JP2021111523A - Power storage module and manufacturing method of flexible printed circuit board - Google Patents

Abstract

To provide a power storage module and a manufacturing method of a flexible printed circuit board capable of suppressing a short circuit between electrode bodies.SOLUTION: A power storage module includes a first bipolar electrode and a second bipolar electrode laminated along a first direction, and a flexible printed substrate 50 including a conductive pattern 52 electrically connected to an electrode body of the first bipolar electrode, a cover film 54 covering the conductive pattern 52, and a heat-resistant member 71 provided on the cover film 54, and the conductive pattern 52 includes a fuse portion 52b having a cross-sectional area smaller than that of a wiring portion 52a, the cover film 54 has a covering region 54a covering the fuse portion 52b, and the heat-resistant member 71 is located on the covering region 54a, and the melting point of the heat-resistant member 71 is higher than the melting point of the cover film 54.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a method for manufacturing a power storage module and a flexible printed circuit board.

A configuration is known in which a flexible printed circuit board is used to measure the voltage of a bipolar battery. For example, in the bipolar secondary battery described in Patent Document 1, the current collector of the bipolar electrode has an extending portion extending outside the cell cell layer, and the conductive pattern of flexible wiring is provided in this extending portion. Are electrically connected. On the other hand, a flexible printed circuit board provided with a fuse portion for cutting off an overcurrent is known (for example, Patent Document 2 and Patent Document 3). In this flexible printed circuit board, a fuse portion is formed by reducing the cross-sectional area of the conductive pattern, and the fuse portion blows when an overcurrent flows.

Japanese Unexamined Patent Publication No. 2008-117626 JP-A-2007-317990 Japanese Unexamined Patent Publication No. 2017-11191

It is conceivable to use the flexible printed circuit board as described above for voltage measurement of a bipolar battery as described in Patent Document 1. However, when an overcurrent flows through the fuse portion, the fuse portion generates heat, and the heat may melt the cover film covering the conductive pattern to expose the conductive pattern. In such a case, a short circuit may occur between the current collectors (electrode bodies) of the electrodes via the exposed conductive pattern.

The present disclosure describes a method for manufacturing a power storage module capable of suppressing a short circuit between electrodes and a flexible printed circuit board.

The power storage module according to one aspect of the present disclosure includes two active material layers having different polarities, each of which is provided on both sides of the electrode body and the electrode body, and is a first bipolar electrode laminated along a first direction. A second bipolar electrode, a conductive pattern electrically connected to the electrode body of the first bipolar electrode, a cover film covering the conductive pattern, and a flexible printed substrate including a heat-resistant member provided on the cover film. .. The conductive pattern has a fuse portion having a smaller cross-sectional area than the other parts of the conductive pattern. The cover film has a covering area that covers the fuse portion. The heat-resistant member is located on the covering area. The melting point of the heat-resistant member is higher than the melting point of the cover film.

In this power storage module, the conductive pattern of the flexible printed circuit board is covered with a cover film. A heat-resistant member having a melting point higher than the melting point of the cover film is provided on the covering region covering the fuse portion of the conductive pattern in the cover film. Therefore, even if the covering region of the cover film is melted by the heat generated by the fuse portion, the possibility that the conductive pattern is exposed by the heat-resistant member can be reduced. As a result, it is possible to reduce the possibility that the electrode body of the first bipolar electrode is short-circuited with the electrode body of the second bipolar electrode via the exposed conductive pattern.

The heat-resistant member may be composed of a coating agent. In this case, since the heat-resistant member is in close contact with the cover film, the heat-resistant member can continue to cover the conductive pattern even if the covering region of the cover film is melted.

The flexible printed circuit board may further include a heat radiating member provided on the cover film. The heat radiating member may be arranged around the covering area. In this case, the heat radiating member may release heat around the covering area to the outside. Therefore, it is possible to prevent the periphery of the covering region from melting.

The heat radiating member may be provided so as to sandwich the covering area. Since the heat radiating member sandwiching the covering region can release the heat around the covering region to the outside, it is possible to more reliably suppress the melting around the covering region.

The heat radiating member may have a frame-like shape surrounding the covering area. In this case, since the heat of the entire periphery of the covering region can be released to the outside, it is possible to more reliably suppress the melting of the periphery of the covering region.

The flexible printed circuit has another conductive pattern electrically connected to the electrode body of the second bipolar electrode, another cover film covering the other conductive pattern, and another heat-resistant member provided on the other cover film. And may be further included. Another conductive pattern may have another fuse portion having a smaller cross-sectional area than the other portion of the other conductive pattern. Another cover film may have another covering area covering another fuse portion. Another heat resistant member may be located on another covering area. The melting point of another heat-resistant member may be higher than the melting point of another cover film. In this case, even if another covering region of another cover film is melted by the heat generated by another fuse portion, the possibility that another conductive pattern is exposed by another heat-resistant member can be reduced. As a result, it is possible to reduce the possibility that the electrode body of the second bipolar electrode is short-circuited with the electrode body of the first bipolar electrode via another exposed conductive pattern.

Another fuse portion may be provided at a position different from that of the fuse portion when viewed from the first direction. In this case, since the distance between the fuse portion and another fuse portion can be secured, it is possible to suppress the heat generated in the other fuse portion from being transferred to the covering region covering the fuse portion and the heat-resistant member. As a result, the possibility that the conductive pattern is exposed can be reduced.

A method for manufacturing a flexible printed circuit board according to another aspect of the present disclosure includes a step of preparing a substrate portion including a base film, a conductive pattern formed on one surface of the base film, and a cover film covering the conductive pattern, and a cover. A step of forming a heat-resistant member on a film is provided. The conductive pattern has a fuse portion having a smaller cross-sectional area than the other parts of the conductive pattern. The cover film has a covering area that covers the fuse portion. The melting point of the heat-resistant member is higher than the melting point of the cover film. In the process of forming the heat-resistant member, the frame is arranged on the cover film so as to surround the covering region, and the space surrounded by the frame is filled with the liquid heat-resistant material that is the source of the heat-resistant member. A heat resistant member is formed.

In this method of manufacturing a flexible printed circuit, a heat-resistant member having a melting point higher than the melting point of the cover film is formed on a covering region covering a fuse portion of the conductive pattern in the cover film covering the conductive pattern of the flexible printed circuit. NS. Therefore, even if the covering region of the cover film is melted by the heat generated by the fuse portion, the possibility that the conductive pattern is exposed by the heat-resistant member can be reduced. For example, the first bipolar is formed by electrically connecting the conductive pattern of the flexible printed substrate to the electrode body of the first bipolar electrode of the power storage module including the first bipolar electrode and the second bipolar electrode laminated via the separator. When measuring the voltage of the electrode body of the electrode, it is possible to reduce the possibility that the electrode body of the first bipolar electrode is short-circuited with the electrode body of the second bipolar electrode via the exposed conductive pattern.

The frame may be fixed to the cover film as a heat radiating member. In this case, since the heat-resistant member can be formed by using the heat-dissipating member, it is possible to simplify the production of the flexible printed circuit board.

According to the present disclosure, a short circuit between the electrode bodies can be suppressed.

FIG. 1 is a schematic side view showing a power storage device according to an embodiment. FIG. 2 is a schematic plan view of the power storage module included in the power storage device of FIG. FIG. 3 is a schematic cross-sectional view taken along the line III-III of FIG. FIG. 4 is an enlarged schematic plan view of a part of the flexible printed circuit board shown in FIG. FIG. 5 is a schematic cross-sectional view taken along the line VV of FIG. FIG. 6 is a schematic cross-sectional view of a flexible printed circuit board according to a modified example. FIG. 7 is a schematic cross-sectional view of the power storage module according to the modified example.

Hereinafter, one embodiment will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate description is omitted. Each figure shows a coordinate system defined by the X-axis, Y-axis, and Z-axis. The X-axis direction is a direction that intersects (here, orthogonal) with the Y-axis direction and the Z-axis direction (first direction), and the Y-axis direction intersects with the X-axis direction and the Z-axis direction (here, orthogonal). It is the direction to do. The Z-axis direction is, for example, the vertical direction, and the X-axis direction and the Y-axis direction are, for example, the horizontal direction.

FIG. 1 is a schematic side view showing a power storage device according to an embodiment. The power storage device 1 shown in FIG. 1 can be used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a laminated body 2, connecting members 3 and 4 electrically connected to the laminated body 2, a pair of restraint members 5 for restraining the laminated body 2, and a pair of restraint members 5 for the laminated body 2. A pair of insulating members 7 arranged between them are provided.

The laminated body 2 has a plurality of power storage modules 11 laminated along the Z-axis direction, and a positive electrode current collector plate 12 and a negative electrode current collector plate 13 provided so as to come into contact with the power storage module 11. .. In the following, the Z-axis direction may be simply referred to as the “stacking direction”. In the example shown in FIG. 1, the laminated body 2 has two power storage modules 11, one positive electrode current collector plate 12, and two negative electrode current collector plates 13. One positive electrode current collector plate 12 is arranged between two power storage modules 11. The two negative electrode current collector plates 13 are arranged at both ends of the laminated body 2 in the Z-axis direction.

The connecting member 3 is a conductive member (bus bar) that functions as a positive electrode of the power storage device 1. The connecting member 3 extends in the stacking direction (Z-axis direction) of the power storage module 11. The connecting member 3 is, for example, a metal plate. The metal plate is, for example, a copper plate, an aluminum plate, a titanium plate, or a nickel plate. The metal plate may be, for example, a stainless steel plate (SUS301, SUS304, etc.) or an alloy plate containing two or more metals selected from the group consisting of copper, aluminum, titanium, and nickel. The connecting member 3 is electrically connected to the positive electrode current collector plate 12 included in the laminated body 2.

The connecting member 4 is a conductive member (bus bar) that functions as a negative electrode of the power storage device 1. The connecting member 4 extends in the stacking direction (Z-axis direction) of the power storage module 11. Like the connecting member 3, the connecting member 4 is, for example, a metal plate. The connecting member 4 may be the same metal plate as the connecting member 3, or may be a different metal plate. The connecting member 4 is electrically connected to the negative electrode current collector plate 13 included in the laminated body 2.

Each of the pair of restraint members 5 is a member that applies a restraining force (load) along the Z-axis direction to the laminated body 2. Each of the pair of restraint members 5 is formed of, for example, a conductive metal material (for example, an alloy such as copper, aluminum, titanium, nickel, or stainless steel). The pair of restraint members 5 may be connected to each other via a connecting member 6 using, for example, a fastening member (for example, a bolt 6A and a nut 6B). In this case, each of the pair of restraint members 5 is provided with a through hole through which the bolt 6A is inserted.

Each of the pair of insulating members 7 is, for example, a sheet-like member having an insulating property, and has a substantially rectangular parallelepiped shape. Each of the pair of insulating members 7 is interposed between the laminated body 2 (negative electrode current collector plate 13) and the restraining member 5. Each of the pair of insulating members 7 is in contact with the negative electrode current collector plate 13. That is, in the present embodiment, the power storage modules 11 are arranged so that the negative electrode termination electrodes 19 (see FIG. 3), which will be described later, are arranged at both ends of the laminated body 2 in the Z-axis direction.

Examples of materials forming each of the pair of insulating members 7 include polypropylene (PP), polyphenylene sulfide (PPS), and nylon 66 (PA66). At least one of the pair of insulating members 7 may have elasticity. The length (thickness) of the insulating member 7 along the Z-axis direction is, for example, 1 mm or more and 10 mm or less.

Next, the details of the power storage module 11 will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic plan view of the power storage module included in the power storage device of FIG. FIG. 3 is a schematic cross-sectional view taken along the line III-III of FIG. As shown in FIGS. 2 and 3, the power storage module 11 is a cell cell having a substantially rectangular parallelepiped shape. The power storage module 11 is, for example, a secondary battery such as a nickel hydrogen secondary battery and a lithium ion secondary battery. The power storage module 11 may be an electric double layer capacitor. The power storage module 11 may be an all-solid-state battery.

In the present embodiment, the power storage module 11 is a bipolar lithium ion secondary battery. The power storage module 11 is sandwiched between the positive electrode current collector plate 12 and the negative electrode current collector plate 13 in the Z-axis direction, and is electrically connected to the connecting member 3 via the positive electrode current collector plate 12 and also negative electrode current collector. It is electrically connected to the connecting member 4 via the plate 13.

The power storage module 11 includes a laminate 14, a sealing member 15, a plurality of flexible printed circuit boards 50, and a plurality of support members 60. The laminate 14 has a plurality of bipolar electrodes 16, a plurality of separators 17, a positive electrode terminal electrode 18, and a negative electrode terminal electrode 19. The plurality of bipolar electrodes 16 and the plurality of separators 17 are alternately arranged along the Z-axis direction. In the present embodiment, the stacking direction of the bipolar electrodes 16 coincides with the stacking direction of the power storage module 11.

Each of the plurality of bipolar electrodes 16 includes an electrode body 21, a positive electrode layer 22 (active material layer), and a negative electrode layer 23 (active material layer). The electrode body 21 has a pair of main surfaces 21a and 21b that intersect the Z-axis direction. A positive electrode layer 22 is provided on the main surface 21a, and a negative electrode layer 23 is provided on the main surface 21b. That is, the bipolar electrode 16 includes two electrode layers having different polarities formed on both surfaces of the electrode body 21. Therefore, the electrode body 21 is sandwiched between the positive electrode layer 22 and the negative electrode layer 23 along the Z-axis direction. The electrode body 21 may be composed of one electrode plate or two electrode plates. When the electrode body 21 is composed of two electrode plates, the bipolar electrode 16 is an electrode plate having a positive electrode layer 22 formed on one surface and another electrode having a negative electrode layer 23 formed on one surface. The plates may be formed by superimposing the plates so that the surfaces on which the electrode layers are not formed are in contact with each other.

The electrode body 21 is a sheet-shaped conductive member. The electrode body 21 has, for example, a structure in which a plurality of metal foils containing different types of metals are integrated. A plurality of metal foils are joined to each other. Each metal foil is, for example, a copper foil, an aluminum foil, a titanium foil, or a nickel foil. Each metal foil is, for example, a stainless steel foil (for example, SUS304, SUS316, and SUS301 specified in JIS G 4305: 2015), a plated steel plate (for example, JIS G 3141: 2011, etc.). It may be a cold-rolled steel sheet (SPCC, etc.)) or a plated stainless steel sheet, or an alloy foil containing two or more metals selected from the group consisting of copper, aluminum, titanium and nickel. You may. From the viewpoint of ensuring mechanical strength, the electrode body 21 may include an aluminum foil. When the electrode body 21 does not contain the aluminum foil, the surface of the metal foil may be coated with aluminum. The thickness of the electrode body 21 is, for example, 5 μm or more and 70 μm or less.

The electrode body 21 has a main body portion 21c having a rectangular shape in a plan view and a tab 21d integrated with the main body portion 21c. The positive electrode layer 22 and the negative electrode layer 23 are formed on the main body portion 21c and not on the tab 21d. The tab 21d extends from the main body 21c in a direction intersecting the Z-axis direction (in the present embodiment, the X-axis direction). The length along the Z-axis direction of the tab 21d and the direction intersecting the extending direction of the tab 21d (in the present embodiment, the Y-axis direction) is the direction intersecting the Z-axis direction of the main body 21c and the extending direction of the tab 21d (the direction intersecting the extending direction of the tab 21d). In this embodiment, it is shorter than the length along the Y-axis direction). Specifically, the tab 21d protrudes in the X-axis direction from the edge extending in the lateral direction (Y-axis direction) of the main body 21c and penetrates the sealing member 15. The tab 21d is used to transmit the voltage of the electrode body 21 to the flexible printed circuit board 50. In the present embodiment, the plurality of bipolar electrodes 16, the positive electrode terminal electrode 18, and the tab 21d of the electrode body 21 of the negative electrode terminal electrode 19 are provided at positions where they overlap each other when viewed from the Z-axis direction.

The positive electrode layer 22 is a layered member containing a positive electrode active material, a conductive auxiliary agent, and a binder, and has a substantially rectangular shape. In other words, the positive electrode layer 22 is an active material layer of the positive electrode. The positive electrode active material of the present embodiment is, for example, a composite oxide, metallic lithium, sulfur and the like. The composition of the composite oxide includes, for example, at least one of iron, manganese, titanium, nickel, cobalt, and aluminum, and lithium. Examples of the composite oxide include olivine-type lithium iron phosphate (LiFePO ₄ ). The binder is a material that holds the active material or the conductive auxiliary agent to the surface of the electrode body 21 and maintains the conductive network in the electrode. Examples of binders include fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, and alkoxysilyl group-containing resins. Examples thereof include acrylic resins such as poly (meth) acrylic acid, styrene-butadiene rubber (SBR), carboxymethyl cellulose, sodium alginate, alginates such as ammonium alginate, water-soluble cellulose ester crosslinked products, and starch-acrylic acid graft polymers. .. These binders are used alone or in combination.

Examples of conductive auxiliaries include acetylene black, carbon black, and graphite. The viscosity adjusting solvent is, for example, N-methyl-2-pyrrolidone (NMP) or the like.

The negative electrode layer 23 is a layered member containing a negative electrode active material, a conductive auxiliary agent, and a binder, and has a substantially rectangular shape. In other words, the negative electrode layer 23 is the active material layer of the negative electrode. The negative electrode active material of the present embodiment is, for example, carbon such as graphite, artificial graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, soft carbon, a metal compound, an element that can be alloyed with lithium or a compound thereof, and boron. Addition carbon etc. Examples of elements that can be alloyed with lithium include silicon and tin. As the conductive auxiliary agent and the binder, the same material as that of the positive electrode layer 22 may be used.

The plurality of bipolar electrodes 16 are laminated along the Z-axis direction. The two bipolar electrodes 16 adjacent to each other in the Z-axis direction include a negative electrode layer 23 provided on the electrode body 21 of one bipolar electrode 16 and a positive electrode layer 22 provided on the electrode body 21 of the other bipolar electrode 16. They are laminated along the Z-axis direction so as to face each other via the separator 17.

The positive electrode terminal electrode 18 is located at one end of the laminated body 14 in the Z-axis direction. The positive electrode terminal electrode 18 includes an electrode body 21 and a positive electrode layer 22 formed on the main surface 21a of the electrode body 21. In the positive electrode terminal electrode 18, an electrode layer such as a negative electrode layer 23 is not formed on the main surface 21b of the electrode body 21. The positive electrode terminal electrode 18 is laminated on the bipolar electrode 16 so that the main surface 21a and the positive electrode layer 22 face the bipolar electrode 16 via the separator 17.

The negative electrode termination electrode 19 is located at the other end of the laminate 14 in the Z-axis direction. The negative electrode terminal electrode 19 includes an electrode body 21 and a negative electrode layer 23 formed on the main surface 21b of the electrode body 21. In the negative electrode terminal electrode 19, an electrode layer such as a positive electrode layer 22 is not formed on the main surface 21a of the electrode body 21. The negative electrode terminal electrode 19 is laminated on the bipolar electrode 16 so that the main surface 21b and the negative electrode layer 23 face the bipolar electrode 16 via the separator 17.

The separator 17 is a layered member that separates two bipolar electrodes 16 adjacent to each other, between the bipolar electrode 16 and the positive electrode terminal electrode 18, and between the bipolar electrode 16 and the negative electrode terminal electrode 19, and is substantially rectangular. It has a shape. The separator 17 is a member that prevents a short circuit between two bipolar electrodes 16 adjacent to each other, between the bipolar electrode 16 and the positive electrode terminal electrode 18, and between the bipolar electrode 16 and the negative electrode terminal electrode 19. The separator 17 may be composed of the electrolyte contained in the positive electrode layer 22 and the negative electrode layer 23. When the separator 17 is composed of a solid electrolyte, the separator 17 may have a substantially rectangular plate shape. The thickness of the separator 17 is, for example, 1 μm or more and 20 μm or less.

The separator 17 is a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP). The separator 17 may be a woven fabric or a non-woven fabric made of polypropylene, methyl cellulose or the like. The separator 17 may be reinforced with a vinylidene fluoride resin compound.

The sealing member 15 is a member that holds a plurality of bipolar electrodes 16, a plurality of separators 17, a positive electrode terminal electrode 18, and a negative electrode terminal electrode 19 included in the laminated body 14, and has insulating properties. More specifically, the sealing member 15 holds the bipolar electrode 16, the positive electrode terminal electrode 18, and the electrode body 21 constituting the negative electrode terminal electrode 19. When viewed from the Z-axis direction, the sealing member 15 has an outer frame shape (here, a rectangular frame shape) that follows the outer shape of the main body portion 21c of the electrode body 21, and is an outer edge portion of the main body portion 21c of the electrode body 21. Is interposed between two electrode bodies 21 adjacent to each other in the Z-axis direction. The sealing member 15 is joined (for example, welded) to at least one of the main surface 21a and the main surface 21b of the electrode body 21. The sealing member 15 can also function as a short-circuit prevention member that seals the side surface of the laminated body 14 along the Z-axis direction and prevents short-circuiting between the electrode bodies 21.

Examples of the material forming the sealing member 15 include a heat-resistant resin member and the like. Examples of the heat-resistant resin member include polyimide, polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), PA66 and the like.

An electrolytic solution (not shown) is housed in the space S sealed by the sealing member 15. Examples of the electrolytic solution include cyclic carbonates, cyclic esters, chain carbonates, chain esters, and ethers. The supporting salt contained in the electrolytic solution is, for example, a lithium salt. Lithium salts are, for example, LiBF ₄ , LiPF ₆ , LiN (FSO ₂ ) ₂ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C2F ₅ ) ₂ , or a mixture thereof.

The plurality of flexible printed substrates 50 transmit signals relating to the voltages of the electrode body 21 of the plurality of bipolar electrodes 16, the electrode body 21 of the positive electrode termination electrode 18, and the electrode body 21 of the negative electrode termination electrode 19 to a monitoring device (not shown). It is a member of. The flexible printed substrate 50 is formed between the electrode bodies 21 of two bipolar electrodes 16 (first bipolar electrode and second bipolar electrode) adjacent to each other, and the electrode body 21 of the bipolar electrode 16 and the electrode body 21 of the positive electrode termination electrode 18. It is provided between the electrode body 21 of the bipolar electrode 16 and between the electrode body 21 of the negative electrode terminal electrode 19. More specifically, one flexible printed circuit board 50 is provided for every two electrode bodies 21. The flexible printed circuit board 50 is inserted into a space defined by two tabs 21d adjacent to each other and a sealing member 15. Details of the flexible printed circuit board 50 will be described later.

The plurality of support members 60 are non-conductive members for supporting the tab 21d. Since the flexible printed circuit 50 is provided for each of the two electrode bodies 21, the support member 60 is not provided with the flexible printed circuit 50 among the electrode bodies 21 of the two bipolar electrodes 16 adjacent to each other in the Z-axis direction. It is provided between the two electrode bodies 21. That is, the flexible printed circuit board 50 and the support member 60 are alternately provided. Similar to the flexible printed circuit board 50, the support member 60 is inserted into a space formed by two tabs 21d adjacent to each other and a sealing member 15. The elastic modulus of the support member 60 is smaller than the elastic modulus of the flexible printed circuit board 50. The elastic modulus of an object is a value obtained by dividing the stress applied to the object by the strain of the object. Specifically, the elastic modulus of the support member 60 in the Z-axis direction is smaller than the elastic modulus of the flexible printed circuit 50 in the Z-axis direction.

The support member 60 is arranged so as to be sandwiched between the two tabs 21d in the Z-axis direction. The tip of the support member 60 is in contact with the outer surface of the sealing member 15. The tip of the support member 60 is located in a space defined by the two tabs 21d and the sealing member 15. The support member 60 supports two tabs 21d in the Z-axis direction. The support member 60 has a surface 60a that intersects the Z-axis direction and a surface 60b that is opposite to the surface 60a. The surface 60a faces one of the tabs 21d. The surface 60b faces the other tab 21d.

The surface 60a is provided with a recessed portion 60c that is recessed in the Z-axis direction. In the present embodiment, the adhesive 61 is filled in the recess 60c, and the support member 60 is fixed to one of the tabs 21d by the adhesive 61. The surface 60b is provided with a recessed portion 60d that is recessed in the Z-axis direction. In the present embodiment, the adhesive 62 is filled in the recess 60d, and the support member 60 is fixed to the other tab 21d by the adhesive 62. As the adhesives 61 and 62, for example, non-conductive adhesives are used.

A support member 60 is provided between the electrode body 21 of the uppermost bipolar electrode 16 and the electrode body 21 of the second-stage bipolar electrode 16 from the top. Similarly, a support member 60 is provided between the electrode body 21 of the lowermost bipolar electrode 16 and the electrode body 21 of the second-stage bipolar electrode 16 from the bottom. For one bipolar electrode 16, a flexible printed circuit board 50 is provided between the bipolar electrode 16 and one of the bipolar electrodes 16 adjacent to each other in the Z-axis direction, and between the two bipolar electrodes 16 adjacent to each other in the Z-axis direction. A support member 60 is provided on the.

Next, the configurations of the positive electrode current collector plate 12 and the negative electrode current collector plate 13 will be described in more detail. As shown in FIG. 1, the positive electrode current collector plate 12 is a conductive member that comes into contact with the laminated body 14, and has a plate shape. The positive electrode current collector plate 12 is adjacent to the power storage module 11 in the Z-axis direction. That is, the positive electrode current collector plate 12 is arranged so as to come into contact with the electrode body 21 of the positive electrode terminal electrode 18. The positive electrode current collector plate 12 has a main body portion 12a that comes into contact with the electrode body 21 and a protruding portion 12c that protrudes from a part of the edge 12b of the main body portion 12a in the X-axis direction. The protrusion 12c is connected to the connecting member 3. The main body portion 12a is a portion that overlaps the bipolar electrode 16 and the separator 17 in the Z-axis direction, and has a substantially rectangular shape. The thickness of the positive electrode current collector plate 12 is, for example, 1 mm or more and 5 mm or less.

The negative electrode current collector plate 13 is a conductive member that comes into contact with the laminated body 14, and has a plate shape. The negative electrode current collector plate 13 is adjacent to the power storage module 11 in the Z-axis direction like the positive electrode current collector plate 12. That is, the negative electrode current collector plate 13 is arranged so as to come into contact with the electrode body 21 of the negative electrode terminal electrode 19. The negative electrode current collector plate 13 has a main body portion 13a that comes into contact with the electrode body 21 and a protruding portion 13c that protrudes from a part of the edge 13b of the main body portion 13a in the X-axis direction. The protrusion 13c is connected to the connecting member 4. The main body 13a is a portion that overlaps the bipolar electrode 16 and the separator 17 in the Z-axis direction, and has a substantially rectangular shape. The thickness of the negative electrode current collector plate 13 is, for example, 1 mm or more and 5 mm or less.

The two power storage modules 11 are arranged so that the positive electrode termination electrodes 18 face each other. The positive electrode current collector plate 12 is arranged so as to be in contact with the two positive electrode terminal electrodes 18 facing each other. That is, in the present embodiment, one positive electrode current collector plate 12 functions as a positive electrode current collector plate of the two power storage modules 11.

Next, the configuration of the flexible printed circuit board 50 will be described in more detail. FIG. 4 is an enlarged schematic plan view of a part of the flexible printed circuit board shown in FIG. FIG. 5 is a schematic cross-sectional view taken along the line VV of FIG. As shown in FIGS. 3 to 5, the flexible printed circuit board 50 is arranged so as to be sandwiched between the two tabs 21d in the Z-axis direction. The tip of the flexible printed circuit board 50 is in contact with the outer surface of the sealing member 15. The flexible printed circuit board 50 is a double-sided flexible printed circuit board, and has a surface 50a that intersects the Z-axis direction and a surface 50b that is opposite to the surface 50a. The flexible printed circuit board 50 includes a substrate portion 59, a heat-resistant member 71, a heat-resistant member 72 (another heat-resistant member), a heat-dissipating member 73, and a heat-dissipating member 74.

The substrate portion 59 includes a base film 51, a conductive pattern 52, a conductive pattern 53 (another conductive pattern), a cover film 54, and a cover film 55 (another cover film). The base film 51 is a film-like insulating member. The material of the base film 51 is polyimide, polyethylene naphthalate, polyethylene terephthalate, or the like.

The conductive patterns 52 and 53 are formed of a conductive metal such as copper. The conductive pattern 52 is electrically connected to one of the two electrode bodies 21 that sandwich the flexible printed circuit board 50, and transmits a signal related to the voltage of the electrode body 21. The conductive pattern 52 is provided on one surface 51a of the base film 51. The conductive pattern 52 includes a wiring portion 52a (another portion) and a fuse portion 52b.

The wiring portion 52a is a portion that functions as an electric circuit. The fuse portion 52b is a portion that functions as a fuse. The fuse portion 52b is formed by narrowing a part of the conductive pattern 52, and has a cross-sectional area smaller than the cross-sectional area of the wiring portion 52a. In the present embodiment, the width of the fuse portion 52b (length in the Y-axis direction) is smaller than the width of the wiring portion 52a (length in the Y-axis direction), and the thickness of the fuse portion 52b (length in the Z-axis direction). ) Is smaller than the thickness (length in the Z-axis direction) of the wiring portion 52a. The cross-sectional area of the fuse portion 52b is set so that Joule heat is generated when an overcurrent flows through the conductive pattern 52 and is blown by the generated Joule heat.

The conductive pattern 53 is electrically connected to the other electrode body 21 of the two electrode bodies 21 that sandwich the flexible printed circuit board 50, and transmits a signal related to the voltage of the electrode body 21. The conductive pattern 53 is provided on the other surface 51b of the base film 51. The conductive pattern 53 includes a wiring portion 53a (another portion) and a fuse portion 53b (another fuse portion).

The wiring portion 53a is a portion that functions as an electric circuit. The fuse portion 53b is a portion that functions as a fuse. The fuse portion 53b is formed by narrowing a part of the conductive pattern 53, and has a cross-sectional area smaller than the cross-sectional area of the wiring portion 53a. In the present embodiment, the width of the fuse portion 53b (length in the Y-axis direction) is smaller than the width of the wiring portion 53a (length in the Y-axis direction), and the thickness of the fuse portion 53b (length in the Z-axis direction). ) Is smaller than the thickness (length in the Z-axis direction) of the wiring portion 53a. The cross-sectional area of the fuse portion 53b is set so that Joule heat is generated when an overcurrent flows through the conductive pattern 53 and is blown by the generated Joule heat. In the present embodiment, the fuse portion 53b is provided at a position overlapping the fuse portion 52b when viewed from the Z-axis direction.

The cover films 54 and 55 are film-shaped insulating members. The materials of the cover films 54 and 55 are polyimide, polyethylene naphthalate, polyethylene terephthalate and the like. The cover film 54 is provided on the conductive pattern 52 formed on the surface 51a and covers the conductive pattern 52. The cover film 54 includes a covering region 54a that covers the fuse portion 52b. The covering region 54a overlaps with the fuse portion 52b when viewed from the Z-axis direction. The cover film 55 is provided on the conductive pattern 53 formed on the surface 51b and covers the conductive pattern 53. The cover film 55 includes a covering region 55a (another covering region) that covers the fuse portion 53b. The covering region 55a overlaps with the fuse portion 53b when viewed from the Z-axis direction. The surface of the cover film 54 constitutes the surface 50a. The surface of the cover film 55 constitutes the surface 50b. In the present embodiment, the covering region 55a overlaps with the covering region 54a when viewed from the Z-axis direction.

The heat-resistant members 71 and 72 are composed of, for example, a coating agent. Examples of the coating agent include a resin coating agent and a ceramic coating agent. The heat-resistant members 71 and 72 may be made of a viscous material. The heat-resistant member 71 is provided on the cover film 54 and is located on the covering region 54a. Specifically, the heat-resistant member 71 covers the covering region 54a. The heat-resistant member 71 has higher heat resistance than the cover film 54. That is, the melting point of the heat-resistant member 71 is higher than the melting point of the cover film 54. The heat-resistant member 72 is provided on the cover film 55 and is located on the covering region 55a. Specifically, the heat-resistant member 72 covers the covering region 55a. The heat-resistant member 72 has higher heat resistance than the cover film 55. That is, the melting point of the heat-resistant member 72 is higher than the melting point of the cover film 55.

The heat radiating members 73 and 74 are members for releasing heat to the outside. The heat radiating members 73 and 74 are formed of a metal or the like having a high thermal conductivity. The heat radiating member 73 is provided on the cover film 54. The heat radiating member 73 is arranged around the covering area 54a and has a frame-like shape surrounding the covering area 54a. That is, the heat radiating member 73 surrounds the heat radiating member 71, and the heat radiating member 71 is housed in the space defined by the heat radiating member 73. The heat radiating member 73 is not provided on the covering region 54a and is not in contact with the covering region 54a. The heat radiating member 73 is in contact with the periphery of the covering region 54a of the cover film 54.

The heat radiating member 74 is provided on the cover film 55. The heat radiating member 74 is arranged around the covering region 55a and has a frame-like shape surrounding the covering region 55a. That is, the heat radiating member 74 surrounds the heat radiating member 72, and the heat radiating member 72 is housed in the space defined by the heat radiating member 74. The heat radiating member 74 is not provided on the covering region 55a and is not in contact with the covering region 55a. The heat radiating member 74 is in contact with the periphery of the covering region 55a of the cover film 55.

The heat radiating members 73 and 74 do not have to be a perfect frame. That is, the shape of the heat radiating members 73 and 74 may be a shape in which the frame is partially missing.

The flexible printed circuit board 50 has a connecting portion 56 in which two electrode bodies 21 sandwiching the flexible printed circuit board 50 and conductive patterns 52 and 53 are electrically connected to each other. In this embodiment, the connection portion 56 is located at one end of the flexible printed circuit board 50. The connecting portion 56 is located in a space defined by two tabs 21d adjacent to each other and a sealing member 15, and is sandwiched between the two tabs 21d in the Z-axis direction. The connecting portion 56 has a surface 56a facing one tab 21d and a surface 56b facing the other tab 21d. The surface 56a is a surface 50a at the connecting portion 56. The surface 56b is a surface 50b at the connecting portion 56.

The surface 56a is provided with an opening 56c. The opening 56c is a portion where the cover film 54 is missing, and a part of the conductive pattern 52 (the tip portion in the present embodiment) is exposed from the opening 56c. The opening 56c is provided at a position overlapping the tab 21d of one of the electrode bodies 21 when viewed from the Z-axis direction. The conductive pattern 52 is electrically connected to the tab 21d of one of the electrode bodies 21 via the opening 56c. In the present embodiment, the conductive adhesive 57 is filled in the opening 56c, and the conductive pattern 52 is connected to the tab 21d of one of the electrode bodies 21 by the adhesive 57.

The surface 56b is provided with an opening 56d. The opening 56d is a portion where the cover film 55 is missing, and a part of the conductive pattern 53 (the tip portion in the present embodiment) is exposed from the opening 56d. The opening 56d is provided at a position overlapping the tab 21d of the other electrode body 21 when viewed from the Z-axis direction. The conductive pattern 53 is electrically connected to the tab 21d of the other electrode body 21 via the opening 56d. In the present embodiment, the conductive adhesive 58 is filled in the opening 56d, and the conductive pattern 53 is connected to the tab 21d of the other electrode body 21 by the adhesive 58.

Next, an example of a method for manufacturing the flexible printed circuit board 50 will be described. First, a step of preparing the substrate portion 59 is performed. In this step, the base film 51 is first prepared. Then, for example, the conductive pattern 52 is formed on the surface 51a of the base film 51 by etching processing, and the conductive pattern 53 is formed on the surface 51b of the base film 51. Then, for example, by laminating, a cover film 54 is formed on the surface 51a so as to cover the conductive pattern 52, and a cover film 55 is formed on the surface 51b so as to cover the conductive pattern 53. As a result, the substrate portion 59 is obtained.

Subsequently, a step of forming the heat-resistant members 71 and 72 on the cover films 54 and 55 is performed. In this step, a frame-shaped heat radiating member 73 (frame body) is arranged on the cover film 54 so as to surround the covering region 54a covering the fuse portion 52b of the conductive pattern 52. At this time, the heat radiating member 73 is fixed on the cover film 54 by the adhesive. Then, a liquid heat-resistant material that is the source of the heat-resistant member 71 is poured into the space surrounded by the heat-dissipating member 73, and the space is filled with the heat-resistant material. After that, the heat-resistant material solidifies (solidifies) to form the heat-resistant member 71.

Similarly, a frame-shaped heat radiating member 74 (frame body) is arranged on the cover film 55 so as to surround the covering region 55a covering the fuse portion 53b of the conductive pattern 53. At this time, the heat radiating member 74 is fixed on the cover film 55 by the adhesive. Then, a liquid heat-resistant material that is the source of the heat-resistant member 72 is poured into the space surrounded by the heat-dissipating member 74, and the space is filled with the heat-resistant material. After that, the heat-resistant material is solidified (solidified) to form the heat-resistant member 72.

From the above, the flexible printed circuit board 50 is obtained. When forming the heat-resistant members 71 and 72, instead of the heat-dissipating members 73 and 74, a frame having the same shape as the heat-dissipating members 73 and 74 may be used. In this case, after the heat-resistant members 71 and 72 are formed, the frame body is removed, and the heat-dissipating members 73 and 74 are fitted into the heat-resistant members 71 and 72, respectively.

Next, an example of a step of assembling the flexible printed circuit board 50 and the support member 60 to the laminated body 14 will be described. First, a plurality of flexible printed circuit boards 50 having adhesives 57 and 58 coated on the openings 56c and 56d, and a plurality of support members 60 having adhesives 61 and 62 coated on the recesses 60c and 60d, respectively, are prepared. Will be done. Then, the flexible printed circuit board 50 and the support member 60 are alternately sandwiched between the tabs 21d of the electrode bodies 21 adjacent to each other. Then, when the power storage module 11 is housed in the laser or the high temperature tank, the adhesives 57, 58, 61, 62 are melted and then solidified, so that the flexible printed circuit board 50 and the support member 60 are each two. It is glued to the tab 21d. After that, the power storage module 11 is activated, and the voltage is measured via the flexible printed circuit board 50.

As described above, in the power storage module 11, the conductive pattern 52 of the flexible printed circuit board 50 is covered with the cover film 54. A heat-resistant member 71 having a melting point higher than the melting point of the cover film 54 is provided on the covering region 54a covering the fuse portion 52b of the conductive pattern 52. Therefore, even if the covering region 54a of the cover film 54 is melted by the heat generated by the fuse portion 52b, the possibility that the conductive pattern 52 is exposed by the heat-resistant member 71 can be reduced. As a result, it is possible to reduce the possibility that the electrode body 21 to which the conductive pattern 52 is connected is short-circuited with another electrode body 21 via the exposed conductive pattern 52.

Similarly, the conductive pattern 53 of the flexible printed circuit board 50 is covered with the cover film 55. A heat-resistant member 72 having a melting point higher than the melting point of the cover film 55 is provided on the covering region 55a covering the fuse portion 53b of the conductive pattern 53. Therefore, even if the covering region 55a of the cover film 55 is melted by the heat generated by the fuse portion 53b, the possibility that the conductive pattern 53 is exposed by the heat-resistant member 72 can be reduced. As a result, it is possible to reduce the possibility that the electrode body 21 to which the conductive pattern 53 is connected is short-circuited with another electrode body 21 via the exposed conductive pattern 53.

Further, foreign matter or the like adheres to the exposed conductive patterns 52 and 53, which may cause a problem that the fused conductive patterns 52 and 53 are reconducted and an overcurrent flows. However, since the possibility that the conductive patterns 52 and 53 are exposed by the heat-resistant members 71 and 72 can be reduced, the possibility that the above-mentioned problems occur can be reduced.

The heat-resistant members 71 and 72 are composed of a coating agent. Therefore, since the heat-resistant members 71 and 72 are in close contact with the cover films 54 and 55, respectively, even if the covering regions 54a and 55a of the cover films 54 and 55 are melted, the heat-resistant members 71 and 72 are conductive like a film. The patterns 52 and 53 can continue to be covered.

When the heat radiating member 73 is arranged on the covering region 54a, the fuse portion 52b may not be blown even if an overcurrent flows through the conductive pattern 52. On the other hand, since the heat radiating member 73 is arranged around the covering region 54a, the heat radiating member 73 can release the heat around the covering region 54a to the outside. Therefore, it is possible to prevent the periphery of the covering region 54a from melting without preventing the fuse portion 52b from being blown. Similarly, since the heat radiating member 74 is arranged around the covering region 55a, the heat radiating member 74 can release the heat around the covering region 55a to the outside. Therefore, it is possible to prevent the periphery of the covering region 55a from melting without preventing the fuse portion 53b from being blown.

The heat radiating member 73 has a frame-like shape surrounding the covering region 54a. Therefore, since the heat of the entire circumference of the covering region 54a can be released to the outside, it is possible to more reliably suppress the melting of the periphery of the covering region 54a. Similarly, the heat radiating member 74 has a frame-like shape surrounding the covering region 55a. Therefore, since the heat of the entire circumference of the covering region 55a can be released to the outside, it is possible to more reliably suppress the melting of the periphery of the covering region 55a.

In the method for manufacturing the flexible printed circuit 50 described above, a heat-resistant member 71 having a melting point higher than the melting point of the cover film 54 is formed on the covering region 54a covering the fuse portion 52b of the conductive pattern 52. Therefore, even if the covering region 54a of the cover film 54 is melted by the heat generated by the fuse portion 52b, the possibility that the conductive pattern 52 is exposed by the heat-resistant member 71 can be reduced. Similarly, a heat-resistant member 72 having a melting point higher than the melting point of the cover film 55 is formed on the covering region 55a covering the fuse portion 53b of the conductive pattern 53. Therefore, even if the covering region 55a of the cover film 55 is melted by the heat generated by the fuse portion 53b, the possibility that the conductive pattern 53 is exposed by the heat-resistant member 72 can be reduced. As described above, when the voltage of the electrode body 21 is measured using the flexible printed circuit board 50, the possibility that the electrode body 21 is short-circuited with another electrode body 21 via the exposed conductive patterns 52 and 53 is reduced. It becomes possible.

Since the heat-resistant member 71 is formed by using the heat-dissipating member 73 and the heat-resistant member 72 is formed by using the heat-dissipating member 74, it is possible to simplify the production of the flexible printed circuit board 50.

Although one embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the above embodiment.

For example, the plurality of flexible printed circuit boards 50 may be integrated at an end opposite to the connecting portion 56. Similarly, the flexible printed circuit board 50 and the support member 60 may be integrated at an end opposite to the connecting portion 56.

The support member 60 may not be provided at a portion that does not overlap with the tab 21d, and the length of the support member 60 in the X-axis direction may be changed as necessary. The support member 60 may not be provided.

The tab 21d may be formed of a member different from the main body 21c. The tab 21d may have the entire edge extending in the lateral direction of the main body 21c extending in the X-axis direction and penetrating the sealing member 15. The tab 21d may extend in the Y-axis direction from an edge extending in the longitudinal direction of the main body 21c.

In the above embodiment, the plurality of bipolar electrodes 16, the positive electrode termination electrode 18, and the tab 21d of the electrode body 21 of the negative electrode termination electrode 19 are provided at positions overlapping each other when viewed from the Z-axis direction, but are adjacent to each other. The tabs 21d of the two electrode bodies 21 may be provided at positions (different positions) that do not overlap each other when viewed from the Z-axis direction.

The heat radiating member 73 may be provided so as to sandwich the covering region 54a. For example, the heat radiating member 73 may be two strip-shaped heat radiating members sandwiching the covering region 54a. In this case, since the heat radiating member 73 sandwiching the covering region 54a can release the heat around the covering region 54a to the outside, it is possible to prevent the periphery of the covering region 54a from melting. Similarly, the heat radiating member 74 may be provided so as to sandwich the covering region 55a. For example, the heat radiating member 74 may be two strip-shaped heat radiating members sandwiching the covering region 55a. Also in this case, since the heat radiating member 74 sandwiching the covering region 55a can release the heat around the covering region 55a to the outside, it is possible to prevent the periphery of the covering region 55a from melting.

By either making the width of the fuse portion 52b smaller than the width of the wiring portion 52a or making the thickness of the fuse portion 52b smaller than the thickness of the wiring portion 52a, the cross-sectional area of the fuse portion 52b becomes the wiring portion 52a. It may be smaller than the cross-sectional area of. Similarly, the cross-sectional area of the fuse portion 53b is increased by either making the width of the fuse portion 53b smaller than the width of the wiring portion 53a or making the thickness of the fuse portion 53b smaller than the thickness of the wiring portion 53a. It may be smaller than the cross-sectional area of the wiring portion 53a.

The fuse portion 53b may be provided at a position different from that of the fuse portion 52b when viewed from the Z-axis direction. FIG. 6 is a schematic cross-sectional view of a flexible printed circuit board according to a modified example. As shown in FIG. 6, the fuse portion 52b and the fuse portion 53b are provided at different positions in the X-axis direction. That is, the fuse portion 52b and the fuse portion 53b are separated from each other in the X-axis direction. Similarly, the fuse portion 52b and the fuse portion 53b may be provided at different positions in the Y-axis direction.

In this case, the distance between the fuse portion 52b and the fuse portion 53b can be secured. Therefore, it is possible to suppress the heat generated in the fuse portion 52b from being transferred to the covering region 55a and the heat-resistant member 72. Similarly, it is possible to suppress the heat generated in the fuse portion 53b from being transferred to the covering region 54a and the heat-resistant member 71. As a result, the possibility that the conductive patterns 52 and 53 are exposed can be further reduced.

The flexible printed circuit board 50 may be a single-sided flexible printed circuit board. FIG. 7 is a schematic cross-sectional view of the power storage module according to the modified example. As shown in FIG. 7, the power storage module 11A of the modified example includes a plurality of flexible printed circuit boards 50A and a plurality of support members 60A instead of the plurality of flexible printed circuit boards 50 and the plurality of support members 60. Mainly different from 11.

The flexible printed circuit board 50A is mainly different from the flexible printed circuit board 50 in that it does not include the conductive pattern 53, the cover film 55, the heat-resistant member 72, and the heat-dissipating member 74, and that it is provided for each electrode body 21. The flexible printed circuit board 50A is a single-sided flexible printed circuit board. The flexible printed circuit board 50A is arranged between the tabs 21d of the two electrode bodies 21 adjacent to each other in the Z-axis direction. Further, the flexible printed circuit board 50A is also arranged under the electrode body 21 of the positive electrode terminal electrode 18. An opening 56c is provided on the surface 50a of the flexible printed circuit board 50A so that a part of the conductive pattern 52 is exposed, and the conductive pattern 52 is electrically connected to the tab 21d of the electrode body 21 via the adhesive 57. It is connected. No opening is provided on the surface 50b of the flexible printed circuit board 50A.

The support member 60A is mainly different from the support member 60 in that it is provided between the flexible printed circuit board 50A and the tab 21d. Since the distance in the Z-axis direction of the tabs 21d of the two electrode bodies 21 adjacent to each other in the Z-axis direction is longer than the length (thickness) in the Z-axis direction of the flexible printed circuit 50A, the support member is used to fill the difference. 60A is provided. The surface 60a of the support member 60A is provided with a recessed portion 60c that is recessed in the Z-axis direction. The adhesive 61 is filled in the recess 60c, and the support member 60A is fixed to the surface 50b of the flexible printed circuit board 50A by the adhesive 61. The surface 60b of the support member 60A is provided with a recessed portion 60d that is recessed in the Z-axis direction. The adhesive 62 is filled in the recess 60d, and the support member 60A is fixed to the tab 21d of the electrode body 21 by the adhesive 62.

The flexible printed circuit board 50A also has the same effect as the flexible printed circuit board 50.

11, 11A ... power storage module, 16 ... bipolar electrode (first bipolar electrode, second bipolar electrode), 17 ... separator, 21 ... electrode body, 21a ... main surface, 21b ... main surface, 22 ... positive electrode layer (active material layer) ), 23 ... Negative electrode layer (active material layer), 50, 50A ... Flexible printed substrate, 51 ... Base film, 51a ... Surface (one surface), 51b ... Surface, 52 ... Conductive pattern, 52a ... Wiring part (other) Part), 52b ... Fuse part, 53 ... Conductive pattern (another conductive pattern), 53a ... Wiring part (other part), 53b ... Fuse part (another fuse part), 54 ... Cover film, 54a ... Covered area, 55 ... Cover film (another cover film), 55a ... Covering area (another covering area), 59 ... Substrate, 71 ... Heat-resistant member, 72 ... Heat-resistant member (another heat-resistant member), 73 ... Heat-dissipating member (frame) ), 74 ... Heat dissipation member.

Claims (9)

A first bipolar electrode and a second bipolar electrode, each containing two active material layers having different polarities provided on both sides of the electrode body and the electrode body, and laminated along the first direction,
A flexible printed circuit including a conductive pattern electrically connected to the electrode body of the first bipolar electrode, a cover film covering the conductive pattern, and a heat-resistant member provided on the cover film.
With
The conductive pattern has a fuse portion having a smaller cross-sectional area than the other parts of the conductive pattern.
The cover film has a covering area that covers the fuse portion.
The heat-resistant member is located on the covering area and
A power storage module in which the melting point of the heat-resistant member is higher than the melting point of the cover film. The power storage module according to claim 1, wherein the heat-resistant member is composed of a coating agent. Further provided with a heat radiating member provided on the cover film,
The power storage module according to claim 1 or 2, wherein the heat radiating member is arranged around the covering region. The power storage module according to claim 3, wherein the heat radiating member is provided so as to sandwich the covering region. The power storage module according to claim 3, wherein the heat radiating member has a frame-like shape surrounding the covering region. The flexible printed circuit is provided on another conductive pattern electrically connected to the electrode body of the second bipolar electrode, another cover film covering the other conductive pattern, and the other cover film. Including another heat-resistant member,
The other conductive pattern has another fuse section having a smaller cross-sectional area than the other parts of the other conductive pattern.
The other cover film has another covering area that covers the other fuse portion.
The other heat resistant member is located on the other covering area and
The power storage module according to any one of claims 1 to 5, wherein the melting point of the other heat-resistant member is higher than the melting point of the other cover film. The power storage module according to claim 6, wherein the other fuse unit is provided at a position different from that of the fuse unit when viewed from the first direction. A step of preparing a substrate portion including a base film, a conductive pattern formed on one surface of the base film, and a cover film covering the conductive pattern.
The process of forming a heat-resistant member on the cover film and
With
The conductive pattern has a fuse portion having a smaller cross-sectional area than the other parts of the conductive pattern.
The cover film has a covering area that covers the fuse portion.
The melting point of the heat-resistant member is higher than the melting point of the cover film.
In the step of forming the heat-resistant member, a frame is arranged on the cover film so as to surround the covering region, and the space surrounded by the frame is filled with a liquid heat-resistant material that is the source of the heat-resistant member. A method for manufacturing a flexible printed circuit, wherein the heat-resistant member is formed by being formed. The method for manufacturing a flexible printed circuit board according to claim 8, wherein the frame is fixed to the cover film as a heat radiating member.

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