JP2019129070A - Manufacturing method of bipolar battery and the bipolar battery - Google Patents

Abstract

To provide a manufacturing method of a bipolar battery, capable of reducing a manufacturing time of a resin frame having a communication port.SOLUTION: A manufacturing method of a bipolar battery, includes: a resin frame manufacturing step of manufacturing a primary seal 22 having a communication port 26; a unit manufacturing step of jointing the primary seal 22 to a peripheral edge part 17c of a nickel foil 17, and manufacturing an electrode unit 38 formed by a bipolar electrode 13 and the primary seal 22; and a lamination step of laminating a plurality of electrode units 38 so that the plurality of bipolar electrodes 13 is laminated through a separator 14. The resin frame manufacturing step includes: a first resin part formation step of forming a first resin part 24 of an U-shaped single layer structure; and a second resin part jointing step of jointing a second resin part 25 of a strip-like second layer structure having a step part 27 constructing the communication port 26 to both end parts of the first resin part 24.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method of manufacturing a bipolar battery and a bipolar battery.

  As a method of manufacturing a bipolar battery, for example, the technology described in Patent Document 1 is known. In the method for manufacturing a bipolar battery described in Patent Document 1, the current collector, the positive electrode layer, the electrolyte layer, and the negative electrode layer are stacked so that the electrolyte layer has a single battery sandwiched between the positive electrode layer and the negative electrode layer. And the resin-made sealing layer is arrange | positioned between the adjacent electrical power collectors so that the circumference | surroundings of the cell may be surrounded and it may protrude outside the electrical power collector. The current collector and the seal layer located on both sides of the seal layer are bonded to each other by heat and pressure, and the adjacent seal layers are bonded to each other by heat and pressure.

JP, 2005-190713, A

  By the way, in order to inject the electrolyte into the bipolar battery, it is necessary to provide a communication port for injecting the resin in the resin frame (corresponding to the above-described conventional sealing layer). However, after forming the resin frame, for example, when a step is formed on the resin frame to form the communication port, a considerable time is required.

  An object of the present invention is to provide a bipolar battery manufacturing method and a bipolar battery capable of shortening the manufacturing time of a resin frame having a communication port.

  According to one embodiment of the present invention, a plurality of bipolar electrodes having a positive electrode formed on one surface of a current collector and a negative electrode formed on the other surface of the current collector, and a peripheral portion of the current collector of the plurality of bipolar electrodes And a resin frame manufacturing step of manufacturing a resin frame having a communication port in a method of manufacturing a bipolar battery including a plurality of resin frames bonded to each other and having a communication port. And a unit manufacturing step of manufacturing an electrode unit comprising the bipolar electrode and the resin frame by bonding a resin frame to the peripheral portion of the current collector, and an electrode unit so that a plurality of bipolar electrodes are stacked via a separator. And a sealing step of sealing the communication port after the liquid injection step of injecting the electrolytic solution into the space inside the resin frame from the communication port, and the liquid injection step. The manufacturing process includes a first resin portion forming step of forming a first resin portion of a U-shaped single layer structure, and a second resin portion of a strip-shaped multi-layer structure having a step portion forming a communication port. And a second resin part bonding step for bonding to both ends of the resin part.

  In the manufacturing method of such a bipolar battery, after forming the first resin portion of the U-shaped single layer structure, the second resin portion of the strip-shaped multi-layer structure having the step portion constituting the communication port is (1) A resin frame is manufactured by bonding to both ends of the resin portion. At this time, since the second resin portion having the step portion constituting the communication port has a multi-layer structure, for example, the step portion is formed as compared with the case where the step processing is performed on the resin frame having a single layer structure. Easy to do. Thereby, the preparation time of the resin frame which has a communicating port is shortened.

  In the second resin portion bonding step, a strip-shaped first resin film and a second resin film and a third resin film having a shorter length than the first resin film are prepared, and the second resin is formed on the first resin film. The second resin portion having the stepped portion may be formed by overlapping the film and the third resin film at intervals. In this case, since the step portion is obtained by overlapping the second resin film and the third resin film on the first resin film, the step portion can be formed more easily.

  In the second resin part bonding step, after preparing a plurality of first resin films, the first resin film may be cut to form the second resin film and the third resin film. In this case, the second resin film and the third resin film can be easily made from the first resin film.

  In the first resin portion forming step, the U-shaped first resin portion may be formed by punching out the resin film in a U-shape. In this case, the U-shaped first resin portion can be easily formed in a short time.

  In the first resin portion forming step, the resin film is formed into a U shape so that the U-shaped punched-out portions are opposite in one side and the other side in the width direction of the resin film and shifted in the longitudinal direction of the resin film. You may punch it out. In this case, since the unused area of the resin film is reduced, it is possible to suppress the waste of the resin film.

  Another aspect of the present invention includes a plurality of bipolar electrodes having a positive electrode formed on one surface of a current collector and a negative electrode formed on the other surface of the current collector, and a peripheral edge of the current collector of the plurality of bipolar electrodes And a plurality of resin frames each having a communication port, wherein the resin frame is a U-shaped single-layer first resin portion. And a second resin part having a strip-like multi-layer structure which is joined to both ends of the first resin part and has a stepped part constituting a communication port.

  When manufacturing such a bipolar battery, the manufacturing method of the bipolar battery mentioned above is implemented. Thereby, the preparation time of the resin frame which has a communicating port is shortened.

  According to the present invention, the production time of a resin frame having a communication port can be shortened.

FIG. 1 is a schematic cross-sectional view showing a power storage device provided with a bipolar battery according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a bipolar battery. FIG. 3 is a schematic perspective view of a bipolar battery. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a flow chart showing the procedure of the process of manufacturing the bipolar battery. FIG. 6 is a perspective view of the primary seal. Fig.7 (a) is a top view which shows a mode that the 1st resin part of a U-shaped single layer structure is formed, FIG.7 (b) comprises the 2nd resin part of a strip-shaped two-layer structure. It is a top view which shows a mode that the strip-shaped resin film to form is formed. FIG. 8 is a plan view of the electrode unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a power storage device provided with a bipolar battery according to an embodiment of the present invention. In FIG. 1, power storage device 1 is used as a battery of a vehicle such as, for example, a forklift, a hybrid car, and an electric car. The storage device 1 includes a bipolar battery 2 as a plurality (three in this case) of storage modules. The bipolar battery 2 is, for example, a nickel hydrogen secondary battery.

  The plurality of bipolar batteries 2 are stacked via a metal conductive plate 3. The conductive plate 3 is also disposed outside the bipolar battery 2 located at both ends in the stacking direction (Z-axis direction). The bipolar battery 2 and the conductive plate 3 have, for example, a rectangular shape (a rectangular shape in a plan view) when viewed in the stacking direction. The conductive plate 3 is electrically connected to the adjacent bipolar battery 2. Thereby, the some bipolar battery 2 is connected in series in the lamination direction. The bipolar battery 2 will be described in detail later.

  The positive electrode terminal 4 is connected to the conductive plate 3 positioned at one end (here, the lower end) in the stacking direction. The negative electrode terminal 5 is connected to the conductive plate 3 positioned at the other end (here, the upper end here) in the stacking direction. The positive electrode terminal 4 and the negative electrode terminal 5 extend in a direction (X-axis direction) perpendicular to the stacking direction. By providing such a positive electrode terminal 4 and a negative electrode terminal 5, charging and discharging of the storage device 1 can be performed.

  The conductive plate 3 can also function as a heat sink for releasing the heat generated in the bipolar battery 2. The conductive plate 3 is provided with a plurality of air gaps 3 a extending in a direction (Y-axis direction) perpendicular to the stacking direction of the bipolar battery 2 and the extending direction of the positive electrode terminal 4 and the negative electrode terminal 5. By passing a refrigerant such as air through these gaps 3a, the heat from the bipolar battery 2 can be efficiently released to the outside.

  The storage device 1 further includes a restraint unit 6 for restraining the bipolar battery 2 and the conductive plate 3 in the stacking direction. The restraint unit 6 includes a pair of restraint plates 7 that sandwich the bipolar battery 2 and the conductive plate 3 in the stacking direction, and a plurality of sets of bolts 8 and nuts 9 that fasten the restraint plates 7 together.

  The restraint plate 7 is made of a metal such as iron. Insulating films 10 such as resin films are respectively disposed between the restraint plates 7 and the conductive plate 3. The constraining plate 7 and the insulating film 10 have, for example, a rectangular shape in plan view. The restraint plate 7 is larger than the bipolar battery 2, the conductive plate 3, and the insulating film 10 when viewed from the stacking direction, and covers the conductive plate 3 and the insulating film 10.

  At the edge portion of the restraint plate 7, a plurality of insertion holes 7 a for inserting the shaft portion 8 a of the bolt 8 are provided. With the shaft portion 8a of the bolt 8 inserted through the insertion hole 7a of each constraining plate 7, the nut 9 is screwed into the tip portion of the shaft portion 8a, so that the bipolar battery 2, the conductive plate 3, and the insulating film 10 are 1 It is sandwiched between a pair of restraint plates 7. Thereby, the restraint load in the stacking direction is applied to the bipolar battery 2, the conductive plate 3 and the insulating film 10.

  FIG. 2 is a schematic sectional view of the bipolar battery 2. FIG. 3 is a schematic perspective view of the bipolar battery 2. In FIGS. 2 and 3, the bipolar battery 2 has a structure (multi-cell structure) in which a plurality of cells (for example, 24 cells) are stacked. The bipolar battery 2 includes a battery main body 11 and a plurality (four in this case) of safety valves 12 attached to one side surface of the battery main body 11.

  The battery body 11 includes an electrode stack 15 in which a plurality of bipolar electrodes 13 are stacked via separators 14, and a frame 16 that surrounds the electrode stack 15.

  The bipolar electrode 13 and the separator 14 have, for example, a rectangular shape in plan view. The separator 14 is disposed between the bipolar electrodes 13 adjacent in the stacking direction. The bipolar electrode 13 includes a nickel foil 17 as a current collector, a positive electrode 18 formed on the upper surface 17 a (one surface) of the nickel foil 17, and a negative electrode 19 formed on the lower surface 17 b (the other surface) of the nickel foil 17. And.

  The positive electrode 18 of the bipolar electrode 13 is opposed to the negative electrode 19 of one bipolar electrode 13 adjacent in the stacking direction with the separator 14 interposed therebetween. The negative electrode 19 of the bipolar electrode 13 faces the positive electrode 18 of the other bipolar electrode 13 adjacent in the stacking direction with the separator 14 interposed therebetween.

  In the lowermost layer of the electrode stack 15, the positive electrode side termination electrode 20 is disposed. The positive electrode-side termination electrode 20 has a nickel foil 17 and a positive electrode 18 formed on the upper surface 17 a of the nickel foil 17. In the uppermost layer of the electrode laminate 15, the negative electrode side termination electrode 21 is disposed. The negative electrode side termination electrode 21 has a nickel foil 17 and a negative electrode 19 formed on the lower surface 17 b of the nickel foil 17. The positive electrode 18 of the positive electrode side termination electrode 20 is opposed to the negative electrode 19 of the lowermost bipolar electrode 13 with the separator 14 interposed therebetween. The negative electrode 19 of the negative electrode-side termination electrode 21 faces the positive electrode 18 of the uppermost bipolar electrode 13 with the separator 14 in between. The nickel foils 17 of the positive electrode side termination electrode 20 and the negative electrode side termination electrode 21 are connected to the conductive plate 3 (see FIG. 1) adjacent in the stacking direction.

  The positive electrode 18 is formed by applying a positive electrode active material to one surface of the nickel foil 17. As the positive electrode active material, for example, nickel hydroxide coated with cobalt (Co) oxide is used. The negative electrode 19 is formed by applying the negative electrode active material to the other surface of the nickel foil 17. As the negative electrode active material, for example, a hydrogen storage alloy is used. The peripheral portion 17 c of the nickel foil 17 is an uncoated region to which the positive electrode active material and the negative electrode active material are not applied.

  The separator 14 is disposed between the positive electrode 18 and the negative electrode 19 and isolates the positive electrode 18 and the negative electrode 19. The separator 14 is smaller than the nickel foil 17 and larger than the positive electrode 18 and the negative electrode 19 when viewed in the stacking direction. The separator 14 is formed in a sheet shape, for example. The separator 14 is formed of a porous film made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP), or a nonwoven fabric or woven cloth made of PE, PP, polyethylene terephthalate (PET), methylcellulose, or the like. The separator 14 may be reinforced with a vinylidene fluoride resin compound or the like.

  The frame body 16 is disposed so as to surround the electrode laminate 15, and a plurality of primary seals 22 that respectively hold the peripheral edge portions 17 c of the nickel foils 17, and secondary seals 23 that are disposed around these primary seals 22. And.

  Each primary seal 22 is disposed for each nickel foil 17 along the stacking direction. The primary seal 22 has a frame shape. The primary seal 22 is joined to the peripheral portion 17 c of the nickel foil 17 by thermal welding. Further, the primary seals 22 adjacent to each other in the stacking direction are also joined by heat welding.

  An internal space V defined by the nickel foil 17, the positive electrode 18, the negative electrode 19, and the primary seal 22 is provided between the nickel foils 17 adjacent in the stacking direction. An alkaline electrolyte is injected into the internal space V including the inside of the separator 14. As the alkaline electrolyte, an alkaline solution containing, for example, an aqueous potassium hydroxide solution is used. The primary seal 22 seals the internal space V.

  One cell in the bipolar battery 2 includes two nickel foils 17, a positive electrode 18, a negative electrode 19, a separator 14, and a primary seal 22. The cell has an internal space V.

  The secondary seal 23 has a rectangular tube shape. The secondary seal 23 surrounds each primary seal 22 and further seals the internal space V.

  The primary seal 22 and the secondary seal 23 are formed of, for example, a resin such as polypropylene (PP), polyphenylene sulfide (PPS) or modified polyphenylene ether (modified PPE). The primary seal 22 constitutes a resin frame.

  4 is a cross-sectional view taken along line IV-IV in FIG. In FIGS. 2 to 4, the primary seal 22 has a U-shaped single-layer first resin portion 24 and a strip-like two-layer structure joined to both ends of the first resin portion 24 by heat welding. And a second resin portion 25 (see also FIG. 6). The second resin portion 25 is provided with a step portion 27 that constitutes the communication port 26.

  The second resin portion 25 is provided with a plurality of (here, four) safety valve attachment areas 28 to which the safety valve 12 is attached. Each safety valve attachment area 28 is provided with a plurality of (here, six) communication ports 26 respectively. These communication ports 26 communicate with the internal spaces V of different cells. The arrangement position of the communication port 26 is different for each cell. In the region corresponding to each safety valve attachment region 28 in the secondary seal 23, an opening is provided. The communication port 26 functions as a liquid injection port for injecting the electrolytic solution into the internal space V, and also functions as a connection port for the safety valve 12 after the electrolytic solution is injected. When the pressure in the internal space V becomes equal to or higher than a predetermined pressure, the gas in the internal space V is released to the outside of the bipolar battery 2 by opening the safety valve 12.

  FIG. 5 is a flowchart showing the procedure of the process of manufacturing the bipolar battery 2 as described above. In FIG. 5, first, a plurality of the bipolar electrodes 13 are produced (step S101). In the step S101, in addition to the bipolar electrode 13, the above-described positive electrode side termination electrode 20 and the negative electrode side termination electrode 21 are also produced.

  Also, a plurality of the above primary seals 22 are manufactured (step S102). As shown in FIG. 6, the primary seal 22 is joined to the first resin portion 24 having a U-shaped single-layer structure and both ends of the first resin portion 24, and a stepped portion 27 constituting the communication port 26. And a second resin portion 25 having a strip-like two-layer structure. In FIG. 6, the primary seal 22 is shown in a simplified manner. Step S102 is a resin frame manufacturing step.

  In step S102, a step (a first resin portion forming step) of forming a first resin portion 24 having a U-shaped single-layer structure is first carried out, and thereafter a strip shape having a step 27 forming the communication port 26 is formed. A step (a second resin portion bonding step) of bonding the second resin portion 25 having a two-layer structure to both end portions of the first resin portion 24 is performed.

  In the first resin portion forming step, as shown in FIG. 7A, the resin film 30 unrolled from the roll 29 is subjected to a punching process so that the resin film 30 is punched into a U shape. A sheet (here, 5 sheets) of U-shaped resin films 31 are formed in a lump. The resin film 31 constitutes the first resin portion 24 having a U-shaped single layer structure. The thickness of the resin film 30 is, for example, about 0.1 mm to 0.2 mm.

  At this time, the U-shaped punched-out portions 32 in the opposite direction on one side and the other side in the width direction (H direction) of the resin film 30 are shifted in the longitudinal direction (N direction) of the resin film 30. The film 30 is punched into a U shape. Specifically, one end side portion 32a of the punching portion 32 faces the one end side portion 32a and the other end side portion 32b of the punching portion 32 in the opposite direction, and the other end side portion 32b of the punching portion 32 is adjacent The resin film 30 is punched in a U shape so as to face the one end side portion 32a and the other end side portion 32b of the punched portion 32 in the opposite direction.

  In the second resin part joining step, as shown in FIG. 7B, first, the resin film 34 unwound from the roll 33 is punched to punch out the resin film 34 into a strip shape. A sheet (10 sheets here) of strip-shaped resin films 35 (first resin film) is formed at one time. The thickness of the resin film 34 is 1/2 of the thickness of the resin film 30. About half (here five sheets) among several resin films 35, it is used as it is.

  As for the remaining half of the plurality of resin films 35, as shown in FIG. 6, a resin film 36 (second resin film) and a resin film 37 (third resin film) that are shorter than the resin film 35 are used. Used in the formation of Specifically, the resin film 35 is cut (cut) to form the resin films 36, 37. At this time, the length of the resin film 35−the length of the resin film 36−the length of the resin film 37 matches the width of the communication port 26. The lengths of the resin films 36 and 37 differ depending on the position of the communication port 26 corresponding to the cell.

  Then, as shown in FIG. 6, the resin films 36 and 37 are overlapped on the resin film 35 at intervals corresponding to the width of the communication port 26, and the resin film 35 and the resin films 36 and 37 are thermally welded. By joining, the 2nd resin part 25 which has the level | step-difference part 27 is formed. Then, both end surfaces of the second resin portion 25 are joined to inner side surfaces of both end portions of the first resin portion 24 by thermal welding. Thereby, the primary seal 22 is obtained.

  At this time, all the resin films 35 to 37 may be joined to the first resin portion 24. However, since the internal space V is kept airtight by the secondary seal 23 described later, only the resin film 35 is attached to the first resin portion 24. The resin films 36 and 37 may not be bonded to the first resin portion 24. In addition, after the resin film 35 is bonded to both end portions of the first resin portion 24, the resin films 36 and 37 may be stacked on the resin film 35 with a space therebetween.

  Returning to FIG. 5, after performing step S <b> 102, as shown in FIG. 8, the primary seal 22 is joined to the peripheral portion 17 c of the nickel foil 17 of the bipolar electrode 13 by thermal welding, so that the bipolar electrode 13 and the primary seal are joined. An electrode unit 38 made of 22 is produced (step S103). In step S103, in addition to the bipolar electrode 13, the primary seal 22 is also bonded to the peripheral edge portion 17c of the positive electrode side termination electrode 20 and the nickel foil 17 of the negative electrode side termination electrode 21. The first resin portion 24 and the resin film 35 of the second resin portion 25 are bonded to the peripheral portion 17 c of the nickel foil 17. Step S103 is a unit manufacturing step.

  Next, the plurality of electrode units 38 are stacked via the separator 14 (step S104). Thus, the electrode stack 15 is obtained, and the primary seals 22 of the electrode units 38 are stacked. At this time, the primary seals 22 adjacent in the stacking direction are joined together by heat welding. Step S104 is a lamination step.

  Next, a secondary seal 23 is formed around each primary seal 22 (step S105). At this time, for example, the secondary seal 23 may be formed by injection molding or the like, or the rectangular cylindrical resin member may be heat welded to the outer peripheral surface of each primary seal 22 to form the secondary seal 23. .

  Next, an electrolytic solution is injected from the communication port 26 provided in the primary seal 22 into the space (internal space V) inside the primary seal 22 (step S106). Step S106 is a liquid injection step.

  Thereafter, the communication valve 26 is sealed by attaching the safety valve 12 to the safety valve attachment region 28 of the second resin portion 25 in the primary seal 22 (step S107). Step S107 is a sealing step. As described above, the bipolar battery 2 is manufactured.

  As described above, in the present embodiment, after the first resin portion 24 having the U-shaped single-layer structure is formed, the second strip-shaped two-layer structure having the step 27 forming the communication port 26 is used. By bonding the resin portion 25 to both end portions of the first resin portion 24, the primary seal 22 is manufactured. At this time, since the second resin portion 25 having the step portion 27 constituting the communication port 26 has a two-layer structure, for example, the step is compared with the case where the step processing is performed on the primary seal of the single layer structure. The formation of the portion 27 can be easily performed. Thereby, the production time of the primary seal 22 having the communication port 26 is shortened. As a result, the equipment cost can be reduced.

  In addition, when the structure of the primary seal is entirely single-layered, it is necessary to process the stepped portion by heat or laser, etc., and therefore, the rising of the edge of the stepped portion and thermal deformation of the stepped portion occur. The quality of the primary seal having the communication port is deteriorated. However, in the present embodiment, since the structure of the second resin portion 25 is a two-layer structure, it is not necessary to process the stepped portion by heat or laser. Accordingly, since the rise of the edge of the stepped portion 27 and the occurrence of thermal deformation of the stepped portion 27 are suppressed, the quality of the primary seal 22 having the communication port 26 can be improved.

  Further, in the present embodiment, the strip-shaped resin film 35 and the resin films 36 and 37 having a length shorter than the resin film 35 are prepared, and the resin films 36 and 37 are overlapped on the resin film 35 with a space. Thus, the second resin portion 25 having the step 27 is formed. Thus, since the step part 27 is obtained by superimposing the resin films 36 and 37 on the resin film 35, the step part 27 can be formed more easily.

  Further, in the present embodiment, after preparing a plurality of resin films 35, the resin films 35 are cut to form the resin films 36 and 37. Therefore, the resin films 36 and 37 can be easily formed from the resin films 35. .

  Further, in the present embodiment, since the first resin portion 24 is formed by punching out the resin film 30 in a U-shape, the U-shaped first resin portion 24 can be easily fabricated in a short time.

  Further, in the present embodiment, the resin film 30 is U-shaped so that the U-shaped punched-out portions 32 in opposite directions on the one side and the other side in the width direction of the resin film 30 are offset in the longitudinal direction of the resin film 30. Punch out in the shape of a letter. Therefore, since the unused area | region of the resin film 30 decreases, the waste of the resin film 30 can be suppressed.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the resin film 35 having a strip shape and the resin films 36 and 37 having a length shorter than the resin film 35 are prepared, and the resin films 36 and 37 are overlapped on the resin film 35 with a space. The second resin portion 25 having the step portion 27 is formed, but the invention is not particularly limited thereto. For example, after laminating the resin film 35 one more time on the resin film 35, the upper resin film 35 is cut. Thus, the second resin portion 25 having the stepped portion 27 may be formed.

  In the above embodiment, the resin film 34 is punched into a strip shape to form a plurality of strip-shaped resin films 35, and the resin films 35 are cut to form the resin films 36 and 37. For example, the resin film 34 may be punched to form the resin films 35 to 37 simultaneously. Alternatively, the resin film 34 delivered from the roll 33 may be directly cut to form the resin films 35 to 37.

  Moreover, in the said embodiment, although the strip-shaped 2nd resin part 25 which has the level | step-difference part 27 which comprises the communicating port 26 has 2 layer structure, as a layer number of the 2nd resin part 25, especially two The layer is not limited, and may be three or more layers as long as it is a plurality of layers.

  Further, in the above embodiment, the resin film 30 is U-shaped so that the U-shaped punched-out portions 32 in opposite directions on one side and the other side in the width direction of the resin film 30 are shifted in the longitudinal direction of the resin film 30. The resin film 30 may be punched into a U-shape so that all U-shaped punched parts 32 have the same direction, for example.

  In the above embodiment, the U-shaped first resin portion 24 is formed by punching out the resin film 30 in a U-shape, but the present invention is not particularly limited thereto. For example, the resin film 30 is punched out in a strip shape. Thus, after forming three strip-shaped resin films, these resin films may be joined in a U shape by heat welding to form a U-shaped first resin portion 24.

  Moreover, in the said embodiment, although the primary seal 22 is joined to the peripheral part 17c of the nickel foil 17 of the bipolar electrode 13, the electrode unit 38 which consists of the bipolar electrode 13 and the primary seal 22 is produced, Especially the form For example, after the primary seal 22 is joined to the peripheral portion 17c of the nickel foil 17, the positive electrode 18 is formed on one side of the nickel foil 17 and the negative electrode 19 is formed on the other side of the nickel foil 17 An electrode unit 38 consisting of the electrode 13 and the primary seal 22 may be produced.

  In the above embodiment, the resin film 35 and the resin films 36 and 37 are joined by heat welding at the time of production of the primary seal 22, and the first resin portion 24 and the second resin portion 25 are joined by heat welding. However, the bonding method is not particularly limited to welding, and may be adhesion or the like. The same applies to the bonding of the nickel foil 17 and the primary seal 22 and the bonding of the primary seals 22 to each other.

  Moreover, in the said embodiment, although the bipolar battery 2 is provided with the secondary seal | sticker 23, this invention is applicable also to the bipolar battery without a secondary seal | sticker.

  Furthermore, in the above embodiment, the bipolar battery 2 is a nickel hydride secondary battery, but the present invention can also be applied to bipolar batteries other than nickel hydride secondary batteries (for example, lithium ion secondary batteries).

  DESCRIPTION OF SYMBOLS 2 ... Bipolar battery, 13 ... Bipolar electrode, 14 ... Separator, 17 ... Nickel foil (current collector), 17a ... Upper surface (one side), 17b ... Lower surface (other side), 17c ... Peripheral part, 18 ... Positive electrode, 19 ... Negative electrode 22 primary seal (resin frame) 24 first resin portion 25 second resin portion 26 communication port 27 step portion 30 resin film 32 to-be-punched portion 35 resin Film (1st resin film), 36 ... Resin film (2nd resin film), 37 ... Resin film (3rd resin film), 38 ... Electrode unit, V ... Internal space (space).

Claims (6)

A plurality of bipolar electrodes having a positive electrode formed on one surface of the current collector and a negative electrode formed on the other surface of the current collector, and bonded to the peripheral portions of the current collector of the plurality of bipolar electrodes, respectively; And a plurality of resin frames having communication openings, wherein the plurality of bipolar electrodes are stacked via a separator.
A resin frame manufacturing step of manufacturing the resin frame having the communication port;
A unit manufacturing step of manufacturing an electrode unit comprising the bipolar electrode and the resin frame by bonding the resin frame to the peripheral portion of the current collector;
A lamination step of laminating a plurality of the electrode units such that the plurality of bipolar electrodes are laminated via the separator;
A liquid injection step of injecting an electrolytic solution into the space inside the resin frame from the communication port;
After performing the liquid injection step, including a sealing step of sealing the communication port,
The resin frame manufacturing step includes a first resin portion forming step for forming a first resin portion having a U-shaped single layer structure, and a second resin having a strip-like multi-layer structure having a step portion constituting the communication port. And a second resin portion bonding step of bonding the second resin portion to both end portions of the first resin portion.   In the second resin part bonding step, a strip-shaped first resin film and a second resin film and a third resin film having a shorter length than the first resin film are prepared, and the first resin film is formed on the first resin film. The method for manufacturing a bipolar battery according to claim 1, wherein the second resin portion having the step portion is formed by overlapping the second resin film and the third resin film at intervals.   In the second resin part bonding step, after preparing a plurality of the first resin films, the first resin film is cut to form the second resin film and the third resin film. The manufacturing method of the bipolar battery of Claim 2.   The bipolar battery according to any one of claims 1 to 3, wherein in the first resin portion forming step, the U-shaped first resin portion is formed by punching out a resin film in a U shape. Manufacturing method.   In the first resin portion forming step, the resin film is made so that the U-shaped punched-out portions are opposite in one side and the other side in the width direction of the resin film and are shifted in the longitudinal direction of the resin film. A method of manufacturing a bipolar battery according to claim 4, characterized in that punching out in a U-shape. A plurality of bipolar electrodes having a positive electrode formed on one surface of the current collector and a negative electrode formed on the other surface of the current collector, and bonded to the peripheral portions of the current collector of the plurality of bipolar electrodes, respectively; A plurality of resin frames having communication openings, wherein the plurality of bipolar electrodes are stacked via a separator,
The resin frame is bonded to both ends of the first resin portion having a U-shaped single-layer structure and a second portion having a strip-like multi-layer structure having step portions constituting the communication port. A bipolar battery comprising a resin portion.

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