Manufacturing method for electrode cells with resin sheets

Abstract

The present disclosure aims to provide a method for manufacturing an electrode cell with a resin sheet, which involves welding resin sheets together by heating current collector foil, and in particular, which allows the welding to be performed simultaneously with product transport during product transport. [Solution] The present disclosure method for manufacturing an electrode cell with a resin sheet includes (a) providing a precursor electrode cell 100, (b) placing a resin sheet 200 on the upper and lower surfaces of a current collector foil 120, respectively, (c) sandwiching the resin sheet 200 between a lower pressing member 320 and an upper pressing member 300, and (d) heating the current collector foil 120 with the resin sheet 200 sandwiched in place to weld the current collector foil 120 and the resin sheet 200 together, wherein in step (d), the distance between the lower pressing member 320 and the upper pressing member 300 at the resin sheet contact portion 200b is smaller than the distance between the lower pressing member 320 and the upper pressing member 300 at the current collector foil contact portion 200a.

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing an electrode cell with a resin sheet. [Background technology]

[0002] An electrode stack module houses an electrode stack in which a positive electrode active material layer, a current collector layer, and a negative electrode active material layer are stacked in that order, within an outer casing or the like. A bipolar battery is known as one type of electrode stack module. A bipolar battery has multiple bipolar electrodes, each with a positive electrode active material layer formed on one side of the current collector and a negative electrode active material layer formed on the other side.

[0003] A known method for manufacturing bipolar batteries involves using electrode cells with resin sheets. These cells consist of a positive electrode active material layer, a current collector layer, and a negative electrode active material layer, stacked in that order, with a resin component welded to the periphery of the current collector layer. Multiple electrode cells with resin sheets are stacked, and the resin components at the peripheries of adjacent cells are welded together to form a sealed single cell layer. Then, electrolyte is injected into each single cell layer. This prevents leakage from the single cell layers and prevents short circuits caused by contact between current collectors.

[0004] For example, Patent Documents 1 and 2 disclose an electrode stack comprising a plurality of bipolar electrodes stacked, each including a pair of electrodes composed of a current collector and active material layers provided on the first and second surfaces of the current collector; and a sealing body that seals the sides of the bipolar electrodes extending in the stacking direction in the electrode stack, wherein the sealing body comprises a plurality of frame-shaped sealing members welded to each edge of the current collector, and a plurality of frame-shaped spacers arranged between adjacent sealing members in the stacking direction, wherein the outer surface of the sealing body is formed by welding an outer edge portion of each spacer that protrudes outward from the edge of the current collector, and an outer edge portion of each adjacent sealing member in the stacking direction that protrudes outward from the edge of the current collector to each spacer, and the melt mass flow rate of the resin material constituting the spacer is greater than the melt mass flow rate of the resin material constituting the sealing member. According to the energy storage devices described in Patent Documents 1 and 2, it is possible to more suitably maintain the spacing between current collectors while further improving the airtightness of the sealing body.

[0005] Patent Document 3 discloses an electric double-layer capacitor (EDLC) in which a first end plate electrode, having an activated carbon electrode impregnated with electrolyte on one side of the collector electrode, one or more bipolar electrodes, having activated carbon electrodes impregnated with electrolyte on both sides of the collector electrode, and a second end plate electrode, having an activated carbon electrode impregnated with electrolyte on one side of the collector electrode, are sequentially laminated with a supporting electrolyte in between. The EDLC is characterized in that a resin frame is bonded with epoxy resin to the peripheral edge of the collector electrode of the first end plate electrode, the peripheral edge of the collector electrode of the bipolar electrode, and the peripheral edge of the collector electrode of the second end plate electrode, and the outer surface of the laminate, which is formed by laminating the first end plate electrode, bipolar electrode, and second end plate electrode equipped with this resin frame, is heat-fused. The electric double-layer capacitor described in Patent Document 3 is said to be able to reduce weight, prevent self-discharge, and eliminate the need to seal the lead wires, in view of the problems of conventional EDLCs. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-152023 [Patent Document 2] International Publication No. 2023 / 189249 [Patent Document 3] Japanese Patent Publication No. 2001-085274 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As described above, it has been proposed to manufacture bipolar batteries using electrode cells with resin sheets, and as a preliminary step, electrode cells with resin sheets have been manufactured. Specifically, according to Patent Documents 1 and 2, frame-shaped sealing members are placed on the first and second surfaces of the edge of the current collector, and the edge of the current collector and the sealing members on both sides are sandwiched between heaters and heated and pressurized, thereby welding the edge of the current collector and the sealing members on both sides. However, it has not been easy to efficiently manufacture electrode cells with resin sheets using this method.

[0008] Therefore, the purpose of this disclosure is to provide a method for efficiently manufacturing electrode cells with resin sheets. [Means for solving the problem]

[0009] This disclosure aims to achieve the above objectives by the following means:

[0010] (Aspect 1) A method for manufacturing an electrode cell with a resin sheet, (a) To provide a precursor electrode cell in which the current collector foil extends from the peripheral edge, (b) A resin sheet is placed on the upper and lower surfaces of at least one side of the current collector foil extending from the peripheral portion. (c) sandwiching the above resin sheet between the lower pressing member and the upper pressing member, (d) With the resin sheet sandwiched between the lower pressing member and the upper pressing member, the current collector foil is heated to weld the current collector foil and the resin sheet together. Includes, The resin sheet has a current collector foil contact portion where the resin sheet and the current collector foil come into contact, and a resin sheet contact portion where the resin sheets come into contact with each other, and in step (d), the distance between the lower pressing member and the upper pressing member at the resin sheet contact portion is smaller than the distance between the lower pressing member and the upper pressing member at the current collector foil contact portion. A method for manufacturing an electrode cell with a resin sheet. (Aspect 2) The method according to embodiment 1, wherein at least one of the lower pressing member and the upper pressing member has a laser-transparent portion, and in step (d), the current collector foil is heated by irradiating it with a laser through the laser-transparent portion. (Aspect 3) While transporting the above-mentioned precursor electrode cell, at least one of steps (b) to (d) is performed, and One side of the transported precursor electrode cell is parallel to the transport direction of the precursor electrode cell. The method according to embodiment 1 or 2. (Aspect 4) The method according to embodiment 3, wherein at least one of steps (b) to (d) is performed while the above-mentioned precursor electrode cell is transported roll-to-roll. [Effects of the Invention]

[0011] According to the method disclosed herein, by heating the current collector foil, not only are the current collector foil and the resin sheet welded together, but the resin sheets are also welded together well, and in particular, the welding can be performed simultaneously with product transport during product transport. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram illustrating the process of providing a precursor electrode cell (step (a)). [Figure 2]FIG. 2 is a schematic diagram for explaining the step of arranging the resin sheet (step (b)). [Figure 3] FIG. 3 is a schematic diagram for explaining the step of sandwiching the resin sheet (step (c)). [Figure 4] FIG. 4 is a schematic diagram for explaining the welding step (step (d)). [Figure 5] FIG. 5 is a schematic diagram for explaining one embodiment of the present embodiment.

Embodiments of the Invention

[0013] ≪Method for Manufacturing an Electrode Cell with a Resin Sheet≫ The method of the present disclosure for manufacturing an electrode cell with a resin sheet is a method for manufacturing an electrode cell with a resin sheet, (a) providing a precursor electrode cell in which a current collector foil extends from a peripheral portion; (b) arranging resin sheets on the upper and lower surfaces of at least one side of the current collector foil extending from the peripheral portion, respectively; (c) sandwiching the resin sheets with a lower pressing member and an upper pressing member, and (d) heating the current collector foil with the resin sheets sandwiched between the lower pressing member and the upper pressing member to weld the current collector foil and the resin sheets. The method includes the resin sheet having a current collector contact portion where the resin sheet and the current collector foil contact, and a resin sheet contact portion where the resin sheets contact each other, and in step (d), the distance between the lower pressing member and the upper pressing member at the resin sheet contact portion is smaller than the distance between the lower pressing member and the upper pressing member at the current collector contact portion.

[0014] According to the method of the present disclosure for manufacturing an electrode cell with a resin sheet, by heating the current collector foil, not only the current collector foil and the resin sheets are welded, but also the resin sheets are welded well to each other. In particular, during product conveyance, the welding can be carried out simultaneously with the conveyance.

[0015] In conventional methods, sealing members are placed on the upper and lower surfaces of the edge of the current collector, and the current collector is heated by sandwiching the edge of the current collector with the sealing members on both sides using a heater. This allows the edge of the current collector to be welded to the sealing members on both sides. However, this method did not make it easy to efficiently manufacture electrode cells with resin sheets.

[0016] In contrast, according to this disclosure, a resin sheet is placed on the upper and lower surfaces of at least one side of the current collector foil extending from the peripheral edge of a precursor electrode cell in which the current collector foil extends from the peripheral edge. The resin sheet is then sandwiched between a lower pressing member and an upper pressing member, and with the resin sheet sandwiched between the lower pressing member and the upper pressing member, the current collector foil is heated to weld the current collector foil and the resin sheet together. Here, the resin sheet has a current collector foil contact portion where the resin sheet and the current collector foil come into contact, and a resin sheet contact portion where the resin sheets come into contact with each other. When the current collector foil is heated, the distance between the lower pressing member and the upper pressing member at the resin sheet contact portion is smaller than the distance between the lower pressing member and the upper pressing member at the current collector foil contact portion.

[0017] According to the method disclosed herein, when heating the current collector foil, the resin sheets are brought into contact with each other, and by heating the current collector foil, not only are the current collector foil and the resin sheets welded together, but the resin sheets themselves are also welded together well. Furthermore, during product transport, particularly in the roll-to-roll (R2R) method, the resin sheets can be welded together.

[0018] (Electrode cell with resin sheet) In this disclosure, the electrode cell with a resin sheet is a current collector foil having a positive electrode active material layer and / or a negative electrode active material layer on its surface, with a resin sheet welded to the upper and lower surfaces of the peripheral edge of the current collector foil extending from the peripheral edge.

[0019] In this disclosure, the surface area of ​​the electrode cell with resin sheet is not particularly limited, but is less than 1 cm². 2 More than 10cm2 Above, 50 cm 2 Above, 100 cm 2 Above, or 500 cm 2 Above, and may be up to 10,000 cm 2 Below, 5,000 cm 2 Below, 3,000 cm 2 Below, 1,000 cm 2 Below, or 700 cm 2 Below, and may be. In the present disclosure, the plane direction is a direction perpendicular to the stacking direction of the precursor electrode cell.

[0020] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present disclosure. In the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0021] <Step of providing a precursor electrode cell (Step (a))> In the method of the present disclosure for manufacturing a resin sheet-attached electrode cell, first, a precursor electrode cell in which a current collector foil extends from a peripheral portion is provided.

[0022] FIG. 1 shows one embodiment of the present embodiment, but is not limited thereto. FIG. 1(a) shows a cross-sectional view of the precursor electrode cell. In the precursor electrode cell 100, a positive electrode active material layer 140 and a negative electrode active material layer 160 are disposed on the upper and lower surfaces of the current collector foil 120. The current collector foil 120 extends from the positive electrode active material layer 140 and the negative electrode active material layer 160. FIG. 1(b) shows a top view of the precursor electrode cell as viewed from the positive electrode active material layer side. As shown in FIG. 1(b), at all four sides of the current collector foil 120, the current collector foil 120 may extend from the positive electrode active material layer 140 and the negative electrode active material layer 160.

[0023] (Precursor electrode cell) In the present disclosure, the precursor electrode cell is a current collector foil having a positive electrode active material layer or a negative electrode active material layer on its surface, and the current collector foil extends from the peripheral portion.

[0024] (Current collector foil) In this disclosure, the current collector foil may extend from the precursor electrode cell and have multiple metal foils collected to form a foil collection section.

[0025] Examples of materials for the current collector foil include, but are not limited to, aluminum, aluminum alloys, and stainless steel. The thickness of the current collector foil is not particularly limited, but may be 20 μm or more, 30 μm or more, or 40 μm or more, or it may be 70 μm or less, 60 μm or less, or 50 μm or less.

[0026] <Process for arranging resin sheets (process (b))> In the method for manufacturing an electrode cell with a resin sheet according to this disclosure, the resin sheet is then placed on the upper and lower surfaces of at least one side of the current collector foil extending from the periphery.

[0027] Figure 2 shows one embodiment of this design, but is not limited to this design. Figure 2 shows a cross-sectional view of a precursor electrode cell and a resin sheet. The resin sheet 200 is placed on the upper and lower surfaces of the current collector foil 120 extending from the precursor electrode cell 100, respectively.

[0028] (Resin sheet) In this disclosure, the resin sheet is disposed on the upper and lower surfaces of at least one side of the current collector foil extending from the periphery, and has a current collector foil contact portion where the resin sheet and the current collector foil come into contact, and a resin sheet contact portion where the resin sheets come into contact with each other.

[0029] In this disclosure, the material of the resin sheet can be freely selected within a range that allows for sufficient welding between the current collector and the resin sheet, and between the resin sheets themselves, and is not particularly limited. Furthermore, the resin sheet may have a uniform thickness.

[0030] <Process of inserting resin sheets (process (c))> In the method for manufacturing an electrode cell with a resin sheet according to this disclosure, the resin sheet is then sandwiched between a lower pressing member and an upper pressing member.

[0031] Figure 3 shows one embodiment of this invention, but is not limited to this. Figure 3 shows a cross-sectional view of a precursor electrode cell and a resin sheet. An upper pressing member 300 is placed above the resin sheet 200 that was placed in step (b), and a lower pressing member 320 is placed below it, so that the resin sheet 200 is sandwiched between the upper pressing member 300 and the lower pressing member 320. At this time, the resin sheet 200 has a current collector foil contact portion 200a where the resin sheet 200 and the current collector foil 120 come into contact, and a resin sheet contact portion 200b where the resin sheets 200 come into contact with each other. The upper pressing member 300 and / or the lower pressing member 320 have a convex shape in part thereof, so that the distance between the upper pressing member 300 and the lower pressing member 320 at the resin sheet contact portion 200b is smaller than the distance between the upper pressing member 300 and the lower pressing member 320 at the current collector foil contact portion 200a.

[0032] (Lower retaining member and upper retaining member) In this disclosure, the lower pressing member and the upper pressing member sandwich the resin sheet.

[0033] In this disclosure, the material and shape of the lower and upper pressing members can be freely selected within the scope that enables the implementation of this embodiment.

[0034] <Welding process (process (d))> In the method for manufacturing an electrode cell with a resin sheet according to this disclosure, the current collector foil is heated while the resin sheet is sandwiched between a lower pressing member and an upper pressing member, thereby welding the current collector foil and the resin sheet together.

[0035] Figure 4 shows one embodiment of this design, but is not limited to this. Figure 4 shows a cross-sectional view of a precursor electrode cell and a resin sheet. For example, the current collector foil 120, preferably the current collector foil contact portion 200a, is heated by a laser 400. This causes the current collector foil 120 and the resin sheet 200 to be welded together. At this time, the heat applied to the current collector foil contact portion 200a is transferred to the resin sheet contact portion 200b, and the resin sheets 200 may be welded together at the resin sheet contact portion 200b.

[0036] In this disclosure, during the welding process, the distance between the lower pressing member and the upper pressing member at the resin sheet contact portion is smaller than the distance between the lower pressing member and the upper pressing member at the current collector foil contact portion.

[0037] In this disclosure, at least one of the lower pressing member and the upper pressing member has a laser-transparent portion, and in the welding process, the current collector foil may be heated by irradiating it with a laser through the laser-transparent portion.

[0038] Furthermore, in this disclosure, at least one of steps (b) to (d) may be performed while transporting the precursor electrode cell, in which case one side of the transported precursor electrode cell is parallel to the transport direction of the precursor electrode cell. In this case, the transport of the precursor electrode cell can be performed by any method, for example, by the R2R method.

[0039] Figure 5 shows, but is not limited to, one embodiment of this design. Figure 5 shows a top view of a precursor electrode cell. When the precursor electrode cell 100 is being transported in the transport direction 600, a resin sheet 200 is placed on one side parallel to the transport direction 600. Simultaneously with the transport of the precursor electrode cell 100, one resin sheet 200 may be placed across multiple precursor electrode cells 100 and sandwiched and / or welded between an upper pressing member and a lower pressing member. [Explanation of symbols]

[0040] 100 Precursor Electrode Cells 120 Current collector foil 140 Cathode active material layer 160 Negative electrode active material layer 200 resin sheets 200a Current collector foil contact part 200b Resin sheet contact area 300 Upper retaining member 320 Lower retaining member 400 lasers 500 Electrode cells with resin sheets 600 Conveying direction

Claims

1. A method for manufacturing an electrode cell with a resin sheet, (a) To provide a precursor electrode cell in which the current collector foil extends from the peripheral edge, (b) Arrange resin sheets on the upper and lower surfaces of at least one side of the current collector foil extending from the peripheral edge, (c) sandwiching the resin sheet between the lower pressing member and the upper pressing member, (d) With the resin sheet sandwiched between the lower pressing member and the upper pressing member, the current collector foil is heated to weld the current collector foil and the resin sheet together. Includes, The resin sheet has a current collector foil contact portion in which the resin sheet and the current collector foil come into contact, and a resin sheet contact portion in which the resin sheets come into contact with each other, and in step (d), the distance between the lower pressing member and the upper pressing member at the resin sheet contact portion is smaller than the distance between the lower pressing member and the upper pressing member at the current collector foil contact portion. A method for manufacturing an electrode cell with a resin sheet.

2. The method according to claim 1, wherein at least one of the lower pressing member and the upper pressing member has a laser-transparent portion, and in step (d), the current collector foil is heated by irradiating it with a laser through the laser-transparent portion.

3. While transporting the precursor electrode cell, at least one of steps (b) to (d) is performed, and One side of the transported precursor electrode cell is parallel to the transport direction of the precursor electrode cell. The method according to claim 1.

4. The method according to claim 3, wherein at least one of steps (b) to (d) is performed while the precursor electrode cell is transported roll-to-roll.

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