Method for manufacturing bipolar battery

Abstract

To reduce loss of a material forming a resin frame provided at a peripheral edge of a current collector.SOLUTION: A method for manufacturing a bipolar battery according to the present disclosure includes forming a plurality of lower resin frames continuous in a ladder shape along a length direction of a belt-shaped release material, and forming a plurality of bipolar electrodes on the plurality of lower resin frames such that a peripheral edge portion of each bipolar electrode overlaps an inner edge portion of an opening portion of the lower resin frame. The bipolar electrode is disposed, a plurality of upper resin frames continuous in a ladder shape along the length direction of the belt-shaped release material are formed, the upper resin frames are disposed on the bipolar electrode such that the peripheral edge portions of the bipolar electrode disposed on the lower resin frame overlap the upper resin frames, respectively, the lower resin frame and the upper resin frames are joined to each other, and the peripheral edge portions of the bipolar electrode are held.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a bipolar battery. [Background technology]

[0002] A bipolar battery is known that has multiple bipolar electrodes, each with a positive electrode on one side of a current collector and a negative electrode on the other side. A resin frame is attached to the edge of each electrode to seal the gap between adjacent electrodes in the stacking direction. The multiple electrodes are stacked one on top of the other with separators between them to form an electrode unit.

[0003] Patent Document 1 discloses a method for manufacturing an electrode unit for a bipolar battery. In this method, a resin film is unwound from a strip-shaped resin film roll and punched to form through-holes in each continuous region, thereby forming a resin film with a series of multiple rectangular ring-shaped resin frames. While the resin frames are being transported in the form of a resin film, bipolar electrodes are placed on the resin frames, and the overlapping resin frames and bipolar electrode current collectors are joined together. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-145340 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a resin frame is formed by punching through holes in a continuous area of ​​a roll of resin film. The outer width of the resin frame in the width direction of the resin film is about 1 m, while the line width of the resin frame may be about 30 mm. In this case, most of the resin film is wasted, which may lead to increased costs.

[0006] The present disclosure has been made in consideration of these problems, and aims to provide a method for manufacturing a bipolar battery that can reduce the loss of material that forms the resin frame provided on the periphery of the current collector. [Means for solving the problem]

[0007] The method for manufacturing a bipolar battery according to the present disclosure comprises forming a plurality of lower resin frames arranged in a ladder-like manner along the length of a strip-shaped release material, arranging bipolar electrodes on the plurality of lower resin frames so that the peripheral edges of each individual bipolar electrode overlap the inner edge of the opening of the lower resin frame, forming a plurality of upper resin frames arranged in a ladder-like manner along the length of the strip-shaped release material, and arranging upper resin frames on the bipolar electrodes so that the peripheral edges of the bipolar electrodes arranged on the lower resin frames overlap the upper resin frames, and joining the lower resin frames and the upper resin frames to hold the peripheral edges of the bipolar electrodes. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to reduce loss of material that forms the resin frame provided on the periphery of the current collector. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a cross section of a bipolar battery according to an embodiment. [Figure 2] FIG. 1 is a flow diagram illustrating a method for manufacturing a bipolar battery according to an embodiment. [Figure 3] 10A to 10C are diagrams illustrating a molding process of the resin frame. [Figure 4] 10A to 10C are diagrams illustrating a step of disposing a bipolar electrode on a lower sealing material. [Figure 5] 10A and 10B are diagrams showing a process of arranging and joining a lower sealing material and a bipolar electrode, and a process of arranging and joining an upper sealing material. [Figure 6] FIG. 10 is a diagram illustrating a sheet cutting process. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In addition, the same elements in each drawing are designated by the same reference numerals, and duplicate explanations have been omitted as necessary.

[0011] The embodiments relate to a bipolar secondary battery (electricity storage module) mounted as a battery in various vehicles such as hybrid vehicles and electric vehicles. The bipolar battery according to the embodiments is a secondary battery such as a lithium ion secondary battery or a nickel-metal hydride secondary battery. The present disclosure can also be applied to an electricity storage module such as an electric double layer capacitor. In the following description, a lithium ion secondary battery is used as an example.

[0012] FIG. 1 is a cross-sectional view of a bipolar battery according to an embodiment. The bipolar battery 10 includes an electrode stack 20 in which positive and negative electrodes are alternately stacked while being insulated from each other. The electrode stack 20 includes a plurality of bipolar electrodes 1, a plurality of separators 2, and a pair of outermost current collectors 3. The plurality of bipolar electrodes 1 are stacked on top of each other. The electrode stack 20 has a rectangular shape when viewed in the stacking direction of the plurality of bipolar electrodes 1. Separators 2 are disposed between adjacent bipolar electrodes 1.

[0013] Each bipolar electrode 1 has a current collector 11, a positive electrode 12, and a negative electrode 13. The current collector 11 is made of a metal member such as Al foil. The current collector 11 is, for example, rectangular in top view. The positive electrode 12 is provided on one surface of the current collector 11. The positive electrode 12 is formed by coating one surface of the current collector 11 with a positive electrode active material. Examples of the positive electrode active material include lithium-containing metal oxides and lithium-containing phosphates. Examples of lithium-containing metal oxides include Li(NiCoMn)O2 and Li(NiCoAl)O2. Examples of lithium-containing phosphates include LiFePO4. The negative electrode 13 is provided on the other surface of the current collector 11. The negative electrode 13 is formed by coating the other surface of the current collector with a negative electrode active material. Examples of negative electrode active materials include carbon-based negative electrode active materials such as graphite, graphitizable carbon, and non-graphitizable carbon, and alloy-based negative electrode active materials containing silicon (Si), tin (Sn), etc. The region of the current collector 11 where the negative electrode 13 is formed may be slightly larger than the region where the positive electrode 12 is formed. The peripheral portion of the current collector 11 is an uncoated region where the positive electrode active material and the negative electrode active material are not coated. In the uncoated region, the current collector is exposed.

[0014] The separator 2 is disposed between the positive electrode 12 and the negative electrode 13 of the adjacent bipolar electrodes 1. The separator 2 allows ions to pass through while insulating the positive electrode 12 and the negative electrode 13 from direct contact. The separator 2 has a rectangular shape. The separator 2 is formed, for example, in a sheet shape. The separator 2 is formed of a porous film made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP), or a nonwoven or woven fabric made of PE, PP, polyethylene terephthalate (PET), methyl cellulose, or the like. The separator 2 may be smaller than the current collector 11 and larger than the positive electrode 12 and the negative electrode 13 when viewed in the stacking direction.

[0015] A pair of outermost current collectors 3 are disposed on the outsides of the multiple bipolar electrodes 1 in the stacking direction. One of the outermost current collectors 3 has a positive electrode 31 formed thereon. This outermost current collector 3 corresponds to the positive electrode terminal electrode. The positive electrode 31 of the positive electrode terminal electrode faces the negative electrode 13 of the adjacent bipolar electrode 1 via a separator 2. The other outermost current collector, not shown in FIG. 1, has a negative electrode formed thereon. This other outermost current collector corresponds to the negative electrode terminal electrode. The negative electrode of the negative electrode terminal electrode faces the positive electrode 12 of the adjacent bipolar electrode 1 via the separator 2. The peripheral portions of the pair of outermost current collectors 3 are uncoated regions where no positive electrode active material or negative electrode active material is applied. The current collectors are exposed in the uncoated regions.

[0016] A pair of adjacent current collectors 11, and the positive electrode 12, separator 2, and negative electrode 13 arranged between the pair of current collectors 11, form one cell. That is, the electrode stack 20 includes a plurality of cells stacked on top of each other. Of the plurality of cells, the outer current collector of the outermost cell becomes the outermost current collector 3. That is, in the bipolar battery 10, each bipolar electrode 1 serves as both the positive electrode and the negative electrode of the adjacent cells, and the plurality of cells are connected in series.

[0017] An external current collector 5 may be provided on the outside of each of the pair of outermost current collectors 3 via a conductive adhesive. A positive electrode terminal is connected to one of the external current collectors 5. A negative electrode terminal is connected to the other external current collector (not shown). A bipolar battery has a structure in which current is extracted from the electrode stack via the external current collectors via the positive electrode terminal and the negative electrode terminal. The external current collector 5 is, for example, a metal sheet. As the external current collector 5, for example, a conductive metal such as stainless steel, iron, copper, aluminum, titanium, or nickel is used. The material of the external current collector 5 is not particularly limited, and a metal can be appropriately used depending on the purpose.

[0018] The bipolar battery 10 includes a cylindrical sealing member 4 that extends in the stacking direction of the bipolar electrodes 1 and houses the electrode stack 20. The sealing member 4 restricts the movement of gas and electrolyte between the cells, thereby ensuring insulation between adjacent cells.

[0019] The sealing member 4 is made of a resin material such as polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). The sealing member 4 holds the ends of the bipolar electrode 1, separator 2, and outermost current collector 3. The uncoated region of the bipolar electrode 1, where the current collector is exposed, is embedded and held in the sealing member 4. That is, the sealing member 4 is configured to surround the electrode stack 20. When viewed from the stacking direction side of the bipolar electrode 1, the sealing member 4 has, for example, a rectangular shape. That is, the sealing member 4 has, for example, a square cylindrical shape.

[0020] The sealing member 4 includes three resin frames. These three resin frames are a lower sealing material 41, an upper sealing material 42, and a spacer 43. The sealing member 4 has a layered structure in which the lower sealing material 41, the upper sealing material 42, and the spacer 43 are repeatedly layered in this order. The lower sealing material 41 and the upper sealing material 42 each have a rectangular ring shape. The spacer 43 has a rectangular ring shape with a portion missing that corresponds to a liquid injection port (described later). The sealing member 4 is formed by joining adjacent resin frames in the layering direction.

[0021] The lower sealing material 41 is provided below the peripheral edge of the current collector 11 of the bipolar electrode 1, over the entire periphery of the current collector 11. The lower sealing material 41 is bonded to the current collector 11 of the bipolar electrode 1. The upper sealing material 42 is provided above the peripheral edge of the current collector 11 of the bipolar electrode 1, over the entire periphery of the current collector 11. The upper sealing material 42 is bonded to the peripheral edge of the current collector 11 of the bipolar electrode 1. The lower sealing material 41 and the upper sealing material 42 are also bonded together. The peripheral edge of the current collector 11 of the bipolar electrode 1 is sandwiched between the lower sealing material 41 and the upper sealing material 42, thereby holding the peripheral edge.

[0022] The separator 2 is placed on the upper sealant 42. The peripheral edge of the separator 2 is bonded to the upper sealant 42. The spacer 43 is provided above the peripheral edge of the separator 2, around the entire periphery of the peripheral edge. The spacer 43 is bonded to the peripheral edge of the separator 2. The upper sealant 42 and the spacer 43 are also bonded together. The peripheral edge of the separator 2 is held in place by sandwiching it between the upper sealant 42 and the spacer 43. In this embodiment, the current collector 11 of the bipolar electrode 1 and the separator 2 are bonded to the resin frame by thermal welding using a laser. The bipolar electrode 1, separator 2, lower sealant 41, upper sealant 42, and spacer 43 constitute an electrode unit.

[0023] By stacking multiple bipolar electrodes 1 and a pair of outermost current collectors 3 using a lower sealing material 41, an upper sealing material 42, and a spacer 43, the peripheral edge of each current collector is held in a state of being embedded in the sealing material 4. As a result, an internal space is formed between adjacent current collectors 11 in the stacking direction, which is partitioned airtight and watertight by the current collectors 11 and the sealing material 4. An electrolyte solution containing lithium ions as carrier ions is accommodated in the internal space. For example, the electrolyte solution can be a carbonate-based solvent in which a lithium salt is dissolved at a predetermined concentration. Examples of carbonate-based solvents include fluoroethylene carbonate (FEC) and ethylene carbonate (EC). Examples of lithium salts include hexafluorophosphate. The spacer 43 is provided with a liquid injection port (not shown). The liquid injection port is used to inject the electrolyte solution into the internal space formed between adjacent current collectors 11. The liquid injection port can also be used as a communication port for a pressure adjustment valve that opens and closes depending on the internal pressure in the sealing member 4. A pressure adjustment unit may be provided in the communication port. The pressure adjustment unit may assist or complement the function of the communication port as a pressure adjustment valve.

[0024] Next, a method for manufacturing a bipolar battery will be described. FIG. 2 is a flow diagram illustrating a method for manufacturing a bipolar battery according to an embodiment. As shown in FIG. 1, first, an electrode forming step (S101) is performed to prepare a bipolar electrode 1. The bipolar electrode 1 is obtained, for example, from a roll of a strip-shaped current collector sheet (current collector sheet roll). The current collector sheet has a positive electrode 12 and a negative electrode 13 intermittently coated in areas corresponding to the individual bipolar electrodes 1. The current collector sheet is unwound and cut at predetermined positions to obtain the individual bipolar electrodes 1.

[0025] Meanwhile, in parallel with the molding process of the bipolar electrode 1, a molding process of the lower seal material 41 is carried out (S201). FIG. 3 is a diagram illustrating the molding process of the resin frame. FIG. 3 shows a schematic configuration of a coating device 200. The coating device 200 can be used when forming the resin frames that will become the lower seal material 41, the upper seal material 42, and the spacer 43.

[0026] The coating device 200 includes a melting station (not shown) that stores molten resin material. The molten resin material is supplied to a first coating unit 201. The first coating unit 201 coats the resin material onto a first roll 202 made of metal, for example, so as to form two continuous parallel straight portions 101 at a predetermined interval in the width direction of the first roll 202. The coating device 200 may include a pump that adjusts the amount of resin material to be coated. The resin material is introduced between the first roll 202 and the second roll 203 and is transported following the contour of the circumferential surface of the second roll 203. The first roll 202 and the second roll 203 sandwich the resin material and cool it to form a film-like resin.

[0027] The resin material is then introduced between the second roll 203 and the third roll 204 and transported to the second coating unit 205. The molten resin material is supplied to the second coating unit 205. The second coating unit 205 intermittently coats the resin material onto the third roll 204, which is made of metal, for example. This allows the second coating unit 205 to form a plurality of connecting portions 102, which connect the two linear portions 101 formed by the first coating unit 201, at predetermined intervals in the transport direction. In other words, the resin material is formed into a ladder-like shape with a plurality of continuous resin frames 100.

[0028] The continuous resin frame 100 is transported to a fourth roll 206, where it is cooled and formed into a film-like resin. The fourth roll 206 aligns the transport direction of the continuous resin frame 100 with the unwinding direction of a release film 103, which is a strip-shaped release material wound into a roll. The continuous resin frame 100 is placed, for example, on top of the unwound portion of the release film 103. Note that instead of the release film 103, for example, a stainless steel belt conveyor may be used.

[0029] The continuous resin frame 100 is then trimmed to remove unnecessary portions, such as excess portions, so as to obtain the desired ladder-shaped continuous resin frame 100. This forms an opening 104 of the desired size in the resin frame 100. A known cutout die, such as a Thomson die, can be used for the trimming process. By processing the edges of the resin frame 100 in this manner, the outer width of the resin frame 100, the width and height of the inner peripheral portion of the resin frame 100, and the line widths of the linear portions 101 and connecting portions 102 can be adjusted to the desired sizes. Here, the width refers to the length of the resin frame 100 in a direction perpendicular to the conveyance direction, and the height refers to the length of the resin frame 100 along the conveyance direction. Here, the length direction of the release film 103 on which the continuous resin frame 100 is formed is defined as the long side, and the width direction is defined as the short side.

[0030] Next, an electrode placement and welding process (S102) is performed in which individual bipolar electrodes 1 are placed on and welded to the lower sealing material 41. FIG. 4 is a diagram illustrating the process of placing the bipolar electrodes 1 on the lower sealing material 41. FIG. 5 is a diagram illustrating the process of placing and bonding the lower sealing material 41 and bipolar electrodes 1 (left side) and the process of placing and bonding the upper sealing material 42 (right side). The resin frames 100 that become the lower sealing material 41 and the upper sealing material 42 have the same configuration. In FIG. 5, the lower resin frame 100 that becomes the lower sealing material 41 is referred to as a lower resin frame 100L, and the upper resin frame 100 that becomes the upper sealing material 42 is referred to as an upper resin frame 100U.

[0031] 4 and 5, while a continuous series of lower resin frames 100L is being transported, a bipolar electrode 1 is placed on each resin frame 100 (lower sealing material 41). In Fig. 4, the location on the lower resin frame 100L where the bipolar electrode 1 is to be placed is indicated by a dashed line.

[0032] The dimensions of the current collector 11 of the bipolar electrode 1 are designed to be smaller than the outer shape of each lower resin frame 100L and larger than the dimensions of the openings 104. Therefore, the peripheral edge of the current collector 11 overlaps the inner edge of the openings 104 of the lower resin frame 100L. Although not shown here, the positive electrode 12 and negative electrode 13 of the bipolar electrode 1 are designed to be smaller than the dimensions of the openings 104. The positive electrode 12 and negative electrode 13 are located inside the openings 104 with the current collector 11 and lower resin frame 100L overlapping.

[0033] The bipolar electrode 1 can be positioned relative to the lower resin frame 100L by, for example, photographing the lower resin frame 100L with an imaging device, detecting the edges of the lower resin frame 100L using known image recognition technology, and adjusting the position of the bipolar electrode 1 to fit the edges. As described above, the lower resin frame 100L is trimmed into a ladder shape, allowing the edges to be accurately detected, improving the positioning accuracy of the bipolar electrode 1. The bipolar electrode 1 is accurately set on the lower resin frame 100L using, for example, a robot.

[0034] Then, while the lower resin frame 100L is being transported, the lower resin frame 100L (lower sealing material 41) and the current collector 11 of the bipolar electrode 1 are bonded together. As shown on the left side of FIG. 5 , for example, by irradiating a laser along a short side in the width direction of the lower resin frame 100L, the short side and the current collector 11 can be welded together. Then, by irradiating a laser along a long side of the lower resin frame 100L, the long side and the current collector 11 can be welded together. In this way, the lower resin frame 100L and the current collector 11 of the bipolar electrode 1 are bonded together along the entire periphery of the current collector 11. Note that the resin frame 100L and the current collector 11 can be bonded together by, for example, heat welding using a known heat roller or heat sealer, or ultrasonic welding.

[0035] Further, a molding step of the upper sealing material 42 is carried out (S202). The upper sealing material 42 has the same configuration as the lower sealing material 41, and can be molded by the method described above with reference to Fig. 3. The plurality of upper sealing materials 42 are formed as a continuous resin frame 100 on the release film 103.

[0036] Next, an upper sealant placement and welding step (S103) is performed in which an upper sealant 42 is placed on and welded to the lower sealant 41 to which the bipolar electrode 1 has been joined. As shown on the right side of FIG. 5, a continuous upper resin frame 100U that will become the upper sealant 42 is transported in the same direction as the lower resin frame 100L. In this manner, the upper sealant 42 is positioned relative to the bipolar electrode 1 while the lower resin frame 100L and the upper resin frame 100U are being transported in the same direction.

[0037] The upper sealant 42 can be positioned relative to the bipolar electrode 1 by, for example, photographing the lower sealant 41 and the bipolar electrode 1 with an imaging device, detecting the edges using a known image recognition technique, and adjusting the transport speed of the upper resin frame 100U that will become the upper sealant 42. The dimensions of the current collector 11 of the bipolar electrode 1 are designed to be smaller than the outer shape of each upper resin frame 100U and larger than the dimensions of the opening 104. Therefore, the peripheral edge of the current collector 11 overlaps the inner edge of the opening 104 of the upper resin frame 100U. Furthermore, the positive electrode 12 and the negative electrode 13 are positioned inside the opening 104 with the current collector 11 and the upper resin frame 100U overlapping.

[0038] Then, while the lower resin frame 100L and the upper resin frame 100U are being transported in the same direction, the release film 103 of the upper resin frame 100U is peeled off, and then the upper resin frame 100U (upper sealant 42), the current collector 11 of the bipolar electrode 1, and the lower resin frame 100L (lower sealant 41) are bonded together. As shown on the right side of FIG. 5 , for example, by irradiating a laser along the long sides of the upper resin frame 100U, the long sides and the current collector 11 can be welded together. Then, by irradiating a laser along the short sides of the upper resin frame 100U in the width direction, the short sides and the current collector 11 can be welded together. As a result, the upper resin frame 100U and the current collector 11 of the bipolar electrode 1 are bonded together around the entire periphery of the current collector 11.

[0039] The release film 103 on the lower resin frame 100L may be peeled off when the lower resin frame 100L and the bipolar electrode 1 are joined together, or when the lower resin frame 100L and the upper resin frame 100U are each joined to the bipolar electrode 1. There is no particular limitation on the timing at which the release film 103 is peeled off.

[0040] Next, a separator placement and welding step (S104) is performed in which separator 2 is placed on and welded to upper sealing material 42. Separators 2 are obtained, for example, by cutting a roll of separator sheet into areas corresponding to individual separators 2. In this embodiment, the dimensions of separator 2 are smaller than the outer shape of resin frame 100 and larger than the dimensions of opening 104. Separator 2 is placed so as to close opening 104, and the area where separator 2 overlaps with upper resin frame 100U is welded. In this way, separator 2 is fixed to upper resin frame 100U.

[0041] Next, a molding step of the spacer 43 is performed (S203). The spacer 43 has substantially the same configuration as the lower sealing material 41 and the upper sealing material 42, and can be molded by the method described above with reference to FIG. 3. The resin frame 100 that will become the spacer 43 has a notch that serves as a liquid injection port. That is, the resin frame 100 that will become the spacer 43 has a portion of the ladder-shaped resin material cut away. The notch that serves as the liquid injection port can be formed, for example, by trimming the connection portion 102 after the continuous resin frame 100 is formed. The notch penetrates the resin frame, for example, when the electrode unit is cut into individual pieces. The liquid injection port is a portion where the upper sealing material 42 and the lower sealing material 41 that are adjacent in the stacking direction are not partially joined.

[0042] Then, a spacer placement and welding step (S105) is performed in which a spacer 43 is placed on and welded to the separator 2. As a result, an electrode unit consisting of the bipolar electrode 1, separator 2, lower seal material 41, upper seal material 42, and spacer 43 is continuously formed.

[0043] Next, a sheet cutting step (S106) is performed in which the resin frame 100 is cut into individual electrode units. FIG. 6 is a diagram illustrating the sheet cutting step. For the sake of explanation, FIG. 6 shows a state in which the bipolar electrode 1 is placed on the lower resin frame 100L. Since the upper resin frame 100U is placed in approximately the same position as the lower resin frame 100L, the position of the resin material of the upper resin frame 100U is approximately the same as that of the lower resin frame 100L.

[0044] As shown in FIG. 6, a predetermined gap G is formed on the connection portion 102 between the bipolar electrodes 1 on adjacent lower resin frames 100L. No bipolar electrodes 1 are arranged in this gap G; only resin material is arranged therein. Individual electrode units are obtained by cutting the resin frame 100 in a direction perpendicular to the extension direction of the resin frame 100. A known cutter such as a shear cutter or a rotary cutter can be used to cut the resin frame 100.

[0045] Then, a lamination step (S107) is performed in which the cut electrode units are laminated, thereby obtaining an electrode laminate 20 having a liquid injection port formed therein. Finally, a terminal joining step (S108) is performed in which a positive electrode terminal and a negative electrode terminal are connected via an external current collector 5, thereby obtaining a bipolar battery 10.

[0046] As described above, according to the embodiment, by forming a continuous resin frame by applying a ladder-like resin material onto a strip-shaped release material, it is possible to reduce the loss of material used to form the resin frame provided around the periphery of the current collector. Furthermore, while multiple continuous lower resin frames 100L are being transported, bipolar electrodes 1 can be stacked and bonded one after another. Furthermore, while the lower resin frame 100L and the upper resin frame 100U are being transported in the same direction, the upper resin frame 100U can be placed on the bipolar electrode 1 placed on the lower resin frame 100L. This allows the process of arranging and bonding the bipolar electrode on the lower resin frame (S102) and the process of arranging and bonding the upper resin frame on the bipolar electrode (S103) to be performed consecutively. This allows the lower resin frame and the upper resin frame to be efficiently arranged on both sides of the bipolar electrode.

[0047] Furthermore, by arranging a spacer made of a plurality of continuous resin frames each having a notch on the upper resin frame, the process of processing the liquid injection port can be eliminated, thereby shortening the manufacturing time of the electrode unit. Furthermore, in the embodiment, the supply of the bipolar electrode 1 onto the lower sealing material 41, and the supply of the upper sealing material 42 and the spacer 43 can be automated, thereby shortening the manufacturing time of the electrode unit and improving efficiency.

[0048] In a comparative example in which resin frames are formed by joining strips of resin material, resin overflow from the overlapping portions of the resin material interferes with the positive and negative electrode active materials. This necessitates the reduction of the positive and negative electrode active materials, resulting in a decrease in energy density. Furthermore, variations in the thickness of the overlapping portions and the length of the overflowing portions increase the number of defects, necessitating processes such as crushing the overlapping portions of the resin-increasing material and measuring the thickness, which increases the manufacturing process. Furthermore, when resin materials are butted together without overlapping, gaps form between the resin materials, resulting in leakage.

[0049] In contrast, according to the embodiment, the sealing member 4 is formed by laminating seamless frame-shaped lower sealing material 41, upper sealing material 42, and spacer 43, so that no resin material protrudes and it is possible to suppress a decrease in the energy density of the bipolar battery 10. In addition, since the process of crushing overlapping portions of the resin material is eliminated, it is possible to reduce costs. Furthermore, quality defects such as leaks are less likely to occur, and the defect rate of the bipolar battery 10 can be reduced.

[0050] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0051] 1 bipolar electrode 2 Separator 3 Outermost current collector 4 Sealing member 5 External current collector 10 Bipolar Battery 11 Current collector 12 Positive electrode 13 Negative electrode 20 Electrode laminate 31 Positive electrode 41 Lower seal material 42 Upper seal material 43 Spacer 100 Resin Frame 100L Lower Resin Frame 100U upper resin frame 101 Straight section 102 Connection 103 Release film 104 Opening 200 Coating device 201 Coating Department 1 202 Roll 1 203 Roll 2 204 Third Roll 205 2nd Coating Department 206 4th Roll

Claims

1. forming a plurality of lower resin frames in a ladder-like manner along the length of the strip-shaped release material; bipolar electrodes are arranged on the plurality of lower resin frames such that the peripheral edge of each individual bipolar electrode overlaps the inner edge of the opening of the lower resin frame; forming a plurality of upper resin frames in a ladder shape along the length direction of the strip-shaped release material; the upper resin frame is disposed on the bipolar electrodes such that peripheral portions of the bipolar electrodes disposed on the lower resin frame overlap the upper resin frame; the lower resin frame and the upper resin frame are joined together to hold the peripheral edge of the bipolar electrode; How to manufacture a bipolar battery.

2. The lower resin frame and the upper resin frame are two continuous parallel straight line portions are formed at a predetermined interval in the width direction of the release material, a plurality of connecting portions connecting the two linear portions are formed by intermittent coating at predetermined intervals in the conveying direction, thereby forming a ladder-like shape; A method for manufacturing the bipolar battery according to claim 1.

3. the upper resin frame is placed on the bipolar electrode placed on the lower resin frame while the lower resin frame and the upper resin frame are being transported in the same direction; A method for manufacturing the bipolar battery according to claim 1.

4. At least one of the positioning of the bipolar electrode relative to the lower resin frame and the positioning of the upper resin frame relative to the bipolar electrode is performed using an image recognition technology. A method for manufacturing the bipolar battery according to claim 1.

5. By applying a resin material, a spacer consisting of a plurality of resin frames arranged in a ladder shape along the length direction of the strip-shaped release material is formed; A notch portion penetrating the resin frame is formed by performing a trimming process on the spacer; bonding the spacer onto the upper resin frame; A method for manufacturing the bipolar battery according to claim 1.

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