Holding structure for electrode laminate

Abstract

A holding structure (1) for a laminated body (10) is provided with: a laminated body (10) in which a plurality of electrodes are laminated; and a holding body (40) that holds the laminated body (10) and fixes the plurality of electrodes to each other. The holding body (40) is provided with: an upper cover member (50) that covers the upper surface (10a) of the laminate (10) and covers the left and right side surfaces (10c, 10d) of the laminate (10); and a lower cover member (60) that covers the lower surface (10b) of the laminate (10) and covers the left and right side surfaces (10c, 10d) of the laminate (10), the upper cover member (50) and the lower cover member (60) being bonded to the left and right side surfaces (10c, 10d) of the laminate (10).

Description

Technical Field

[0001] The present invention relates to a structure for holding an electrode stack. Background Art

[0002] An all-solid-state battery includes an electrode stack formed by alternately stacking electrode layers and solid electrolyte layers, and an exterior body that houses the electrode stack (Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-119558 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When manufacturing such an all-solid-state battery, a process is required to seal the electrode stack in an outer package such as a laminate package. During this process, when the electrode stack is transported, there is a problem of movement of the electrode layers and solid electrolyte layers, resulting in positional displacement of the electrode layers and solid electrolyte layers.

[0008] An object of the present invention is to provide a structure for holding a stacked body that can suppress displacement of electrodes in the stacked body.

[0009] Solutions for solving problems

[0010] The present invention solves the above problems by combining a first covering member covering one end face of the stacked body in the stacking direction and covering the side face of the stacked body with a second covering member covering the other end face of the stacked body in the stacking direction and covering the side face of the stacked body.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to suppress the displacement of electrodes in the laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an exploded perspective view showing the all-solid-state battery in the first embodiment of the present invention.

[0014] Figure 2 It is an exploded perspective view showing a holding structure for a stacked body according to a first embodiment of the present invention.

[0015] Figure 3A This is a front view showing a holding structure for a stacked body according to a first embodiment of the present invention.

[0016] Figure 3BIt is a left side view showing the holding structure of the stacked body according to the first embodiment of the present invention.

[0017] Figure 4 It is an exploded perspective view showing a first modified example of the holding body according to the embodiment of the present invention.

[0018] Figure 5 It is an exploded perspective view showing a second modified example of the holding body according to the embodiment of the present invention. DETAILED DESCRIPTION

[0019] [First embodiment]

[0020] Hereinafter, examples of embodiments of the present invention will be described with reference to the drawings. Figure 1 is an exploded perspective view showing the all-solid-state battery 100 in the first embodiment. Figure 2 It is an exploded perspective view showing the holding structure 1 of the stacked body 10 in the first embodiment. Figure 3A 1 is a front view showing a holding structure 1 of a stacked body 10 in the first embodiment. Figure 3B It is a left side view showing the holding structure 1 of the stacked body 10 in the first embodiment.

[0021] like Figure 1 As shown, all-solid-state battery (cell) 100 includes a holding structure 1, a pair of laminate films 70, 70, and a pair of tab leads 80, 80. The holding structure 1 is sandwiched from above and below by the laminate films 70, 70, serving as an exterior body, and is housed between the laminate films 70, 70. The tab leads 80 extend from the interior of the exterior body to the exterior.

[0022] like Figure 1 As shown in FIG. 1 , the holding structure 1 includes a stacked body 10 and a holding body 40. The stacked body 10 is formed by stacking a plurality of plate-like members and has a rectangular shape when viewed from above. Figure 2 As shown, the laminate 10 in this embodiment includes an electrode laminate 20 .

[0023] The electrode stack 20 includes multiple electrodes and multiple solid electrolytes. Although not specifically shown, the positive electrode, solid electrolyte layer, and negative electrode may be stacked one on top of the other in the electrode stack 20. Furthermore, the positive electrode may include a positive electrode active material layer and a positive electrode current collector. The negative electrode may include a negative electrode active material layer and a negative electrode current collector. Furthermore, the negative electrode may omit the negative electrode active material layer. Furthermore, the negative electrode may include a lithium metal layer primarily composed of lithium metal, in place of the negative electrode active material layer.

[0024] The electrode stack 20 includes an electrode portion 21 and a tab portion 22. The electrode portion 21 is a portion where at least a positive electrode active material layer, a solid electrolyte layer, and positive and negative electrode current collectors are located.

[0025] The tabs 22 are formed at both ends of the electrode portion 21. The positive and negative current collectors extending from the electrode portion 21 are located in the tabs 22. Multiple current collectors are bonded to the tab leads 80 in the tabs 22 by welding or other means. Alternatively, the tabs 22 may be formed only on one end of the electrode portion 21. In other words, both the positive and negative current collectors may extend from one end of the electrode portion 21.

[0026] The holder 40 is not particularly limited, but it covers the circumference of the stack 10 to constrain the stack 10. More specifically, the holder 40 in this embodiment presses the stack 10 from above and below and clamps the stack 10 from the sides, thereby holding the stack 10. Thus, the holder 40 fixes the positive electrode, solid electrolyte layer, and negative electrode to each other in the stack 10.

[0027] like Figure 2 As shown, the holding body 40 includes an upper cover member 50 and a lower cover member 60. The upper cover member 50 in this embodiment corresponds to an example of the "first cover member" in the present invention, and the lower cover member 60 in this embodiment corresponds to an example of the "second cover member" in the present invention.

[0028] The upper cover member 50 is composed of a resin film and covers the stacked body 10 from its upper surface 10a. From the perspective of heat dissipation performance, the upper cover member 50 is preferably composed of a resin film containing metal fillers. Furthermore, to maintain the insulating properties of the resin film, the metal fillers are preferably dispersed within the resin film. The upper surface 10a in this embodiment corresponds to an example of "one end surface of the stacked body in the stacking direction" in the present invention.

[0029] The upper cover member 50 includes an upper surface cover portion 51 and a plurality of (four in this example) upper side cover portions 52a to 52d. The upper surface cover portion 51 in this embodiment corresponds to an example of a "first end surface cover portion" in the present invention, and the upper side cover portions 52a to 52d in this embodiment correspond to an example of a "first side surface cover portion" in the present invention.

[0030] The upper surface covering portion 51 has a rectangular planar shape corresponding to the planar shape of the upper surface 10a of the laminate 10. Figure 3A and Figure 3B As shown, the upper surface covering portion 51 in this embodiment covers the upper surface 10a of the electrode portion 21 and the upper surface 10a of the tab portion 12. In other words, the upper surface covering portion 51 covers the entire upper surface 10a. Furthermore, the upper surface covering portion 51 does not necessarily need to cover the entire upper surface 10a and may cover only a portion of the upper surface 10a. For example, the upper surface covering portion 51 may cover only the upper surface of the electrode portion 21, or may cover only a portion of the upper surface of the electrode portion 21.

[0031] like Figure 2 As shown in FIG. 1 , four upper side covering portions 52a to 52d are provided at the corners of the upper surface covering portion 51. The upper side covering portion 52a is a rectangular film provided at the left front corner of the upper surface covering portion 51 in the figure. Figure 3A As shown, the upper side surface covering portion 52a extends downward from the end edge of the upper surface covering portion 51, and overlaps and is connected to a lower side surface covering portion 62a described later.

[0032] In this embodiment, the inner side surface of the upper side covering portion 52a is bonded to the outer side surface of the lower side covering portion 62a. The upper side covering portion 52a and the lower side covering portion 62a may also be bonded using an adhesive or the like. In this embodiment, the inner side surface of the upper side covering portion 52a is bonded to the outer side surface of the lower side covering portion 62a, but the present invention is not limited thereto. The outer side surface of the upper side covering portion 52a may also be bonded to the inner side surface of the lower side covering portion 62a.

[0033] like Figure 3B As shown, in this embodiment, the width W2 of the upper side covering portion 52a is smaller than the width W1 of the left side 10c (W2 < W1). Therefore, the upper side covering portion 52a covers the front end of the left side 10c of the stacked body 10. Furthermore, the upper side covering portion 52a abuts at least a portion of the left side 10c of the stacked body 10. Alternatively, the entire upper side covering portion 52a may not contact the left side 10c. In this case, the entire upper side covering portion 52a may be slightly separated from the left side 10c. Alternatively, only a portion of the upper side covering portion 52a may be slightly separated from the left side 10c, with the remaining portion of the upper side covering portion 52a in contact with the left side 10c.

[0034] like Figure 3B As shown, an upper side cover 52b is provided behind the upper side cover 52a (on the +Y direction side in the figure). The upper side cover 52b is provided on the same side surface (left side 10c) as the upper side cover 52a. The upper side cover 52b is provided at the left inner corner of the upper side cover 51 in the figure, and is separated from the upper side cover 52a on the same side surface.

[0035] The upper side covering portion 52b is a film having the same shape as the upper side covering portion 52a. The upper side covering portion 52b also extends downward from the edge of the upper side covering portion 51, overlapping and joining with the lower side covering portion 62b described later. Furthermore, the shape of the upper side covering portion 52b may differ from that of the upper side covering portion 52a.

[0036] The inner side surface of the upper side covering portion 52b is joined to the outer side surface of the lower side covering portion 62b. The upper side covering portion 52b and the lower side covering portion 62b may also be joined using an adhesive or the like, similar to the upper side covering portion 52a and the lower side covering portion 62a. Furthermore, in this embodiment, the inner side surface of the upper side covering portion 52b is joined to the outer side surface of the lower side covering portion 62b, but the present invention is not limited thereto. The outer side surface of the upper side covering portion 52b may also be joined to the inner side surface of the lower side covering portion 62b.

[0037] The upper side surface covering portion 52b in this embodiment covers the rear end portion of the left side surface 10c of the stacked body 10. The upper side surface covering portion 52b contacts at least a portion of the left side surface 10c of the stacked body 10.

[0038] like Figure 2 As shown, an upper side cover 52c is provided on the opposite side of the upper side cover 52a across the stacked body 10. The upper side cover 52c is provided on the right side surface 10d opposite the upper side cover 52a. The upper side cover 52c is provided at the right front corner of the upper surface cover 51 in the figure.

[0039] Upper side covering portion 52c is a film having the same shape as upper side covering portion 52a. Upper side covering portion 52c also extends downward from the edge of upper side covering portion 51, overlapping and joining lower side covering portion 62c (described later). Alternatively, upper side covering portion 52c may have a different shape from upper side covering portion 52a.

[0040] The inner side surface of the upper side covering portion 52c is joined to the outer side surface of the lower side covering portion 62c. The upper side covering portion 52c and the lower side covering portion 62c may be joined using an adhesive or the like, similar to the upper side covering portion 52c and the lower side covering portion 62c. Furthermore, in this embodiment, the inner side surface of the upper side covering portion 52c is joined to the outer side surface of the lower side covering portion 62c, but the present invention is not limited thereto. The outer side surface of the upper side covering portion 52c may also be joined to the inner side surface of the lower side covering portion 62c.

[0041] The upper side covering portion 52c in this embodiment covers the front end portion of the right side 10d of the stacked body 10. The upper side covering portion 52b contacts at least a portion of the left side 10c of the stacked body 10. Alternatively, the upper side covering portion 52c may be slightly separated from the right side 10d.

[0042] An upper side cover 52d is provided behind the upper side cover 52c. The upper side cover 52d is provided on the same side surface (right side 10d) as the upper side cover 52c. The upper side cover 52d is provided at the inner right corner of the upper side cover 51 in the figure, and is separated from the upper side cover 52c on the same side surface.

[0043] The upper side covering portion 52d is a film having the same shape as the upper side covering portion 52a. The upper side covering portion 52d also extends downward from the edge of the upper side covering portion 51, overlapping and joining the lower side covering portion 62d described later. Furthermore, the shape of the upper side covering portion 52d may differ from that of the upper side covering portion 52a.

[0044] The inner side surface of the upper side covering portion 52d is joined to the outer side surface of the lower side covering portion 62d. The upper side covering portion 52d and the lower side covering portion 62d may also be joined using an adhesive or the like, similar to the upper side covering portion 52a and the lower side covering portion 62a. Furthermore, in this embodiment, the inner side surface of the upper side covering portion 52d is joined to the outer side surface of the lower side covering portion 62d, but the present invention is not limited thereto. The outer side surface of the upper side covering portion 52d may also be joined to the inner side surface of the lower side covering portion 62d.

[0045] The upper side surface covering portion 52d in this embodiment covers the rear end portion of the right side surface 10d of the stacked body 10. The upper side surface covering portion 52d contacts at least a portion of the right side surface 10d of the stacked body 10.

[0046] like Figure 2 As shown, the lower cover member 60 is also made of a resin film, similar to the upper cover member 50, and covers the stacked body 10 from the lower surface 10b side. Like the upper cover member 50, the lower cover member 60 is preferably a resin film containing metal fillers from the perspective of heat dissipation performance. The lower surface 10b in this embodiment corresponds to an example of the "other end surface of the stacked body in the stacking direction" in the present invention.

[0047] The lower cover member 60 is essentially a top-down inversion of the upper cover member 50 and includes a lower surface cover portion 61 and a plurality of (four in this example) lower side surface cover portions 62a through 62d. The lower surface cover portion 61 in this embodiment corresponds to an example of a "second end surface cover portion" in the present invention, and the lower side surface cover portions 62a through 62d in this embodiment correspond to an example of a "second side surface cover portion" in the present invention.

[0048] The lower surface covering portion 61 has a structure substantially similar to that of the upper surface covering portion 51. However, the lower surface covering portion 61 covers the lower surface 10b of the electrode portion 21 and the lower surface 10b of the tab portion 12. Furthermore, like the upper surface covering portion 51, the lower surface covering portion 61 does not necessarily need to cover the entire lower surface 10b and may cover only a portion of the upper surface 10b.

[0049] The lower side covering portions 62a-62d also have a structure substantially similar to that of the upper side covering portions 52a-52d. The lower side covering portions 62a-62d are located at the four corners of the lower surface covering portion 61 so as to correspond to the positions of the upper side covering portions 52a-52d. The width W3 of the lower side covering portions 62a-62d is the same as the width W2 of the upper side covering portions 52a-52d (W3 = W2 < W1).

[0050] On the other hand, the lower side covering parts 62a to 62d extend upward and are connected to the upper side covering parts 52a to 52d. Figure 2 and Figure 3B As shown, the length L2 of the lower side covering portions 62a to 62d in the stacking direction of the stacked body 10 (Z direction in the figure) is different from the length L1 of the upper side covering portions 52a to 52d in the same direction. In this embodiment, it is shorter than the length L1 (L2<L1).

[0051] Furthermore, in this embodiment, the bonding force between the upper side covering portions 52a-52d and the lower side covering portions 62a-62d (the total bonding force at all four locations) is set to be smaller than the expansion force of the electrodes (electrode stack 20) ​​when the stack 10 is charged in the all-solid-state battery 100. In other words, the upper side covering portions 52a-52d are designed to separate from the lower side covering portions 62a-62d when the stack 10 expands during charging. This prevents misalignment between the electrodes during transport of the stack 10 and also prevents deformation of the electrode ends caused by excessive pressure applied to the stack 10 from the retaining member 40 when the stack 10 expands. It should be noted that the bonding force is not particularly limited and can be adjusted by adjusting the adhesive coating area, thickness, and other factors.

[0052] In addition, if Figure 3B As shown, in this embodiment, on the left side 10c of the stacked body 10, the upper side covering portion 52a is separated from the upper side covering portion 52b, and the lower side covering portion 62a is separated from the lower side covering portion 62b. Therefore, an opening 41 is formed on the left side 10c, which is defined by the upper side covering portion 52a, the upper side covering portion 52b, the lower side covering portion 62a, the lower side covering portion 62b, the upper surface covering portion 51, and the lower surface covering portion 61. Similarly, as Figure 2 As shown, an opening 42 is formed in the right side surface 10d. By exposing the stacked body 10 from the holder 40 through these openings 41 and 42, it is possible to suppress misalignment between the electrodes and improve the heat dissipation of the holding structure 1. Furthermore, the upper side surface covering portion 52a, the upper side surface covering portion 52b, the lower side surface covering portion 62a, and the lower side surface covering portion 62b cover the front and rear ends of each side surface 10c and 10d, thereby effectively suppressing misalignment between the electrodes.

[0053] With the retaining structure 1 of this embodiment as described above, by applying pressure from the upper and lower directions of the stack 10 using the retaining member 40, the stack 10 can be fixed during the manufacturing process of the all-solid-state battery 100 so that the electrodes do not move when the stack 10 is transported. In other words, the vibration resistance of the stack 10 can be improved. In particular, in this embodiment, in addition to the upper and lower surfaces 10a, 10b of the electrode portion 21 of the electrode stack 20, the upper and lower surfaces 10a, 10b of the tab portion 22 are pressed by the retaining member, thereby further suppressing the occurrence of electrode displacement.

[0054] Furthermore, by covering the upper and lower surfaces 10a, 10b of the stack 10 with the retaining member 40, the unevenness of the upper and lower surfaces 10a, 10b can be absorbed, thereby reducing the unevenness of the upper and lower surfaces of the retaining structure 1. Therefore, when pressure is applied to the stack 10 in the stacking direction in the all-solid-state battery 100, the pressure can be applied uniformly across the entire upper and lower surfaces 10a, 10b of the stack 10. Furthermore, by reducing the unevenness described above, gaps between multiple all-solid-state batteries 100 can also be reduced.

[0055] Furthermore, by shortening the length L2 of the inner lower side covering portions 62a to 62d as in this embodiment, even when a thin laminate is covered with a resin film, the lower side covering portions 62a to 62d can be prevented from entering between the upper surface 10a of the laminate 10 and the upper side covering portions 52a to 52d. Consequently, the unevenness of the upper and lower surfaces of the holding structure 1 can be reduced.

[0056] In addition, in the present embodiment, the upper side covering portions 52a to 52d are joined to the lower side covering portions 62a to 62d on both the left and right side surfaces 10c and 10d of the stack 10. In the case where the upper side covering portion and the lower side covering portion are joined only on one side, in the process of fixing the stack 10 using the retaining member 40, it is necessary to lift the stack 10 and then wind the retaining member 40 around the stack 10, but this may also cause electrode displacement. On the other hand, in the present embodiment where the joint portion exists on both the left and right side surfaces 10c and 10d of the stack 10, when the stack 10 is placed on the lower covering member 60, the upper covering member 50 can be used to cover the stack 10 from above the stack 10. Therefore, it is not easy to cause electrode displacement in the stack 10 during the installation operation of the retaining member 40. In addition, since the workability is also improved, the productivity of the retaining structure 1 is also improved.

[0057] Furthermore, as in this embodiment, it is preferred that the upper surface covering portion 51 covers the entire upper surface 10a of the electrode portion 21, and the lower surface covering portion 61 covers the entire lower surface 10b of the electrode portion 21. This can suppress variations in the surface pressure applied to the electrode portion 21, allowing for uniform surface pressure to be applied. Consequently, within the all-solid-state battery 100, the occurrence of resistance distribution caused by variations in surface pressure can be suppressed, and the occurrence of uneven reactions can be suppressed.

[0058] In addition, in this embodiment, the number of upper side covering parts and the number of lower side covering parts are each four, but the number of upper side covering parts is not particularly limited. For example, the number of upper side covering parts and the number of lower side covering parts may each be one, covering the entire surface of the left and right side surfaces 10c and 10d.

[0059] [Second embodiment]

[0060] Below, refer to Figure 4 The second embodiment will be described. Figure 4 As shown, the retaining structure 1B of this embodiment differs from the retaining structure 1 of the first embodiment in that the upper side covering portions 52a-52d and the lower side covering portions 62a-62d cover the front side 10e and rear side 10f of the stacked body 10. However, the structure otherwise remains the same as that of the aforementioned embodiment. The following description of the retaining structure 1B of the second embodiment will focus solely on the differences from the first embodiment. Components identical to those of the first embodiment will be designated with the same reference numerals and their description will be omitted.

[0061] In the retaining body 40B of the second embodiment, the upper side covering portions 52e to 52h of the upper cover member 50B have an L-shaped shape corresponding to the edge of the corner of the upper surface covering portion 51. Similarly, the lower side covering portions 62e to 62h of the lower cover member 60B have an L-shaped shape corresponding to the edge of the corner of the lower surface covering portion 61. The upper side covering portions 52e to 52h and the lower side covering portions 62e to 62h are combined to cover the front and rear side surfaces 10e and 10f in addition to the left and right side surfaces 10c and 10d of the laminate 10. Furthermore, the upper side covering portions 52e to 52h and the lower side covering portions 62e to 62h cover the vicinity of the ends of the front and rear side surfaces 10e and 10f so as not to interfere with the tab leads 80.

[0062] According to the holding structure 1B of the second embodiment, by covering the front and rear side surfaces 10 e and 10 f of the stacked body 10 , it is possible to suppress the electrodes in the stacked body 10 from being displaced in the front-rear direction.

[0063] [Third embodiment]

[0064] Below, refer to Figure 5The third embodiment will be described. Figure 5 As shown, the retention structure 1C of this embodiment differs from the retention structure 1 of the first embodiment in that the stacked body 10C includes a pair of reinforcing plates 30, 30. However, the remaining structure is the same as that of the above-mentioned embodiment. Below, the retention structure 1C of the third embodiment will be described only with respect to the differences from the first embodiment. Components identical to those of the first embodiment will be assigned the same reference numerals and their description will be omitted.

[0065] The stack 10C in the third embodiment includes a pair of reinforcing plates 30, 30 that sandwich the electrode stack 20 from above and below. The reinforcing plates 30 are plate-shaped members that reinforce the electrode stack 20. While the reinforcing plates 30 are not particularly limited, metal plates made of stainless steel, aluminum, or the like can be used. Alternatively, resin plates or the like can be used as the reinforcing plates 30, but metal plates are preferred from the perspective of heat dissipation performance.

[0066] In this embodiment, the upper surface 10a of the stack 10C is the upper surface of the upper reinforcing plate 30, and the lower surface 10b of the stack 10C is the lower surface of the lower reinforcing plate 30. Furthermore, the side surfaces 10c to 10f of the stack 10C include the side surfaces of the electrode stack 20 and the side surfaces of the pair of reinforcing plates 30.

[0067] The stack 10C in this embodiment is pressed at least from the top and bottom by the holder 40. Since the electrodes included in the electrode stack 20 are relatively thin, there is a possibility that the ends of the electrodes will warp due to this pressure. However, in this embodiment, the electrode stack 20 is reinforced by the reinforcing plate 30, thereby suppressing the occurrence of warping in the electrode stack 20.

[0068] Description of Reference Numerals

[0069] 1. Retaining structure; 10. Laminated body; 10a, 10b, upper and lower surfaces; 10c~10f, side surfaces; 20. Electrode laminate; 21. Electrode portion; 22. Tab portion; 30. Reinforcing plate; 40. Retaining body; 41, 42, opening; 50. Upper covering member; 51. Upper surface covering portion; 52a~52d, upper side covering portion; 60. Lower covering member; 61. Lower surface covering portion; 62a~62d, lower side covering portion; 100. All-solid-state battery (monobody); 70. Laminated film; 80. Tab lead.

Claims

1. A structure for holding a stacked body, wherein: The holding structure of the stacked body comprises: A laminate formed by stacking a plurality of electrodes; and a holder that fixes the plurality of electrodes to each other by holding the stacked body, The holding body comprises: a first covering member covering one end surface of the stacked body in the stacking direction and covering a side surface of the stacked body; and a second covering member that covers the other end surface of the stacked body in the stacking direction and covers the side surfaces of the stacked body, The first covering member and the second covering member are bonded on a side surface of the stacked body.

2. The holding structure for a stacked body according to claim 1, wherein: The first covering member comprises: a first end surface covering portion covering the one end surface; and a first side covering portion covering a side surface of the stacked body, The second covering member includes, a second end surface covering portion that covers the other end surface; and a second side covering portion that covers the side surface of the stacked body and is combined with the first side covering portion; The width of the first side covering portion is smaller than the width of the side surface, The second side covering portion has a width smaller than a width of the side surface.

3. The holding structure for a stacked body according to claim 2, wherein: The first covering member includes a pair of first side covering portions located on the same side and separated from each other. The second covering member includes a pair of second side covering portions located on the same side and corresponding to the pair of first side covering portions. An opening is formed between one of the first side cover and the second side cover and the other of the first side cover and the second side cover.

4. The holding structure for a stacked body according to claim 1, wherein: The stacked body has a rectangular shape in plan view, Part of the first covering member and part of the second covering member are bonded to a corner portion of a side surface of the stacked body, thereby covering the corner portion.

5. The holding structure for a stacked body according to claim 1, wherein: The first covering member further covers one end surface of the tab portion of the stacked body in the stacking direction. The second covering member also covers the other end surface of the tab portion of the stacked body in the stacking direction.

6. The holding structure for a stacked body according to claim 1, wherein: The first covering member and the second covering member are resin films containing metal fillers therein.

7. The holding structure for a stacked body according to claim 1, wherein: The stacked body includes a pair of reinforcing plates respectively arranged at one end and the other end of the stacked body in a stacking direction.

8. The holding structure for a stacked body according to claim 1, wherein: A bonding force between a portion of the first covering member and a portion of the second covering member is smaller than an expansion force of the electrode when the stacked body is charged.

9. The holding structure for a stacked body according to claim 1, wherein: The laminated body has: First side; and a second side surface, located on the side opposite to the first side surface, The first covering member and the second covering member are combined on the first side surface and the second side surface.

10. The holding structure for a stacked body according to claim 1, wherein: The first covering member comprises: a first end surface covering portion covering the one end surface; and a first side covering portion covering a side surface of the stacked body, The second covering member includes: a second end surface covering portion that covers the other end surface; and a second side covering portion that covers the side surface of the stacked body and overlaps and is bonded to the first side covering portion; The length of the first side cover in the stacking direction is different from the length of the second side cover in the stacking direction.

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