Cell holding device

Abstract

To provide a cell holding device that can improve the manufacturing accuracy of solid-state battery cells. [Solution] A cell holding device 1 used in the manufacture of a solid battery cell 100 comprising an electrode assembly 110 in which positive electrodes and negative electrodes are alternately stacked via a solid electrolyte, and a laminate film 120 covering the electrode assembly 110, the cell holding device 1 further comprising a current collector foil regulating jig 10 for guiding current collector foils 111 protruding from the electrode assembly 110, and a cell regulating jig 20 for holding the electrode assembly 110 in conjunction with the current collector foil regulating jig 10.

Description

Technical Field

[0001] The present invention relates to a cell holding device.

Background Art

[0002] An all-solid-state battery includes an electrode assembly in which a positive electrode and a negative electrode are alternately laminated via a solid electrolyte, and a current collector foil protruding from the electrode assembly. The all-solid-state battery expands in the stacking direction of the electrode assembly. Therefore, a surplus length is formed in the current collector foil so that the current collector foil is not stretched and broken due to the expansion of the all-solid-state battery. In order to form a surplus length in the current collector foil, the electrode assembly is sealed with a laminate film in a state where the current collector foil is pushed 2 mm toward the electrode assembly side along the direction perpendicular to the stacking direction of the electrode assembly.

[0003] When forming a surplus length in the current collector foil, the following problems occur. Since the rigidity of the current collector foil of the positive electrode and the current collector foil of the negative electrode are different, when pushing the current collector foil toward the electrode assembly side, the electrode group including the positive electrode and the negative electrode shifts. When the current collector foil is pushed in, due to the rigidity of the current collector foil, the electrode group protrudes to the outermost surface side in the stacking direction of the electrode assembly, damaging the laminate film covering the end of the electrode assembly. It is important that the center position of the current collector foil coincides with the center position of the electrode group. However, due to gravity, the electrode assembly is sealed with a laminate film in a state where the center position of the current collector foil and the center position of the electrode group are displaced.

[0004] As a method for solving the above problems, for example, it is known to provide a guide for reducing the tensile force of the current collector foil protruding from the electrode assembly (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] To solve the above-mentioned problems, this invention aims to provide a cell holding device that can improve the manufacturing accuracy of solid-state battery cells, thereby contributing to the stabilization of battery performance and, ultimately, to the efficiency of energy use. [Means for solving the problem]

[0007] [1] A cell holding device used in the manufacture of a solid battery cell, comprising an electrode assembly in which positive electrodes and negative electrodes are alternately stacked via a solid electrolyte, and a laminate film covering the electrode assembly, A current collector foil regulating jig that guides the current collector foil protruding from the electrode assembly, A cell holding device comprising a cell regulating jig that holds the electrode assembly in conjunction with the current collector foil regulating jig.

[0008] According to the above embodiment, the manufacturing accuracy of the solid battery cell can be improved by guiding the current collector foil and simultaneously holding the electrode assembly, thereby defining the position of the electrode assembly.

[0009] [2] The current collector foil regulating jig is movable along the stacking direction of the positive electrode and the negative electrode in the electrode assembly, The cell holding device according to [1], wherein the cell regulating jig is movable along the stacking direction of the positive electrode and the negative electrode in the electrode assembly in accordance with the movement of the current collector foil regulating jig.

[0010] According to the above embodiment, when the current collector foil regulating jig and the cell regulating jig move simultaneously, and the solid battery cell sinks downward in the stacking direction of the positive and negative electrodes in the electrode assembly due to its own weight, the solid battery cell can be positioned in the correct position between the two holding jigs.

[0011] [3] The cell holding device according to [1], further comprising a tab lead pressing jig, the tab lead pressing jig being movable along a direction perpendicular to the stacking direction of the positive electrode and the negative electrode in the electrode assembly, and pressing the current collector foil toward the electrode assembly along the vertical direction to form an excess length in the current collector foil.

[0012] According to the above embodiment, the current collector foil can be pushed into the electrode assembly to form an excess length.

[0013] [4] The cell holding device according to [3], wherein the current collector foil regulating jig offsets the position in which the current collector foils are bundled in the stacking direction.

[0014] According to the above embodiment, it is possible to suppress the occurrence of crank-shaped steps in the current collector foil.

[0015] [5] The cell holding device according to [1], comprising a jig positioned in the middle of the current collector foil to form an excess length on the current collector foil before sealing the laminate film.

[0016] According to the above embodiment, before sealing the laminate film, the middle of the current collector foil can be expanded to create excess length in the current collector foil.

[0017] [6] The cell holding device according to [5], wherein the jig is a wide plate that rotates 90 degrees with respect to the direction of convergence of the current collector foil.

[0018] According to the above embodiment, an excess length can be formed in the current collector foil.

[0019] [7] The cell holding device according to [5], further comprising a tab lead pushing jig, the tab lead pushing jig being movable along a direction perpendicular to the stacking direction of the positive electrode and the negative electrode in the electrode assembly, and pushing the current collector foil toward the electrode assembly side along the vertical direction to form an excess length in the current collector foil, and the tab lead pushing jig inserts the current collector foil toward the position where the jig was located.

[0020] According to the above aspect, the excess length of the current collector foil is formed into a shape that curves and separates from the center line in the stacking direction of the electrode assembly, and it is possible to suppress the current collector foil from being damaged by an external force.

Effect of the Invention

[0021] According to the present invention, it is possible to provide a cell holding device that can improve the manufacturing accuracy of a solid-state battery cell.

Brief Description of the Drawings

[0022] [Figure 1] It is a cross-sectional view showing a cell holding device according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view showing a cell holding device according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0024] [Cell Holding Device] FIG. 1 and FIG. 2 are cross-sectional views showing a cell holding device according to an embodiment of the present invention. In the drawings used in the following description, for the sake of clarity of the features, parts that are characteristic may be enlarged for convenience, and the dimensional ratios of each component are not limited to those shown in the drawings.

[0025] As shown in FIG. 1, the cell holding device 1 of the present embodiment includes a current collector foil regulating jig 10 and a cell regulating jig 20. The current collector foil regulating jig 10 and the cell regulating jig 20 are provided on one main surface 30a of the base 30. Specifically, the cell holding device 1 includes two (a pair) of holding jigs 40 including a current collector foil regulating jig 10, a cell regulating jig 20, and a base 30.

[0026] The cell holding device 1 of this embodiment is used in the manufacture of a solid battery cell 100 comprising an electrode assembly 110 in which positive and negative electrodes are alternately stacked via a solid electrolyte, and a laminate film 120 covering the electrode assembly 110. The holding jig 40 holds the solid battery cell 100 by sandwiching it from both sides (the outermost surface 100a and outermost surface 100b sides of the solid battery cell 100) in the stacking direction of the positive and negative electrodes in the electrode assembly 110. Specifically, the solid battery cell 100 is held by the two holding jigs 40 such that the surfaces 10a of each current collector foil regulating jig 10 of the two holding jigs 40 that contact the solid battery cell 100 (laminated film 120) face each other, and the surfaces 20a of each cell regulating jig 20 of the two holding jigs 40 that contact the solid battery cell 100 (laminated film 120) face each other.

[0027] The current collector foil regulating jig 10 guides the current collector foil 111 that protrudes from the electrode assembly 110. The current collector foil regulating jig 10 is provided at one end 30A of the base body 30 in a direction along the outermost surfaces 100a, 100b of the solid battery cell 100, perpendicular to one main surface 30a of the base body 30. That is, the current collector foil regulating jig 10 is provided so as to protrude from one main surface 30a of the base body 30 in a direction perpendicular to the other main surface 30a of the base body 30.

[0028] The cell regulating jig 20 holds the electrode assembly 110. The cell regulating jig 20 is positioned on one main surface 30a of the base body 30, spaced apart from the current collector foil regulating jig 10, and facing the edge 100A of the solid battery cell 100. The cell regulating jig 20 is also positioned perpendicular to one main surface 30a of the base body 30. That is, the cell regulating jig 20 is positioned so as to protrude perpendicularly from one main surface 30a of the base body 30. The cell regulating jig 20 can hold down the electrode assembly 110 to prevent it from shifting when the tab lead is pushed towards the electrode assembly 110 by the tab lead pushing jig 140.

[0029] The cell regulating jig 20 is preferably set close to the current collector foil 111 in order to prevent the electrode assembly 110 from shifting when the tab lead 130 is pressed in. Furthermore, the area in contact between the cell regulating jig 20 and the solid battery cell 100 is preferably 10% or more of the total surface area of ​​the outermost surfaces 100a and 100b of the solid battery cell 100, as if it is too small, a pressing load will be applied to a localized area of ​​the electrode assembly 110, causing damage to the electrode assembly 110.

[0030] As described above, the current collector foil restricting jig 10 and the cell restricting jig 20 are provided on the base body 30. Therefore, the current collector foil restricting jig 10 and the cell restricting jig 20 work in conjunction to hold the solid battery cell 100 (electrode assembly 110). In detail, when the holding jig 40 is moved in the direction of stacking of the positive and negative electrodes in the electrode assembly 110, the current collector foil restricting jig 10 and the cell restricting jig 20 move simultaneously in the direction of stacking of the positive and negative electrodes in the electrode assembly 110.

[0031] When the holding jig 40 is moved in the stacking direction of the positive and negative electrodes in the electrode assembly 110, the lengths of the current collector foil regulating jig 10 and the cell regulating jig 20 are set with reference to one main surface 30a of the base 30 so that the current collector foil regulating jig 10 holds the current collector foil 111 and the cell regulating jig 20 holds the solid battery cell 100 at the same time.

[0032] The solid-state battery cell 100 comprises an electrode assembly 110 and a laminate film 120. The laminate film 120 covers the outer surface of the electrode assembly 110 and also houses the electrode assembly 110. The electrode assembly 110 also has a current collector foil 111 protruding from the electrode assembly 110. The current collector foil 111 is bundled at the end opposite to the electrode assembly 110 to form a bundled portion 112. The bundled portion 112 is connected to a tab lead 130.

[0033] The electrode assembly 110 includes a positive electrode, a negative electrode, and a solid electrolyte layer.

[0034] (positive electrode) The positive electrode is formed by laminating a first current collector foil and a first active material layer containing at least a positive electrode active material. The first current collector foil is current collector foil 111.

[0035] The first current collector foil is preferably composed of at least one material with high conductivity. Examples of highly conductive materials include metals or alloys containing at least one metallic element from silver (Ag), palladium (Pd), gold (Au), platinum (Pt), aluminum (Al), chromium (Cr), and nickel (Ni), or nonmetals such as carbon (C). Considering both high conductivity and manufacturing cost, aluminum, nickel, or stainless steel are preferred. Furthermore, aluminum is less reactive with the positive electrode active material and electrolyte. Therefore, using aluminum in the first current collector layer can reduce the internal resistance of the battery.

[0036] Examples of the shape of the first current collector foil include foil-like, plate-like, mesh-like, nonwoven fabric-like, and foam-like forms. Furthermore, in order to improve adhesion with the first active material layer, carbon or the like may be placed on the surface of the first current collector foil, or the surface may be roughened.

[0037] The first active material layer contains a positive electrode active material that exchanges lithium ions and electrons. The positive electrode active material is not particularly limited as long as it is a material that can reversibly release and absorb lithium ions and transport electrons, and known positive electrode active materials applicable to the positive electrode of a lithium-ion battery can be used. For example, lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), solid solution oxide (Li2MnO3-LiMO2 (M=Co, Ni, etc.)), lithium-manganese-nickel-cobalt oxide (LiNi x Mn y Co zExamples include composite oxides such as O2 (x+y+z=1), olivine-type lithium phosphate oxide (LiFePO4); conductive polymers such as polyaniline and polypyrrole; sulfides such as Li2S, CuS, Li-Cu-S compounds, TiS2, FeS, MoS2, and Li-Mo-S compounds; and mixtures of sulfur and carbon. The positive electrode active material may consist of one of the above materials alone or of two or more materials.

[0038] The first active material layer contains an electrolyte that facilitates the exchange of lithium ions with the positive electrode active material. The electrolyte is not particularly limited as long as it has lithium-ion conductivity; generally, materials used in lithium-ion batteries can be used. Examples of electrolytes include inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, and lithium-containing salts; polymer-based solid electrolytes such as polyethylene oxide; and gel-based solid electrolytes containing lithium-containing salts or lithium-ion-conductive ionic liquids. Of these, sulfide solid electrolyte materials are preferred from the viewpoint of high lithium-ion conductivity, good structural moldability by pressing, and good interfacial bonding properties. The electrolyte may consist of one of the above materials alone, or it may consist of two or more materials. The electrolyte contained in the first active material layer may be the same material as the electrolyte contained in the second active material layer or the solid electrolyte layer, or it may be a different material.

[0039] The first active material layer may contain a conductive additive from the viewpoint of improving the conductivity of the positive electrode. Conductive additives generally usable in lithium-ion batteries can be used. Examples include carbon black such as acetylene black and kecheng black; carbon fiber; vapor-processed carbon fiber; graphite powder; and carbon nanotubes. The conductive additive may consist of one of the above materials alone or of two or more materials.

[0040] Furthermore, the first active material layer may include a binder that serves to bond the positive electrode active materials together and the positive electrode active materials together with the first current collector foil.

[0041] The first current collector foil is assembled at one end in the width direction of the all-solid-state battery. The first active material layer is in contact with the solid electrolyte layer and may therefore contain sulfides present in the solid electrolyte layer.

[0042] (Negative electrode) The negative electrode is formed by laminating a second current collector foil and a second active material layer containing at least the negative electrode active material. The second current collector foil is current collector foil 111.

[0043] The second current collector foil contains at least copper (Cu). The second current collector foil, like the first current collector foil, may also contain a substance other than copper with high conductivity. Examples of substances other than copper with high conductivity include metals or alloys containing at least one of the following metallic elements: silver (Ag), palladium (Pd), gold (Au), platinum (Pt), chromium (Cr), and nickel (Ni), or nonmetals such as carbon (C). Considering both high conductivity and manufacturing cost, nickel or stainless steel are preferred as the substance other than copper. Furthermore, stainless steel is less reactive with the positive electrode active material, negative electrode active material, and electrolyte. Therefore, using stainless steel in the second current collector layer can reduce the manufacturing cost of the battery.

[0044] Examples of the shape of the second current collector layer include foil, plate, mesh, nonwoven fabric, and foam forms. Furthermore, in order to improve adhesion with the second active material layer, carbon or the like may be placed on the surface of the second current collector layer, or the surface may be roughened.

[0045] The second active material layer contains a negative electrode active material that exchanges lithium ions and electrons. The negative electrode active material is not particularly limited as long as it is a material that can reversibly release and absorb lithium ions and transport electrons, and known negative electrode active materials applicable to the negative electrode of a lithium-ion battery can be used. For example, carbonaceous materials such as natural graphite, artificial graphite, resin carbon, carbon fiber, activated carbon, hard carbon, and soft carbon; alloy materials mainly composed of tin, tin alloys, silicon, silicon alloys, gallium, gallium alloys, indium, indium alloys, aluminum, and aluminum alloys; conductive polymers such as polyacene, polyacetylene, and polypyrrole; metallic lithium; lithium titanium composite oxide (e.g., Li4Ti5O) 12 Examples include lithium alloys such as ). These negative electrode active materials may consist of one of the above materials alone or of two or more materials.

[0046] The second active material layer contains an electrolyte that exchanges lithium ions with the negative electrode active material. The electrolyte is not particularly limited as long as it has lithium-ion conductivity; generally, materials used in lithium-ion batteries can be used. Examples of electrolytes include inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, and lithium-containing salts; polymer-based solid electrolytes such as polyethylene oxide; and gel-based solid electrolytes containing lithium-containing salts or lithium-ion-conductive ionic liquids. The electrolyte may be composed of one of the above materials alone, or of two or more materials. The electrolyte contained in the second active material layer may be the same as or different from the electrolyte contained in the first active material layer or the solid electrolyte layer.

[0047] The second active material layer may contain conductive additives and binders, etc. There are no particular restrictions on these materials, but for example, materials similar to those used in the first active material layer described above can be used.

[0048] (Solid electrolyte layer) The solid electrolyte layer is positioned between the first active material layer and the second active material layer.

[0049] As for the electrolyte, there are no particular restrictions as long as it has lithium-ion conductivity and insulating properties, and materials commonly used in lithium-ion batteries can be used. Examples include inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, and lithium-containing salts, as well as polymer-based solid electrolytes such as polyethylene oxide, and gel-based electrolytes containing lithium-containing salts or lithium-ion conductive ionic liquids. Of these, sulfide solid electrolyte materials are preferred from the viewpoint of high lithium-ion conductivity, good structural moldability by pressing, and good interfacial bonding properties. There are no particular restrictions on the form of the electrolyte material, but for example, it can be in the form of particulate matter.

[0050] The solid electrolyte layer may contain an adhesive to provide mechanical strength and flexibility.

[0051] The solid electrolyte layer may be in the form of a sheet having a porous substrate and a solid electrolyte held in the porous substrate. There are no particular restrictions on the form of the porous substrate, but examples include woven fabric, nonwoven fabric, mesh cloth, porous membrane, expanded sheet, punched sheet, etc. Of these forms, nonwoven fabric is preferred from the viewpoint of handling, which allows for a higher amount of solid electrolyte filling.

[0052] The porous substrate described above is preferably made of an insulating material. This improves the insulating properties of the solid electrolyte layer. Examples of insulating materials include nylon, polyester, polyethylene, polypropylene, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polyvinylidene chloride, polyvinyl chloride, polyurethane, vinylon, polybenzimidazole, polyimide, polyphenylene sulfite, polyetheretherketone, cellulose, acrylic resins, and other resin materials; natural fibers such as hemp, wood pulp, and cotton linters; and glass.

[0053] (Laminating film) The laminate film 120 is a laminated film having an inner resin layer, a metal layer, and an outer resin layer. Examples of resins constituting the inner and outer resin layers include polyester resins such as polyethylene terephthalate (PET). The metal layer is made of, for example, aluminum foil.

[0054] The current collector foil regulating jig 10 is movable along the stacking direction of the positive and negative electrodes in the electrode assembly 110. The cell regulating jig 20 is also movable along the stacking direction of the positive and negative electrodes in the electrode assembly 110 in conjunction with the movement of the current collector foil regulating jig 10. By moving the current collector foil regulating jig 10 and the cell regulating jig 20 simultaneously in this way, if the solid battery cell 100 sinks downward in the stacking direction due to its own weight, the solid battery cell 100 can be positioned in the correct location between the two holding jigs 40.

[0055] The tab lead pressing jig 140 is movable along the direction perpendicular to the stacking direction of the positive and negative electrodes in the electrode assembly 110. The tab lead pressing jig 140 also pushes the current collector foil 111 toward the electrode assembly 110 along the aforementioned vertical direction, creating an excess length in the current collector foil 111.

[0056] The current collector foil regulating jig 10 offsets the position where the current collector foils 111 are bundled (the bundling portion 112) in the direction of stacking of the positive and negative electrodes in the electrode assembly 110. Preferably, the offset amount is (1 / 2 the thickness of the tab lead 130) + (1 / 2 the thickness of the bundling portion 112). This makes it possible to suppress the occurrence of crank-shaped steps in the current collector foils 111.

[0057] The cell holding device 1 of this embodiment may include a jig 50 positioned in the middle of a plurality of current collector foils 111, which forms excess length on the current collector foils 111 before sealing the laminate film 120. This allows the middle of the current collector foils 111 to be expanded and excess length to be formed on the current collector foils 111 before sealing the laminate film 120.

[0058] The jig 50 is a wide plate that rotates 90 degrees relative to the direction of convergence of the current collector foil 111. This allows the current collector foil 111 to change from a state where no excess length is formed, as shown in Figure 1, to a state where excess length is formed, as shown in Figure 2.

[0059] The tab lead insertion jig 140 inserts the current collector foil 111 toward the position where the jig 50 was located. This forms the excess length of the current collector foil 111 in a curved and spaced-away shape from the center line in the stacking direction of the electrode assembly 110, as shown in Figure 2, thereby suppressing damage to the current collector foil 111 from external forces.

[0060] According to the cell holding device 1 of this embodiment, the manufacturing accuracy of the solid battery cell 100 can be improved by guiding the current collector foil 111 and simultaneously holding the electrode assembly 110, thereby defining the position of the electrode assembly 110.

[0061] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0062] 1. Cell holding device 10 Current collector foil regulating jig 20 Cell Regulation Fixture 30 Base 40 Holding fixture 100 solid-state battery cells 110 Electrode assembly 111 Current collector foil 112 Focusing section 120 Laminating Film 130 Tabread 140 Tab lead pressing jig

Claims

1. A cell holding device used in the manufacture of a solid battery cell, comprising an electrode assembly in which positive and negative electrodes are alternately stacked via a solid electrolyte, and a laminate film covering the electrode assembly, A current collector foil regulating jig that guides the current collector foil protruding from the electrode assembly, A cell holding device comprising a cell regulating jig that holds the electrode assembly in conjunction with the current collector foil regulating jig.

2. The current collector foil regulating jig is movable along the stacking direction of the positive electrode and the negative electrode in the electrode assembly. The cell holding device according to claim 1, wherein the cell regulating jig is movable along the stacking direction of the positive electrode and the negative electrode in the electrode assembly in accordance with the movement of the current collector foil regulating jig.

3. Furthermore, the cell holding device according to claim 1, further comprising a tab lead pressing jig, wherein the tab lead pressing jig is movable along a direction perpendicular to the stacking direction of the positive electrode and the negative electrode in the electrode assembly, and pushes the current collector foil toward the electrode assembly along the vertical direction to form an excess length in the current collector foil.

4. The cell holding device according to claim 3, wherein the current collector foil regulating jig offsets the position in which the current collector foils are bundled in the stacking direction.

5. The cell holding device according to claim 1, comprising a jig positioned in the middle of the current collector foil to form an excess length on the current collector foil before sealing the laminate film.

6. The cell holding device according to claim 5, wherein the jig is a wide plate that rotates 90 degrees with respect to the direction of convergence of the current collector foil.

7. Furthermore, the cell holding device according to claim 5, further comprising a tab lead pushing jig, the tab lead pushing jig being movable along a direction perpendicular to the stacking direction of the positive electrode and the negative electrode in the electrode assembly, and pushing the current collector foil toward the electrode assembly side along the vertical direction to form an excess length in the current collector foil, and the tab lead pushing jig inserts the current collector foil toward the position where the jig was located.

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