JP2009117052A - Method and device for manufacturing bipolar battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a bipolar battery having high battery performance by suppressing mixing of air bubbles. <P>SOLUTION: The method of manufacturing the bipolar battery includes: an electrolyte arranging process arranging gel polymer-based electrolytes 34, 35 on at least one surface of a bipolar electrode in which a positive electrode 23 is formed on one surface of a current collector 21 and a negative electrode 22 is formed on the other surface; a separator arranging process arranging a separator 31 having gas permeability so as to permeate the electrolytes 34, 35 on either one surface of the positive electrode 23 and the negative electrode 22 on which the electrolytes 34, 35 are arranged; and a viscosity control process lowering the viscosity of the electrolytes 34, 35 before the separator 31 is arranged. Thereby, the viscosity of the electrolyte 35 on which the separator 31 is arranged in the separator arranging process is lowered. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

When manufacturing a bipolar battery, a separator is superimposed on a gel polymer electrolyte, and the separator is impregnated with the gel polymer electrolyte (see, for example, Patent Document 1).
JP-A-11-204136

  However, when the separators are stacked on the gel polymer electrolyte, wrinkles may be formed in the separators to form minute gaps or bubbles may be mixed. In that case, the gel polymer electrolyte has high adhesiveness. For this reason, the gel polymer electrolyte and the separator are in close contact with each other while leaving bubbles, and the bubbles cannot be easily discharged, so that a bipolar battery having residual bubbles may be manufactured. Residual bubbles generate a dead space in which ions cannot pass through and move electrons, causing a problem in that the battery performance is degraded.

  The present invention has been made in order to solve the problems associated with the above-described prior art, and provides a manufacturing method and a manufacturing apparatus for manufacturing a bipolar battery having good battery performance by suppressing the mixing of bubbles. The purpose is to do.

  In order to achieve the above object, the uniform phase of the present invention is such that a gel polymer electrolyte is disposed on at least one surface of a bipolar electrode in which a positive electrode is formed on one surface of a current collector and a negative electrode is formed on the other surface. An electrolyte disposing step, a separator disposing step of disposing a separator having air permeability so that the electrolyte permeates on one surface of the positive electrode and the negative electrode where the electrolyte is disposed, and before the separator is disposed. And a method of manufacturing a bipolar battery having a viscosity control step of reducing the viscosity of the electrolyte.

  Another uniform phase of the present invention for achieving the above object is that the gel polymer electrolyte permeates the bipolar electrode in which the positive electrode is formed on one surface of the current collector and the negative electrode is formed on the other surface. This is an apparatus for manufacturing a bipolar battery in which an electrolyte layer including a breathable separator is provided and a plurality of these layers are stacked. The said manufacturing apparatus has a viscosity control means to reduce the viscosity of the said electrolyte, and the said separator is arrange | positioned at the said electrolyte with which the viscosity fell.

  According to the uniform phase of the present invention, as the viscosity of the electrolyte in the viscosity control step decreases, the tackiness also decreases. Therefore, in the separator placement step, the separator is the surface of the electrolyte (the bipolar electrode on which the electrolyte is placed). On one side). Therefore, it is possible to suppress the formation of minute gaps in the separator due to wrinkles in the separator or the inclusion of bubbles, and the generation of dead spaces that cannot transmit ions and move electrons, resulting in residual bubbles that cause a decrease in battery performance. Reduced. That is, by suppressing the mixing of bubbles, a manufacturing method for manufacturing a bipolar battery having good battery performance can be provided.

According to another uniform phase of the present invention, when the viscosity of the electrolyte is lowered by the viscosity control means, the adhesiveness of the electrolyte is lowered, so that the separator can be smoothly disposed on the surface of the electrolyte. Therefore, it is possible to suppress the formation of minute gaps due to the formation of wrinkles in the separator and the introduction of bubbles, and to create a dead space where ions cannot permeate and move electrons. It is possible to reduce. That is, it is possible to provide a manufacturing apparatus for manufacturing a bipolar battery having good battery performance by suppressing the mixing of bubbles.

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

  FIG. 1 is a perspective view for explaining the bipolar battery according to the first embodiment, and FIG. 2 is a cross-sectional view for explaining the bipolar battery according to the first embodiment.

  The bipolar battery 10 is a lithium secondary battery, and, as will be described later, has an excellent battery performance by suppressing the mixing of bubbles, and is disposed in the exterior case 14 and the exterior case 14. 16 and terminal plates 11 and 12.

  The exterior case 14 is used to prevent external impacts and environmental degradation, and is formed by joining a part or all of the outer peripheral portion of the sheet material by thermal fusion. The sheet material is a sheet material such as a polymer-metal composite laminate film in which a metal (including an alloy) such as aluminum, stainless steel, nickel, or copper is covered with an insulator such as a polypropylene film from the viewpoint of weight reduction and thermal conductivity. It is preferable that it is comprised.

  The laminate 16 includes a plurality of single cells (battery elements), and includes a bipolar electrode 20, an electrolyte layer 30, a first seal portion 25, and a second seal portion 27. The bipolar electrode 20 has a negative electrode 22, a positive electrode 23, and a current collector 21. The positive electrode 23 and the negative electrode 22 are formed on one and the other surfaces of the current collector 21, and the current collector 21 is located between the positive electrode 23 and the negative electrode 22.

The negative electrode 22 has a negative electrode active material made of hard carbon (non-graphitizable carbon material). As the negative electrode active material, for example, a graphite-based carbon material or a lithium-transition metal composite oxide can be used. However, a negative electrode active material composed of carbon and a lithium-transition metal composite oxide is preferable from the viewpoint of capacity and output characteristics. The positive electrode 23 has a positive electrode active material made of LiMn ₂ O ₄ . The positive electrode active material is not limited to LiMn ₂ O ₄ , but it is preferable to apply a lithium-transition metal composite oxide from the viewpoint of capacity and output characteristics. The thicknesses of the positive electrode 23 and the negative electrode 22 are appropriately set in consideration of the intended use of the battery (for example, emphasis on output or energy) and ion conductivity.

  The current collector 21 is formed from a stainless steel foil. As a material for the current collector 21, an aluminum foil, a nickel / aluminum clad material, a copper / aluminum clad material, or a plating material of a combination of these metals can be used.

  The electrolyte layer 30 includes a base layer formed by infiltrating the electrolyte into a breathable separator, and a surface layer formed of an electrolyte that conducts ions between the separator and the positive electrode 23 or between the separator and the negative electrode 22.

  The separator is formed from porous (porous) PE (polyethylene). As a material for the separator, other polyolefins such as PP (polypropylene), a laminate having a three-layer structure of PP / PE / PP, polyamide, polyimide, aramid, and non-woven fabric can be used. Nonwoven fabrics are, for example, cotton, rayon, acetate, nylon, and polyester. In addition, although a separator is an insulator, when electrolyte penetrates, it will exhibit ion permeability and electrical conductivity.

  The electrolyte is a gel polymer system and has an electrolytic solution and a host polymer.

The electrolytic solution contains an organic solvent composed of PC (propylene carbonate) and EC (ethylene carbonate), and a lithium salt (LiPF ₆ ) as a supporting salt. As the organic solvent, for example, other cyclic carbonates, chain carbonates such as dimethyl carbonate, and ethers such as tetrahydrofuran can be applied. As the lithium salt, for example, other inorganic acid anion salts and organic acid anion salts such as LiCF ₃ SO ₃ can be applied.

  The host polymer is PVDF-HFP (copolymer of polyvinylidene fluoride and hexafluoropropylene) containing 10% of HFP (hexafluoropropylene) copolymer. As the host polymer, other polymer having no lithium ion conductivity or polymer having ion conductivity (solid polymer electrolyte) can be applied. Other polymers having no lithium ion conductivity are, for example, PAN (polyacrylonitrile) and PMMA (polymethyl methacrylate). Examples of the polymer having ion conductivity include PEO (polyethylene oxide) and PPO (polypropylene oxide).

  The separator is used when the bipolar battery 10 is manufactured. Arranged in electrolyte with reduced viscosity. Since the adhesiveness of the electrolyte decreases as its viscosity decreases, the separator is smoothly disposed on the surface of the electrolyte (one side of the bipolar electrode on which the electrolyte is disposed). Therefore, it is possible to suppress the formation of minute gaps in the separator due to wrinkles in the separator or the inclusion of bubbles, and the generation of dead spaces that cannot transmit ions and move electrons, resulting in residual bubbles that cause a decrease in battery performance. Has been reduced.

  The first seal portion 25 is a filling portion that is disposed on one surface of the current collector 21 and extends so as to surround the periphery of the positive electrode 23 and exhibits a good sealing effect, for example, internal mixing of moisture Suppress. The electrolyte layer 30 is disposed so as to cover the positive electrode 23 and the first seal portion 25. The second seal portion 27 is a filling portion that is aligned with the first seal portion 25, is disposed on the other surface of the current collector 21, and extends so as to surround the periphery of the negative electrode 22. An effect is exhibited, for example, internal mixing of moisture is controlled.

  The sealing material constituting the first seal part 25 and the second seal part 27 is a one-component thermosetting epoxy resin. As the sealing material, other thermosetting resins (polypropylene, polyethylene, etc.) and thermoplastic resins can be applied. However, for example, it is preferable to select a material that exhibits a good sealing effect in the usage environment according to the application.

  The terminal plates 11 and 12 are made of a highly conductive member, extend from the inside of the outer case 14 to the outside, and also serve as electrode tabs for drawing current from the laminate 16. It is also possible to draw current from the stacked body 16 by disposing independent electrode tabs and connecting them to the terminal plates 11 and 12 directly or using leads. The highly conductive member is, for example, aluminum, copper, titanium, nickel, stainless steel, or an alloy thereof.

  The terminal plates 11 and 12 are arranged in the outermost layer (the uppermost layer and the lowermost layer) of the multilayer body 16 and are configured to cover at least all of the electrode projection surfaces. Therefore, the current extraction portion (current extraction in the surface direction) in the outermost layer is reduced in resistance, and the output of the battery can be increased. Note that the terminal plates 11 and 12 can also be configured by the current collector 21 located in the outermost layer of the laminate 16. It is also possible to arrange a reinforcing plate on the outer side of the terminal plates 11 and 12.

  FIG. 3 is a perspective view for explaining an assembled battery using the bipolar battery shown in FIG.

  The bipolar battery 10 can be used alone, but can be used in the form of the assembled battery 50. The assembled battery 50 is configured by serializing and / or paralleling bipolar batteries 10 and connecting a plurality of them, and has conductive bars 52 and 54. The conductive bars 52 and 54 are connected to terminal plates 11 and 12 extending from the outer case 14 of each bipolar battery 10. The connection method is, for example, ultrasonic welding, heat welding, laser welding, rivet, caulking, or electron beam. For example, when the bipolar battery 10 is connected, the capacity and voltage can be freely adjusted by appropriately connecting in series or in parallel.

  FIG. 4 is a schematic view of a vehicle on which the assembled battery shown in FIG. 3 is mounted.

  The assembled battery 50 itself can be provided in the form of an assembled battery module (large-sized assembled battery) 140 by serializing and / or parallelizing and connecting a plurality of the batteries. Since the assembled battery module 60 can ensure a large output, for example, it can be mounted as a motor driving power source for the vehicle 70. The vehicle is, for example, an electric vehicle, a hybrid electric vehicle, or a train.

  The assembled battery module 60 can perform very fine control such as performing charging control for each built-in exterior case 14 or each assembled battery 50, so that the travel distance per charge can be extended, and the life as an in-vehicle battery can be achieved. It is possible to improve the performance such as prolonging the time.

  FIG. 5 is an overall process diagram for explaining the manufacturing method of the bipolar battery according to the first embodiment, FIG. 6 is a process diagram for explaining the assembly forming process shown in FIG. 5, and FIG. FIG. 8 is a cross-sectional view for explaining the second sealing material placement step shown in FIG. 6, and FIG. 9 is a joined body formation shown in FIG. It is process drawing for demonstrating a process.

  The manufacturing method of the bipolar battery according to the first embodiment includes an assembly forming process for forming an assembly (sub-assembly unit), and an assembly forming process (assembly) for forming a stacked body (joint) of the assembly. Step) and an assembly step for accommodating the laminate in the outer case.

  The assembly forming process is divided into an electrode forming process, an electrolyte arranging process, a first sealing material arranging process, a viscosity control process, a separator arranging process, and a second sealing material arranging process.

  In the electrode forming step, the positive electrode slurry and the negative electrode slurry are respectively applied to one and the other surfaces of the current collector 21.

The positive electrode slurry has, for example, a positive electrode active material [85 wt%], a conductive additive [5 wt%], and a binder [10 wt%], and is adjusted to a predetermined viscosity by adding a viscosity adjusting solvent. Yes. The positive electrode active material is LiMn ₂ O ₄ . The conductive auxiliary agent is acetylene black. The binder is PVDF (polyvinylidene fluoride). The viscosity adjusting solvent is NMP (N-methyl-2-pyrrolidone). Carbon black or graphite can also be used as the conductive assistant. The binder and viscosity adjusting solvent are not limited to PVDF and NMP.

  The negative electrode slurry has, for example, a negative electrode active material [90% by weight] and a binder [10% by weight], and is adjusted to a predetermined viscosity by adding a viscosity adjusting solvent. The negative electrode active material is hard carbon. The binder and viscosity adjusting solvent are PVDF and NMP.

  The coating film of the positive electrode slurry and the coating film of the negative electrode slurry are dried using, for example, a vacuum oven to form the positive electrode 23 made of the positive electrode active material layer and the negative electrode 22 made of the negative electrode active material layer. At this time, NMP is removed by volatilization.

  In the electrolyte arrangement step, electrolytes 34 and 35 are applied to one and the other surfaces of the current collector 21. The application sites of the electrolytes 34 and 35 are the electrode portions of the positive electrode 23 and the negative electrode 22. A protective film is attached to the surface of the electrolyte 34 applied first. The protective film is formed from a resin such as polyethylene, for example.

  The electrolytes 34 and 35 include, for example, an electrolytic solution [90% by weight] and a host polymer [10% by weight], and are adjusted to a viscosity suitable for application by adding a viscosity adjusting solvent. The electrolytic solution contains an organic solvent composed of PC and EC, and a lithium salt as a supporting salt. The lithium salt concentration is 1M. The host polymer is PVDF-HFP containing 10% HFP copolymer. The viscosity adjusting solvent is DMC (dimethyl carbonate). The viscosity adjusting solvent is not limited to DMC. In this embodiment, the electrolytes 35 and 34 are applied to the positive electrode 23 and the negative electrode 22, and a protective film is attached to the electrolyte 34 on the negative electrode 22 side where the separator is not overlapped. In this case, the electrolyte 34 may be applied before the lamination process described later without applying the electrolyte 34.

  In the first sealing material arranging step, the first sealing material 24 is arranged so as to extend around the positive electrode side outer peripheral portion where the current collector 21 is exposed and the periphery of the positive electrode 23, and the semi-assembly 40 is formed. . The first sealing material 24 is a one-component thermosetting epoxy resin that constitutes the first sealing portion 25. For example, application using a dispenser is applied to the arrangement of the first sealing material 24.

  In the viscosity control step, the viscosity of the electrolyte 35 located on the surface of the semi-assembly 40 is lowered in a state where it is disposed on the bipolar electrode.

  In the separator arrangement step, the separator 31 is arranged so as to cover all of the positive electrode side surface (the surface of the electrolyte 35) of the current collector 21 included in the semi-assembly 40 (see FIG. 7). As a result, the separator 31 is overlaid on the electrolyte 35 and the first sealing material 24.

  The electrolyte 35 in which the separator 31 is disposed has a reduced viscosity. Since the adhesiveness of the electrolyte 35 decreases as its viscosity decreases, the separator 31 is arranged smoothly. Therefore, it is possible to suppress the formation of minute gaps in the separator due to wrinkles in the separator or the inclusion of bubbles, and the generation of dead spaces that cannot transmit ions and move electrons, resulting in residual bubbles that cause a decrease in battery performance. Reduced.

  In the second sealing material arranging step, the second sealing material 26 is arranged on the separator 31 to form an assembly (sub-assembly unit) 45 (see FIG. 8). At this time, the second sealing material 26 is positioned so as to be opposed (overlapped) with the arrangement site of the first sealing material 24. The second sealing material 26 is a one-component thermosetting epoxy resin that constitutes the second sealing portion 27. For example, application using a dispenser is applied to the second sealing material 26.

The thickness of the first sealing material 24 is set to be less than the total thickness of the positive electrode 23 and the electrolyte 34, and the thickness of the second sealing material 26 is set to be less than the total thickness of the negative electrode 22 and the electrolyte 35. Is preferred. In this case, since the separator 31 comes into contact with the central portion where the electrolytes 34 and 35 are provided before coming into contact with the first sealing material 24 and the second sealing material 26 located on the outer peripheral portion, the first sealing material 24 and the first sealing material 24 It is possible to suppress air bubbles from remaining inside the two sealing materials 26.

  Next, with reference to FIG. 9, a joined body forming process subsequent to the assembly forming process will be described.

  The joined body forming process is divided into a laminating process, a pressing process, a sealing material curing process, a gel interface forming process, an initial charging process, and a bubble discharging process.

  In the lamination step, the protective film is removed from the assembly 45 and sequentially set in a magazine. At this time, the assemblies 45 are arranged at intervals in the stacking direction so as not to contact each other. The stacking direction is a direction perpendicular to the surface direction of the assembly 45. When the set of the predetermined number of the assemblies 45 is completed, for example, the assemblies 45 are sequentially lowered to form a stacked body.

In the pressing step, the laminated body composed of the plurality of assemblies 45 is pressurized under vacuum so that the first and second sealing materials 24 and 26 have a predetermined thickness. For example, the degree of vacuum is 0.2 to 0.5 × 10 ⁵ Pa, and the applied pressure is 1 to 2 × 10 ⁶ Pa.

  In addition, since it is pressurization under a vacuum and mixing of the bubble with respect to the lamination | stacking interface of an electrode and an electrolyte layer is suppressed, possibility that the bipolar battery which has a residual bubble will be manufactured is further reduced. In addition, it is also preferable from the viewpoint of suppressing the mixing of bubbles that the magazine is placed under vacuum after the assembly 45 has been set in the stacking step to form a stack.

  In the sealing material curing step, the first and second sealing materials 24 and 26 are thermally cured by heating the laminate, and the first and second sealing portions 25 and 27 are formed. The heating condition is, for example, 80 ° C. For example, an oven can be used for heating the laminate.

  The bipolar battery 10 is a lithium secondary battery and dislikes moisture, but since the first and second seal portions 25 and 27 are made of resin, mixing of moisture is inevitable. Therefore, the predetermined thickness of the first and second sealing members 24 and 26 in the pressing process minimizes the thickness of the first and second sealing portions 25 and 27 that touch the outside air, thereby reducing the intruding moisture. It is set from the viewpoint.

In the gel interface forming step, by pressing the laminate under heating, the electrolytes 34 and 35 are permeated into the separator 31 included in the laminate, and a gel interface is formed. The heating temperature and the pressurizing condition are, for example, 80 ° C. and 1-2 × 10 ⁶ Pa. Thereby, the laminated body (joined body) 16 (refer FIG. 2) with which the some assembly 45 was integrated is obtained.

  In the initial charge step, the initial charge is performed by the charge / discharge device electrically connected to the laminate 16 to generate bubbles. The initial charging condition is, for example, 4 hours at 21 V-0.5 C on a capacity basis estimated from the coating weight of the positive electrode.

  In the bubble discharging step, for example, by pressing the surface of the laminate 16 with a roller, the bubbles located at the center of the laminate 16 are moved to the outer peripheral portion and removed. Therefore, it is possible to improve the output density of the battery. In the gel interface forming step, the bubbles are already sufficiently discharged, so the bubble discharging step is not always necessary, but this step makes it possible to more reliably suppress the bubbles.

  In the assembly process subsequent to the joined body forming process (assembly process), the laminate 16 is accommodated in the outer case 14 to manufacture the bipolar battery 10 (see FIG. 1).

  Next, the viscosity control apparatus applied to the viscosity control step will be described in detail.

  10 is a side view for explaining the viscosity control device applied to the viscosity control step shown in FIG. 5, FIG. 11 is a front view of the viscosity control device shown in FIG. 9, and FIG. 13 is a cross-sectional view relating to XIII-XIII in FIG. 12, FIG. 14 is a cross-sectional view relating to XIV-XIV in FIG. 12, and FIG. 15 is for explaining the collar shown in FIG. FIG. 16 is a side view of the collar of FIG. 15, FIG. 17 is a plan view for explaining the sleeve shown in FIG. 12, and FIG. 18 is a side view of the sleeve of FIG.

  The bipolar battery manufacturing apparatus according to the first embodiment includes a viscosity control device (viscosity control unit) 100 including a pallet 110, a pedestal unit 120, a roller unit (cooling unit) 130, a driving unit 170, and a chamber 190.

  The pallet 110 is used to load the semi-assembly 40 from the first sealing material arranging step, and has a clamp portion 112 for fixing the end of the semi-assembly 40. The semi-assembly 40 includes electrolytes 34 and 35 disposed on both surfaces of the bipolar electrode, and a first sealing material extending around the positive electrode 23 and the positive electrode 23 on the positive electrode side outer periphery. 24.

  The pedestal part 120 includes a support part 122 on which the pallet 110 is placed, a stopper 124 for stopping the movement of the pallet 110, and a locating pin 126 for positioning the pallet 110 at a predetermined position.

  The roller unit 130 is used to reduce the viscosity of the electrolyte 35 located on the surface of the semi-assembly 40, and includes a roller 131, a shaft 137, a refrigerant passage 140, and a bearing unit 150.

  The roller 131 includes a central portion 133 and end portions 132 and 134 positioned on both sides of the central portion 133, and is disposed so as to be in contact with the electrolyte 35 positioned on the surface of the semi-assembly 40. The central portion 133 and the end portions 132 and 134 are separate members, and are integrated by appropriate fastening means such as bolts via a first O-ring 134 that extends in the vicinity of the outer periphery along the outer periphery. The shaft 137 is disposed through the shaft portion of the roller 131, and the roller 131 is rotatable.

  The refrigerant passage 140 is used for circulating a refrigerant that cools the roller 131, and includes a connecting portion 142, a radial portion 143, an annular portion 144, and a cylindrical portion 145.

  The connecting portion 142 is a passage that extends the shaft portion of one end and the other end of the shaft 137. The connecting portion 142 on the end 132 side of the roller 131 is communicated with a tube 138 through which a refrigerant is supplied via a connector 141. The connecting portion 142 on the end portion 134 side of the roller 131 is communicated with a tube 139 through which a refrigerant is discharged via a connector 149. It is preferable that the tubes 138 and 139 are insulated by wrapping a heat insulating material to prevent moisture in the atmosphere from condensing.

  The radial portion 143 is a cross-shaped passage extending from the central portion of the roller 131 toward the outer periphery, and communicates with the connecting portion 142. The annular portion 144 is a passage extending along the outer periphery of the roller 131 and communicates with the radial portion 143. In the first embodiment, a cross-shaped groove and an annular groove extending along the outer periphery are formed on the end surface of the central portion 133 of the roller 131, and the radial portion is brought into contact with the end surface of the central portion 133. 143 and an annular portion 144 are formed (see FIG. 13).

  The cylindrical portion 145 is arranged at eight locations along the outer periphery, extends in the vicinity of the outer periphery of the central portion 133 of the roller 131 along the longitudinal direction, and is a radial portion located on one end surface of the central portion 133. 143 and the radial portion 143 located on the other end face of the central portion 133 are communicated with each other. The number of installation places of the cylindrical portion 145 is not particularly limited to eight places.

  In the refrigerant passage 140 configured as described above, when a refrigerant is introduced into the tube 138, the refrigerant is supplied into the roller 131 via the connector 141, and after cooling the roller 131, the tube passes through the connector 149. 139 is discharged. Thereby, compared with the electrolyte located on the surface of the semi-assembly 40, the temperature of the roller 131 is lowered. Therefore, when contacting the electrolyte, the electrolyte is cooled and its viscosity is also lowered.

  The refrigerant is not particularly limited. However, when the electrolyte is cured, for example, when the electrolyte is cooled to −58 ° C., it is preferable to use a cryogenic fluid such as liquid nitrogen (−196 ° C. (77 K)) as the refrigerant.

  The bearing portion 150 is configured to rotatably support the roller 131 and prevent the refrigerant flowing through the refrigerant passage 140 from leaking out. The bearing 152, the collar 153, the second O-ring 154, the sleeve 155, and the third O-ring 156 are arranged. Have.

  The bearing 152 is disposed on the end surfaces of the end portions 132 and 134 of the roller 131, and the shaft 137 passes therethrough. The second O-ring 154 is disposed inside the bearing 152. The collar 153 (see FIGS. 14 and 15) is disposed between the bearing 152 and the second O-ring 154.

  The sleeve 155 (see FIGS. 16 and 17) has a cylindrical shape, an opening corresponding to the radial portion 143 of the refrigerant passage 140 is formed in the outer peripheral portion, and the connecting portion of the refrigerant passage 140 disposed on the shaft 137. 142 and the radial surface 143 disposed on the roller 131 are positioned on the connection surface. The third O-ring 156 is disposed inside the sleeve 155 and is located in the vicinity of the end surface of the central portion 133 of the roller 131.

  The material of the first O-ring 134, the second O-ring 154, and the third O-ring 156 is not particularly limited as long as it has a good sealing property. However, for example, when a cryogenic fluid such as liquid nitrogen is used as the refrigerant, it is preferable to apply fluororesin such as fluoro rubber, polytetrafluoroethylene (PTFE), or PTFE-coated metal.

  The driving unit 170 is used for rotation and horizontal movement of the roller 131, and includes a frame 172, a first servo motor 176, an air cylinder unit 178, and a linear actuator 180.

  The frame 172 supports the shaft 137 of the roller unit 130. The first servo motor 176 is connected to the roller 131 via a harmonic drive speed reducer 174 and a gear mechanism 175. Therefore, the roller 131 can be rotated by controlling the first servo motor 176.

  The air cylinder portion 178 is connected to the upper center of the frame 172 and is set so that the roller 131 is brought into contact with the electrolyte 35 located on the surface of the semi-assembly 40 by lowering the frame 172. Yes.

The linear actuator 180 supports the air cylinder part 178 and is used to move the roller 131 horizontally via a frame 172 connected to the air cylinder part 178. The linear actuator 180 supports the support part 182, the guide rail part 183, and the ball. A screw portion 185 and a second servo motor 188 are provided.

  The support portion 182 is connected to the chamber 190, and the guide rail portion 183 and the ball screw portion 185 are fixed thereto. The guide rail portion 183 supports the air cylinder portion 178 so as to be slidable. The ball screw part 185 is set to drive the air cylinder part 178 in the horizontal direction by rotating.

  The second servo motor 188 is connected to the ball screw portion 185 via the coupling 186. Therefore, by controlling the second servo motor 188, the roller 131 can be moved horizontally via the ball screw portion 185, the air cylinder portion 178, and the frame 172. The first servo motor 176 and the second servo motor 188 are synchronously controlled.

  The chamber 190 is used to accommodate the pallet 110, the pedestal part 120, the roller part 130, and the driving means 170. The support part 122 of the pedestal part 120 is placed on the lower part, and the linear actuator 180 of the driving means 170 is placed on the upper part. The support part 182 is connected.

  Therefore, the viscosity control apparatus 100 cools the entire surface of the electrolyte 35 by causing the low temperature roller 131 to contact the electrolyte 35 positioned on the surface of the semi-assembly 40 and horizontally move it while rotating, so that the viscosity of the electrolyte 35 is reduced. Can be reduced.

  As described above, the method for manufacturing a bipolar battery according to Embodiment 1 has a viscosity control step for reducing the viscosity of the electrolyte. As the viscosity of the electrolyte in the viscosity control step decreases, its adhesiveness also decreases. Therefore, in the separator placement step, the separator is smoothly placed on the electrolyte surface (one side of the bipolar electrode on which the electrolyte is placed). The Therefore, it is possible to suppress the formation of minute gaps in the separator due to wrinkles in the separator or the inclusion of bubbles, and the generation of dead spaces that cannot transmit ions and move electrons, resulting in residual bubbles that cause a decrease in battery performance. Reduced. That is, by suppressing the mixing of bubbles, a manufacturing method for manufacturing a bipolar battery having good battery performance can be provided.

  Moreover, the viscosity of the electrolyte is lowered by cooling the electrolyte, and the viscosity of the electrolyte can be easily lowered.

  The electrolyte is preferably cooled until it is cured. in this case. Since the adhesiveness of the cured electrolyte is extremely low, the separator is arranged more smoothly on the surface of the electrolyte. Therefore, the occurrence of wrinkles in the separator to form a minute gap or the mixing of bubbles is reliably suppressed.

  Further, the viscosity control step is located after the electrolyte placement step, and in the viscosity control step, the electrolyte is cooled in a state of being placed on both surfaces of the bipolar electrode. Therefore, workability is good because the electrolyte is cooled immediately before the separator is disposed.

  The electrolyte is cooled by bringing a roller having a temperature lower than that of the electrolyte into contact therewith. In other words, the cooling of the electrolyte is efficient because it is caused by the heat conduction of the abutting roller. Further, since the refrigerant circulates inside the roller, the roller can be cooled easily and efficiently.

On the other hand, the bipolar battery manufacturing apparatus according to Embodiment 1 has a viscosity control apparatus for reducing the viscosity of the electrolyte. Therefore, when the viscosity of the electrolyte is lowered by the viscosity control means, the adhesiveness of the electrolyte is lowered, so that the separator can be smoothly disposed on the surface of the electrolyte. Therefore, it is possible to suppress the formation of minute gaps due to the formation of wrinkles in the separator and the introduction of bubbles, and to create a dead space where ions cannot permeate and move electrons. It is possible to reduce. That is, it is possible to provide a manufacturing apparatus for manufacturing a bipolar battery having good battery performance by suppressing the mixing of bubbles.

  Since the viscosity control device has a roller portion for cooling the electrolyte, the viscosity of the electrolyte can be easily reduced. The roller portion can be cooled until the electrolyte is cured. In this case, since the adhesiveness of the cured electrolyte is extremely low, the separator can be arranged more smoothly on the surface of the electrolyte. Therefore, it is possible to reliably suppress the occurrence of wrinkles in the separator and the formation of a minute gap or the mixing of bubbles.

  The roller portion can cool the electrolyte in a state where the electrolyte is disposed on both surfaces of the bipolar electrode. In this case, since the electrolyte is cooled immediately before the separator is disposed, it is possible to ensure good workability. The roller portion has a roller that is lower than the temperature of the electrolyte and that can freely come into contact with the electrolyte. Cooling of the electrolyte is caused by the heat conduction of the contacting roller, and thus becomes efficient. Since a piping system in which the refrigerant circulates is arranged inside the roller, the roller can be easily and efficiently cooled.

  FIG. 19 is a cross-sectional view for explaining the second embodiment.

  The second embodiment is generally different from the first embodiment regarding the structure of the chamber of the viscosity control device. In the following, members having the same functions as those of the first embodiment are denoted by similar reference numerals, and the description thereof is omitted to avoid duplication.

  The chamber 290 of the viscosity control apparatus 200 according to the second embodiment has a vacuum heat insulating double structure wall portion, and a cooling coil (dew point lowering means) 292 is disposed inside the wall portion. The refrigerant that circulates inside the cooling coil 292 is liquid nitrogen. For example, the cooling coil 292 is set such that the atmospheric temperature and the dew point inside the chamber 290 are −60 ° C. and −65 ° C.

  As described above, the second embodiment has the cooling coil 292 for reducing the dew point of the atmosphere. Therefore, in the viscosity control step, the roller 231 of the viscosity control device can cool the electrolyte 35 located on the surface of the semi-assembly 40 in an atmosphere in which the dew point is lowered, and moisture in the atmosphere is reduced. Since condensation (for example, condensation on the roller surface) does not occur, it is possible to avoid problems due to moisture mixing.

  FIG. 20 is a process diagram for explaining the manufacturing method of the bipolar secondary battery according to the third embodiment, and FIG. 21 is a cross-sectional view for explaining the viscosity control process according to the third embodiment.

  The third embodiment is generally different from the first embodiment regarding the execution order of the viscosity control step, and the viscosity control step is performed between the electrolyte arrangement step and the first seal material arrangement step. In this case, since the first sealing material 24 does not exist around the electrolyte 35 that lowers the viscosity, and there is no need to consider interference with the first sealing material 24, the control of the roller 331 for cooling the electrolyte 35 can be performed. Easy.

FIG. 22 is a process diagram for explaining the manufacturing method of the bipolar secondary battery according to the fourth embodiment, and FIG. 23 is a cross-sectional view for explaining the bipolar secondary battery manufacturing apparatus according to the fourth embodiment. Figure 24
FIG. 23 is a cross-sectional view for explaining an electrolyte arrangement step shown in FIG. 22.

  The fourth embodiment is generally different from the first embodiment with respect to the execution order of the viscosity control process and the configuration of the viscosity control device.

  The viscosity control process according to Embodiment 4 is located before the electrolyte placement process. Therefore, since electrolyte 35 is before being disposed on the bipolar electrode, it can be easily cooled as compared with the first embodiment.

  The viscosity control device 400 applied to the viscosity control step includes, for example, a chamber 490, a pedestal 420, and a cooling coil (cooling means and dew point lowering means) 430. The chamber 490 has a wall portion having a vacuum insulation double structure. The cooling coil 430 is disposed inside the wall portion of the chamber 490. The pedestal portion 420 is used to cure the electrolyte into a plate shape.

  The refrigerant that circulates inside the cooling coil 430 is liquid nitrogen. For example, the cooling coil 430 is set so that the atmospheric temperature inside the chamber 490 is −60 ° C. and the dew point is −65 ° C.

  Therefore, the electrolyte 35 placed on the pedestal part 420 is cooled and cured by the cooling coil 430, whereby the viscosity decreases. Moreover, since the electrolyte is cooled and the moisture in the atmosphere does not condense in an atmosphere where the dew point is lowered, problems due to the mixing of moisture can be avoided.

  In the electrolyte placement step, the cured electrolyte 35 is placed on the bipolar electrode.

  As described above, the viscosity control step according to the fourth embodiment is located before the electrolyte placement step, and the electrolyte 35 is before being placed on the bipolar electrode. Therefore, compared to the first embodiment, Cooling can be easily performed, and the configuration of the viscosity control device 400 can be simplified.

  From the viewpoint of productivity, it is also preferable to increase the size of the electrolyte 35 cured in the viscosity control device 400 and cut it into a strip shape as appropriate. In addition, the electrolyte placement step, the first seal material placement step, the separator placement step, and the second seal material placement step are performed in an atmosphere with a reduced dew point so that moisture in the atmosphere does not condense in the low temperature electrolyte 35. It is also preferable to carry out. Further, the electrolyte 34 can also be used after being cured in a plate shape.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.

  For example, a thermoplastic resin can be applied to the first and second sealing materials 24 and 26. In this case, the first and second seal members 24 and 26 are plastically deformed by heating to form the first and second seal portions 25 and 27.

  The electrolyte is not limited to the thermoplastic type, and a thermosetting type can also be applied. In this case as well, liquid leakage is prevented by curing the electrolyte layer by pressurization under heating, and a liquid junction can be prevented.

The surface pressure in the pressing step is not limited to 1 to 2 × 10 ⁶ Pa, and can be appropriately set in consideration of physical properties such as the strength of the constituent material of the laminate 16. The heating temperature in the sealing material curing step is not limited to 80 ° C., the heat resistance of the electrolytic solution, and the curing of the first sealing material 24 (first sealing portion 25) and the second sealing material 26 (second sealing portion 27). Considering physical properties such as temperature, for example, it is preferably 60 ° C to 150 ° C.

  By appropriately selecting the electrolytes 34 and 35 and the first and second sealing materials 24 and 26, the sealing material curing step and the gel interface forming step are integrated, and the first and second sealing materials 24 and 26 are cured and the electrolyte layer. It is possible to shorten the manufacturing process by simultaneously completing the above. It is also possible to add a step for attaching a tab (lead wire) for monitoring the potential of each layer (bipolar cell) of the laminate 16 between the sealing material curing step and the gel interface forming step. .

1 is a perspective view for explaining a bipolar battery according to Embodiment 1. FIG. 4 is a cross-sectional view for explaining the bipolar battery according to Embodiment 1. FIG. It is a perspective view for demonstrating the assembled battery using the bipolar battery shown by FIG. It is the schematic of the vehicle by which the assembled battery shown by FIG. 3 is mounted. FIG. 3 is an overall process diagram for explaining the manufacturing method of the bipolar battery according to the first embodiment. It is process drawing for demonstrating the assembly formation process shown by FIG. It is sectional drawing for demonstrating the separator arrangement | positioning process shown by FIG. It is sectional drawing for demonstrating the 2nd sealing material arrangement | positioning process shown by FIG. It is process drawing for demonstrating the conjugate | zygote formation process shown by FIG. It is a side view for demonstrating the viscosity control apparatus applied to the viscosity control process shown by FIG. It is a front view of the viscosity control apparatus shown by FIG. It is sectional drawing of the roller part shown by FIG. It is sectional drawing regarding XIII-XIII of FIG. It is sectional drawing regarding XIV-XIV of FIG. It is a top view for demonstrating the color shown by FIG. FIG. 16 is a side view of the collar of FIG. 15. It is a top view for demonstrating the sleeve shown by FIG. FIG. 18 is a side view of the sleeve of FIG. 17. FIG. 6 is a cross-sectional view for illustrating the second embodiment. FIG. 6 is a process diagram for explaining the manufacturing method of the bipolar secondary battery according to the third embodiment. 6 is a cross-sectional view for explaining a viscosity control step according to Embodiment 3. FIG. FIG. 10 is a process diagram for explaining the manufacturing method of the bipolar secondary battery according to the fourth embodiment. 6 is a cross-sectional view for explaining a bipolar secondary battery manufacturing apparatus according to Embodiment 4. FIG. FIG. 23 is a cross-sectional view for explaining an electrolyte arrangement step shown in FIG. 22.

Explanation of symbols

10 Bipolar battery,
11,12 terminal plate,
14 exterior case,
16 laminates,
20 bipolar electrodes,
21 current collector,
22 negative electrode,
23 positive electrode,
24, 26 sealing material,
25, 27 seal part,
30 electrolyte layer,
31 separator,
34,35 electrolyte,
40 semi-aggregates,
45 Assembly,
50 battery packs,
52, 54 conductive bar,
60 battery module,
70 vehicles,
100 Viscosity control device (viscosity control means),
110 palettes,
112 Clamp part,
120 pedestal,
122 support part,
124 stopper,
126 Locate pin,
130 roller section (cooling means),
131 Laura,
132,134 ends,
133 Central part,
134 1st O-ring,
137 shaft,
138, 139 tubes,
140 refrigerant passage,
141 149 connector,
142 connecting part,
143 radial part,
144 annulus,
145 cylindrical part,
150 bearing part,
152 bearing,
153 colors,
154 2nd O-ring,
155 sleeve,
156 3rd O-ring,
170 driving means,
172 frames,
174 Harmonic drive reducer,
175 gear mechanism,
176 1st servo motor,
178 Air cylinder part,
180 linear actuator,
182 support,
183 guide rail,
185 ball screw part,
186 coupling,
188 Second servo motor,
190 chambers,
200 Viscosity control device (viscosity control means),
231 Laura,
290 chambers,
292 cooling coil (dew point lowering means),
331 Roller,
400 Viscosity control device (viscosity control means),
420 pedestal,
430 cooling coil (cooling means and dew point lowering means),
490 chamber.

Claims (16)

A bipolar electrode in which a positive electrode is formed on one surface of a current collector and a negative electrode is formed on the other surface, and an electrolyte layer including a separator having air permeability is provided so that the electrolyte can permeate. A battery manufacturing method comprising:
An electrolyte disposing step of disposing a gel polymer electrolyte on at least one surface of the positive electrode and the negative electrode formed on the current collector;
A separator disposition step of disposing the separator on one surface of the positive electrode and the negative electrode where the electrolyte is disposed;
A bipolar battery manufacturing method comprising: a viscosity control step of reducing the viscosity of the electrolyte before the separator is disposed on one of the positive electrode and the negative electrode in the separator disposing step.   A step of forming a sub-assembly unit by a separator arrangement step of arranging the separator on one surface of the positive electrode and the negative electrode on which the electrolyte is arranged, and a plurality of the sub-assembly units are laminated to form a laminate. The bipolar battery manufacturing method according to claim 1, further comprising an assembly step.   The method for manufacturing a bipolar battery according to claim 1, wherein the viscosity of the electrolyte is lowered by cooling the electrolyte.   The method for manufacturing a bipolar battery according to claim 3, wherein the electrolyte is cooled until it is cured. The viscosity control step is located after the electrolyte placement step,
The method for manufacturing a bipolar battery according to claim 3 or 4, wherein, in the viscosity control step, the electrolyte is cooled in a state of being disposed on the electrode.   The method for manufacturing a bipolar battery according to claim 3, wherein the electrolyte is cooled by bringing a roller having a temperature lower than normal temperature into contact therewith.   The bipolar battery manufacturing method according to claim 6, wherein a refrigerant circulates inside the roller. The viscosity control step is located before the electrolyte placement step,
The method for manufacturing a bipolar battery according to claim 4, wherein, in the electrolyte placement step, the cured electrolyte is placed on at least one surface of the bipolar electrode.   The method for manufacturing a bipolar battery according to claim 3, wherein the electrolyte is cooled in an atmosphere having a dew point lowered. A bipolar electrode in which a positive electrode is formed on one surface of a current collector and a negative electrode is formed on the other surface, and an electrolyte layer including a separator having air permeability is provided so that the electrolyte can permeate. A battery manufacturing apparatus,
Having a viscosity control means for reducing the viscosity of the electrolyte,
The bipolar battery manufacturing apparatus, wherein the separator is disposed on the electrolyte having a reduced viscosity. The bipolar battery manufacturing apparatus according to claim 10, wherein the viscosity control unit includes a cooling unit that cools the electrolyte.   12. The bipolar battery manufacturing apparatus according to claim 11, wherein the cooling means cools the electrolyte until it is cured.   The bipolar battery manufacturing apparatus according to claim 11, wherein the cooling unit cools the electrolyte in a state where the electrolyte is disposed on the bipolar electrode.   The bipolar battery manufacturing apparatus according to claim 13, wherein the cooling unit includes a roller that can freely contact the electrolyte.   The bipolar battery manufacturing apparatus according to claim 14, wherein a passage through which a refrigerant circulates is disposed inside the roller. It has dew point lowering means to lower the dew point of the atmosphere,
The bipolar battery manufacturing apparatus according to any one of claims 11 to 15, wherein the cooling means cools the electrolyte under an atmosphere in which a dew point is lowered.

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