JP7081432B2 - Electrode for power storage module and power storage module - Google Patents

Description

The present invention relates to an electrode for a power storage module and a power storage module.

Patent Document 1 describes a power storage module including a plurality of stacked bipolar electrodes. The bipolar electrode has a current collector, a positive electrode layer provided on one surface of the current collector, and a negative electrode layer provided on the other surface of the current collector. This power storage module includes a resin frame that covers the peripheral edge of the bipolar electrode. The resin frame is a sealing material provided so that the electrolytic solution or the like inside the battery does not leak to the outside.

Japanese Unexamined Patent Publication No. 2005-5163

As an example of the power storage module as described above, a bipolar electrode to which a resin frame is attached may be used. In this case, the bipolar electrode is formed, for example, by attaching a resin frame, which is a processed product of a resin sheet, to a current collector. The resin frame has a communication hole for injecting an electrolytic solution or the like into the inside of the power storage module. From the viewpoint of efficiently injecting an electrolytic solution or the like into the power storage module, the location where the communication hole is provided may be shifted in at least a part of the plurality of bipolar electrodes.

As a method of shifting the formation position of the communication hole, it is possible to manufacture a resin frame in which the communication hole is provided at a position corresponding to the position of the power storage module. In this case, a mold or the like for forming a plurality of types of resin frames and a space for storing each resin frame are required. Therefore, in the above method, the manufacturing cost of the resin frame, the inventory management cost of each resin frame, and the like increase.

An object of the present invention is to provide an electrode for a power storage module and a power storage module capable of reducing manufacturing costs and the like.

The electrode for a power storage module according to one aspect of the present invention has a first main surface and a second main surface located on the opposite side of the first main surface, and has a plate-shaped current collector and a first main surface. It includes a positive electrode layer located above, a negative electrode layer located on the second main surface, and a resin frame located on the peripheral edge of the current collector located outside the positive electrode layer and the negative electrode layer. The resin frame has a first layer exhibiting a frame shape and a second layer overlapping the first layer and exhibiting a frame shape, and the second layer has a plurality of communication extending from the outer edge to the inner edge of the second layer. It has a planned hole formation area, and each of the plurality of communication hole forming planned areas is partitioned by a cut line.

According to this storage module electrode, communication extending from the outer edge to the inner edge of the second layer by removing any of the communication hole formation planned regions of the second layer of the resin frame along the corresponding cut line. Holes can be easily formed. Here, the location where the communication hole is formed in the second layer can be easily changed by selecting the area where the communication hole is planned to be formed. Therefore, without using a plurality of types of resin frames, it is possible to prepare an electrode for a power storage module having a resin frame in which communication holes are provided at locations corresponding to the positions of the power storage modules. By using such an electrode for a power storage module, a power storage module can be manufactured without manufacturing a plurality of types of resin frames. Therefore, since it is not necessary to manage the inventory of a plurality of types of resin frames, it is possible to reduce the manufacturing cost of the power storage module.

Perforations may be provided on the cut line. In this case, since only the desired area where the communication hole is to be formed can be easily removed along the cut line, the communication hole can be easily formed in the second layer.

The outer edge of the first layer and the outer edge of the second layer may be continuous with each other. In this case, the disposal rate of the resin sheet used when forming the resin frame can be reduced.

The plurality of areas where the communication holes are planned to be formed may be arranged along the first direction in a plan view and may be located asymmetrically with respect to the central axis of the resin frame along the second direction orthogonal to the first direction. .. In this case, in a plan view, the position of the communication hole formation planned region when the resin frame is inverted with the central axis as the rotation axis can be shifted from the position of the communication hole formation planned region before the inversion. Therefore, by using both the electrode for the power storage module including the resin frame before inversion and the electrode for the power storage module including the resin frame after inversion, the pattern of the formed portion of the communication hole in the plan view can be easily up to 2 Can be doubled.

When a plurality of communication hole formation planned regions are located asymmetrically with respect to the central axis of the resin frame along the second direction, the distance between adjacent communication hole formation planned regions along the first direction is constant and plural. The shape of each of the areas where the communication holes are planned to be formed may be the same. In this case, in a plan view, all the positions of the communication hole formation planned region when the resin frame is inverted with the central axis as the rotation axis are surely shifted from the positions of the communication hole formation planned region before the inversion. be able to. Therefore, by using both the electrode for the electricity storage module including the resin frame before inversion and the electrode for the electricity storage module including the resin frame after inversion, the pattern of the formed portion of the communication hole in the plan view can be doubled.

One of the plurality of communication hole formation planned regions may be provided with a communication hole extending from the outer edge to the inner edge of the second layer.

The power storage module according to one aspect of the present invention includes the electrode for the power storage module and an electrode laminate having a separator, and extends from the outer edge of the second layer to the inner edge in one of a plurality of areas where communication holes are planned to be formed. An existing communication hole is provided. Such a power storage module is manufactured by using a power storage module electrode provided with a resin frame in which communication holes are provided at locations corresponding to the positions of the power storage modules, without using a plurality of types of resin frames. This makes it possible to manufacture a power storage module without manufacturing a plurality of types of resin frames. Therefore, since it is not necessary to manage the inventory of a plurality of types of resin frames, it is possible to reduce the manufacturing cost of the power storage module.

According to the present invention, it is possible to provide an electrode for a power storage module and a power storage module capable of reducing manufacturing costs and the like.

FIG. 1 is a schematic cross-sectional view showing a power storage device according to an embodiment. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. FIG. 3 is a schematic plan view showing electrodes for a power storage module. 4 (a) is a schematic cross-sectional view taken along the line IVa-IVa of FIG. 3, and FIG. 4 (b) is a schematic cross-sectional view taken along the line IVb-IVb of FIG. FIG. 5 is a schematic plan view of the frame body. FIG. 6A is an enlarged plan view of a main part of the frame body before inversion, and FIG. 6B is an enlarged plan view of a main part of the resin frame after inversion. FIG. 7A is a schematic plan view showing the first frame body according to the comparative example. Further, FIG. 7B is an enlarged plan view of a main part showing the second frame body according to the comparative example, and FIG. 7C is an enlarged plan view of the main part showing the third frame body according to the comparative example. be.

Hereinafter, one embodiment will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing a power storage device according to an embodiment. The power storage device 1 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a module stack 2 including a plurality of stacked power storage modules 4, and a restraint member 3 that applies a restraining load to the module stack 2 in the stacking direction.

The module stack 2 includes a plurality of (three in this embodiment) power storage modules 4 and a plurality of (here, four) conductive plates 5. The power storage module 4 is, for example, a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, or an electric double layer capacitor. In the present embodiment, the power storage module 4 is a nickel-metal hydride secondary battery. In the following, the direction in which the power storage modules 4 are stacked is simply referred to as the “stacking direction (Z-axis direction)”. Further, the direction intersecting or orthogonal to the stacking direction is defined as the horizontal direction. The horizontal direction has, for example, an X-axis direction (first direction) and a Y-axis direction (second direction) orthogonal to each other. In the present embodiment, "viewing from the stacking direction" corresponds to a plan view.

The storage modules 4 adjacent to each other in the stacking direction are electrically connected to each other via the conductive plate 5. Therefore, a conductive plate 5 is provided between the adjacent power storage modules 4. The conductive plates 5 are also arranged on the outside of the power storage modules 4 located at both ends in the stacking direction.

A positive electrode terminal 6 is connected to a conductive plate 5 located at one end (lower end in this embodiment) in the stacking direction. The negative electrode terminal 7 is connected to the conductive plate 5 located at the other end (upper end in this embodiment) in the stacking direction. The positive electrode terminal 6 and the negative electrode terminal 7 extend in the X-axis direction, for example. By providing the positive electrode terminal 6 and the negative electrode terminal 7, the power storage device 1 can be charged and discharged.

The conductive plate 5 can also function as a heat sink in the power storage device 1. The conductive plate 5 can release the heat generated in the power storage module 4, for example. Inside the conductive plate 5, a plurality of flow paths 5a through which a refrigerant such as air flows are provided. The flow path 5a is, for example, a void extending along the Y-axis direction. By passing a refrigerant such as air through these flow paths 5a, the heat from the power storage module 4 can be efficiently released to the outside. In the example of FIG. 1, the area of the conductive plate 5 in a plan view is smaller than the area of the power storage module 4. However, from the viewpoint of improving heat dissipation, the area of the conductive plate 5 may be the same as the area of the power storage module 4 or may be larger than the area of the power storage module 4.

The restraint member 3 is composed of a pair of end plates 8 that sandwich the module laminate 2 in the stacking direction, and fastening bolts 9 and nuts 10 that fasten the end plates 8 to each other. The end plate 8 is a rectangular metal plate having an area one size larger than the area of the power storage module 4 and the conductive plate 5 when viewed from the stacking direction. A film F having electrical insulation is provided on the inner side surface of the end plate 8 (the surface on the module laminate 2 side). The film F insulates between the end plate 8 and the conductive plate 5.

An insertion hole 8a is provided at the edge of the end plate 8 at a position outside the module laminate 2. The fastening bolt 9 is passed from the insertion hole 8a of one end plate 8 toward the insertion hole 8a of the other end plate 8, and is attached to the tip portion of the fastening bolt 9 protruding from the insertion hole 8a of the other end plate 8. , The nut 10 is screwed. As a result, the power storage module 4 and the conductive plate 5 are sandwiched by the end plate 8 to be unitized as the module laminate 2, and a restraining load is applied to the module laminate 2 in the stacking direction.

Next, the configuration of the power storage module 4 will be described in detail. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. As shown in FIG. 2, the power storage module 4 includes an electrode laminated body 11 and a cylindrical sealing body 12 surrounding the electrode laminated body 11. The electrode laminate 11 includes a plurality of electrodes laminated along the Z-axis direction (a plurality of bipolar electrodes 14, a negative electrode termination electrode 18, and a positive electrode termination electrode 19), and a plurality of separators 13. The electrode laminate 11 is formed by alternately laminating the electrodes and the separator 13. The electrode laminate 11 has a side surface 11a extending in the Z-axis direction.

The separator 13 is an insulating member located between adjacent bipolar electrodes 14 in the Z-axis direction, and exhibits, for example, a sheet shape. In plan view, the separator 13 is located inside the edge of the bipolar electrode 14. Examples of the separator 13 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene, methyl cellulose and the like, or a non-woven fabric. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The shape of the separator 13 is not limited to the sheet shape, but may be a bag shape.

The bipolar electrode 14 includes a current collector 15 having a second main surface 15b located on the opposite side of the first main surface 15a and the first main surface 15a, a positive electrode layer 16 located on the first main surface 15a, and a first surface. 2 A negative electrode layer 17 located on the main surface 15b is provided. In a plan view, the current collector 15 is larger than the separator 13, and each of the positive electrode layer 16 and the negative electrode layer 17 is smaller than the separator 13.

The current collector 15 is a conductor having a plate shape extending in the horizontal direction and exhibits flexibility. Therefore, the horizontal direction can be said to be the extending direction of the current collector 15. The current collector 15 is, for example, a nickel foil, a plated steel plate, or a plated stainless steel plate. Examples of the steel sheet include cold-rolled steel sheets (SPCC and the like) specified in JIS G 3141: 2005. Examples of the stainless steel sheet include SUS304 specified in JIS G 4305: 2015. The thickness of the current collector 15 is, for example, 0.1 μm or more and 1000 μm or less.

The positive electrode layer 16 of the bipolar electrode 14 faces the negative electrode layer 17 of one of the bipolar electrodes 14 adjacent to each other in the stacking direction with the separator 13 interposed therebetween. The positive electrode layer 16 is formed, for example, by applying a positive electrode active material to the first main surface 15a of the current collector 15. The positive electrode active material is, for example, nickel hydroxide. Nickel hydroxide may be coated with cobalt oxide or the like.

The negative electrode layer 17 of the bipolar electrode 14 faces the positive electrode layer 16 of the other bipolar electrode 14 adjacent to each other in the stacking direction with the separator 13 interposed therebetween. The negative electrode layer 17 is formed, for example, by applying a negative electrode active material to the second main surface 15b of the current collector 15. The negative electrode active material is, for example, a hydrogen storage alloy. In the present embodiment, the formation region of the negative electrode layer 17 on the second main surface 15b of the current collector 15 is larger than the formation region of the positive electrode layer 16 on the first main surface 15a of the current collector 15.

The negative electrode terminal electrode 18 has a current collector 15 and a negative electrode layer 17 provided on the second main surface 15b of the current collector 15. The negative electrode terminal electrode 18 is arranged at one end (upper end in this embodiment) in the Z-axis direction. The negative electrode layer 17 of the negative electrode terminal electrode 18 faces the positive electrode layer 16 of the bipolar electrode 14 via the separator 13. The positive electrode terminal electrode 19 has a current collector 15 and a positive electrode layer 16 provided on the first main surface 15a of the current collector 15. The positive electrode terminal electrode 19 is arranged at the other end in the Z-axis direction (the lower end in this embodiment). The positive electrode layer 16 of the positive electrode terminal electrode 19 faces the negative electrode layer 17 of the bipolar electrode 14 via the separator 13.

The conductive plate 5 is in contact with the first main surface 15a of the current collector 15 of the negative electrode terminal electrode 18. Further, another conductive plate 5 is in contact with the second main surface 15b of the current collector 15 of the positive electrode terminal electrode 19. The restraint load from the restraint member 3 is applied to the electrode laminate 11 from the negative electrode terminal electrode 18 and the positive electrode terminal electrode 19 via the conductive plate 5. That is, the conductive plate 5 can function as a restraining member that applies a restraining load to the electrode laminate 11 along the Z-axis direction.

The peripheral edge portion 15c of the current collector 15 has, for example, a rectangular frame shape. The peripheral edge portion 15c is an uncoated area in which the positive electrode active material and the negative electrode active material are not coated. That is, the peripheral edge portion 15c in a plan view corresponds to a portion of the current collector 15 located outside the positive electrode layer 16 and the negative electrode layer 17.

The sealing body 12 is a resin member configured to surround the electrode laminated body 11. The sealing body 12 has, for example, a rectangular frame shape in a plan view. The sealing body 12 has, for example, a square tube shape. In the present embodiment, the sealing body 12 is provided on the side surface 11a of the electrode laminated body 11 so as to surround the peripheral edge portion 15c. The sealing body 12 holds the peripheral edge portion 15c on the side surface 11a. The sealing body 12 has a resin frame 21 as a primary seal surrounding the peripheral edge portion 15c of the current collector 15, and a secondary seal 22 arranged around the resin frame 21.

The resin frame 21 is a member provided for each current collector 15 included in the power storage module 4, and is overlapped with each edge of the current collector 15. The resin frame 21 is formed of, for example, a resin sheet having a predetermined thickness (length along the Z-axis direction). The resin frame 21 is continuously provided over the entire circumference of the peripheral edge portion 15c of the current collector 15. The resin frame 21 is airtightly (liquid-tightly) bonded (for example, welded) to the first main surface 15a of the current collector 15. Each resin frame 21 is integrated with a corresponding bipolar electrode 14, a negative electrode termination electrode 18, or a positive electrode termination electrode 19. Therefore, the power storage module 4 includes a structure in which the resin frame 21 and the bipolar electrode 14 are integrated. Hereinafter, the structure is also referred to as an electrode ME for a power storage module. That is, the electrode ME for the power storage module includes the bipolar electrode 14 and the resin frame 21. The resin frame 21 is welded to the current collector 15 through, for example, ultrasonic treatment or heat treatment.

The secondary seal 22 is a member constituting the outer wall of the sealing body 12, and has, for example, a square cylinder shape. The secondary seal 22 covers the outer peripheral surface of each resin frame 21. The inner peripheral surface of the secondary seal 22 is welded to the outer peripheral surface of each resin frame 21. In the present embodiment, the secondary seal 22 is hermetically bonded to each resin frame 21. Therefore, an internal space V that is liquid-tight and airtightly partitioned is formed between the adjacent electrodes ME for the power storage module. Although not shown, the internal space V contains, for example, an aqueous electrolytic solution (specifically, an alkaline electrolytic solution such as a potassium hydroxide aqueous solution, a lithium hydroxide aqueous solution, or a mixed solution thereof). .. This electrolytic solution is accommodated in the internal space V via the communication hole 41 provided in the resin frame 21 (see FIG. 3 described later). Each of the resin frame 21 and the secondary seal 22 is formed of a resin such as polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). The "volume of the internal space" may mean the volume including the voids of the separator 13.

Next, the detailed structure of the resin frame 21 will be described with reference to FIGS. 3 and 4 (a) and 4 (b). FIG. 3 is a schematic plan view showing electrodes for a power storage module. 4 (a) is a schematic cross-sectional view taken along the line IVa-IVa of FIG. 3, and FIG. 4 (b) is a schematic cross-sectional view taken along the line IVb-IVb of FIG. As shown in FIGS. 3 and 4 (a) and 4 (b), the resin frame 21 included in the power storage module electrode ME is formed on the first layer 27 having a frame shape and the first layer 27 in the Z-axis direction. It has a second layer 29 that overlaps and exhibits a frame shape. In this embodiment, at least a part of the second layer 29 overlaps the first layer 27 in the Z-axis direction. That is, not all of the second layer 29 may overlap with the first layer 27 in the Z-axis direction.

The first layer 27 is a frame-shaped main body portion of the resin frame 21, is located on the first main surface 15a of the current collector 15, and is joined to the peripheral edge portion 15c. The inner portion 27a, which is a part of the first layer 27, overlaps the current collector 15 in the Z-axis direction. That is, the inner portion 27a is a portion joined to the peripheral portion 15c of the current collector 15. Further, in a plan view, the inner edge 27b of the first layer 27 is located outside the positive electrode layer 16. That is, the first layer 27 and the positive electrode layer 16 are separated from each other in the horizontal direction. On the other hand, the outer portion 27c, which is another portion of the first layer 27, does not overlap the current collector 15 in the Z-axis direction. That is, the outer portion 27c is a portion that protrudes outward from the current collector 15 along the horizontal direction in a plan view. Therefore, in a plan view, the outer edge 27d of the first layer 27 is located outside the peripheral edge portion 15c of the current collector 15.

The second layer 29 is a frame-shaped portion for defining a space for arranging the separator 13 on the electrode ME for the power storage module. A part of the second layer 29 is located on the first layer 27, and the other part of the second layer 29 is joined to the peripheral edge portion 15c. A part of the second layer 29 may be heated and pressurized with respect to the first layer 27. Thereby, the separation of the second layer 29 from the first layer 27 can be suppressed. In the present embodiment, the outer edge 27d of the first layer 27 and the outer edge 29a of the second layer 29 coincide with each other in a plan view. Therefore, the secondary seal 22 can easily come into contact with both the outer edge 27d of the first layer 27 and the outer edge 29a of the second layer 29. On the other hand, the inner edge 27b of the first layer 27 and the inner edge 29b of the second layer 29 are separated from each other in a plan view. In the present embodiment, in a plan view, a part of the inner edge 29b is located outside the inner portion 27a, and the other part of the inner edge 29b is located closer to the center of the resin frame 21 than the inner portion 27a. The second layer 29 has a first portion 291 and a second portion 292 including the above portion of the inner edge 29b, and a third portion 293 and a fourth portion 294 including the other portion of the inner edge 29b.

The first portion 291 and the second portion 292 are portions facing each other in the X-axis direction, and have a substantially rectangular shape in a plan view. The first portion 291 has a central portion 291a in the Y-axis direction and end portions 291b and 291c sandwiching the central portion 291a in the Y-axis direction. The central portion 291a is a portion that may overlap the opening of the resin frame 21. A part of the central portion 291a is in contact with the first layer 27, and the other portion of the central portion 291a is in contact with the current collector 15. In the present embodiment, the outer edge side of the central portion 291a is in contact with the first layer 27, and the inner edge 291d side of the central portion 291a is in contact with the current collector 15. The ends 291b and 291c have the same shape as each other. Each of the ends 291b and 291c does not overlap the opening of the resin frame 21 and is located on the first layer 27. That is, each of the end portions 291b and 291c is in contact with the first layer 27 and is not in contact with the current collector 15. In the Y-axis direction, the ratio of the total length of the end portions 291b and 291c to the length of the first portion 291 is, for example, 2% or more and 16% or less. In this case, deterioration of the liquidtightness and airtightness of the resin frame 21 caused by the second layer 29 can be satisfactorily suppressed. In addition, "identity" in this specification is a concept including not only "exactly identical" but also "substantially identical". Substantially the same shape contains an error of, for example, about ± 5%. Similarly, "constant" in the present specification is a concept including not only "completely constant" but also "substantially constant". Substantially constant intervals include, for example, an error of about ± 5%.

The second portion 292 has a central portion 292a in the Y-axis direction and end portions 292b and 292c sandwiching the central portion 292a in the Y-axis direction, similarly to the first portion 291. Similar to the first portion 291, a part of the central portion 292a is in contact with the first layer 27, and the other portion of the central portion 292a is in contact with the current collector 15. On the other hand, each of the end portions 292b and 292c is in contact with the first layer 27 and not with the current collector 15. The shapes of the ends 292b and 292c may be the same as or different from the shapes of the ends 291b and 291c. In the present embodiment, the first portion 291 and the second portion 292 have the same shape as each other.

The third portion 293 and the fourth portion 294 are portions facing each other in the Y-axis direction, and have a substantially rectangular shape in a plan view. In the X-axis direction, one end of the third portion 293 is welded to the end 291b of the first portion 291 and the other end of the third portion 293 is to the end 292b of the second portion 292. It is welded. Further, in the X-axis direction, one end of the fourth portion 294 is welded to the end portion 291c of the first portion 291 and the other end portion of the fourth portion 294 is the end portion of the second portion 292. It is welded to 292c. Thereby, for example, leakage of the electrolytic solution between the first portion 291 and the third portion 293 can be prevented. Further, the entire third portion 293 and the entire fourth portion 294 are located on the first layer 27, respectively. Therefore, the resin frame 21 is formed with a stepped portion 21t formed by the third portion 293 and the first layer 27 and the fourth portion 294 and the first layer 27. The separator 13 is arranged in a portion of the first layer 27 that constitutes the step portion 21t. The separator 13 may be arranged on a part of the central portion 291a in the first portion 291 and on a part of the central portion 292a in the second portion 292. In this case, the bending of the separator 13 can be satisfactorily suppressed.

The third portion 293 includes the communication hole forming planned regions 31 to 35 extending from the outer edge 29a to the inner edge 29b of the second layer 29 (more specifically, the third portion 293), and the second layer 29 (more specifically). Has a communication hole 41 extending from the outer edge 29a to the inner edge 29b of the third portion 293). Each of the communication hole formation planned regions 31 to 35 is a region that can be removed in the third portion 293, and exhibits a substantially rectangular shape in a plan view. By removing any of the areas 31 to 35 for which the communication hole is to be formed, the third portion 293 is provided with the same communication hole as the communication hole 41. In the present embodiment, the areas 31 to 35 where the communication holes are planned to be formed have the same shape as each other. Each of the communication hole formation planned regions 31 to 35 is partitioned by a cut line L provided in the third portion 293. The cut line L is a line that serves as a mark when the communication hole formation planned regions 31 to 35 are removed from the second layer 29, and exhibits a substantially U-shape in a plan view. For example, the cut line L for partitioning the communication hole formation planned region 31 is a pair of lines extending from the outer edge 29a to the inner edge 29b of the second layer 29, as well as connecting the pair of lines and connecting the first layer 27 and the first layer 27. It has a line extending along the boundary with the second layer 29. The cut line L is formed, for example, by drawing or pressing on the second layer 29. In the present embodiment, a perforation is provided on the cut line L. In this case, the areas 31 to 35 where the communication holes are planned to be formed can be easily removed along the cut line L without using a special tool or the like.

The communication hole 41 is an opening for injecting the electrolytic solution into the internal space V (see FIG. 2) of the electrode laminate 11. The communication hole 41 is formed by removing the communication hole formation planned region in the third portion 293. That is, the communication hole 41 is provided from one of the plurality of communication hole formation planned regions provided in the third portion 293. Therefore, the shape of the communication hole 41 in a plan view is the same as the shape of the communication hole formation planned regions 31 to 35. Further, in the present embodiment, the communication hole 41 is located on the opposite side of the communication hole formation planned region 32 via the communication hole formation planned region 31 in the X-axis direction, but the present invention is not limited to this. The communication hole may be provided in any of the areas 31 to 35 where the communication hole is planned to be formed, for example. In this case, the portion where the communication hole 41 is formed in the third portion 293 becomes a communication hole formation planned region defined by the cut line.

The areas 31 to 35 where the communication holes are planned to be formed and the communication holes 41 are arranged along the X-axis direction in a plan view. The distance P1 between adjacent communication hole formation planned regions along the X-axis direction is constant. Therefore, in the X-axis direction, the intervals between the areas 31 and 32 where the communication holes are planned to be formed and the intervals between the areas 32 and 33 where the communication holes are planned to be formed are the same. Further, in the X-axis direction, the distance P2 between the communication hole formation planned region 31 and the communication hole 41 is the same as the distance P1. Therefore, in the third portion 293, the communication hole 41 and the communication hole formation planned regions 31 to 35 are sequentially arranged at regular intervals in the X-axis direction. In addition, what is the distance along the X-axis direction from the inner edge 291d of the first portion 291 to the communication hole 41 and the distance along the X-axis direction from the inner edge 292d of the second portion 292 to the communication hole formation planned region 35? , Different from each other. Therefore, the communication hole formation planned regions 31 to 35 and the communication hole 41 are asymmetrically located with respect to the axis passing through the center C of the resin frame 21 along the Y-axis direction (the central axis A of the resin frame 21).

The first layer 27 and the second layer 29 are continuous with each other. In the present embodiment, the outer edge 27d of the first layer 27 and the outer edge 29a of the second layer 29 are continuous with each other. This is because the first layer 27 and the second layer 29 are formed by folding back the frame 51 shown in FIGS. 5 and 6 (a) and 6 (b) described later along the folding lines 61 to 64. Yes (details will be described later). Therefore, the first layer 27 and the second layer 29 are formed without being separated from one resin sheet.

Next, with reference to FIGS. 5 and 6 (a) and 6 (b), a frame body corresponding to the resin frame before welding to the bipolar electrode 14 and before the formation of the second layer 29 will be described. FIG. 5 is a schematic plan view of the frame body. FIG. 6A is an enlarged plan view of a main part of the frame body before inversion, and FIG. 6B is an enlarged plan view of a main part of the resin frame after inversion. The frame body 51 shown in FIG. 5 is a member for forming the resin frame 21. The frame 51 is a molded product obtained by processing, for example, a resin sheet drawn from a roll. In the present embodiment, the frame 51 is formed by punching a part of the resin sheet with a die. The frame body 51 has a main body frame portion 52 that later becomes the first layer 27, and a first protruding portion 53 to a fourth protruding portion 56 that later becomes the first portion 291 to the fourth portion 294 of the second layer 29. The main body frame portion 52 and the first protruding portion 53 to the fourth protruding portion 56 are continuous with each other.

The main body frame portion 52 has the same shape as the first layer 27 in a plan view. Each of the first protruding portion 53 to the fourth protruding portion 56 has a substantially rectangular shape in a plan view, similarly to the first portion 291 to the fourth portion 294. Each of the first protruding portion 53 and the second protruding portion 54 is a portion that protrudes toward the outside of the main body frame portion 52 in the X-axis direction. Each of the third protruding portion 55 and the fourth protruding portion 56 is a portion that protrudes toward the outside of the main body frame portion 52 in the Y-axis direction. The main body frame portion 52 and the first protruding portion 53 are separated by a folding line 61, and the main body frame portion 52 and the second protruding portion 54 are separated by a folding line 62, and the main body frame portion 52 and the third protruding portion 55 are separated. Is partitioned by a folding line 63, and the main body frame portion 52 and the fourth protruding portion 56 are partitioned by a folding line 64. The resin frame 21 having the first layer 27 and the second layer 29 is formed by folding back the first protruding portion 53 to the fourth protruding portion 56 along the folding lines 61 to 64, respectively.

Each of the folding lines 61 and 62 is a straight line extending along the Y-axis direction in a plan view, and each of the folding lines 63 and 64 is a straight line extending along the X-axis direction in a plan view. In the present embodiment, the folded line 61 is aligned with one short side of the third protruding portion 55 and the fourth protruding portion 56, and the folded line 62 is aligned with the other short sides of the third protruding portion 55 and the fourth protruding portion 56. There is.

The third protruding portion 55 has a notched planned area 71 to 76 which will later become a communication hole formation planned area 31 to 35 or a communication hole 41. In the present embodiment, each of the planned cutout areas 71 to 76 has the same shape and is partitioned by a cut line L formed by perforations. Perforations are provided, for example, when punching out the resin sheet. In this case, the die for punching out the resin sheet has a structure for forming the perforations. The folded line 63 overlaps the portion extending along the X-axis direction in the cut line L. As a result, when the communication hole 41 (see FIG. 3) is later provided from any of the planned notch regions 71 to 76, the obstruction of the communication hole 41 by the first layer 27 can be satisfactorily suppressed.

The planned notch regions 71 to 76 are arranged along the X-axis direction in a plan view. The distance P3 between adjacent planned notch regions along the X-axis direction is constant with the distance P1 shown in FIG. That is, the planned notch regions 71 to 76 are sequentially provided at regular intervals in the X-axis direction. Further, the distance D1 from one short side of the third protrusion 55 to the planned notch region 71 and the distance D2 from the other short side of the third protrusion 55 to the planned notch region 76 are different from each other. Therefore, the planned notch regions 71 to 76 are located asymmetrically with respect to the central axis A passing through the center C of the frame body 51 along the Y-axis direction. Therefore, the positions of the planned notch regions 71 to 76 before inversion (see FIGS. 5 and 6A) and the planned notch regions 71 to 76 when the frame 51 is inverted with the central axis A as the rotation axis. The positions (see FIG. 6 (b)) do not exactly match each other. In the present embodiment, for example, when the frame body 51 is inverted with the central axis A as the rotation axis, the planned notch area 72 before the inversion and the planned notch areas 75 and 76 after the inversion partially overlap, but completely. Do not overlap. When the frame body 51 is inverted with the central axis A as the rotation axis, the planned notch area 74 before the inversion and the planned notch area 74 after the inversion also partially overlap, but do not completely overlap.

As described above, the areas 31 to 35 in which the communication holes are planned to be formed in the resin frame 21 which is a work piece of the frame body 51 are located asymmetrically with respect to the central axis A of the resin frame 21 along the Y-axis direction. Therefore, when the resin frame 21 is inverted with the central axis A as the axis of rotation, the positions of the communication hole formation planned regions 31 to 35 before the inversion in the plan view and the communication hole formation planned regions 31 to after the inversion in the plan view are The positions of 35 do not exactly match each other.

Next, the effects obtained by the electricity storage module electrode ME and the electricity storage module 4 provided with the electrode ME for the electricity storage module according to the present embodiment described above will be described with reference to FIGS. 7 (a) to 7 (c). FIG. 7A is a schematic plan view showing the first frame body according to the comparative example. Further, FIG. 7B is an enlarged plan view of a main part showing the second frame body according to the comparative example, and FIG. 7C is an enlarged plan view of the main part showing the third frame body according to the comparative example. be. As shown in FIG. 7A, the first frame body 151 according to the comparative example is a frame according to the present embodiment in that a cutout planned area and a cut line are not provided, and a cutout 141 is provided. It is different from the body 51. Further, the second frame body 251 shown in FIG. 7B is different from the frame body 51 according to the present embodiment in that the planned notch area and the cut line are not provided and the notch 241 is provided. The third frame body 351 shown in FIG. 7 (c) is different from the frame body 51 according to the present embodiment in that the planned notch area and the cut line are not provided and the notch 341 is provided. There is.

The notch 141 of the first frame body 151, the notch 241 of the second frame body 251 and the notch 341 of the third frame body 351 are provided at different positions. By manufacturing a power storage module using all of the first frame body 151, the second frame body 251 and the third frame body 351 such a place where a communication hole for injecting an electrolytic solution or the like is provided in the power storage module. Can be dispersed. As a result, in the comparative example, the electrolytic solution or the like can be efficiently injected into the power storage module. On the other hand, in the comparative example, at least a mold for forming the first frame body 151, the second frame body 251 and the third frame body 351 and a space for storing each resin frame are required. .. Therefore, in the comparative example, the manufacturing cost of each resin frame, the inventory management cost of each resin frame, and the like increase.

On the other hand, according to the electrode ME for the power storage module according to the present embodiment, the outer edge of the second layer 29 is removed by removing the communication hole formation planned region of the second layer 29 of the frame body 51 along the cut line. A communication hole 41 extending from 29a to the inner edge 29b can be easily formed. Here, the location where the communication holes are formed in the second layer 29 can be easily changed by selecting, for example, the areas 31 to 35 where the communication holes are planned to be formed. Therefore, without using a plurality of types of resin frames, it is possible to prepare an electrode ME for a power storage module having a frame body 51 in which communication holes are provided at locations corresponding to the positions of the power storage module 4. By using such an electrode ME for a power storage module, the power storage module 4 can be manufactured without manufacturing a plurality of types of resin frames. Therefore, since it is not necessary to manage the inventory of a plurality of types of resin frames, it is possible to reduce the manufacturing cost of the power storage module.

In the present embodiment, a perforation is provided on the cut line L. Therefore, since only the desired area where the communication hole is planned to be formed can be easily removed along the cut line L, the communication hole can be easily formed in the second layer 29.

In the present embodiment, the outer edge 27d of the first layer 27 and the outer edge 29a of the second layer 29 are continuous with each other. Therefore, the disposal rate of the resin sheet used when forming the frame 51 can be reduced.

In the present embodiment, the communication hole formation planned regions 31 to 35 are arranged along the X-axis direction in a plan view, and are located asymmetrically with respect to the central axis A of the frame body 51 along the Y-axis direction. Therefore, when the resin frame 21 is inverted with the central axis A as the axis of rotation, the positions of the communication hole formation planned regions 31 to 35 before the inversion in the plan view are changed to the communication hole formation planned regions 31 to after the inversion in the plan view. It can be shifted with respect to the position of 35. Therefore, by using both the electricity storage module electrode ME including the resin frame 21 formed from the frame body 51 before inversion and the electricity storage module electrode including the resin frame formed from the frame body 51 after inversion. , The pattern of the formation points of the communication holes in the plan view can be easily increased up to twice.

Here, in the present embodiment, the distance P1 between the adjacent communication hole formation planned regions along the X-axis direction is constant, and the shapes of the communication hole formation planned regions 31 to 35 are the same. Therefore, when the resin frame 21 is inverted with the central axis A as the axis of rotation, all the positions of the communication hole formation planned regions 31 to 35 after the inversion in the plan view are the communication hole formation planned regions before the inversion in the plan view. It can be reliably displaced with respect to the positions 31 to 35. Therefore, by using both the electricity storage module electrode ME including the resin frame 21 formed from the frame body 51 before inversion and the electricity storage module electrode including the resin frame formed from the frame body 51 after inversion. , The pattern of the formation points of the communication holes in the plan view can be doubled.

In the present embodiment, one of the communication hole formation planned regions is provided with a communication hole 41 extending from the outer edge 29a to the inner edge 29b of the second layer 29, and the communication hole formation planned region 31 is provided in the X-axis direction. The distance P2 between the communication hole 41 and the communication hole 41 is the same as the distance P1. Therefore, the communication holes 41 and the areas 31 to 35 where the communication holes are planned to be formed are arranged in order at regular intervals in the X-axis direction. Therefore, the areas 31 to 35 where the communication holes are planned to be formed and the communication holes 41 are located asymmetrically with respect to the central axis A of the resin frame 21 along the Y-axis direction.

The electrode for the power storage module and the power storage module according to the present invention are not limited to the above-described embodiment, and various other modifications are possible. For example, in the present invention, all the electrodes for the power storage module included in the power storage module do not have to be provided with the resin frame according to the above embodiment. That is, in the present invention, at least one of the electrodes for the power storage module included in the power storage module may be the electrode for the power storage module according to the above embodiment. Further, in the above embodiment, the electrode laminate is a laminate of various electrodes and a separator, but the present invention is not limited to this. The electrode laminate may include an electrode for a power storage module and a separator. That is, the electrode laminate may include a part of the sealed body.

In the above embodiment, the communication hole formation planned region and the communication hole are formed only in the first portion of the resin frame, but the present invention is not limited to this. For example, a communication hole formation planned region and a communication hole may be formed only in the second portion of the resin frame, or a communication hole formation planned region and a communication hole may be formed in at least one of the first to fourth portions of the resin frame. May be done. In this case, the locations where the communication holes are provided in the power storage module can be further dispersed.

In the above embodiment, the regions where the communication holes are planned to be formed have the same shape as each other, but the present invention is not limited to this. For example, at least one of the areas where the communication holes are planned to be formed may have a different shape from the other areas where the communication holes are planned to be formed. Similarly, the planned notch regions do not have to have the same shape as each other. Further, the communication hole formation planned region and the communication hole may have different shapes from each other. In addition, in the above embodiment, the distance between adjacent communication hole formation planned regions is constant, but the distance is not limited to this. Similarly, the distance between adjacent planned notch areas is constant, but is not limited to this.

In the above embodiment, the frame is formed by punching a part of the resin sheet with a die, but the frame is not limited to this. Further, the planned notch area does not have to be provided at the same time as the formation of the frame.

In the above embodiment, the timing at which the communication holes are formed is not particularly limited. The communication hole may be formed by removing the planned notch region, or may be formed by removing the planned communication hole formation region. That is, the communication hole may be formed before a part of the frame is folded back through the folding line, or may be formed after the part is folded back.

In the above embodiment, the first layer and the second layer of the resin frame are continuous, but the present invention is not limited to this. For example, the outer edge of the first layer and the outer edge of the second layer may be separated from each other. In this case, the first layer and the second layer may be formed by being separated from one resin sheet. Alternatively, the first layer and the second layer may be formed of different resin sheets or the like. Further, in the above embodiment, a part of the second layer of the resin frame is in contact with the current collector, but the present invention is not limited to this. The second layer may be separated from the current collector. In this case, for example, the first layer is located between the current collector and the second layer.

In the above embodiment, in the resin frame, a part of the inner edge of the second layer is located outside the inner edge of the first layer, and the other part of the inner edge of the second layer is the center of the resin frame than the inner edge of the first layer. It is located on the side, but it is not limited to this. For example, the entire inner edge of the second layer may be located outside the inner edge of the first layer, or the entire inner edge of the second layer may be located closer to the center of the resin frame than the inner edge of the first layer. May be good.

1 ... power storage device, 2 ... module laminate, 3 ... restraint member, 4 ... power storage module, 5 ... conductive plate, 5a ... flow path, 6 ... positive electrode terminal, 7 ... negative electrode terminal, 8 ... end plate, 8a ... insertion hole , 9 ... Fastening bolt, 10 ... Nut, 11 ... Electrode laminate, 11a ... Side surface, 12 ... Sealing body, 13 ... Separator, 14 ... Bipolar electrode, 15 ... Current collector, 15a ... First main surface, 15b ... Second main surface, 15c ... peripheral portion, 16 ... positive electrode layer, 17 ... negative electrode layer, 18 ... negative electrode terminal electrode, 19 ... positive electrode terminal electrode, 21 ... resin frame, 21t ... stepped portion, 22 ... secondary seal, 27 ... 1st layer, 27a ... inner part, 27b ... inner edge, 27c ... outer part, 27d ... outer edge, 29 ... second layer, 29a ... outer edge, 29b ... inner edge, 31-35 ... area where communication holes are to be formed, 41 ... communication holes , 51 ... Frame body, 52 ... Main body frame part, 61-64 ... Folded line, 71-76 ... Notch planned area, 141,241,341 ... Notch, 291 ... First part, 291a, 292a ... Central part, 291b, 291c , 292b, 292c ... end, 291d, 292d ... inner edge, 292 ... second part, 293 ... third part, 294 ... fourth part, A ... central axis, C ... center, D1, D2 ... distance, L ... cut line , ME ... Electrode for power storage module, P1 to P3 ... Spacing, V ... Internal space.

Claims (7)

A current collector having a first main surface and a second main surface located on the opposite side of the first main surface and exhibiting a plate shape,
The positive electrode layer located on the first main surface and
The negative electrode layer located on the second main surface and
A resin frame located on the peripheral edge of the current collector located outside the positive electrode layer and the negative electrode layer is provided.
The resin frame has a first layer having a frame shape and a second layer overlapping the first layer and having a frame shape.
The second layer has a plurality of areas for forming communication holes extending from the outer edge to the inner edge of the second layer.
Each of the plurality of areas where the communication holes are planned to be formed is partitioned by a cut line.
Electrode for power storage module. The electrode for a power storage module according to claim 1, wherein a perforation is provided on the cut line. The electrode for a power storage module according to claim 1 or 2, wherein the outer edge of the first layer and the outer edge of the second layer are continuous with each other. The plurality of communication hole formation planned regions are arranged along the first direction in a plan view, and are asymmetrically located with respect to the central axis of the resin frame along the second direction orthogonal to the first direction. , The electrode for a power storage module according to any one of claims 1 to 3. The distance between adjacent areas where communication holes are planned to be formed is constant along the first direction.
The electrode for a power storage module according to claim 4, wherein each of the plurality of communication hole formation planned regions has the same shape. The storage module according to any one of claims 1 to 5, wherein a communication hole extending from the outer edge to the inner edge of the second layer is provided in one of the plurality of communication hole formation planned regions. electrode. The electrode for the power storage module according to any one of claims 1 to 5 and an electrode laminate having a separator are provided.
A storage module provided with a communication hole extending from the outer edge to the inner edge of the second layer in one of the plurality of communication hole formation planned regions.

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