Apparatus for manufacturing electrode units and method for manufacturing electrode units

Abstract

An electrode unit manufacturing device 50 for manufacturing an electrode unit 11A by welding a resin member 21B to a bipolar electrode 11 including a current collector 15 and active material layers provided on one surface 15a and another surface 15b of the current collector 15 comprises: a robot hand 30 for transporting the bipolar electrode 11 in the air while holding the same by suction attachment; and a welding device 40 including a welding unit 45 for welding the resin member 21B to the bipolar electrode 11 that is being held in the air by suction attachment by the robot hand 30.

Description

Technical Field

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[0001] The present disclosure relates to an electrode unit manufacturing apparatus and an electrode unit manufacturing method.

Background Art

[0002] Patent Document 1 discloses a method of forming a bipolar electrode unit by welding a resin frame to a bipolar electrode. In this method, first, the bipolar electrode and the resin frame are conveyed between a pair of pressure members adjusted to a predetermined clearance in a state where the resin frame is temporarily fixed to the first surface of the electrode plate of the bipolar electrode. Then, the electrode plate and the resin frame of the bipolar electrode are heated by a heater and pressed by a pressure roller, and then cooled by a cooling plate. Thereby, the resin frame is welded to the electrode plate of the bipolar electrode, and a bipolar electrode unit is formed.

Prior Art Documents

Patent Documents

[0003] <​​​​​​​​​​​​​​Therefore, the present disclosure aims to provide an electrode unit manufacturing apparatus and an electrode unit manufacturing method that can weld resin members while suppressing the adhesion of foreign matter to the electrodes. [Means for solving the problem]

[0006] The electrode unit manufacturing apparatus according to this disclosure is an electrode unit manufacturing apparatus for manufacturing an electrode unit by welding a resin member to an electrode including a current collector and an active material layer provided on the surface of the current collector, comprising a transport unit that transports the electrode in the air while adsorbing and holding it, and a welding apparatus that includes a welding unit for welding a resin member to the electrode while it is adsorbed and held in the air by the transport unit.

[0007] The electrode unit manufacturing method according to this disclosure is an electrode unit manufacturing method for welding a resin member to an electrode including a current collector and an active material layer provided on the surface of the current collector, comprising: a first step of transporting the electrode in the air while adsorbing and holding it; and a second step of welding a resin member to the electrode in the state of being adsorbed and held in the air after the first step.

[0008] In these manufacturing apparatuses and methods, when manufacturing electrode units by welding a resin component to an electrode, the electrode is held in place by adsorption in the air while the resin component is welded to the electrode. Therefore, foreign matter that slides off one electrode and adheres to the next electrode is prevented. Thus, it is possible to weld the resin component while suppressing the adhesion of foreign matter to the electrode.

[0009] In the electrode unit manufacturing apparatus according to this disclosure, the welding apparatus includes a placement section that holds the resin member before it is welded to the electrode and places the resin member on the surface of the electrode while it is held in the air by adsorption in the transport section, and the welding section may weld the resin member placed on the surface by the placement section to the current collector. In this case, the resin member is placed and welded to the surface of the current collector of the electrode. Therefore, foreign matter that slides off from the electrode is prevented from adhering to the next electrode, and thus the presence of foreign matter between the electrode and the resin member during the placement and welding of the resin member is prevented.

[0010] The electrode unit manufacturing apparatus according to this disclosure may include a welding apparatus that pulls out a base material from a holding part by moving while gripping one end of the base material held in the holding part, a second gripping part that further grips the base material pulled out by the movement of the first gripping part at a position separated from the first gripping part, and a cutting part that forms a resin member by cutting the base material while maintaining the state in which it is gripped by the first gripping part and the second gripping part. In this case, the formation of a resin member from the base material can be easily performed.

[0011] In the electrode unit manufacturing apparatus according to this disclosure, the welding apparatus may include a sensor that detects a resin member in a state where it is gripped by a first gripping part and a second gripping part, and a moving part that moves the first gripping part and the second gripping part before the resin member is held by the placement part, thereby aligning the resin member based on the detection result of the sensor. In this case, the positional accuracy of the resin member with respect to the welding position is improved.

[0012] In the electrode unit manufacturing apparatus according to this disclosure, the first gripping section pulls out a pair of base materials from the holding section by gripping and moving a pair of base materials stacked and held in the holding section, the second gripping section further grips the pair of base materials pulled out by the movement of the first gripping section at a position separated from the first gripping section, the cutting section forms a pair of resin members by cutting the pair of base materials, the placement section changes the distance between the pair of resin members by moving in the stacking direction of the resin members while holding at least one of the pair of resin members, the transport section transports the electrode so that the current collector is sandwiched between the pair of resin members whose distance has been widened by the movement of the placement section, and the welding section may weld each of the pair of resin members to the current collector when the pair of resin members are positioned on the surface of the current collector and on the back surface opposite the surface of the current collector, respectively, due to the movement of the placement section. In this case, it is possible to form and weld a pair of resin members to the front and back surfaces of the current collector by pulling out the base materials once by the first gripping section and cutting the base materials once by the cutting section.

[0013] In the electrode unit manufacturing apparatus according to this disclosure, the welding apparatus may include a sensor that detects a resin member held by a placement unit, and a moving unit that moves the placement unit while the resin member is held by the placement unit, thereby aligning the resin member based on the detection result of the sensor. In this case, the positional accuracy of the resin member with respect to the welding position is improved. [Effects of the Invention]

[0014] According to this disclosure, it is possible to provide an electrode unit manufacturing apparatus and an electrode unit manufacturing method that can weld resin members while suppressing the adhesion of foreign matter to the electrodes. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic cross-sectional view of the energy storage module according to this embodiment. [Figure 2] Figure 2 shows an example of an electrode unit. [Figure 3] Figure 3 is a schematic diagram showing a part of the electrode unit manufacturing apparatus. [Figure 4] Figure 4 is a schematic diagram showing another part of the electrode unit manufacturing apparatus. [Figure 5] Figure 5 is a schematic diagram showing another part of the electrode unit manufacturing apparatus. [Figure 6] Figure 6 is a flowchart showing one step in the electrode unit manufacturing method. [Figure 7] Figure 7 is a side view showing one step in the electrode unit manufacturing method. [Figure 8] Figure 8 shows a modified example of a welding apparatus. [Modes for carrying out the invention]

[0016] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the attached drawings. In the description of the drawings, the same reference numerals will be used for identical or equivalent elements, and redundant explanations may be omitted.

[0017] FIG. 1 is a schematic cross-sectional view of the power storage module according to the present embodiment. The power storage module 1 shown in FIG. 1 is a power storage module used for batteries of various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage module 1 is a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion secondary battery. The power storage module 1 may be an electric double layer capacitor or an all-solid-state battery. Here, the case where the power storage module 1 is a lithium-ion secondary battery is illustrated.

[0018] The power storage module 1 includes a laminate 10 and a resin frame 22. The laminate 10 has a plurality of bipolar electrodes 11, a negative terminal electrode 12, a positive terminal electrode 13, a plurality of separators 14, a plurality of first resin layers 21 and a plurality of second resin layers 23, and an electrolyte (not shown).

[0019] The bipolar electrode 11 has a current collector 15, a positive electrode active material layer 16, and a negative electrode active material layer 17. The current collector 15 has, for example, a rectangular sheet shape. The positive electrode active material layer 16 is provided on one surface 15a of the current collector 15. The negative electrode active material layer 17 is provided on the other surface 15b of the current collector 15. The plurality of bipolar electrodes 11 are laminated such that the positive electrode active material layer 16 of one bipolar electrode 11 faces the negative electrode active material layer 17 of another bipolar electrode 11. Here, the direction in which the bipolar electrodes 11 are laminated is referred to as the lamination direction D.

[0020] The positive electrode active material layer 16 and the negative electrode active material layer 17 are rectangular when viewed from the lamination direction D. The negative electrode active material layer 17 is slightly larger than the positive electrode active material layer 16 when viewed from the lamination direction D. That is, in a plan view when viewed from the lamination direction D, the entire formation region of the positive electrode active material layer 16 is located within the formation region of the negative electrode active material layer 17.

[0021] The negative electrode terminal electrode 12 has a current collector 15 and a negative electrode active material layer 17 provided on the other side 15b of the current collector 15. The negative electrode terminal electrode 12 does not have a positive electrode active material layer 16. In other words, there is no active material layer on one side 15a of the current collector 15 of the negative electrode terminal electrode 12. The negative electrode terminal electrode 12 is laminated on the bipolar electrode 11 at one end of the laminate direction D of the laminate 10. The negative electrode terminal electrode 12 is laminated on the bipolar electrode 11 such that its negative electrode active material layer 17 faces the positive electrode active material layer 16 of the bipolar electrode 11. Therefore, one side 15a of the current collector 15 of the negative electrode terminal electrode 12 faces outward from the laminate 10, and a portion of it is exposed to the outside of the laminate 10.

[0022] The positive terminal electrode 13 comprises a current collector 15 and a positive electrode active material layer 16 provided on one side 15a of the current collector 15. The positive terminal electrode 13 does not have a negative electrode active material layer 17. In other words, the other side 15b of the current collector 15 of the positive terminal electrode 13 does not have an active material layer. The positive terminal electrode 13 is laminated on the bipolar electrode 11 at the other end of the laminate 10 in the lamination direction D. The positive terminal electrode 13 is laminated on the bipolar electrode 11 such that its positive electrode active material layer 16 faces the negative electrode active material layer 17 of the bipolar electrode 11. Therefore, the other side 15b of the current collector 15 of the positive terminal electrode 13 faces outward from the laminate 10, and a portion of it is exposed to the outside of the laminate 10.

[0023] The separator 14 is positioned between adjacent bipolar electrodes 11, between the negative electrode terminal electrode 12 and the bipolar electrode 11, and between the positive electrode terminal electrode 13 and the bipolar electrode 11. The separator 14 is interposed between the positive electrode active material layer 16 and the negative electrode active material layer 17. By isolating the positive electrode active material layer 16 and the negative electrode active material layer 17, the separator 14 prevents short circuits caused by contact between adjacent electrodes while allowing charge carriers such as lithium ions to pass through.

[0024] The current collector 15 is a chemically inert electrical conductor that allows current to continue flowing through the positive electrode active material layer 16 and the negative electrode active material layer 17 during the discharge or charging of the lithium-ion secondary battery. The material of the current collector 15 is, for example, a metal material, a conductive resin material, or a conductive inorganic material. Examples of conductive resin materials include conductive polymer materials or resins to which conductive fillers are optionally added to non-conductive polymer materials. The current collector 15 may comprise multiple layers. In this case, each layer of the current collector 15 may contain the above-mentioned metal material or conductive resin material.

[0025] A coating layer may be formed on the surface of the current collector 15. This coating layer may be formed by known methods such as plating or spray coating. The current collector 15 may be in the form of a plate, foil (e.g., metal foil), film, or mesh. Examples of metal foils include aluminum foil, copper foil, nickel foil, titanium foil, or stainless steel foil. Examples of stainless steel foils include SUS 304, SUS 316, or SUS 301 as specified in JIS G 4305:2015. By using stainless steel foil as the current collector 15, the mechanical strength of the current collector 15 can be ensured. The current collector 15 may be an alloy foil of the above metals or a foil in which multiple above metal foils are integrated. When the current collector 15 is in the form of foil, the thickness of the current collector 15 may be, for example, 1 μm to 100 μm.

[0026] The positive electrode active material layer 16 contains a positive electrode active material capable of intercalating and releasing charge carriers such as lithium ions. Examples of positive electrode active materials include lithium composite metal oxides having a layered rock salt structure, metal oxides having a spinel structure, and polyanionic compounds. The positive electrode active material can be any material suitable for use in lithium-ion secondary batteries. The positive electrode active material layer 16 may contain multiple positive electrode active materials. In this embodiment, the positive electrode active material layer 16 contains olivine-type lithium iron phosphate (LiFePO4) as a composite oxide.

[0027] The negative electrode active material layer 17 contains a negative electrode active material capable of intercalating and releasing charge carriers such as lithium ions. The negative electrode active material may be an element, an alloy, or a compound. Examples of negative electrode active materials include Li, carbon, and metal compounds. The negative electrode active material may also be an element or compound thereof that can be alloyed with lithium. Examples of carbon include natural graphite, artificial graphite, hard carbon (carbon that is difficult to graphitize), or soft carbon (carbon that is easily graphitized). Examples of artificial graphite include highly oriented graphite and mesocarbon microbeads. Examples of elements that can be alloyed with lithium include silicon or tin. In this embodiment, the negative electrode active material layer 17 contains graphite as a carbon-based material.

[0028] Each of the positive electrode active material layer 16 and the negative electrode active material layer 17 (hereinafter sometimes simply referred to as the "active material layer") may further contain, as necessary, conductive additives, binders, electrolytes (polymer matrix, ion-conducting polymer, electrolyte solution, etc.), electrolyte-supporting salts (lithium salts) to enhance ionic conductivity, etc. Conductive additives are added to enhance the conductivity of each electrode (bipolar electrode 11, negative electrode terminal electrode 12, positive electrode terminal electrode 13). Examples of conductive additives include acetylene black, carbon black, or graphite.

[0029] 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; alkoxysilyl group-containing resins; acrylic resins such as acrylic acid or methacrylic acid; styrene-butadiene rubber (SBR); alginates such as carboxymethylcellulose, sodium alginate, and ammonium alginate; water-soluble cellulose ester crosslinked polymers; and starch-acrylic acid graft polymers. These binders can be used individually or in combination. Examples of solvents include water and N-methyl-2-pyrrolidone (NMP).

[0030] The separator 14 may be, for example, a porous sheet or nonwoven fabric containing a polymer that absorbs and retains electrolytes. Examples of materials for the separator 14 include polypropylene, polyethylene, polyolefin, and polyester. The separator 14 may have a single-layer structure or a multilayer structure. The multilayer structure may include, for example, a ceramic layer as an adhesive layer or a heat-resistant layer. The separator 14 may be impregnated with an electrolyte. The separator 14 may be composed of an electrolyte such as a polymer electrolyte or an inorganic electrolyte. Examples of electrolytes impregnated into the separator 14 include a liquid electrolyte (electrolyte solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent, or a polymer gel electrolyte containing an electrolyte held in a polymer matrix.

[0031] When the separator 14 is impregnated with an electrolyte, known lithium salts such as LiClO4, LiAsF6, LiPF6, LiBF4, LiCF3SO3, LiN(FSO2)2, and LiN(CF3SO2)2 may be used as the electrolyte salt. Furthermore, known solvents such as cyclic carbonates, cyclic esters, linear carbonates, linear esters, and ethers may be used as the non-aqueous solvent. Two or more of these known solvent materials may be used in combination.

[0032] The first resin layer 21, the resin frame 22, and the second resin layer 23 constitute a sealing portion 20. The sealing portion 20 is formed in a frame shape on the periphery of the laminate 10 so as to surround the laminate 10. The sealing portion 20 is joined to one side 15a and the other side 15b of each current collector 15 at the periphery 15c of each current collector 15. The sealing portion 20 seals each of the spaces S between adjacent current collectors 15 in the lamination direction D. An electrolyte is contained in each space S. When the electrolyte is liquid, the sealing portion 20 prevents the electrolyte from permeating to the outside. The sealing portion 20 suppresses the intrusion of moisture and other substances from the outside of the laminate 10 into the space S. The edges of each separator 14 are embedded in the sealing portion 20. The sealing portion 20 contains an insulating material. Examples of materials for the sealing portion 20 include various resin materials such as polypropylene, polyethylene, polystyrene, ABS resin, modified polypropylene, and acrylonitrile styrene resin.

[0033] The first resin layer 21 is provided on each of the current collectors 15. Therefore, the first resin layers 21 are stacked on each other along the stacking direction D. The first resin layer 21 is frame-shaped and is provided on the peripheral edge 15c of the current collector 15. In other words, the first resin layer 21 is provided so as to extend from one side 15a of the current collector 15 through the end face to the other side 15b, covering the peripheral edge 15c. The first resin layer 21 is welded to one side 15a and the other side 15b of the current collector 15.

[0034] The second resin layer 23 is positioned between adjacent first resin layers 21 in the stacking direction D. This ensures that the second resin layer 23 maintains space between adjacent first resin layers 21, i.e., between adjacent current collectors 15. The second resin layer 23 is frame-shaped and positioned on the peripheral edge 15c of the current collector 15 when viewed from the stacking direction D. The second resin layer 23 can be welded to at least one of a pair of adjacent first resin layers 21 in the stacking direction D. Here, the end of the separator 14 is embedded between the first resin layer 21 and the second resin layer 23.

[0035] The resin frame 22 is formed by integrating multiple first resin layers 21 and multiple second resin layers 23. The resin frame 22 seals multiple spaces S together by welding the end of the first resin layer 21 opposite to the space S and the end of the second resin layer 23 opposite to the space S to each other. The surface of the resin frame 22 opposite to the space S constitutes the outer surface 10s of the laminate 10.

[0036] The energy storage module 1 described above is composed of multiple electrode units. Figure 2 shows an example of an electrode unit. Figure 2(a) is a cross-sectional view, and Figure 2(b) is a plan view. Figure 2 illustrates an electrode unit 11A including a bipolar electrode 11. The electrode unit 11A includes a bipolar electrode 11 and a first resin layer 21 welded to the bipolar electrode 11. One side (front) 15a and the other side (back) 15b of the current collector 15 include a first region A1 on which an active material layer (positive electrode active material layer 16 and negative electrode active material layer 17) is formed, and a second region A2 exposed from the active material layer. The first resin layer 21 is welded to the one side 15a and the other side 15b of the current collector 15 in the second region A2.

[0037] Although Figure 2 shows electrode unit 11A including bipolar electrode 11, the energy storage module 1 also includes electrode units including positive terminal electrode 13 and negative terminal electrode 12. Compared to electrode unit 11A, the electrode unit including positive terminal electrode 13 differs only in that the negative electrode active material layer 17 is not formed on the other side 15b of the current collector 15, and the electrode unit including negative terminal electrode 12 differs only in that the positive electrode active material layer 16 is not formed on one side 15a of the current collector 15; otherwise, they are the same. The laminate 10 is constructed by stacking multiple of the above electrode units via a second resin layer 23 and a separator 14. The manufacturing apparatus for the electrode unit and the manufacturing method for the electrode unit will be described below, using electrode unit 11A as an example.

[0038] Figure 3 is a schematic diagram showing a part of the electrode unit manufacturing apparatus. Figure 3(a) is a side view, and Figure 3(b) is a top view. As shown in Figure 3, the electrode unit manufacturing apparatus 50 includes a robot hand (transporting unit) 30. The robot hand 30 includes a plurality of suction pads 31, air piping 32, and a support unit 33. The robot hand 30 is connected to a drive unit (not shown) via the support unit 33, and is capable of moving in three dimensions by the drive unit. The plurality of suction pads 31 are spaced apart from each other. Here, the plurality of suction pads 31 are arranged so that when the negative electrode active material layer 17 (or positive electrode active material layer 16, hereinafter sometimes simply referred to as "active material layer") is positioned facing the robot hand 30, the active material layer is distributed across the entire active material layer in the same plane.

[0039] The air piping 32 is connected to each of the multiple suction pads 31. The air piping 32 draws in and exhausts air from the multiple suction pads 31, thereby causing a component (e.g., a negative electrode active material layer 17) positioned opposite the multiple suction pads 31 to be adsorbed onto the suction pads 31, or releasing the adsorption of the component onto the suction pads 31. The support part 33 is connected to the air piping 32 and supports the air piping 32 and the suction pads 31 in the robot hand 30. A pipe leading to the air piping 32 may be provided within the support part 33.

[0040] In this way, the robot hand 30 is able to aerial transport the bipolar electrode 11 to any position while holding it in place, by adsorbing the suction pad 31 onto the active material layer. The transport by the robot hand 30 is performed so that the surface of the bipolar electrode 11 that is adsorbed by the suction pad 31 is the upper surface in the vertical direction (direction of gravity). Furthermore, aerial transport here means transport in a state where the surface of the bipolar electrode 11 opposite to the surface adsorbed by the suction pad 31 is not in contact with or supported by any other device or component. As described above, multiple suction pads 31 are distributed throughout the entire active material layer. Therefore, when the robot hand 30 adsorbs and holds the bipolar electrode 11, warping of the bipolar electrode 11 is suppressed.

[0041] Figures 4 and 5 are schematic diagrams showing another part of the electrode unit manufacturing apparatus. The following drawings show a Cartesian coordinate system consisting of the X, Y, and Z axes. For example, the X-axis and Y-axis directions are the first and second horizontal directions, respectively, and the Z-axis direction is the vertical direction. Figure 4(a) is a side view (viewed from the Y direction), Figure 4(b) is a top view (viewed from the Z direction), and Figure 5 is another side view (viewed from the X direction).

[0042] As shown in Figures 4 and 5, the electrode unit manufacturing apparatus 50 includes a welding apparatus 40. The welding apparatus 40 includes a first gripping section 41, a second gripping section 42, a cutting section 43, multiple pairs of suction sections (placement sections) 44, multiple pairs of welding sections 45, moving sections 46 and 47, a pair of guide sections 48, and multiple sensors 49. In addition, a holding section PA for holding the base material 21A for the resin member 21B is arranged in front of the welding apparatus 40. In the holding section PA, the base material 21A is wound around a reel PR and held in a roll shape. The resin member 21B is obtained by cutting this base material 21A to an appropriate length. As will be described later, the first resin layer 21 is formed by arranging the resin member 21B obtained by cutting the base material 21A in a frame shape and integrating them. Therefore, in this embodiment, the resin member 21B is a component that becomes part of the first resin layer 21.

[0043] The first gripping part 41 grips one end of the base material 21A held by the holding part PA and is moved along the X-axis direction by the moving part 46, thereby pulling the base material 21A out of the holding part PA. The first gripping part 41 is, for example, a chuck. The second gripping part 42 further grips the base material 21A that has been pulled out by the movement of the first gripping part 41 at a position separated from the first gripping part 41 (approximately by the length of the first resin layer 21). The second gripping part 42 is a pair of elastic members (for example, sponges) arranged to sandwich the base material 21A along the Z direction, and can grip the base material 21A by sandwiching it along the Z direction.

[0044] The cutting section 43 cuts the base material 21A while maintaining the gripping state between the first gripping section 41 and the second gripping section 42, thereby forming the first resin layer 21 in the state gripped by the first gripping section 41 and the second gripping section 42. The cutting section 43 includes, for example, a Thomson blade and cuts the base material 21A at the position gripped by the second gripping section 42. As a result, a strip-shaped resin member 21B is formed between the first gripping section 41 and the second gripping section 42.

[0045] Each of the multiple pairs of suction parts 44 is a suction pad, and they are distributed along the longitudinal direction (in this case, the X-axis direction) of the resin member 21B at a position between the first gripping part 41 and the second gripping part 42. A pair of suction parts 44 are arranged facing each other via the resin member 21B along the Z-axis direction. In other words, each of the pair of suction parts 44 is arranged to sandwich the resin member 21B from above and below.

[0046] To put it another way, the multiple pairs of suction parts 44 include a group of suction parts 44 (hereinafter sometimes referred to as the "upper suction part") arranged on the upper side of the resin member 21B in the Z-axis direction, and another group of suction parts 44 (hereinafter sometimes referred to as the "lower suction part") arranged on the lower side of the resin member 21B in the Z-axis direction. Each of the suction parts 44 is supported by a support part 44a which is an air pipe and an upper and lower cylinder, and is movable along the Z-axis direction. In other words, a pair of suction parts 44 are movable so that the distance between them in the Z-axis direction changes.

[0047] Here, the first gripping portion 41 moves while gripping the pair of base materials 21A that are stacked and held in the holding portion PA, thereby pulling the pair of base materials 21A that are stacked on top of each other out of the holding portion PA. The second gripping portion 42 grips the pair of base materials 21A that have been pulled out by the movement of the first gripping portion 41 at a position separated from the first gripping portion 41. The cutting portion 43 then cuts the pair of base materials 21A together while maintaining the state in which they are gripped by the first gripping portion 41 and the second gripping portion 42, thereby forming a pair of resin members 21B that are stacked in the Z-axis direction and gripped by the first gripping portion 41 and the second gripping portion 42.

[0048] Therefore, one of the pair of suction parts 44 (i.e., each of the upper suction parts) faces one of the overlapping resin members 21B, and the other of the pair of suction parts 44 (i.e., each of the lower suction parts) faces the other of the overlapping resin members 21B. As a result, each of the upper and lower suction parts can be moved closer to the resin members 21B and brought into contact with each of the pair of resin members 21B, thereby allowing each of the pair of resin members 21B to be adsorbed.

[0049] Furthermore, each of the upper and lower suction parts can be moved away from each other while holding each of the pair of resin members 21B, thereby increasing the distance DB between the pair of resin members 21B (it is also possible to decrease the distance DB by moving them in the opposite direction). In other words, the suction part 44 can change the distance DB between the pair of resin members 21B by moving in the stacking direction (Z-axis direction) of the resin members 21B while holding at least one (in this case both) of the pair of resin members 21B.

[0050] The robot hand 30 can transport the bipolar electrode 11 such that the second region A2 of one side 15a and the other side 15b of the current collector 15 is sandwiched between a pair of resin members 21B whose spacing DB has been widened by the movement of the suction unit 44. As a result, the resin members 21B are positioned relative to the bipolar electrode 11 so that the second region A2 faces the resin members 21B. In this way, the suction unit 44 holds the resin members 21B before they are welded to the bipolar electrode 11 and functions as a positioning unit that positions the resin members 21B on one side 15a and the other side 15b of the bipolar electrode 11 while it is held by the robot hand 30 in mid-air.

[0051] Each of the multiple welding sections 45 welds a resin member 21B to the bipolar electrode 11. The multiple pairs of welding sections 45 are arranged in a different position from the adsorption section 44, dispersed along the longitudinal direction of the resin member 21B (here, the X-axis direction). Here, a pair of welding sections 45 are arranged facing each other along the Z-axis direction via the resin member 21B. In other words, a pair of welding sections 45 are arranged to sandwich the resin member 21B from above and below. As a result, each of the multiple welding sections 45 can weld a pair of resin members 21B to one side 15a and the other side 15b of the current collector 15, respectively, in the second region A2, with respect to the bipolar electrode 11 held by the robot hand 30. The welding section 45 is a device that heats the resin member 21B by contact or non-contact, and is composed of, for example, a soldering iron or a laser welding machine. In this manner, the welding portion 45 welds each of the pair of resin members 21B to the current collector 15 when the pair of resin members 21B are positioned on one side 15a and the other side 15b of the current collector 15, respectively, by the movement of the suction portion (placement portion) 44.

[0052] The movable part 46 is provided on the first gripping part 41 and moves the first gripping part 41. The movable part 47 is provided on the second gripping part 42 and moves the second gripping part 42. Therefore, the movable parts 46 and 47 can adjust the position of the resin member 21B by moving the first gripping part 41 and the second gripping part 42 while the first gripping part 41 and the second gripping part 42 are gripping the resin member 21B. The movable parts 46 and 47 are devices that move the first gripping part 41 and the second gripping part 42 horizontally in the Y-axis direction, and are configured, for example, by a ball screw.

[0053] A pair of guide portions 48 are provided at the pulling position of the base material 21A in the holding portion PA. In a plan view, the pair of guide portions 48 are arranged opposite each other in the Y-axis direction, which intersects the pulling direction (X-axis direction) of the base material 21A, and restrict the movement of the base material 21A in the Y-axis direction. The base material 21A is interposed between the pair of guide portions 48, and a small clearance DA is provided between the guide portions 48 and the base material 21A along the Y-axis direction. Therefore, when the base material 21A is pulled out to form the resin member 21B, there is a possibility that the position of the resin member 21B in the Y-axis direction will vary by the amount of the clearance DA between the guide portions 48 and the base material 21A.

[0054] In contrast, the movable parts 46 and 47 can align the resin member 21B in the Y-axis direction by moving the first gripping part 41 and the second gripping part 42 along the Y-axis direction while the first gripping part 41 and the second gripping part 42 are gripping the resin member 21B. In particular, in the welding apparatus 40, the sensor 49 is capable of detecting the resin member 21B, and the movable parts 46 and 47 can align the resin member 21B based on the detection result of the sensor 49. For example, the movable parts 46 and 47 can align the resin member 21B in the Y-axis direction so that the edges of the resin member 21B are detected by a plurality (in this case, two) of sensors 49 (e.g., photoelectric sensors or cameras) arranged along the X-axis direction. The movable parts 46 and 47 are provided independently of each other, and the amount of movement of the first gripping part 41 along the Y-axis direction and the amount of movement of the second gripping part 42 along the Y-axis direction can be made different. This also makes it possible to correct the tilt of the resin member 21B with respect to the X-axis direction.

[0055] Next, an embodiment of the electrode unit manufacturing method will be described. Figure 6 is a flowchart of one step in the electrode unit manufacturing method. Here, the case using the electrode unit manufacturing apparatus 50 described above will be explained. As shown in Figure 6, in this manufacturing method, first, the base material 21A is pulled out from the holding part PA (step S101). More specifically, in step S101, the first gripping part 41 of the welding apparatus 40 grips one end of the base material 21A held in the holding part PA and is moved along the X-axis direction by the moving part 46, thereby pulling out the base material 21A from the holding part PA. Here, as described above, a pair of base materials 21A that are superimposed on each other are pulled out.

[0056] Next, the base material 21A is cut (step S102). More specifically, in step S102, the second gripping part 42 first grips the base material 21A, which has been pulled out by the movement of the first gripping part 41, at a position separated from the first gripping part 41. In step S102, in that state, the cutting part 43 cuts the base material 21A, thereby forming a resin member 21B that is gripped by the first gripping part 41 and the second gripping part 42. Here, as described above, a pair of resin members 21B that are superimposed on each other are formed.

[0057] Next, the resin members 21B are aligned (step S103). More specifically, in step S103, based on the detection result of the sensor 49 for the resin members 21B, the moving parts 46 and 47 move the first gripping part 41 and the second gripping part 42, which are gripping the resin members 21B, along the Y-axis direction, thereby aligning the pair of resin members 21B in the Y-axis direction. As a result, the pair of resin members 21B are aligned with respect to each of the welding parts 45 and set at the specified welding position.

[0058] Next, the resin members 21B are adsorbed (step S104). More specifically, in step S104, each of the pair of resin members 21B is adsorbed by the upper adsorption parts and the lower adsorption parts, which are positioned on either side of the pair of resin members 21B. In this state, after the gripping of the resin members 21B by the first gripping part 41 and the second gripping part 42 is released, the distance DB between the pair of resin members 21B is increased by moving the upper adsorption parts and the lower adsorption parts so that they are separated from each other.

[0059] Next, the bipolar electrode 11 is positioned on the resin member 21B (step S105, first step). More specifically, in step S105, the robot hand 30 holds the bipolar electrode 11 by adsorption and transports it in the air so that the second region A2 of one side 15a and the other side 15b of the current collector 15 of the bipolar electrode 11 faces the resin member 21B. Here, as shown in Figure 7, the robot hand 30 transports the bipolar electrode 11 so that the second region A2 is sandwiched between the pair of resin members 21B, whose spacing DB has been widened by the movement of the adsorption part 44. As a result, each of the pair of resin members 21B is positioned on one side 15a and the other side 15b of the current collector 15. In other words, in step S105, the adsorption unit 44 holds the resin member 21B before it is welded to the bipolar electrode 11, and also positions the resin member 21B on the current collector 15 (one side 15a and the other side 15b) of the bipolar electrode 11, which is held in mid-air by the robot hand 30.

[0060] Then, a pair of resin members 21B are welded to the bipolar electrode 11 (step S106, second step). More specifically, in step S106, the welding section 45 welds each of the pair of resin members 21B to one side 15a and the other side 15b of the current collector 15 in the second region A2. That is, in step S106, the welding section 45 welds each of the pair of resin members 21B to the current collector 15 while the pair of resin members 21B are positioned on one side 15a and the other side 15b of the current collector 15, respectively, due to the movement of the adsorption section 44. Here, the welding sections 45 are scattered in the longitudinal direction of the resin members 21B. Therefore, here, temporary welding is performed by the welding sections 45 to fix the resin members 21B to the current collector 15 by spot welding at multiple positions in the longitudinal direction of the resin members 21B.

[0061] In this embodiment, two welding devices 40 are arranged in parallel in the Y-axis direction. Therefore, the resin member 21B can be welded to each of the two side portions of the current collector 15 of the bipolar electrode 11 all at once. Subsequently, by repeating the same process on each of the other two side portions of the current collector 15 of the bipolar electrode 11, the resin member 21B is provided (temporarily welded) around the entire circumference of the peripheral edge 15c of the current collector 15. Therefore, in a later process, the entirety of these resin members 21B are welded to the current collector and the resin members 21B are integrated with each other, thereby providing a frame-shaped first resin layer 21 on the peripheral edge 15c of the current collector 15, and obtaining the electrode unit 11A.

[0062] As described above, the electrode unit manufacturing apparatus 50 according to this embodiment is for manufacturing an electrode unit 11A by welding a resin member 21B to a bipolar electrode 11 which includes a current collector 15 and an active material layer provided on one surface 15a and the other surface 15b of the current collector 15. The electrode unit manufacturing apparatus 50 includes a robot hand 30 that transports the bipolar electrode 11 in the air while adsorbing and holding it, and a welding apparatus 40 which includes a welding section 45 for welding the resin member 21B to the bipolar electrode 11 which is adsorbed and held in the air by the robot hand 30.

[0063] Furthermore, the electrode unit manufacturing method according to this embodiment is for manufacturing an electrode unit 11A by welding a resin member 21B to a bipolar electrode 11 which includes a current collector 15 and an active material layer provided on one surface 15a and the other surface 15b of the current collector 15. The electrode unit manufacturing method comprises a first step of transporting the bipolar electrode 11 in the air while adsorbing and holding it, and a second step of welding the resin member 21B to the bipolar electrode 11 in the state of being adsorbed and held in the air after the first step.

[0064] In the electrode unit manufacturing apparatus 50 and electrode unit manufacturing method according to this embodiment, when manufacturing an electrode unit 11A by welding a resin member 21B to a bipolar electrode 11, the resin member 21B is welded to the bipolar electrode 11 while the bipolar electrode 11 is held by adsorption and suspended in the air. Therefore, foreign matter that slides off from the bipolar electrode 11 is prevented from adhering to the next bipolar electrode 11. Thus, it is possible to weld the resin member 21B while suppressing the adhesion of foreign matter to the bipolar electrode 11.

[0065] Furthermore, in the electrode unit manufacturing apparatus 50 according to this embodiment, the welding apparatus 40 includes a suction unit 344 that holds the resin member 21B before it is welded to the bipolar electrode 11, and also places the resin member 21B on the surface (one surface 15a, the other surface 15b) of the bipolar electrode 11 while it is held in mid-air by the robot hand 30. The welding unit 45 then welds the resin member 21B, which has been placed on the surface by the suction unit 44, to the current collector 15. In this way, the resin member 21B is placed and welded to the surface of the current collector 15 of the bipolar electrode 11. Therefore, foreign matter that slides off from the bipolar electrode 11 is prevented from adhering to the next electrode, thus preventing foreign matter from being interposed between the bipolar electrode 11 and the resin member 21B during the placement and welding of the resin member 21B.

[0066] Furthermore, in the electrode unit manufacturing apparatus 50 according to this embodiment, one side 15a and the other side 15b of the current collector 15 have a first region A1 where an active material layer is formed and a second region A2 exposed from the active material layer, and the robot hand 30 transports the bipolar electrode 11 so that the second region A2 faces the resin member 21B. Then, the welding unit 45 welds the resin member 21B to the current collector 15 in the second region A2. In this way, the resin member 21B is positioned and welded to the second region A2 of the current collector 15 of the bipolar electrode 11 that is exposed from the active material layer. Therefore, foreign matter that slides off from the bipolar electrode 11 is prevented from adhering to the next bipolar electrode 11, and thus foreign matter is prevented from being interposed between the bipolar electrode 11 and the resin member 21B in the second region A2.

[0067] Furthermore, in the electrode unit manufacturing apparatus 50 according to this embodiment, the welding apparatus 40 includes a first gripping part 41 that pulls out the base material 21A from the holding part PA by gripping and moving one end of the base material 21A for the resin member 21B held in the holding part PA; a second gripping part 42 that further grips the base material 21A pulled out by the movement of the first gripping part 41 at a position separated from the first gripping part 41; and a cutting part 43 that forms the resin member 21B by cutting the base material 21A while maintaining the state of being gripped by the first gripping part 41 and the second gripping part 42. Therefore, the formation of the resin member 21B from the base material 21A can be easily performed.

[0068] Furthermore, in the electrode unit manufacturing apparatus 50 according to this embodiment, the welding apparatus 40 includes a sensor 49 that detects the resin member 21B after it has been formed by cutting the base material 21A of the cutting section 43 and is being held by the first gripping section 41 and the second gripping section 42, and moving sections 46 and 47 that, based on the detection result of the sensor 49, move the first gripping section 41 and the second gripping section 42 before the resin member 21B is held by the suction section 44 to align the resin member 21B. As a result, the positional accuracy of the resin member 21B with respect to the welding position is improved.

[0069] Furthermore, in the electrode unit manufacturing apparatus 50, the first gripping unit 41 grips and moves the pair of base materials 21A that are stacked and held in the holding unit PA, thereby pulling the pair of base materials 21A out from the holding unit PA. The second gripping unit 42 further grips the pair of base materials 21A that have been pulled out by the movement of the first gripping unit 41 at a position separated from the first gripping unit 41, and the cutting unit 43 cuts the pair of base materials 21A to form a pair of resin members 21B. Furthermore, the welding apparatus 40 includes a suction unit 44 that changes the spacing DB between the pair of resin members 21B by adsorbing at least one of the pair of resin members 21B formed by the cutting of the base materials 21A by the cutting unit 43 and moving in the stacking direction of the resin members 21B. The robot hand 30 then transports the bipolar electrode 11 so that the second region A2 is sandwiched between the pair of resin members 21B in a state where the spacing DB has been expanded by the movement of the suction unit 44. Then, the welding portion 45 welds the pair of resin members 21B to each of the one side 15a and the other side 15b of the current collector 15, respectively, when the pair of resin members 21B are positioned on each of the one side 15a and the other side 15b of the current collector 15 due to the movement of the suction portion 44. In this way, it is possible to form and weld the pair of resin members 21B to each of the one side 15a and the other side 15b of the current collector 15 by pulling out the base material 21A in one step by the first gripping portion 41 and cutting the base material 21A in one step by the cutting portion 43.

[0070] The embodiments described above illustrate one aspect of the present disclosure. Therefore, the present disclosure can be modified at will without limiting it to the embodiments described above.

[0071] For example, in the above embodiment, the process of temporarily welding a resin member 21B to the current collector 15 of the bipolar electrode 11 was described. However, the electrode unit manufacturing apparatus is not limited to one that places the resin member 21B and performs temporary welding by spot welding it to the current collector 15, but may also perform full welding to weld the entire resin member 21B to the current collector 15. In this case, the electrode unit manufacturing apparatus has a robot hand 30 that, while adsorbing and holding the electrode formed by temporarily welding a plurality (four) of resin members 21B to the current collector 15 as described above, transports it to another welding device. Then, with the robot hand 30 adsorbing and holding the electrode and suspending it in the air, the impulse sealer of the other welding device welds the entire plurality of resin members 21B to the current collector 15. As a result, the full welding of the resin member 21B is performed and a first resin layer 21 is formed on the peripheral edge 15c of the current collector 15 (i.e., the electrode unit 11A is manufactured).

[0072] Furthermore, the electrodes of the electrode unit manufacturing apparatus are not limited to the bipolar electrodes 11 described above, but can be any electrodes, such as a positive terminal electrode 13 and a negative terminal electrode 12, for example, where the active material layer is provided on only one side of the current collector. Moreover, the resin members welded to the electrodes are not limited to those that constitute the first resin layer 21, but can be any resin members, such as those that constitute the second resin layer 23.

[0073] Furthermore, the transport unit that holds the electrodes by adsorption and transports them in the air is not limited to the robot hand 30 described above, but other devices such as an overhead transport device may be used. In addition, the arrangement unit that holds the resin member 21B before it is welded to the electrodes is not limited to the adsorption unit 44 described above, but other devices such as a gripping device that grips the resin member 21B from a direction intersecting the stacking direction of the resin member 21B (Z-axis direction) may be used.

[0074] Here, Figure 8 shows a modified example of the welding apparatus. Figure 8(a) is a side view (viewed from the Y direction), and Figure 8(b) is a top view (viewed from the Z direction). As shown in Figure 8, the welding apparatus 40 (i.e., the electrode unit manufacturing apparatus 50) may further include a movable part 44b and a sensor 59. For example, the movable part 44b is provided on each of a plurality of pairs of suction parts 44. The movable part 44b can move the suction parts 44 at least along the Y axis.

[0075] The movable part 44b can align the resin member 21B in the Y-axis direction by moving the suction part 44 along the Y-axis direction while the suction part 44 is adsorbing (holding) the resin member 21B. At this time, the gripping of the resin member 21B by the first gripping part 41 and the second gripping part 42 may be released. In the welding apparatus 40, the sensor 49 is capable of detecting the resin member 21B adsorbed by the suction part 44, and the movable part 44b can align the resin member 21B based on the detection result of the sensor 49. As an example, the movable part 44b can align the resin member 21B in the Y-axis direction so that the edges of the resin member 21B are detected by a plurality of sensors 49 arranged along the X-axis direction. The movable parts 44b are provided independently of each other, and it is also possible to correct the inclination of the resin member 21B with respect to the X-axis direction by making the amount of movement of each along the Y-axis direction different. Furthermore, if the welding device 40 is equipped with a movable part 44b, the functions of the movable parts 46 and 47 related to the alignment of the resin member 21B (movement functions of the first gripping part 41 and the second gripping part 42 along the Y-axis direction) may be omitted. In the example shown in Figure 8, the movable parts 46 and 47 are not provided.

[0076] Furthermore, if the welding device 40 is equipped with a movable part 44b, the order of steps S103 and S104 of the electrode unit manufacturing method described above can be reversed. In this case, first, in step S104, the resin member 21B is adsorbed and held by the adsorption part 44. Then, for example, after the first gripping part 41 and the second gripping part 42 release the grip of the resin member 21B, in step S103, based on the detection result of the sensor 49 for the resin member 21B, the movable part 44b moves the adsorption part 44, which is holding the resin member 21B, along the Y-axis direction, thereby aligning the resin member 21B in the Y-axis direction. As a result, the resin member 21B is aligned with each of the welding parts 45 and set at the specified welding position.

[0077] Furthermore, the welding apparatus 40 (i.e., the electrode unit manufacturing apparatus 50) may be further equipped with a sensor 59. The sensor 59 is positioned at the tip of the base material 21A in the withdrawal direction (in this case, the X-axis direction). The sensor 59 may be, for example, a photoelectric sensor or a camera, and may be positioned to detect the boundary between the base material 21A and the first gripping part 41 when the base material 21A is withdrawn to a specified length. This makes it possible for the welding apparatus 40 to determine whether the withdrawal length of the base material 21A is sufficient based on the detection result of the sensor 59.

[0078] The welding device 40 does not necessarily have to be equipped with a first gripping section 41, a second gripping section 42, and a cutting section 43. In this case, the welding device 40 can receive a supply of resin material 21B from an external source. In this case, the welding device 40 can adsorb and hold the resin material 21B supplied from an external source, or arrange the resin material 21B on one side 15a and the other side 15b of the bipolar electrode 11, by receiving movement in the Z-axis direction, for example, to expand the spacing DB, or movement in the Y-axis direction by the moving section 44b.

[0079] Furthermore, the welding apparatus 40 is not limited to the case where, after pulling out a pair of stacked base materials 21A from the holding part PA, a pair of resin members 21B are obtained by moving the suction part 44 in the Z-axis direction to widen the distance DB between them. For example, the apparatus may be configured to pull out the base materials 21A from a plurality of holding parts that each hold a pair of base materials 21A, and then cut each of the base materials 21A to obtain the resin members 21B.

[0080] Furthermore, in the welding apparatus 40, alignment of the resin member 21B using sensors 49, 59 and movable parts 46, 47, 44b is not required. [Explanation of Symbols]

[0081] 11...Bipolar electrode (electrode), 11A...Electrode unit, 15...Current collector, 15a...One side (front), 15b...Other side (back), 21A...Base material, 21B...Resin component, 30...Robot hand (transport section), 40...Welding device, 41...First gripping section, 42...Second gripping section, 43...Cutting section, 44...Adsorption section (placement section), 44b...Moving section, 45...Welding section, 46,47...Moving section, 48...Guide section, 49...Sensor, 50...Electrode unit manufacturing device.

Claims

1. An electrode unit manufacturing apparatus for manufacturing an electrode unit by welding a resin member to an electrode that includes a current collector and an active material layer provided on the current collector, A transport unit that transports the electrodes in the air while adsorbing and holding them, A welding apparatus including a welding section for welding the resin member to the electrode, which is held in a state of adsorption in the air by the transport section, Equipped with, The current collector includes the front surface and the back surface opposite to the front surface, The welding portion is formed by welding the resin member to the peripheral edge on the surface and the peripheral edge on the back surface of the current collector of the electrode, which is held in a state of adsorption in the air by the transport portion. The electrode has the active material layer provided on its surface and the active material layer provided on its back surface. Electrode unit manufacturing equipment.

2. The welding apparatus includes a section for holding the resin member before it is welded to the electrode, and a section for positioning the resin member on the surface of the electrode while it is held in air by adsorption in the transport section. The welding portion welds the resin member, which is positioned on the surface by the arrangement portion, to the current collector. The electrode unit manufacturing apparatus according to claim 1.

3. The welding apparatus is, A first gripping part pulls the base material out of the holding part by moving while gripping one end of the base material held in the holding part, A second gripping portion further grips the base material, which has been pulled out by the movement of the first gripping portion, at a position separated from the first gripping portion. A cutting portion is formed by cutting the base material while maintaining the gripped state between the first gripping portion and the second gripping portion, including, The electrode unit manufacturing apparatus according to claim 2.

4. The welding apparatus is, A sensor for detecting the resin member being held by the first gripping portion and the second gripping portion, The system includes a moving unit that moves the first gripping unit and the second gripping unit before the resin member is held by the arrangement unit, thereby aligning the resin member based on the detection result of the sensor. The electrode unit manufacturing apparatus according to claim 3.

5. The first gripping portion moves while gripping the pair of base materials stacked and held in the holding portion, thereby pulling the pair of base materials out from the holding portion. The second gripping portion further grips the pair of base materials that have been pulled out by the movement of the first gripping portion at a position separated from the first gripping portion. The cut portion forms a pair of resin members by cutting a pair of the base material. The arrangement unit moves in the stacking direction of the resin members while holding at least one of the pair of resin members, thereby changing the distance between the pair of resin members. The transport unit transports the electrodes such that the current collector is sandwiched between a pair of resin members whose spacing has been widened by the movement of the arrangement unit. The welding portion welds each of the pair of resin members to the current collector when the pair of resin members are positioned on the surface and back surfaces of the current collector, respectively, due to the movement of the arrangement portion. The electrode unit manufacturing apparatus according to claim 3 or 4.

6. The welding apparatus is, A sensor for detecting the resin member in the state held by the arrangement portion, A moving unit that moves the arrangement unit while the resin member is held by the arrangement unit, thereby aligning the resin member based on the detection result of the sensor, is included. The electrode unit manufacturing apparatus according to claim 2 or 3.

7. A method for manufacturing an electrode unit, comprising welding a resin member to an electrode including a current collector and an active material layer provided on the current collector, The first step involves transporting the electrode in the air while adsorbing and holding it, Following the first step, a second step is performed in which the resin member is welded to the electrode, which is held in place by adsorption in the air. Equipped with, The current collector includes the front surface and the back surface opposite to the front surface, In the second step, the resin member is welded to the peripheral edge on the surface and the peripheral edge on the back surface of the current collector of the electrode, which is held in place by adsorption in the air. The electrode has the active material layer provided on its surface and the active material layer provided on its back surface. Method for manufacturing electrode units.

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