will not be limited to the above.

  Next, the gas discharge process according to the present embodiment will be described. First, in a state where the open / close door 11a of the gas discharge device 100 is slid to the right side in FIG. 4 and opened, the secondary battery 20 that is placed on the placement case 30 and is sandwiched is carried into the storage container. . An apparatus for carrying in the secondary battery 20 may be a robot arm, for example.

  When the secondary battery 20 and the mounting case 30 can be carried into the cutting area 20 a, the side roller conveyors 55 a and 55 b are operated and fixed close to the mounting case 30.

  When the loading case 30 can be fixed by the side roller conveyors 55a and 55b, as shown in FIG. 5, the open / close door 11a is closed and the vacuum pump is operated to evacuate the inside of the storage container so that the dew point is about -40 degrees. Adjust to a dry environment.

  Next, the cutting device 40 is operated, and the gas discharge part 29 of the secondary battery 20 is cut by the cutter 41 as shown in FIGS. The joint portion 22b constituting the gas discharge portion 29 is cut off by the cutter 41, and the joint portions 22a and 22c are partially cut off.

  If the opening part 23 is formed, the roller conveyor 51 and the side roller conveyors 55a and 55b will be operated, and the secondary battery 20 and the mounting case 30 will be conveyed from the cutting area 20a to the gas discharge area 20b.

  Since gas such as hydrogen generated during charging is retained in the gas retention portion 28 shown in FIG. 6, the gas is discharged from the interior of the exterior member 25 to the internal space of the storage container 10 by forming the opening 23. The The exhaust gas is sucked from the piping duct 12b shown in FIG. 7 for a predetermined time by a vacuum pump.

  When the gas is discharged from the opening 23 in the secondary battery 20 for a predetermined time, the side roller conveyors 55c and 55d are operated, and the secondary battery 20 and the mounting case 30 are transported from the gas discharge process position 20b to the sealing process position 20c. To do.

  Next, as shown in FIG. 8, the sealing device 60 is operated, and the opening 23 is sealed with a predetermined amount of heat for a predetermined time to form the joint 24. The joint 24 is formed on the same straight line as the joints 21 a and 21 b in FIG. 3, but is formed at any position from the position on the same straight line as the joints 21 a and 21 b to the edge of the opening 23. May be.

  Thus, by sealing the opening 23 with the joints 22a and 22c left, the secondary battery 20 has the joints 22a and 22c and the opening above the joint 24 as shown in FIG. The state where the gas discharge part 29 formed with the part is left is maintained.

  When the joint 24 is formed in the secondary battery 20, the door 11c is opened, and the secondary battery 20 is taken out from the inside of the storage container 10 as shown in FIG. It conveys to the line of this charge process which is a process.

  The room where the gas discharge process of the secondary battery is performed has conventionally been provided with a plurality of secondary battery lines for discharging gas as shown in FIG. 2, and a height at which an operator's passage is provided outside the line. It is a vast space of about 3m. Thus, in order to construct a gas discharge chamber that adjusts the humidity and maintains a vacuum state, a large capital investment is required, and considerable air conditioning costs are required even after construction.

  On the other hand, the gas discharge device 100 according to the present embodiment includes a storage container in which the secondary battery 20, the cutting device 40, and the sealing device 60 are stored and the area and height are extremely smaller than the conventional gas discharge chamber. It is installed inside and the interior space is isolated from the building space, and gas is discharged.

  Since the containment vessel 10 is extremely compact as compared with the gas discharge chamber B as described above, the cost required for manufacturing the gas discharge device 100 and the air conditioning cost are extremely low compared with the capital investment and the air conditioning cost in the gas discharge chamber B. The cost can be reduced. Further, since the storage container 10 can be installed in various indoor spaces, the storage container 10 can be installed and gas can be discharged not only after the initial charging but also after the main charging and the aging process. Thereby, the gas generated from the secondary battery 20 can be sufficiently discharged, and the performance deterioration of the secondary battery 20 can be effectively prevented.

  As described above, the gas discharge device 100 according to the present embodiment is installed in a building space, stores the secondary battery 20 in which the power generation element 26 is covered by the exterior member 25, and is isolated from the building space. A storage container 10 having an internal space is provided. The storage container 10 stores a cutting device 40 that forms the opening 23 and a sealing device 60 that seals the opening 23 so that the internal space of the storage container 10 is dehumidified and adjusted to a dry environment. It is configured. And the dry environment adjustment process, the cutting | disconnection process, the gas discharge process, and the sealing process are performed in the storage container 10, and the gas generated by initial charge etc. is discharged | emitted.

  Therefore, gas can be discharged in a compact containment vessel without constructing a large gas discharge chamber B in the factory, and the investment and air conditioning costs necessary for manufacturing the gas discharge device 100 can be reduced with the gas discharge chamber B. In comparison, the cost can be reduced to a very low cost. In addition, since the storage container 10 can be installed in various building spaces, the gas discharge device 100 can be installed in other processes where gas can be generated and gas can be discharged as appropriate, thereby reducing the performance of the secondary battery. It can be effectively suppressed.

  Further, the adjustment mechanism is configured to connect a vacuum pump to the pipe ducts 12a to 12c, and the inside of the containment vessel is adjusted to a dry environment by evacuating in the dry environment adjustment step. For this reason, the inside of the storage container can be dehumidified and the exhausted gas can be sucked by evacuation, so that the air conditioning cost can be greatly reduced.

  Further, since the evaporation of moisture in the storage container can be promoted by forming the storage container 10 in a vacuum chamber, the inside of the storage container can be easily adjusted to a dry environment, and thus the battery characteristics of the secondary battery 20 can be improved. A decrease can be prevented.

  Further, the joining portion of the secondary battery 20 protrudes outward from the first portions 21 a and 21 b that always join the exterior members together and forms the opening 23 by cutting with the cutting device 40. The gas discharge part 29 containing these parts 22a-22c is provided. In the cutting process, the gas discharge unit 29 is cut in the cutting process, whereby the gas generated from the secondary battery 20 is discharged in the gas discharging process.

  Therefore, only the portion necessary for gas discharge is cut in the joint, and moisture can enter the exterior member and the electrolyte solution can be prevented from leaking to the outside, and the deterioration of the battery performance is suppressed. The secondary battery 20 can be obtained.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  FIGS. 10A to 10E are diagrams for explaining a gas discharge method for a secondary battery according to a modification of the present embodiment. Although the cutting apparatus 40 and the sealing apparatus 60 demonstrated embodiment which cuts or seals what the gas exhaust part 29 comprised from the junction parts 22a-22c formed in one place in the secondary battery 20, It is limited to this. Not.

  As described above, the gas may be generated not only after the initial charging but also after the main charging or after the aging process. Therefore, it seems that what is necessary is just to increase the protrusion amount from joining part 21a, 21b supposing joining part 22a-22c cut | disconnecting several times. However, if the amount of protrusion from the joint portions 21a and 21b increases, the material yield of the exterior member 25 may be deteriorated.

  Therefore, the joint portion in the exterior member 25 of the secondary battery 20d protrudes outward from the joint portions 21a, 21b, and 21c in the exterior member 25 as shown in FIG. A plurality of gas discharge portions 29 a and 29 b including joint portions 22 d to 22 f and 22 g to 22 i formed in the portion 23 may be arranged along the joint portions 21 a, 21 b, and 21 c of the exterior member 25.

  Then, at the time of initial charging, as shown in FIGS. 10B and 10C, the joint portions 22d to 22f are cut to form the opening portion 23a, and sealed after the gas is discharged to form the joint portion 24a. To do. Further, at the time of the main charge, as shown in FIGS. 10D and 10E, the joint portions 22g to 22i are cut to form the opening portion 23b, and sealed after the gas is discharged to form the joint portion 24b. . Similarly to the above-described embodiment, the secondary battery 20d after the sealing step has a gas discharge part 29a composed of the joining parts 22d and 22f and the opening above the joining part 24a, and 22g and 22i above the joining part 24b. And the state where the gas discharge part 29b which consists of an opening part was left is maintained.

  By comprising in this way, gas can be discharged | emitted in several processes, without deteriorating the material yield of the exterior member 25, and the performance fall of the secondary battery 20d can be suppressed more effectively. In addition, the secondary battery 20d is formed with the gas discharge portions 29a and 29b, so that the secondary battery 20d can sufficiently discharge gas compared to the case where the gas is discharged only after the initial charging, and the deterioration of the battery performance is further suppressed. It can be set as a secondary battery.

  In addition, it has been explained that the gas discharged in the gas discharge process is discharged from the containment vessel using a vacuum pump, but in addition to this, the vacuum vessel is filled with an inert gas such as nitrogen and replaced. The gas may be discharged by

10 containment vessel,
11, 11a, 11b, 11c doors,
12a-12c piping duct,
20 Secondary battery,
20a Stop position (area) at the time of carrying in a secondary battery, at the time of a dry environment adjustment process, and at the time of a cutting process,
20b Stop position (area) during the gas discharge process
20c sealing step, secondary battery stop position (area) when carrying out secondary battery,
21a, 21b joint (first part),
22a-22i joint part (2nd part),
23, 23a, 23b opening,
24, 24a, 24b joints,
25 exterior body,
25a edge,
25b-25d end side (joint part),
26 electrodes,
27a, 27b electrode tabs,
28 Gas retention part,
29, 29a, 29b gas discharge part,
30 mounting case,
31 mounting plate,
32, 33 clamping plate,
34a-34d spring,
40 Cutting device (cutting means),
41 cutter,
42 Cutter guide,
50 transfer device,
51 roller conveyor,
52, 52a-52y roller,
53a, 53b support plate,
55a, 55c Back side roller conveyor,
55b, 55d Front side roller conveyor,
56a-56l roller,
57a-57d support pillar,
58a-58d guide rail,
60 Sealing device (sealing means).

Claims (3)

Power generation elements,
An exterior member covering the power generation element;
A joint provided on the exterior member and sealing the power generation element;
The joining portion protrudes outward from the first portion that always joins the exterior members to each other and forms an opening that discharges gas generated by charging by being cut. A secondary battery comprising a plurality of gas discharge portions including a portion arranged along one edge of the exterior member. One of the plurality of gas discharge portions is provided in the second portion, and is disconnected in a process between an initial charging process and a main charging process after the initial charging process, and is generated by the initial charging process. A first gas discharge unit for discharging gas;
The other gas discharge unit is provided in a portion different from the first gas discharge unit in the second part, and discharges the gas generated after the main charging step or after the aging step. The secondary battery according to claim 1, wherein The exterior member is stored in a standing state in a storage container that is installed in a building space and forms an internal space isolated from the building space,
3. The gas discharge portion according to claim 1, wherein a plurality of the gas discharge portions are arranged side by side along the one edge in the upper portion of the exterior member in a state where the exterior member is stored in the storage container. Next battery.