Retaining structure of electrode stack

Abstract

This holding mechanism (1) for a laminate (10) comprises the laminate (10) in which a plurality of electrodes are laminated, and a holder (40) that holds the laminate (10) to thereby fix the plurality of electrodes to each other. The holder (40) includes an upper covering member (50) that covers an upper surface (10a) of the laminate (10), and also covers left and right side surfaces (10c, 10d) of the laminate (10), and a lower covering member (60) that covers a lower surface (10b) of the laminate (10), and also covers the left and right side surfaces (10c, 10d) of the laminate (10). The upper covering member (50) and the lower covering member (60) are coupled on the left and right side surfaces (10c, 10d) of the laminate (10).

Description

Technical Field

[0001] The present invention relates to a holding structure for an electrode laminate.

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When manufacturing such an all-solid-state battery, a step of sealing the electrode laminate in an exterior body such as a laminar pack is required. When transporting the electrode laminate in this step, there is a problem that the electrode layer or the solid electrolyte layer may move, and the positions of the electrode layer and the solid electrolyte layer may shift.

[0005] The problem to be solved by the present invention is to provide a holding structure for a laminate that can suppress displacement of electrodes in the laminate.

Means for Solving the Problems

[0006] The present invention solves the above problems by joining a first covering member that covers one end face of the laminate in the lamination direction and also covers the side surface of the laminate, and a second covering member that covers the other end face of the laminate in the lamination direction and also covers the side surface of the laminate, on the side surface of the laminate, and making the width of the first side surface covering portion of the first covering member and the width of the second side surface covering portion of the second covering member smaller than the width of the side surface of the laminate.

Effects of the Invention

[0007] According to the present invention, electrode displacement can be suppressed in a laminate. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an exploded perspective view showing an all-solid-state battery according to a first embodiment of the present invention. [Figure 2] Figure 2 is an exploded perspective view showing the laminate holding structure in the first embodiment of the present invention. [Figure 3A] Figure 3A is a front view showing the laminate holding structure in the first embodiment of the present invention. [Figure 3B] Figure 3B is a left side view showing the laminate holding structure in the first embodiment of the present invention. [Figure 4] Figure 4 is an exploded perspective view showing a first modified example of the retainer in an embodiment of the present invention. [Figure 5] Figure 5 is an exploded perspective view showing a second modified example of the retainer in an embodiment of the present invention. [Modes for carrying out the invention]

[0009] [First Embodiment] Hereinafter, examples of embodiments for carrying out 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, and Figure 2 is an exploded perspective view showing the holding structure 1 of the laminate 10 in the first embodiment. Figure 3A is a front view showing the holding structure 1 of the laminate 10 in the first embodiment, and Figure 3B is a left side view showing the holding structure 1 of the laminate 10 in the first embodiment.

[0010] As shown in Figure 1, the all-solid-state battery (cell) 100 comprises a holding structure 1, a pair of laminate films 70, 70, and a pair of tab leads 80, 80. The holding structure 1 is housed between the laminate films 70, 70, which act as an outer casing, by being sandwiched from above and below. At this time, the tab leads 80, 80 extend from the inside to the outside of the outer casing.

[0011] As shown in Figure 1, the holding structure 1 comprises a laminate 10 and a holder 40. The laminate 10 is composed of multiple plate-shaped members stacked together and has a rectangular planar shape. As shown in Figure 2, the laminate 10 in this embodiment includes an electrode laminate 20.

[0012] The electrode stack 20 includes a plurality of electrodes and a plurality of solid electrolytes. Although not specifically shown in the figures, in the electrode stack 20, a positive electrode, a solid electrolyte layer, and a negative electrode may be stacked on top of each other. 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. The negative electrode may also omit the negative electrode active material layer. Furthermore, in the negative electrode, a lithium metal layer mainly composed of lithium metal may be provided instead of the negative electrode active material layer.

[0013] The electrode laminate 20 includes an electrode portion 21 and a tab portion 22. The electrode portion 21 is the portion in which at least a positive electrode active material layer, a solid electrolyte layer, and positive and negative electrode current collectors are located.

[0014] The tab portions 22 are formed on both ends of the electrode portion 21. The positive and negative electrode current collectors extending from the electrode portion 21 are located in these tab portions 22. In these tab portions 22, the multiple current collectors are joined to the tab lead 80 by welding or the like. Note that the tab portions 22 may be formed only on one end of the electrode portion 21. In other words, both the positive electrode current collector and the negative electrode current collector may extend from one end of the electrode portion 21.

[0015] The holding body 40 is not particularly limited, but binds the laminate 10 by covering the periphery of the laminate 10. More specifically, the holding body 40 in the present embodiment holds the laminate 10 by pressing the laminate 10 from above and below and sandwiching the laminate 10 from the sides. Thereby, the holding body 40 fixes the positive electrode, the solid electrolyte layer, and the negative electrode to each other in the laminate 10.

[0016] As shown in FIG. 2, the holding body 40 includes an upper covering member 50 and a lower covering member 60. The upper covering member 50 in the present embodiment corresponds to an example of the "first covering member" in the present invention, and the lower covering member 60 in the present embodiment corresponds to an example of the "second covering member" in the present invention.

[0017] The upper covering member 50 is made of a resin film and covers the laminate 10 from the upper surface 10a side of the laminate 10. This upper covering member 50 is preferably made of a resin film containing a metal filler inside from the viewpoint of heat dissipation performance. The metal fillers are preferably scattered in the resin film in order to maintain the insulating properties of the resin film. The upper surface 10a in the present embodiment corresponds to an example of the "one end face in the lamination direction of the laminate" in the present invention.

[0018] The upper covering member 50 includes an upper surface covering portion 51 and a plurality (four in this example) of upper side surface covering portions 52a to 52d. The upper surface covering portion 51 in the present embodiment corresponds to an example of the "first end face covering portion" in the present invention, and the upper side surface covering portions 52a to 52d in the present embodiment correspond to an example of the "first side surface covering portion" in the present invention.

[0019] The upper covering portion 51 has a rectangular planar shape corresponding to the planar shape of the upper surface 10a of the laminate 10. Therefore, as shown in FIGS. 3A and 3B, the upper covering portion 51 in the present embodiment covers the upper surface 10a of the electrode portion 21 and also covers the upper surface 10a of the tab portion 12. That is, the upper covering portion 51 covers the entire upper surface 10a. Note that the upper covering portion 51 does not necessarily have to cover the entire upper surface 10a and may cover only a part of the upper surface 10a. For example, it may cover only the upper surface of the electrode portion 21 or may cover a part of the upper surface of the electrode portion 21.

[0020] As shown in FIG. 2, four upper side covering portions 52a to 52d are provided at the corners of the upper covering portion 51. The upper side covering portion 52a is a rectangular film and is provided at the front left corner of the upper covering portion 51 in the drawing. As shown in FIG. 3A, this upper side covering portion 52a extends downward from the edge of the upper covering portion 51 and is overlapped and joined with a lower side covering portion 62a described later.

[0021] Also, in the present embodiment, the inner surface of the upper side covering portion 52a is joined to the outer surface of the lower side covering portion 62a. The upper side covering portion 52a and the lower side covering portion 62a may be joined by an adhesive or the like. Note that in the present embodiment, the inner surface of the upper side covering portion 52a is joined to the outer surface of the lower side covering portion 62a, but it is not limited thereto, and the outer surface of the upper side covering portion 52a may be joined to the inner surface of the lower side covering portion 62a.

[0022] As shown in FIG. 3B, the width W2 of the upper surface covering portion 52a in the present embodiment is smaller than the width W1 of the left side surface 10c (W2 < W1). Therefore, the upper surface covering portion 52a covers the front end portion of the left side surface 10c of the laminate 10 on the left side surface 10c. Further, the upper surface covering portion 52a abuts on at least a part of the left side surface 10c of the laminate 10. Note that the entire upper surface covering portion 52a does not necessarily contact the left side surface 10c. In this case, the entire upper surface covering portion 52a may be slightly separated from the left side surface 10c. Alternatively, only a part of the upper surface covering portion 52a may be slightly separated from the left side surface 10c, and the remaining part of the upper surface covering portion 52a may contact the left side surface 10c.

[0023] As shown in FIG. 3B, an upper surface covering portion 52b is provided behind the upper surface covering portion 52a (on the +Y direction side in the figure). The upper surface covering portion 52b is provided on the same side surface (left side surface 10c) as the upper surface covering portion 52a. This upper surface covering portion 52b is provided at the left back corner portion of the upper surface covering portion 51 in the figure and is separated on the same side surface as the upper surface covering portion 52a.

[0024] Further, the upper surface covering portion 52b is a film having the same shape as the upper surface covering portion 52a. This upper surface covering portion 52b also extends downward from the edge of the upper surface covering portion 51 and is overlapped and joined with a lower surface covering portion 62b described later. Note that the shape of the upper surface covering portion 52b may be different from that of the upper surface covering portion 52a.

[0025] The inner surface of the upper surface covering portion 52b is joined to the outer surface of the lower surface covering portion 62b. The upper surface covering portion 52b and the lower surface covering portion 62b may be joined by an adhesive or the like, similar to the upper surface covering portion 52a and the lower surface covering portion 62a. Further, in the present embodiment, the inner surface of the upper surface covering portion 52b is joined to the outer surface of the lower surface covering portion 62b, but is not limited thereto, and the outer surface of the upper surface covering portion 52b may be joined to the inner surface of the lower surface covering portion 62b.

[0026] In this embodiment, the upper side covering portion 52b covers the rear end of the left side surface 10c of the laminate 10. This upper side covering portion 52b abuts against at least a portion of the left side surface 10c of the laminate 10.

[0027] As shown in Figure 2, an upper side covering portion 52c is provided on the opposite side of the upper side covering portion 52a, with the laminate 10 in between. The upper side covering portion 52c is provided on the right side surface 10d, which is opposite to the upper side covering portion 52a. This upper side covering portion 52c is provided at the front right corner of the upper covering portion 51 in the figure.

[0028] The upper side covering portion 52c is a film having the same shape as the upper side covering portion 52a. This upper side covering portion 52c also extends downward from the edge of the upper side covering portion 51 and is overlapped and joined with the lower side covering portion 62c, which will be described later. Note that the shape of the upper side covering portion 52c may differ from that of the upper side covering portion 52a.

[0029] The inner surface of the upper side covering portion 52c is joined to the outer surface of the lower side covering portion 62c. The upper side covering portion 52c and the lower side covering portion 62c may be joined together by an adhesive or the like, similar to the upper side covering portion 52c and the lower side covering portion 62c. In this embodiment, the inner surface of the upper side covering portion 52c is joined to the outer surface of the lower side covering portion 62c, but this is not limited to this, and the outer surface of the upper side covering portion 52c may be joined to the inner surface of the lower side covering portion 62c.

[0030] In this embodiment, the upper side covering portion 52c covers the front end of the right side surface 10d of the laminate 10. The upper side covering portion 52b abuts against at least a portion of the left side surface 10c of the laminate 10. The upper side covering portion 52c may be slightly separated from the right side surface 10d.

[0031] An upper side covering portion 52d is provided behind the upper side covering portion 52c. The upper side covering portion 52d is provided on the same side (right side 10d) as the upper side covering portion 52c. This upper side covering portion 52d is provided at the rear right corner of the upper covering portion 51 in the figure, and is located separately from the upper side covering portion 52c on the same side.

[0032] Furthermore, the upper side covering portion 52d is a film having the same shape as the upper side covering portion 52a. This upper side covering portion 52d also extends downward from the edge of the upper side covering portion 51 and is overlapped and joined with the lower side covering portion 62d, which will be described later. Note that the shape of the upper side covering portion 52d may differ from that of the upper side covering portion 52a.

[0033] The inner surface of the upper side covering portion 52d is joined to the outer surface of the lower side covering portion 62d. The upper side covering portion 52d and the lower side covering portion 62d may be joined by an adhesive or the like, similar to the upper side covering portion 52a and the lower side covering portion 62a. In this embodiment, the inner surface of the upper side covering portion 52d is joined to the outer surface of the lower side covering portion 62d, but this is not limited to this, and the outer surface of the upper side covering portion 52d may be joined to the inner surface of the lower side covering portion 62d.

[0034] In this embodiment, the upper side covering portion 52d covers the rear end of the right side surface 10d of the laminate 10. This upper side covering portion 52d abuts against at least a portion of the right side surface 10d of the laminate 10.

[0035] As shown in Figure 2, the lower covering member 60, like the upper covering member 50, is made of a resin film and covers the laminate 10 from the lower surface 10b side. Like the upper covering member 50, it is preferable that the lower covering member 60 is a resin film containing a metal filler inside from the viewpoint of heat dissipation performance. In this embodiment, the lower surface 10b corresponds to an example of the "other end surface in the lamination direction of the laminate" in the present invention.

[0036] The lower covering member 60 basically has the shape of the upper covering member 50 inverted vertically, and includes a lower covering portion 61 and a plurality (four in this example) of lower side covering portions 62a to 62d. In this embodiment, the lower covering portion 61 corresponds to an example of the "second end covering portion" in the present invention, and in this embodiment, the lower side covering portions 62a to 62d correspond to an example of the "second side covering portion" in the present invention.

[0037] The lower covering portion 61 has basically the same configuration as the upper covering portion 51. However, the lower covering portion 61 covers the lower surface 10b of the electrode portion 21 and the lower surface 10b of the tab portion 12. Note that, similar to the upper covering portion 51, the lower covering portion 61 does not necessarily need to cover the entire lower surface 10b, and may cover only a part of the upper surface 10b.

[0038] The lower side coverings 62a to 62d have basically the same configuration as the upper side coverings 52a to 52d. The lower side coverings 62a to 62d are provided at the four corners of the lower covering 61 so as to correspond to the positions of the upper side coverings 52a to 52d, and the width W3 of the lower side coverings 62a to 62d is the same as the width W2 of the upper side coverings 52a to 52d (W3 = W2 <W1)。

[0039] On the other hand, the lower side covering portions 62a to 62d extend upward and are connected to the upper side covering portions 52a to 52d. Also, as shown in Figures 2 and 3B, the length L2 of the laminate 10 of the lower side covering portions 62a to 62d in the stacking direction (Z direction in the figures) is different from the length L1 of the upper side covering portions 52a to 52d in the same direction, and in this embodiment, it is shorter than length L1 (L2 <L1)。

[0040] Furthermore, in this embodiment, the bonding force between the upper side covering portions 52a to 52d and the lower side covering portions 62a to 62d (the sum of the bonding forces at 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 design is such that when the stack 10 is charged and expands, the upper side covering portions 52a to 52d and the lower side covering portions 62a to 62d will peel off. In this way, displacement between electrodes can be suppressed when transporting the stack 10, and deformation of the electrode ends due to excessive pressure being applied to the stack 10 from the holder 40 when the stack 10 expands can be suppressed. The bonding force is not particularly limited, but can be adjusted by the application area and thickness of the adhesive.

[0041] Furthermore, as shown in Figure 3B, in this embodiment, on the left side surface 10c of the laminate 10, the upper side covering portion 52a and the upper side covering portion 52b are separated, and the lower side covering portion 62a and the lower side covering portion 62b are separated. As a result, an opening 41 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 side covering portion 51, and the lower side covering portion 61 is formed on the left side surface 10c. Similarly, as shown in Figure 2, an opening 42 is formed on the right side surface 10d. These openings 41 and 42 expose the laminate 10 from the holder 40, thereby suppressing displacement between electrodes and improving the heat dissipation of the holding structure 1. Furthermore, since the upper side covering portion 52a, the upper side covering portion 52b, the lower side covering portion 62a, and the lower side covering portion 62b cover the front and rear ends of each side 10c and 10d, displacement between electrodes can be effectively suppressed.

[0042] With the holding structure 1 in this embodiment as described above, the laminate 10 can be fixed in place so that the electrodes do not move when the laminate 10 is transported during the manufacturing process of the all-solid-state battery 100, by applying pressure from the top and bottom directions of the laminate 10 with the holder 40. In other words, the vibration resistance of the laminate 10 can be improved. In particular, in this embodiment, in addition to the top and bottom surfaces 10a and 10b of the electrode portion 21 of the electrode laminate 20, the top and bottom surfaces 10a and 10b of the tab portion 22 are also pressed by the holder, so the occurrence of electrode displacement can be further suppressed.

[0043] Furthermore, by covering the upper and lower surfaces 10a and 10b of the laminate 10 with the holder 40, it is possible to absorb the irregularities on the upper and lower surfaces 10a and 10b and reduce the irregularities on the upper and lower surfaces of the holder structure 1. Therefore, when applying pressure to the laminate 10 in the stacking direction in the all-solid-state battery 100, the pressure can be applied uniformly to the entire surface of the upper and lower surfaces 10a and 10b of the laminate 10. In addition, by reducing the above-mentioned irregularities, the gaps that occur between multiple all-solid-state batteries 100 can also be reduced.

[0044] Furthermore, by shortening the length L2 of the inner lower side covering portions 62a to 62d as in this embodiment, it is possible to prevent the lower side covering portions 62a to 62d from getting stuck between the upper surface 10a of the laminate 10 and the upper side covering portions 52a to 52d, even when covering a thin laminate with a resin film. Thus, it is possible to reduce the unevenness of the upper and lower surfaces of the holding structure 1.

[0045] Furthermore, in this embodiment, the upper side covering portions 52a-52d and the lower side covering portions 62a-62d are connected on both the left and right sides 10c and 10d of the laminate 10. If the upper and lower side covering portions were connected on only one side, the process of fixing the laminate 10 with the holder 40 would require lifting the laminate 10 before wrapping the holder 40 around it, which could cause electrode misalignment. On the other hand, in this embodiment, where the connection portions exist on both the left and right sides 10c and 10d of the laminate 10, the laminate 10 can be placed on the lower covering member 60 and then covered with the upper covering member 50 from above, making it less likely for the electrodes in the laminate 10 to misalign during the attachment of the holder 40. In addition, workability is improved, and the productivity of the holding structure 1 is also improved.

[0046] Furthermore, as in this embodiment, it is preferable that the upper covering portion 51 covers the entire upper surface 10a of the electrode portion 21, and the lower covering portion 61 covers the entire lower surface 10b of the electrode portion 21. This suppresses unevenness in the surface pressure applied to the electrode portion 21 and allows for the application of uniform surface pressure. As a result, it is possible to suppress the occurrence of resistance distribution caused by uneven surface pressure within the all-solid-state battery 100, and to suppress the occurrence of uneven reaction.

[0047] In this embodiment, the number of upper and lower side coverings is shown as four, but the number of upper side coverings is not particularly limited. For example, the number of upper and lower side coverings may be one each, covering the entire left and right sides 10c and 10d.

[0048] [Second Embodiment] The second embodiment will now be described with reference to Figure 4. The holding structure 1B of this embodiment differs from the holding structure 1 of the first embodiment in that, as shown in Figure 4, the upper side covering portions 52a to 52d and the lower side covering portions 62a to 62d cover the front side 10e and the rear side 10f of the laminate 10. However, the other configurations are the same as in the above embodiment. Below, only the differences between the holding structure 1B of the second embodiment and the first embodiment will be described, and components that are the same as in the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0049] In the second embodiment of the holder 40B, the upper side covering portions 52e to 52h of the upper covering member 50B have an L-shape corresponding to the edge of the corner of the upper covering portion 51. Similarly, the lower side covering portions 62e to 62h of the lower covering member 60B have an L-shape corresponding to the edge of the corner of the lower covering portion 61. The upper side covering portions 52e to 52h and the lower side covering portions 62e to 62h are connected to each other and cover the front and rear sides 10e and 10f in addition to the left and right sides 10c and 10d of the laminate 10. 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 sides 10e and 10f so as not to interfere with the tab lead 80.

[0050] With the holding structure 1B in this second embodiment, since it covers the front and rear sides 10e and 10f of the laminate 10, it is possible to suppress displacement of the electrodes in the laminate 10 in the front and rear direction.

[0051] [Third Embodiment] The third embodiment will now be described with reference to Figure 5. The holding structure 1C of this embodiment differs from the holding structure 1 of the first embodiment in that the laminate 10C includes a pair of reinforcing plates 30, 30, as shown in Figure 5. However, the other configurations are the same as those of the above embodiment. Below, only the differences between the holding structure 1C of the third embodiment and the first embodiment will be described, and components that are the same as those of the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0052] The laminate 10C in the third embodiment includes a pair of reinforcing plates 30, 30 that sandwich the electrode laminate 20 from above and below. The reinforcing plates 30 are plate-shaped members for reinforcing the electrode laminate 20, and while not particularly limited, metal plates made of stainless steel, aluminum, etc., can be used as the reinforcing plates 30. Alternatively, resin plate members, etc., may be used as the reinforcing plates 30, but it is preferable to use metal plates from the viewpoint of heat dissipation performance.

[0053] In this embodiment, the upper surface 10a of the laminate 10C is the upper surface of the upper reinforcing plate 30, and the lower surface 10b of the laminate 10C is the lower surface of the lower reinforcing plate 30. Furthermore, the side surfaces 10c to 10f of the laminate 10C include the side surfaces of the electrode laminate 20 and the side surfaces of the pair of reinforcing plates 30.

[0054] In this embodiment, the laminate 10C is pressed by the holder 40 from at least the vertical direction. Since the electrodes included in the electrode laminate 20 are relatively thin, there is a possibility that the ends of the electrodes may warp due to this pressing. However, in this embodiment, the electrode laminate 20 is reinforced by the reinforcing plate 30, so that the occurrence of warping of the electrode laminate 20 can be suppressed. [Explanation of Symbols]

[0055] 1...Retention structure 10…Laminate 10a,10b…Top and bottom surfaces 10c~10f…side 20… Electrode stack 21...Electrode part 22... Tab section 30…Reinforcement plate 40...Holding body 41,42...Aperture 50...Top covering member 51... Upper covering portion 52a~52d... Upper side covering portion 60... Lower covering member 61…Bottom covering part 62a~62d...Lower side covering 100... All-solid-state battery (cell) 70... Laminating film 80... Tabread

Claims

1. A holding structure for a laminate housed in a laminate film as an outer casing, A laminate in which multiple electrodes are stacked, The laminate is held in place by a holder that fixes the plurality of electrodes to each other, The holder is A first covering member covers one end face of the laminate in the stacking direction and covers the side surface of the laminate, It includes a second covering member that covers the other end face of the laminate in the stacking direction and covers the side surface of the laminate, The first covering member and the second covering member are joined on the side surface of the laminate. A laminate holding structure in which the first and second coating members peel off when the laminate is charged, because the bonding force between a part of the first coating member and a part of the second coating member is smaller than the expansion force of the electrodes when the laminate is charged.

2. In the laminate holding structure according to claim 1, The first covering member includes a pair of first side covering portions located on the same side surface and spaced apart from each other. The second covering member is located on the same side surface and includes a pair of second side covering portions corresponding to the pair of first side covering portions, A holding structure for a laminate, wherein an opening is formed between one of the first and second side covering portions and the other of the first and second side covering portions.

3. In the laminate holding structure according to claim 1, The laminate has a rectangular planar shape, A holding structure for a laminate in which a part of the first covering member and a part of the second covering member are joined on the corner of the side surface of the laminate, thereby covering the corner.

4. In the laminate holding structure according to claim 1, The first and second covering members are a holding structure for a laminate that is a resin film containing a metal filler inside.

5. In the laminate holding structure according to claim 1, The laminate is a holding structure for the laminate, which includes a pair of reinforcing plates arranged at one end and the other end of the laminate in the stacking direction.

6. In the laminate holding structure according to claim 1, The laminated body is The first aspect and, It has a second side located opposite to the first side, A holding structure for a laminate in which the first covering member and the second covering member are joined on the first side surface and the second side surface.

7. In the laminate holding structure according to claim 1, The first covering member is, A first end face covering portion that covers one of the aforementioned end faces, The laminate includes a first side covering portion that covers the side surface of the laminate, The second covering member is A second end face covering portion covers the other end face, It includes a second side covering portion that covers the side surface of the laminate and is superimposed on and bonded with the first side covering portion, A laminate holding structure in which the length of the first side covering portion in the stacking direction is different from the length of the second side covering portion in the stacking direction.

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