Laminated electrode body, power storage device having the same, and method for manufacturing the same

Abstract

To provide a method for manufacturing a laminated electrode body in which lamination deviation is hard to occur.SOLUTION: A manufacturing method includes: a first adhesive layer forming step of forming a first adhesive layer AL1 (27) on part of a first surface 261 of a separator 26; a first placing step of placing a first electrode plate 24 on the first adhesive layer AL1; and a first folding back step of pressing the separator 26 with a first pressing member and folding back the separator 26 at predetermined intervals to form a first folding back portion 26b1. In the first adhesive layer forming step, the first adhesive layer AL1 is formed on a portion that does not come into contact with the first pressing member when the first folding back portion is formed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a stacked electrode assembly, an electricity storage device including the same, and methods for manufacturing the same. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2018-18712 discloses a stacked electrode assembly having a zigzag structure in which a strip-shaped separator is folded back alternately at predetermined intervals to form a zigzag shape, and a plurality of first electrode plates and a plurality of second electrode plates are sandwiched alternately between the zigzag separators. Japanese Patent Application Laid-Open No. 2018-18712 describes that the separator and the first electrode plate (or the second electrode plate) can be bonded together by using a separator having an adhesive layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-18712 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the inventor's findings, when folding a strip-shaped separator zigzag, the separator is usually folded by fixing it with a presser member or forming a shape. Therefore, if an adhesive layer is provided on the entire surface of the separator, there is a risk that the adhesive may come into contact with the presser member. If this happens, the adhesive may not exhibit the desired adhesiveness, and stacking misalignment may occur in the stacked electrode assembly.

[0005] The present invention has been made in view of the above circumstances, and its main object is to provide a novel laminated electrode assembly in which lamination misalignment is unlikely to occur, and a method for manufacturing the same. [Means for solving the problem]

[0006] The present invention provides a method for manufacturing a stacked electrode assembly having a zigzag structure in which a strip-shaped separator is alternately folded at predetermined intervals to form a zigzag shape, and a plurality of first electrode plates and a plurality of second electrode plates are alternately sandwiched between the zigzag-shaped separator. This manufacturing method includes a first adhesive layer forming step of applying an adhesive to a portion of a first surface of the separator to form a first adhesive layer, a first placing step of placing the first electrode plate on the first adhesive layer of the separator after the first adhesive layer forming step, and a first folding step of pressing the separator with a first pressing member after the first placing step and folding the separator at the predetermined intervals to cover the first electrode plate to form a first folded portion. In the first adhesive layer forming step, the first adhesive layer is formed on a portion that does not come into contact with the first pressing member when forming the first folded portion in the first folding step.

[0007] In the manufacturing method disclosed herein, adhesive is applied to a portion of the first surface of the separator that does not overlap with the first pressing member when forming the first folded portion, forming a first adhesive layer. This prevents the adhesive from transferring to the pressing member. As a result, the desired adhesive strength can be stably exerted, and stacking misalignment can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view schematically illustrating an electricity storage device according to one embodiment. [Figure 2] FIG. 2 is a plan view schematically showing the internal structure of the electricity storage device of FIG. [Figure 3] FIG. 3 is a vertical cross-sectional view of the laminated electrode body of FIG. [Figure 4] 4A and 4B are exploded views of the laminated electrode body of FIG. 3, with FIG. 4A showing the first surface side of the separator and FIG. 4B showing the second surface side of the separator. [Figure 5] 5A and 5B are schematic diagrams of a manufacturing apparatus in the first adhesive layer forming step, with FIG. 5A being a front view and FIG. 5B being a plan view. [Figure 6]FIG. 6A is a view equivalent to FIG. 5A when the first adhesive layer forming step is completed, and FIG. 6B is a view equivalent to FIG. 5B when the first adhesive layer forming step is completed. [Figure 7] 7A is a view corresponding to FIG. 5A in the first placing step, and FIG. 7B is a view corresponding to FIG. 5B in the first placing step. [Figure 8] FIG. 8 is a view corresponding to FIG. 5A in the first lamination step. [Figure 9] FIG. 9A is a view equivalent to FIG. 5A when the first lamination step is completed, and FIG. 9B is a view equivalent to FIG. 5B when the first lamination step is completed. [Figure 10] FIG. 10A is a view equivalent to FIG. 5A in the second placing step, and FIG. 10B is a view equivalent to FIG. 5B in the second placing step. [Figure 11] FIG. 11 is a view corresponding to FIG. 5A in the second lamination step. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the technology disclosed herein will be described below with reference to the drawings. It should be noted that matters other than those specifically mentioned in this specification that are necessary for implementing the technology disclosed herein (for example, the general configuration and manufacturing process of an electricity storage device that does not characterize the technology disclosed herein) can be understood as design matters for a person skilled in the art based on prior art in the relevant field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the relevant field. Furthermore, the expression "A to B" indicating a range in this specification is intended to include the meaning of "greater than A" and "smaller than B" as well as "greater than A."

[0010] In this specification, the term "electricity storage device" refers to a device in general that can be repeatedly charged and discharged by the movement of charge carriers between a positive electrode and a negative electrode via an electrolyte. The concept of an electricity storage device encompasses secondary batteries such as lithium-ion secondary batteries and nickel-metal hydride batteries, and capacitors such as lithium-ion capacitors and electric double layer capacitors.

[0011] 1. Structure of the electricity storage device Fig. 1 is a perspective view of an electricity storage device 100 according to one embodiment. Fig. 2 shows the internal structure of the electricity storage device 100 of Fig. 1. In the following description, the symbols L, R, F, Rr, U, and D in the drawings represent left, right, front, rear, top, and bottom, and the symbols X, Y, and Z in the drawings represent the short side direction, the long side direction perpendicular to the short side direction, and the thickness direction perpendicular to the short side direction and the long side direction, respectively, of the electricity storage device 100. However, these directions are determined for the convenience of description and do not limit the installation mode of the electricity storage device 100 in any way.

[0012] As shown in Fig. 2, the electricity storage device 100 includes a battery case 10, a stacked electrode body 20, a positive electrode terminal 30, and a negative electrode terminal 40. Although not shown, the electricity storage device 100 further includes an electrolyte. The electricity storage device 100 is configured by accommodating the stacked electrode body 20 and the electrolyte in a battery case 10 equipped with the positive electrode terminal 30 and the negative electrode terminal 40. The electricity storage device 100 is characterized by including the stacked electrode body 20 disclosed herein, and other configurations may be similar to conventional devices.

[0013] The battery case 10 is a housing that houses the stacked electrode assembly 20 and an electrolyte. As shown in FIG. 1, the battery case 10 has a flat, bottomed, rectangular parallelepiped (square) outer shape. The material of the battery case 10 may be the same as that conventionally used, and is not particularly limited. The battery case 10 is preferably made of metal, and more preferably made of, for example, aluminum, an aluminum alloy, iron, an iron alloy, or the like. As shown in FIG. 2, the battery case 10 includes a square cylindrical case body 12 having a pair of openings 12h, and two sealing plates 14 that close the pair of openings 12h.

[0014] The case body 12 is formed, for example, by bending a single metal plate into a cylindrical shape and joining (e.g., welding) the seams. As shown in FIG. 1 , the case body 12 has a pair of narrow faces 12a facing each other and a pair of wide faces 12b facing each other. The narrow faces 12a and the wide faces 12b are substantially rectangular. The area of the wide faces 12b is larger than that of the narrow faces 12a. The pair of wide faces 12b form the upper and lower faces of the battery case 10. In this specification, the term "substantially rectangular" encompasses not only a perfect rectangular shape (rectangular shape), but also, for example, a shape in which the corners connecting the long and short sides of the rectangle are rounded or a shape in which the corners have notches.

[0015] The pair of sealing plates 14 face each other. As shown in FIG. 2, the pair of sealing plates 14 are plate-like members that seal the pair of openings 12h, respectively. The sealing plates 14 are generally rectangular. The area of the sealing plates 14 is smaller than the narrow faces 12a. The battery case 10 is integrated by joining (for example, welding) the sealing plates 14 to the peripheries of the pair of openings 12h of the case body 12. The battery case 10 is hermetically sealed (sealed).

[0016] The positive electrode terminal 30 and the negative electrode terminal 40 are each exposed on the outer surface of the sealing plate 14. Here, the positive electrode terminal 30 and the negative electrode terminal 40 are each fixed to opposing surfaces of the battery case 10 (specifically, the sealing plates 14). Specifically, the positive electrode terminal 30 is attached to the sealing plate 14 located on one side in the long side direction Y (the right side in FIGS. 1 and 2). The negative electrode terminal 40 is attached to the sealing plate 14 located on the other side in the long side direction Y (the left side in FIGS. 1 and 2). In this embodiment, the positive electrode terminal 30 and the negative electrode terminal 40 are respectively provided on a pair of sealing plates 14. However, in other embodiments, the positive electrode terminal 30 and / or the negative electrode terminal 40 may be provided on the same sealing plate 14 or on the case body 12.

[0017] The positive electrode terminal 30 is preferably made of metal, and more preferably made of, for example, aluminum or an aluminum alloy. As shown in FIG. 2, the positive electrode terminal 30 is electrically connected to the positive electrode 22 (more specifically, a positive electrode tab 22t described later) of the stacked electrode body 20 via a positive electrode current collector 32 inside the battery case 10. The negative electrode terminal 40 is preferably made of metal, and more preferably made of, for example, copper or a copper alloy. As shown in FIG. 2, the negative electrode terminal 40 is electrically connected to the negative electrode 24 (more specifically, a negative electrode tab 24t described later) of the stacked electrode body 20 via a negative electrode current collector 42 inside the battery case 10.

[0018] The electrolyte may be the same as conventional ones and is not particularly limited. The electrolyte is, for example, a non-aqueous electrolyte containing a non-aqueous solvent (organic solvent) and a supporting salt (electrolyte salt, for example, lithium salt or sodium salt). Examples of non-aqueous solvents include carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Examples of supporting salts include fluorine-containing lithium salts such as lithium hexafluorophosphate (LiPF6). The electrolyte is typically in a liquid state, but may also be in a gel state.

[0019] The laminated electrode body 20 is housed inside the battery case 10. The number of laminated electrode bodies 20 arranged inside one battery case 10 may be one, or two or more (plural). The laminated electrode body 20 may be housed inside the battery case 10 in a state where it is covered with a resin insulating sheet (electrode body holder).

[0020] Fig. 3 is a longitudinal cross-sectional view of the laminated electrode body 20. As shown in Fig. 3, the laminated electrode body 20 includes a plurality of positive electrodes 22, a plurality of negative electrodes 24, a zigzag separator 26, and adhesive layers 27 and 28. Note that, although the case where the negative electrode 24 is the first electrode plate and the positive electrode 22 is the second electrode plate will be described as an example here, in other embodiments, the positive electrode 22 may be the first electrode plate and the negative electrode 24 may be the second electrode plate.

[0021] The laminated electrode body 20 has a zigzag structure in which multiple positive electrodes 22 and multiple negative electrodes 24 are alternately sandwiched between zigzag separators 26. The laminated electrode body 20 here has a first layer L1 to an n-th layer Ln. The positive electrodes 22 and negative electrodes 24 are stacked in n layers. The number of positive electrodes 22 here is n. The number of negative electrodes is (n+1), which is one more than the number of negative electrodes. Here, the thickness direction Z is the stacking direction of the positive electrodes 22 and negative electrodes 24.

[0022] 4A and 4B are exploded views of the laminated electrode assembly 20, with FIG. 4A showing the first surface 261 of the separator 26 and FIG. 4B showing the second surface 262 of the separator 26. In the following drawings, the symbol Y indicates the width direction of the separator 26, which corresponds to the long side direction Y in FIG. 2. In FIG. 4B, the symbol LD indicates the longitudinal direction of the separator 26. As can be seen from FIGS. 4A and 4B, the separator 26 is formed in a zigzag shape by folding a strip-shaped separator sheet alternately in mountain folds and valley folds. As shown in FIG. 4A, the negative electrode 24 is sandwiched so as to face the first surface 261 of the separator 26, which is zigzag folded. As shown in FIG. 4B, the positive electrode 22 is sandwiched so as to face the second surface 262 of the separator 26, which is zigzag folded.

[0023] The positive electrode 22 may be the same as a conventional one and is not particularly limited. The positive electrode 22 typically includes a positive electrode current collector and a positive electrode active material layer 22a (see FIG. 4B) fixed to at least one surface (both surfaces in this case) of the positive electrode current collector. The positive electrode current collector is preferably a metal foil, and is preferably made of, for example, aluminum or an aluminum alloy. The positive electrode active material layer 22a contains a positive electrode active material capable of reversibly absorbing and releasing charge carriers. The positive electrode active material may be the same as a conventional one and is not particularly limited. An example of a positive electrode active material is a lithium transition metal composite oxide. The positive electrode active material layer 22a may contain optional components other than the positive electrode active material, such as a binder or a conductive material.

[0024] As shown in FIG. 4B, the positive electrode 22 has a convex positive electrode tab 22t protruding outward (upward in FIG. 4B) from one end side in the long side direction Y. The positive electrode tab 22t is a portion where the positive electrode active material layer 22a is not formed and where the positive electrode current collector is exposed (current collector exposed portion). As shown in FIG. 2, multiple positive electrode tabs 22t are stacked at one end side in the long side direction Y (the right end side in FIG. 2) and are electrically connected to the positive electrode terminal 30 via the positive electrode current collector 32. A positive electrode protective layer containing an inorganic filler may be provided at the boundary between the positive electrode tab 22t and the positive electrode active material layer 22a.

[0025] The negative electrode 24 may be the same as a conventional negative electrode and is not particularly limited. The negative electrode 24 typically includes a negative electrode current collector and a negative electrode active material layer 24a (see FIG. 4A) fixed to at least one surface (both surfaces in this case) of the negative electrode current collector. The negative electrode current collector is preferably a metal foil, and is preferably made of, for example, copper or a copper alloy. The negative electrode active material layer 24a contains a negative electrode active material capable of reversibly absorbing and releasing charge carriers. The negative electrode active material may be the same as a conventional negative electrode and is not particularly limited. Examples of negative electrode active materials include carbon materials such as graphite and silicon-based materials. The negative electrode active material layer 24a may contain optional components other than the negative electrode active material, such as a binder, a thickener, a dispersant, etc.

[0026] 3, in the short side direction X orthogonal to the stacking direction Z, the length W2 of the negative electrode 24 (here, the same as the length of the negative electrode active material layer 24a) is preferably the same as or longer than the length W1 of the positive electrode 22 (here, the same as the length of the positive electrode active material layer 22a), from the viewpoint of charge carrier acceptance. The negative electrode 24 (typically the negative electrode active material layer 24a) preferably protrudes outward from both ends of the short side direction X beyond the positive electrode 22 (typically the positive electrode active material layer 22a).

[0027] As shown in Fig. 4A, the negative electrode 24 has a convex negative electrode tab 24t protruding outward (downward in Fig. 4A) from one end side in the long side direction Y. The negative electrode tab 24t is a portion where the negative electrode active material layer 24a is not formed and where the negative electrode current collector is exposed (current collector exposed portion). As shown in Fig. 2, the multiple negative electrode tabs 24t are stacked at one end side in the long side direction Y (the left end side in Fig. 2) and are electrically connected to the negative electrode terminal 40 via the negative electrode current collector 42.

[0028] It is preferable that at least one of the positive electrode 22 and the negative electrode 24 (first electrode plate) is adhered to the separator 26 via adhesive layers 27, 28, and it is more preferable that both the positive electrode 22 and the negative electrode 24 (first electrode plate and second electrode plate) are adhered to the separator 26 via adhesive layers 27, 28.

[0029] The separator 26 is interposed between the positive electrode 22 and the negative electrode 24. The separator 26 is an insulating sheet having a plurality of fine through-holes formed therein through which charge carriers can pass. By interposing the separator 26 between the positive electrode 22 and the negative electrode 24, contact between the positive electrode 22 and the negative electrode 24 is prevented and charge carriers (e.g., lithium ions) can be transferred between the positive electrode 22 and the negative electrode 24.

[0030] Although not shown, separator 26 preferably includes a separator substrate and one or more heat-resistant layers (Heat Resistant Layers: HRL layers). The heat-resistant layer is preferably formed on at least one surface of the separator substrate. The heat-resistant layer may be provided on only one surface of the separator substrate, or on both surfaces. In this example, separator 26 includes a heat-resistant layer on one surface of the separator substrate. As shown in FIG. 3, separator 26 has a surface on the separator substrate side (first surface 261) and a surface on which the heat-resistant layer is formed (second surface 262).

[0031] The separator base material may be the same as the conventional one and is not particularly limited. The separator base material may have a single-layer structure or may have a structure of two or more layers with different properties and characteristics (such as thickness and porosity), for example, a three-layer structure. The separator base material is typically made of resin, and preferably made of a polyolefin resin. As the polyolefin resin, polyethylene (PE), polypropylene (PP), or a mixture thereof is preferable, and it is more preferable to be made of PE.

[0032] The heat-resistant layer typically includes an inorganic filler and a heat-resistant layer binder. By providing the heat-resistant layer, the thermal shrinkage of the separator 26 can be suppressed, contributing to an improvement in the safety of the power storage device 100. As the inorganic filler, ceramic particles such as alumina, zirconia, boehmite, aluminum hydroxide, silica, and titania are preferable, and from the viewpoint of suppressing the thermal shrinkage of the separator 26, compounds containing aluminum are particularly preferable. Examples of the heat-resistant layer binder include acrylic resins, fluorine-based resins, urethane resins, ethylene vinyl acetate resins, and epoxy resins. Among them, acrylic resins are preferable.

[0033] As shown in FIG. 3, in the short side direction X, the length W3 of the separator 26 is preferably longer than the length W2 of the negative electrode 24 (typically the negative electrode active material layer 24a). Here, the length W3 of the separator 26, the length W1 of the positive electrode 22 (typically the positive electrode active material layer 22a), and the length W2 of the negative electrode 24 (typically the negative electrode active material layer 24a) satisfy the relationship of W1 < W2 < W3.

[0034] As shown in FIG. 3, the separator 26 is formed in a zigzag shape (also called a bellows shape) that is alternately folded back at a predetermined interval (length W3). The separator 26 has a flat portion 26f, a first folded-back portion 26b1, and a second folded-back portion 26b2.

[0035] The flat portion 26f here extends along the XY plane. The flat portion 26f is a portion facing at least one of the positive electrode 22 (typically the positive electrode active material layer 22a) and the negative electrode 24 (typically the negative electrode active material layer 24a). In the short side direction X, the flat portion 26f is located in the center of the stacked electrode body 20. Here, the flat portion 26f has the same length as the length W2 of the negative electrode 24 (typically the negative electrode active material layer 24a).

[0036] The first folded portion 26b1 and the second folded portion 26b2 are portions that do not face either the positive electrode 22 or the negative electrode 24. In other words, the first folded portion 26b1 and the second folded portion 26b2 are protruding portions that protrude in the short side direction X from the flat portion 26f having the length W2. Here, the first folded portion 26b1 and the second folded portion 26b2 are made up only of the separator 26. Here, the first folded portion 26b1 and the second folded portion 26b2 face a pair of narrow sides 12a of the battery case 10, respectively.

[0037] The terminal end 26e of the separator 26 is wrapped around the outermost periphery of the zigzag structure sandwiching the positive electrode 22 and the negative electrode 24, forming the outer peripheral surface of the stacked electrode body 20. A stop tape 29 is attached to the terminal end of the separator 26 to prevent loosening of the winding. Note that the width W in Figures 3, 4A, and 4B is the overall width of the stacked electrode body 20, and the height T is the overall thickness of the stacked electrode body 20. The height t is the thickness from the top end of the stacked electrode body 20 to the stop tape 29.

[0038] The adhesive layers 27 and 28 are interposed between at least one of the positive electrode 22 (typically the positive electrode active material layer 22a) and the negative electrode 24 (typically the negative electrode active material layer 24a) and the separator 26. This more effectively prevents the occurrence of stacking misalignment. In the example shown in Fig. 3, both surfaces of the positive electrode 22 and both surfaces of the negative electrode 24 are bonded to the opposing separators 26 via the adhesive layers 27 and 28, respectively, in the stacking direction Z.

[0039] In Figures 3, 4A, and 4B, due to the manufacturing method described below, a distinction is made between adhesive layer 27 formed directly on the surface of separator 26 and adhesive layer 28 formed indirectly on the surface of separator 26 by contacting electrode-on adhesive layer EL formed on the surface of the opposing positive electrode 22 and / or negative electrode 24, but the configurations of adhesive layers 27 and 28 may be the same or different.

[0040] The adhesive layers 27 and 28 are typically layers containing the adhesive layer binder at the highest mass ratio. Examples of adhesive layer binders include fluorine-based resins, acrylic resins, urethane resins, ethylene vinyl acetate resins, and epoxy resins. Among these, fluorine-based resins and acrylic resins are preferred because of their high flexibility. The adhesive layer binder may be the same type as the heat-resistant layer binder described above, or may be different. The adhesive layers 27 and 28 may further contain other materials (e.g., inorganic fillers, etc.).

[0041] As will be described in more detail below, in the technology disclosed herein, when first folded portion 26b1 to second folded portion 26b2 are formed, adhesive layers 27, 28 are not formed in the areas that come into contact with the presser members (presser plates P1, P2 and presser rollers 121, 122, which will be described later), as shown imaginarily in Figures 4A and 4B. Note that in Figures 4A and 4B, the areas that are directly pressed by presser plates P1, P2 and presser rollers 121, 122 in the first lamination step (step 3) to second lamination step (step 5), which will be described later, are shown by imaginary lines (chain double-dashed lines), and the areas that overlap presser plates P1, P2 are shown by dashed lines.

[0042] 4A and 4B, in this embodiment, adhesive layers 27 and 28 are provided intermittently in the longitudinal direction LD of separator 26. First adhesive layer-free regions N1 and N2, where adhesive layers 27 and 28 are not formed, are provided in first folded-back portion 26b1 and second folded-back portion 26b2 of separator 26. This effectively prevents the adhesive from being transferred to the pressure members (pressure plates P1 and P2 and pressure rollers 121 and 122), particularly in the first lamination step (step 3) and second lamination step (step 5) described below.

[0043] 4A and 4B, in this embodiment, adhesive layers 27 and 28 are provided in the center in the width direction Y of separator 26. Second adhesive layer-free regions N3, in which adhesive layers 27 and 28 are not formed, are provided along the longitudinal direction at both ends of separator 26 in the width direction Y. This effectively prevents the adhesive from being transferred to the presser members (particularly presser plates P1 and P2) particularly in the first lamination step (step 3) to the second lamination step (step 5) described below.

[0044] 2. Method for manufacturing an electricity storage device The above-described electricity storage device 100 can be manufactured by a manufacturing method including an electrode assembly fabrication step of fabricating a stacked electrode assembly 20 having a zigzag structure using a positive electrode 22, a negative electrode 24, and a separator 26. The remaining manufacturing processes may be the same as conventional methods. The manufacturing method disclosed herein may also include other steps at any stage. For example, after the electrode assembly fabrication step, the method may optionally include a press-molding step of compressing the stacked electrode assembly 20 in the stacking direction Z, a drying step of removing moisture contained in the stacked electrode assembly 20, a housing step of housing the stacked electrode assembly 20 and an electrolyte solution in a battery case 10, and the like.

[0045] In this embodiment, the electrode assembly fabrication process includes, in this order, a first adhesive layer forming step (step 1), a first placement step (step 2), a first lamination step (step 3) including a first folding step and a second adhesive layer forming step, a second placement step (step 4), and a second lamination step (step 5) including a second folding step and a third adhesive layer forming step. That is, in this embodiment, in step 3, the first folding step and the second adhesive layer forming step are performed simultaneously. Also, in step 5, the second folding step and the third adhesive layer forming step are performed simultaneously. However, in other embodiments, the second adhesive layer forming step may be performed after the first folding step, or the third adhesive layer forming step may be performed after the second folding step. Note that, in this specification, "performed simultaneously" means that at least some operations overlap, and it is not necessary that the start and end of the operations be completely synchronized. Furthermore, this term also allows for slight deviations due to, for example, mechanical or human error.

[0046] In this embodiment, a manufacturing apparatus 200 as shown in Figures 5A to 11 is used in steps 1 to 5. For example, as shown in Figure 5A etc., the manufacturing apparatus 200 includes a stacking stage 110, a separator supply unit 120, adhesive supply units 130 and 140, a carriage 150, a positive electrode supply unit (not shown), a negative electrode supply unit (not shown), and a control unit (not shown).

[0047] The stacking stage 110 is a forming table on which strip-shaped separators 26 are stacked in a zigzag pattern to form the zigzag-structured stacked electrode body 20. For example, as shown in FIG. 5A etc., the surface of the stacking stage 110 (the surface facing the carriage 150) is flat. The surface area of the stacking stage 110 is larger than the flat portion 26f of the separator 26.

[0048] The carriage 150 is supported, for example, by a guide rail (not shown). A transport path for the separator 26, which is part of the separator supply unit 120, is provided on the carriage 150. Two adhesive supply units 130 and 140 are also mounted on the carriage 150. The carriage 150 is configured to be movable relative to the stacking stage 110 by a carriage movement mechanism (not shown). In this embodiment, the carriage 150 is configured to be movable above the stacking stage 110 along the scanning direction (here, the short side direction X).

[0049] As shown in Figure 5A and other figures, the carriage 150 is configured to move back and forth between a first position SA and a second position SB. The distance from the first position SA to the second position SB is approximately the same as the length W3 in Figure 3. In the following, the direction from the first position SA to the second position SB is referred to as the first direction S1, and the opposite direction is referred to as the second direction S2. The arrows in the figures indicate the scanning direction, i.e., the movement direction, of the carriage 150.

[0050] The separator supply unit 120 is configured to supply the separator 26 onto the stacking stage 110. Although not shown in the figure, a strip-shaped separator sheet is wound on a reel and set at the starting end of the separator supply unit 120. The separator supply unit 120 unwinds the strip-shaped separator sheet and transports it as a separator 26 along a predetermined transport path to the stacking stage 110. For example, as shown in FIG. 5A and other figures, a portion of the transport path for the separator 26 is provided inside the carriage 150. Therefore, the transport path moves in the scanning direction X as the carriage 150 moves. A pair of pressure rollers 121 and 122 are arranged on the transport path. In addition to the pressure rollers 121 and 122, guide rollers, a dancer roll mechanism for removing slack, a tensioner for adjusting tension, and the like may also be appropriately arranged on the transport path.

[0051] The pressure rollers 121 and 122 are disposed directly below the carriage 150. The pressure rollers 121 and 122 are configured to sandwich the separator 26 from both sides in the scanning direction X. The pressure rollers 121 and 122 are supported by a support member (not shown). The support member is attached to the carriage 150. Therefore, the pressure rollers 121 and 122 move back and forth in the scanning direction X together with the carriage 150. It is preferable that at least one of the pressure rollers 121 and 122 is arranged so as to abut against the separator 26 placed on the stacking stage 110.

[0052] For example, as shown in FIG. 5B and other figures, the pressure rollers 121 and 122 are rod-shaped members that extend in the width direction Y of the separator 26, which is perpendicular to the scanning direction X, and are longer than the width WS of the separator 26. Here, the pressure rollers 121 and 122 have a substantially cylindrical outer shape and a substantially circular side surface. The pressure rollers 121 and 122 are rotatably supported by a support member (not shown) around a rotation axis extending in the width direction Y. The pressure rollers 121 and 122 are electrically connected to a control unit (not shown) and are configured to be movable in the stacking direction Z by the control unit. The pressure rollers 121 and 122 are examples of a first pressure member and a second pressure member.

[0053] The adhesive supply units 130, 140 are each configured to eject adhesive ink toward the stacking stage 110. More specifically, they are configured to eject adhesive ink onto at least one of the separator 26, the positive electrode 22, and the negative electrode 24 on the stacking stage 110. For example, as shown in FIG. 5A and other figures, the adhesive supply units 130, 140 are mounted on a carriage 150. Therefore, the adhesive supply units 130, 140 move back and forth together with the carriage 150 in the scanning direction X. In the carriage 150, the adhesive supply units 130, 140 sandwich the transport path of the separator 26 from the scanning direction X.

[0054] Each of the adhesive supply units 130 and 140 has a nozzle (not shown) that ejects adhesive ink. The adhesive supply units 130 and 140 are so-called ejection heads, and in this case, they are line heads in which a plurality of nozzles are arranged in the width direction Y of the separator 26, which is perpendicular to the scanning direction X. Each of the adhesive supply units 130 and 140 is electrically connected to a control unit (not shown), which controls the ejection of adhesive ink from the nozzles. For example, as shown in FIG. 5B and other figures, each of the adhesive supply units 130 and 140 has a width WA. In this embodiment, the width WA of each of the adhesive supply units 130 and 140 in the width direction Y is shorter than the width WS of the separator 26. The adhesive supply units 130 and 140 eject adhesive ink in a strip shape with a width equal to or shorter than the width WA.

[0055] The adhesive ink essentially contains the components that make up the adhesive layers 27 and 28 (e.g., adhesive layer binder), and typically further contains a solvent, and is prepared in a liquid state. The compositions of the adhesive inks ejected from the adhesive supply units 130 and 140, respectively (e.g., the type and concentration of the adhesive layer binder, the type of solvent, and the viscosity) may be the same or different. The solvent for the adhesive ink is not particularly limited as long as it can dissolve or disperse the adhesive layer binder. From the viewpoint of drying properties, etc., a non-aqueous solvent made of an organic solvent is preferred. Examples of organic solvents include alcohol-based solvents, ether-based solvents, ester-based solvents, amide-based solvents, and hydrocarbon-based solvents. Among these, alcohol-based solvents are preferred because they evaporate easily at room temperature and are easy to dry.

[0056] In some preferred embodiments, the adhesive ink has adhesive properties at room temperature. This allows the adhesive ink to exhibit adhesive properties immediately after being applied to the separator 26, etc., and allows the positive electrode 22 (second electrode plate) or the negative electrode 24 (first electrode plate) to be quickly bonded to the separator 26 without other treatments such as heat pressing. This allows for greater suppression of stacking misalignment. In this specification, "room temperature" typically refers to 25±10°C, for example, 25±5°C.

[0057] Although not shown, the positive electrode supply unit is configured to supply positive electrodes 22 onto the stacking stage 110 (more specifically, onto the second surfaces 262 of the separators 26 placed on the stacking stage 110). The negative electrode supply unit is configured to supply negative electrodes 24 onto the stacking stage 110 (more specifically, onto the first surfaces 261 of the separators 26 placed on the stacking stage 110). The configurations of the positive electrode supply unit and the negative electrode supply unit are not particularly limited and may be similar to conventional ones. For example, the positive electrode supply unit (or the negative electrode supply unit) may be configured to include an adsorption mechanism that adsorbs the positive electrodes 22 (or the negative electrodes 24), and to supply the positive electrodes 22 (or the negative electrodes 24) onto the stacking stage 110 by the adsorption mechanism.

[0058] The control unit is electrically connected to at least the carriage movement mechanism, adhesive supply units 130 and 140, the positive electrode supply unit, the negative electrode supply unit, the pressure plates P1 and P2 provided on the stacking stage 110, and the pressure rollers 121 and 122, and is configured to be able to control these. The hardware configuration of the control unit is not particularly limited. The control unit includes, for example, an interface (I / F), a central processing unit (CPU) that executes instructions from a control program, a read-only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as a memory that stores the program and various data. In this embodiment, steps 1 to 5 of the electrode body fabrication method are performed using the manufacturing apparatus 200 described above.

[0059] 5A and 5B, the first adhesive layer forming process (step 1) is a process of forming a first adhesive layer AL1 by applying an adhesive to at least a portion of the first surface 261 of the separator 26. Here, the carriage 150 is scanned to supply the separator 26 onto the stacking stage 110, and adhesive ink is ejected from the adhesive supply unit 130 onto the first surface 261 of the separator 26, thereby forming the first adhesive layer AL1 on the supplied separator 26.

[0060] In this process, first, the starting end of the separator 26 is supplied onto the lamination stage 110 with the first surface 261 facing the adhesive supply unit 130. More specifically, first, the starting end of the separator 26 is drawn out from the separator supply unit 120 through a conveyance path. The drawn separator 26 passes between a pair of pressure rollers 121, 122 and is placed on the lamination stage 110. As shown in FIGS. 5A and 5B , the starting end of the separator 26 is pressed down by a pressure plate P1 on the lamination stage 110.

[0061] The pressure plate P1 is a jig that temporarily fixes the separator 26 to the stacking stage 110. The pressure plate P1 may be in the form of a clamp. The pressure plate P1 is typically made of metal, such as stainless steel. The surface of the pressure plate P1 may be coated with fluororesin or diamond-like carbon (DLC). As shown in FIG. 5B, the pressure plate P1 is composed of multiple parts. Each part of the pressure plate P1 is rectangular in plan view, and the length in the width direction Y is shorter than the width WS of the separator 26 and the width WA of the adhesive supply units 130 and 140.

[0062] Each portion of the pressure plate P1 is electrically connected to a control unit (not shown) and configured to be movable, for example, in the width direction Y perpendicular to the scanning direction X, by the control unit. Here, each portion of the pressure plate P1 moves from the outside in the width direction Y (the upper or lower side in FIG. 5B ) toward the center and is placed on the starting end of the separator 26 (more specifically, a pair of corners on the starting end side). From the viewpoint of highly preventing the separator 26 from shifting position, the pressure plate P1 is preferably disposed so as to protrude outward from the end of the separator 26. Here, the pressure plate P1 protrudes outward from the end of the separator 26 in the width direction Y. The pressure plate P1 fixes the starting end of the separator 26 and is an example of a second pressure member used when forming the second folded portion 26b2 in the second lamination step (step 5) described later.

[0063] In this state, as shown in Figures 5A and 5B, when the carriage 150 moves from the first position SA in the first direction S1, the separators 26 are sequentially supplied onto the stacking stage 110 from the separator supply unit 120, guided by the pressure rollers 121 and 122. At this time, adhesive ink is ejected from the adhesive supply unit 130 mounted on the carriage 150 toward the first surfaces 261 of the separators 26 on the stacking stage 110. As described above, the adhesive ink preferably contains, for example, an adhesive layer binder and a solvent (for example, an alcohol-based solvent) and has adhesive properties at room temperature. This allows the adhesive ink to exhibit adhesive properties immediately after application.

[0064] As described above, the carriage 150 moves from the first position SA to the second position SB (one movement in the first direction S1), forming the first adhesive layer AL1 on the first surface 261 of the separator 26, as shown in FIGS. 6A and 6B. As shown in FIG. 6B, in this embodiment, the first adhesive layer AL1 is rectangular in plan view. The first adhesive layer AL1 is provided at the center of the separator 26, which has a width W3, in the scanning direction X and the width direction Y. In the scanning direction X, the length W4 of the first adhesive layer AL1 is preferably shorter than the length W3 of the separator 26. The length W4 of the first adhesive layer AL1 is preferably equal to or shorter than the length W2 (see FIG. 7B) of the negative electrode 24 (first electrode plate) used in the first placement step (step 2) described later. Furthermore, in the width direction Y, the length of the first adhesive layer AL1 is preferably shorter than the width WS of the separator 26. The length of the first adhesive layer AL1 is preferably equal to or shorter than the width WA of the adhesive supply portions 130 and 140 (see FIG. 5B).

[0065] In the technology disclosed herein, in this process, adhesive ink is ejected to a portion that does not overlap with the pressure members (pressure rollers 121, 122 and pressure plate P2 (see FIG. 8, etc.)) used when forming the first folded portion 26b1 in the first lamination process (step 3) described below, thereby forming the first adhesive layer AL1. This prevents the adhesive from being transferred to the pressure members (pressure rollers 121, 122 and pressure plate P2). As a result, the desired adhesive force can be stably exerted, and stacking misalignment can be suppressed. Furthermore, in this embodiment, adhesive ink is ejected to a portion that does not overlap with the pressure plate P1, thereby forming the first adhesive layer AL1. This allows the effects of the technology disclosed herein to be exerted at a higher level.

[0066] In some embodiments, as shown in FIG. 6B, it is preferable to secure first adhesive layer non-forming regions N1 and N2 at both ends in the scanning direction X. In other words, it is preferable not to apply adhesive ink to the first folded portion 26b1 (see FIG. 3, etc.) formed in the first lamination step (step 3) described below. This can highly effectively suppress stacking misalignment, particularly when the adhesive has adhesive properties at room temperature. It also makes it easier to form the first folded portion 26b1.

[0067] 6B, it is preferable to secure second adhesive layer non-forming regions N3 along the longitudinal direction LD (see FIG. 3) at both ends of the separator 26 in the width direction Y without applying adhesive ink. This makes it easier to fix the separator 26 on the stacking stage 110 with a strong force, and prevents misalignment.

[0068] As shown in FIGS. 7A and 7B, the first placement process (step 2) is a process of placing a negative electrode 24 (first electrode plate) on the first adhesive layer AL1. This process is typically performed with the carriage 150 stopped at the second position SB. The negative electrode 24 is supplied onto the stacking stage 110 (specifically, onto the first adhesive layer AL1 of the separator 26) from a negative electrode supply unit (not shown). The negative electrode 24 is preferably placed on the first adhesive layer AL1 so that a portion of the negative electrode tab 24t extends beyond one end of the separator 26 in the width direction Y (the lower portion in FIG. 7B). As shown in FIG. 7B, in this embodiment, the length W2 of the negative electrode 24 (first electrode plate) in the scanning direction X is approximately the same as the length W4 of the first adhesive layer AL1. Therefore, in a plan view, the first adhesive layer AL1 is covered and hidden by the negative electrode 24 (first electrode plate). If the adhesive of the first adhesive layer AL1 has adhesiveness at room temperature, the negative electrode 24 (first electrode plate) placed on the first adhesive layer AL1 is quickly bonded to the separator 26 via the first adhesive layer AL1.

[0069] In this embodiment, as shown in FIGS. 7A and 7B , a pressure plate P2 presses down the separator 26 and the negative electrode 24 from above the negative electrode 24. The pressure plate P2 is a jig that temporarily fixes the negative electrode 24 and the separator 26 to the stacking stage 110. Like the pressure plate P1, the pressure plate P2 is composed of multiple parts. The pressure plate P2 is disposed symmetrically to the pressure plate P1 in the scanning direction X. The pressure plate P2 has the same material and shape as the pressure plate P1. However, in other embodiments, the pressure plate P2 may have a different material or shape from the pressure plate P1. Like the pressure plate P1, each part of the pressure plate P2 is electrically connected to a control unit (not shown) and is configured to be movable by the control unit, for example, in the width direction Y perpendicular to the scanning direction X.

[0070] Each portion of the pressure plate P2 moves from the outer side in the width direction Y (the upper or lower side in FIG. 7B ) toward the center and is placed at a position that will serve as a starting point for folding back the separator 26 in the first lamination step (step 3) described later. Each portion of the pressure plate P2 presses down the end of the negative electrode 24 on the second position SB side in the scanning direction X (more specifically, a pair of corners) and a portion of the separator 26 that is a length W3 away from the starting end. However, if the adhesive has adhesive properties at room temperature and the negative electrode 24 and the separator 26 are already bonded together, the pressure plate P2 may press down only the separator 26. Here, the pressure plate P2 protrudes outward from the end of the separator 26 in the width direction Y. The pressure plate P2 is an example of a first pressing member used when forming the first folded-back portion 26b1 in the first lamination step (step 3) described later.

[0071] The first lamination step (step 3) includes a first folding step and a second adhesive layer forming step. That is, in this step, as shown in FIG. 8, the separator 26 is pressed by a first pressing member (pressing rollers 121, 122 and pressing plate P2) and folded over a length W3 to cover the negative electrode 24 (first electrode plate) to form a first folded portion 26b1. The second adhesive layer forming step also includes applying an adhesive to at least a portion of the second surface 262 of the separator 26 folded over at the first folded portion 26b1 to form a second adhesive layer AL2. Specifically, the first folding step and the second adhesive layer forming step are performed while the carriage 150 moves once in the second direction S2.

[0072] Specifically, first, at second position SB, the folded portion of separator 26 is pressed and shaped by pressure rollers 121 and 122 (see also FIG. 4B). Next, as shown in FIG. 8, when carriage 150 moves from second position SB in second direction S2, separator 26 moves along the surface of negative electrode 24 while being sandwiched between the pair of pressure rollers 121 and 122. As a result, separator 26 is folded back starting from pressure plate P2, and first folded portion 26b1 is formed.

[0073] In this embodiment, the carriage 150 is provided with adhesive supply units 130 and 140 on either side of the transport path of the separator 26. Therefore, as the first folded portion 26b1 is formed, adhesive ink is ejected from the adhesive supply unit 130 onto the negative electrode 24 (specifically, the negative electrode active material layer 24a), and adhesive ink is ejected from the adhesive supply unit 140 onto a portion of the second surface 262 of the separator 26 folded back at the first folded portion 26b1. As a result, an electrode adhesive layer EL is formed on the negative electrode 24, and a second adhesive layer AL2 is formed on the second surface 262 of the separator 26. In other words, as the carriage 150 moves from the second position SB to the first position SA (one movement in the second direction S2), the second adhesive layer AL2 is formed on the separator 26, and the electrode adhesive layer EL is formed on the negative electrode 24. If the adhesive of the adhesive layer EL on the electrode has adhesiveness at room temperature, the separator 26 folded back at the first folded portion 26b1 is quickly bonded to the negative electrode 24 via the adhesive layer EL on the electrode.

[0074] 8, when the carriage 150 moves in the second direction S2, the pressure roller 121 located at the front side in the second direction (movement direction) S2 is preferably raised higher than the pressure roller 122 located at the rear side. This makes it difficult for the pressure roller 121 to come into contact with the adhesive layer EL on the negative electrode 24, preventing the transfer of adhesive to the pressure roller 121. Therefore, the effects of the technology disclosed herein can be exerted at a higher level.

[0075] As shown in FIG. 9A, when the carriage 150 moves from the second position SB to the first position SA, a laminated structure of the electrode adhesive layer EL, the separator 26, and the second adhesive layer AL2 is formed on the negative electrode 24. As shown in FIG. 9B, the second adhesive layer AL2 has a rectangular shape in a plan view and is approximately the same size as the first adhesive layer AL1. The second adhesive layer AL2 is provided at the center of the separator 26, which has a width W3, in the scanning direction X and the width direction Y. In the scanning direction X, the length W5 of the second adhesive layer AL2 is preferably shorter than the length W3 of the separator 26. The length W5 of the second adhesive layer AL2 is preferably equal to or shorter than the length W2 (see FIG. 7B) of the negative electrode 24 (first electrode plate). The length of the second adhesive layer AL2 is preferably equal to or longer than the length W1 (see FIG. 10B) of the positive electrode 22 (second electrode plate) used in the second placement step (step 4) described below. Furthermore, in the width direction Y, the length of the second adhesive layer AL2 is preferably shorter than the width WS of the separator 26. The length of the second adhesive layer AL2 is preferably the same as or shorter than the width WA of the adhesive supply portions 130, 140 (see FIG. 5B).

[0076] In the technology disclosed herein, in this process, adhesive ink is ejected to a portion that does not overlap with the pressure members (pressure rollers 121, 122 and pressure plate P1 (see FIG. 10A, etc.)) used when forming the second folded portion 26b2 in the second lamination process (step 5) described later, thereby forming the second adhesive layer AL2. This prevents the adhesive from being transferred to the pressure members (pressure rollers 121, 122 and pressure plate P1). As a result, the desired adhesive force can be stably exerted, and stacking misalignment can be suppressed. Furthermore, in this embodiment, adhesive ink is ejected to a portion that does not overlap with the pressure plate P2, thereby forming the second adhesive layer AL2. This allows the effects of the technology disclosed herein to be exerted at a higher level.

[0077] In some embodiments, similarly to the first adhesive layer forming step (step 1) described above, it is preferable to secure first adhesive layer non-forming regions N1 and N2 at both ends in the scanning direction X, as shown in Fig. 9B. It is also preferable to secure second adhesive layer non-forming regions N3 along the longitudinal direction LD (see Fig. 3) at both ends in the width direction Y of the separator 26 without applying adhesive ink.

[0078] 10A and 10B, the second placement process (step 4) is a process of placing the positive electrode 22 (second electrode plate) on the second adhesive layer AL2 so as to face the negative electrode 24 (first electrode plate). This process is typically performed with the carriage 150 stopped at the first position SA. The positive electrode 22 is supplied onto the stacking stage 110 (specifically, onto the second adhesive layer AL2 of the separator 26) from a positive electrode supply unit (not shown). The positive electrode 22 is preferably placed on the second adhesive layer AL2 so that a portion of the positive electrode tab 22t protrudes from one end of the separator 26 in the width direction Y (upper side in FIG. 10B). As shown in FIG. 10B, in this embodiment, the length W1 of the positive electrode 22 (second electrode plate) is shorter than the length W5 of the second adhesive layer AL2 in the scanning direction X. Therefore, the second adhesive layer AL2 protrudes from the positive electrode 22 (second electrode plate) in a plan view. If the adhesive of the second adhesive layer AL2 has adhesiveness at room temperature, the positive electrode 22 (second electrode plate) placed on the second adhesive layer AL2 is quickly bonded to the separator 26 via the second adhesive layer AL2.

[0079] In this embodiment, as shown in FIGS. 10A and 10B, the separator 26 and the positive electrode 22 are re-pressed by a presser plate P1 from above the positive electrode 22. For example, first, each portion of the presser plate P1 moves from the center toward the outside in the width direction Y (the upper or lower side in FIG. 10B) and is pulled out from between the separator 26 and the negative electrode 24 in the stacking direction Z. Next, each portion of the presser plate P1 moves from the outside toward the center in the width direction Y and is placed at a position that will serve as a starting point for folding back the separator 26 in the second stacking step (step 5) described below. Here, each portion of the presser plate P1 presses down the end of the positive electrode 22 on the first position SA side in the scanning direction X (more specifically, a pair of corners) and the starting end of the separator 26.

[0080] The second lamination step (step 5) includes a second folding step and a third adhesive layer forming step. That is, in this step, as shown in FIG. 11 , similar to the first lamination step (step 3), the separator 26 is pressed by the second pressing member (pressing rollers 121, 122 and pressing plate P1) and folded over the separator 26 by a length W3 to cover the positive electrode 22 (second electrode plate) to form a second folded portion 26b2. The second folding step and the third adhesive layer forming step are simultaneously performed. The third adhesive layer forming step applies adhesive to at least a portion of the first surface 261 of the separator 26 folded over at the second folded portion 26b2 to form a third adhesive layer AL3. Specifically, the second folding step and the third adhesive layer forming step are performed while the carriage 150 moves once in the first direction S1.

[0081] Specifically, first, at the first position SA, the folded portion of the separator 26 is pressed by the pressure rollers 121 and 122 to form a crease (see also FIG. 4A). Next, as shown in FIG. 11, when the carriage 150 moves from the first position SA in the first direction S1, the separator 26 moves along the surface of the positive electrode 22 while being sandwiched between the pair of pressure rollers 121 and 122. As a result, the separator 26 is folded back starting from the pressure plate P1, and a second folded portion 26b2 is formed.

[0082] In addition, as the second folded portion 26b2 is formed, adhesive ink is ejected from the adhesive supply unit 130 onto a portion of the first surface 261 of the separator 26 folded at the second folded portion 26b2, and adhesive ink is ejected from the adhesive supply unit 140 onto the positive electrode 22 (specifically, the positive electrode active material layer 22a) on the stacking stage 110. As a result, a third adhesive layer AL3 is formed on the first surface 261 of the separator 26, and an electrode adhesive layer EL is formed on the positive electrode 22. Although not shown in the drawings, in this embodiment, the third adhesive layer AL3 has the same position, shape, and size as the first adhesive layer AL1. If the adhesive of the electrode adhesive layer EL has adhesive properties at room temperature, the separator 26 folded at the second folded portion 26b2 is quickly bonded to the positive electrode 22 via the electrode adhesive layer EL.

[0083] 11, when the carriage 150 moves in the first direction S1, the pressure roller 122 located at the front side in the first direction (movement direction) S1 is preferably raised higher than the pressure roller 121 located at the rear side. This makes it difficult for the pressure roller 122 to come into contact with the electrode adhesive layer EL on the positive electrode 22, preventing the transfer of adhesive to the pressure roller 122. Therefore, the effects of the technology disclosed herein can be exerted at a higher level.

[0084] In this way, steps 2 to 5 are repeated for the number of negative electrodes 24 (first electrode plates) and positive electrodes 22 (second electrode plates) to form a zigzag structure portion in which n-th layers are stacked. Thereafter, as shown in Figures 4A and 4B, the outer periphery of the zigzag structure is covered with terminal end portion 26e of separator 26, thereby producing stacked electrode body 20 as shown in Figure 3.

[0085] <3. Uses of electricity storage devices> An electricity storage device 100 including a stacked electrode body 20 can be used for a variety of purposes, but can be suitably used, for example, as a power source (driving power source) for a motor mounted on a vehicle such as a passenger car, truck, etc. The type of vehicle is not particularly limited, but examples include a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), and a battery electric vehicle (BEV).

[0086] Although several embodiments of the present invention have been described above, the above embodiments are merely examples. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed in this specification and the common general technical knowledge in the relevant field. The technology described in the claims includes various modifications and alterations of the above-exemplified embodiments. For example, it is possible to replace part of the above-described embodiments with other modified embodiments, and it is also possible to add other modified embodiments to the above-described embodiments. Furthermore, if a technical feature is not described as essential, it may be deleted as appropriate.

[0087] In the above-described embodiment, the pressure plates P1 and P2 are each composed of a plurality of rectangular plate members, but this is not limiting. The pressure plates P1 and / or P2 may be a single member. In this case, the pressure plates P1 and / or P2 may be rod-shaped, for example, with a length in the width direction Y longer than the length W3 of the separator 26.

[0088] In the above-described embodiment, the stacking stage 110 is fixed, but this is not limiting. The stacking stage 110 is electrically connected to a control unit (not shown) and may be configured to be movable, for example, in the vertical direction.

[0089] In the above-described embodiment, the carriage 150 (or the transport path and adhesive supply units 130, 140 mounted on the carriage 150) is moved relative to the stacking stage 110 in the scanning direction X, but this is not limiting. For example, the stacking stage 110 may be moved relative to the carriage 150 while the carriage 150 remains fixed.

[0090] In the above-described embodiment, the adhesive supply units 130 and 140 are mounted on the carriage 150 and configured to be movable integrally with the carriage 150, but this is not limiting. The adhesive supply unit 130 and / or the adhesive supply unit 140 may be supported by a support member different from the carriage 150 and configured to be independently movable. Furthermore, in the above-described embodiment, the pressure rollers 121 and 122 are indirectly supported by the carriage 150 via a support member, but this is not limiting. The pressure rollers 121 and 122 may be supported by a support member different from the carriage 150 and configured to be independently movable.

[0091] In the above-described embodiment, the manufacturing apparatus 200 is used in steps 1 to 5 of the electrode body manufacturing process, but this is not limiting. Some or all of the steps of the electrode body manufacturing process may be performed using other manufacturing apparatuses, or may be performed manually.

[0092] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Item 1: A method for manufacturing a stacked electrode body having a zigzag structure in which a strip-shaped separator is folded back alternately at predetermined intervals to form a zigzag shape, and a plurality of first electrode plates and a plurality of second electrode plates are alternately sandwiched between the zigzag-shaped separator, the method comprising: a first adhesive layer forming step of applying an adhesive to a portion of a first surface of the separator to form a first adhesive layer; a first placing step of placing the first electrode plate on the first adhesive layer of the separator after the first adhesive layer forming step; and a first folding step of pressing the separator with a first pressing member after the first placing step, and folding the separator back at the predetermined intervals to cover the first electrode plate, to form first folded portions, wherein in the first adhesive layer forming step, the first adhesive layer is formed on a portion that does not come into contact with the first pressing member when forming the first folded portion in the first folding step. Item 2: A manufacturing method according to item 1, wherein in the first adhesive layer forming step, the adhesive is not applied to the first folded portion formed in the first folding step, and the first folded portion is made into an adhesive layer non-forming area. Item 3: The manufacturing method according to Item 1 or 2, wherein in the first adhesive layer forming step, the adhesive is not applied to both widthwise ends of the separator, and the both ends are each an adhesive layer-free region along the longitudinal direction. Item 4: The manufacturing method according to any one of Items 1 to 3, wherein the adhesive used has adhesive properties at room temperature. Item 5: The manufacturing method according to any one of items 1 to 4, further comprising a second adhesive layer forming step, which is carried out simultaneously with the first folding step, of applying an adhesive to a portion of the second surface of the separator folded at the first folding portion to form a second adhesive layer. Item 6: The manufacturing method according to Item 5, further comprising: a second placing step of placing the second electrode plate on the second adhesive layer of the separator after the second adhesive layer forming step; and a second folding step of pressing the separator with a second pressing member after the second placing step and folding the separator at the predetermined interval to cover the second electrode plate, thereby forming a second folded portion, wherein in the second adhesive layer forming step, the second adhesive layer is formed in a portion that does not come into contact with the second pressing member when forming the second folded portion in the second folding step. Item 7: The manufacturing method according to Item 5 or 6, wherein in the second adhesive layer forming step, the second adhesive layer is formed on the separator and an adhesive is applied to the second electrode plate to form an on-electrode adhesive layer. Item 8: The manufacturing method described in Item 7, wherein the first pressing member includes a pair of pressing rollers, and in the first folding process, the separator is moved along the surface of the first electrode plate while being sandwiched between the pair of pressing rollers, and at this time, the pressing roller on the front side in the moving direction is raised higher than the pressing roller on the rear side in the moving direction. Item 9: A method for producing an electricity storage device using a stacked electrode body produced by the production method according to any one of items 1 to 8. Item 10: A stacked electrode body having a zigzag structure in which a strip-shaped separator is folded back alternately at predetermined intervals to form a zigzag shape, and a plurality of first electrode plates and a plurality of second electrode plates are alternately sandwiched between the zigzag-shaped separator, wherein at least the separator and the first electrode plate are bonded via an adhesive layer, and the strip-shaped separator has, in a cross-sectional view in the stacking direction, a flat portion facing at least one of the first electrode plate and the second electrode plate, and folded portions provided on both ends of the flat portion and facing neither the first electrode plate nor the second electrode plate, and an adhesive layer-free region where the adhesive layer is not formed is provided in the folded portions. Item 11: The stacked electrode body according to item 10, wherein the separator has adhesive layer-free regions at both widthwise ends thereof along the longitudinal direction, where the adhesive layer is not formed. Item 12: An electricity storage device comprising the stacked electrode assembly according to item 10 or 11. [Explanation of symbols]

[0093] 10 Battery case 20. Laminated electrode body 22 positive electrode (second electrode plate) 24 Negative electrode (first electrode plate) 26 Separator 261 Page 1 262 2nd page 26f flat area 26b1 First fold 26b2 Second fold 27, 28 Adhesive layer 100 Energy storage device 200 Manufacturing equipment

Claims

1. A method for manufacturing a stacked electrode assembly having a zigzag structure in which a strip-shaped separator is folded back alternately at predetermined intervals to form a zigzag shape, and a plurality of first electrode plates and a plurality of second electrode plates are sandwiched alternately between the zigzag-shaped separators, a first adhesive layer forming step of applying an adhesive to a portion of the first surface of the separator to form a first adhesive layer; a first placing step of placing the first electrode plate on the first adhesive layer of the separator after the first adhesive layer forming step; a first folding step of pressing the separator with a first pressing member after the first placing step and folding the separator at the predetermined interval so as to cover the first electrode plate, thereby forming a first folded portion; Including, In the first adhesive layer forming step, the first adhesive layer is formed on a portion that does not come into contact with the first pressing member when the first folded portion is formed in the first folding step. A method for manufacturing a laminated electrode body.

2. In the first adhesive layer forming step, the adhesive is not applied to the first folded portion formed in the first folding step, and the first folded portion is made into an adhesive layer non-formation region. The method of claim 1.

3. In the first adhesive layer forming step, the adhesive is not applied to both end portions in the width direction of the separator, and the both end portions are formed as adhesive layer-free regions along the longitudinal direction. The method of claim 1.

4. The adhesive used is one that has adhesiveness at room temperature. The method of claim 1.

5. a second adhesive layer forming step, which is carried out simultaneously with the first folding step, of applying an adhesive to a part of the second surface of the separator folded at the first folding portion to form a second adhesive layer. The method of claim 1.

6. a second placing step of placing the second electrode plate on the second adhesive layer of the separator after the second adhesive layer forming step; a second folding step of pressing the separator with a second pressing member after the second placing step and folding the separator back at the predetermined interval so as to cover the second electrode plate, thereby forming a second folded portion; further comprising In the second adhesive layer forming step, the second adhesive layer is formed on a portion that does not come into contact with the second pressing member when the second folded portion is formed in the second folding step. The method of claim 5.

7. In the second adhesive layer forming step, the second adhesive layer is formed on the separator, and an adhesive is applied to the second electrode plate to form an on-electrode adhesive layer. The method of claim 5.

8. the first pressing member includes a pair of pressing rollers, In the first folding process, the separator is moved along the surface of the first electrode plate while being sandwiched between the pair of pressure rollers, At this time, the pressure roller on the front side in the moving direction is raised higher than the pressure roller on the rear side in the moving direction. The method of claim 7.

9. A laminated electrode body manufactured by the manufacturing method of any one of claims 1 to 8 is used. A method for manufacturing an electricity storage device.

10. A stacked electrode body having a zigzag structure in which a strip-shaped separator is folded back alternately at predetermined intervals to form a zigzag shape, and a plurality of first electrode plates and a plurality of second electrode plates are alternately sandwiched between the zigzag-shaped separators, At least the separator and the first electrode plate are bonded via an adhesive layer, The strip-shaped separator has, in a cross-sectional view in the stacking direction, a flat portion facing at least one of the first electrode plate and the second electrode plate; Folded portions provided at both ends of the flat portion and facing neither the first electrode plate nor the second electrode plate; and The folded portion has an adhesive layer-free region where the adhesive layer is not formed. Layered electrode body.

11. The separator has adhesive layer-free regions in which the adhesive layer is not formed along the longitudinal direction at both ends in the width direction. The laminated electrode assembly according to claim 10.

12. An electricity storage device comprising the stacked electrode assembly according to claim 10 or 11.

Images