Electrode component

Abstract

This suppresses the peeling of the conductive layer in the electrode material. [Solution] The first current collector 100A (electrode member) comprises an insulating substrate 110 and a first conductive layer 120 provided on the surface of the insulating substrate 110. Multiple fillers 180 are dispersed inside the insulating substrate 110 to reduce the difference in the coefficient of linear expansion between the insulating substrate 110 and the first conductive layer 120. The difference between the coefficient of linear expansion of the insulating substrate 110 with the multiple fillers 180 dispersed and the coefficient of linear expansion of the first conductive layer 120 is within ±20% of the coefficient of linear expansion of the first conductive layer 120.

Description

Technical Field

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[0001] The present disclosure relates to an electrode member.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2019-96592 discloses an electrode member including an insulating substrate and a conductive layer provided on the surface of the insulating substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the temperature of such an electrode member changes, the conductive layer is likely to peel off from the insulating substrate.

[0005] One object of the present disclosure is to suppress peeling of the conductive layer in the electrode member.

Means for Solving the Problems

[0006] An electrode member according to an aspect of the present disclosure includes an insulating substrate and a conductive layer provided on the surface of the insulating substrate. Inside the insulating substrate, a plurality of fillers that reduce the difference in the linear expansion coefficients of the insulating substrate and the conductive layer are dispersed. The difference between the linear expansion coefficient of the insulating substrate in which the plurality of fillers are dispersed and the linear expansion coefficient of the conductive layer is within ±20% of the linear expansion coefficient of the conductive layer.

[0007] Preferably, the plurality of fillers are glass fibers.

[0008] Preferably, the insulating substrate includes a main body portion on which an active material layer is laminated, and a protruding piece portion connected to the main body portion and protruding from the main body portion to the outside. The plurality of fillers have an longitudinal shape. In the protruding piece portion, the longitudinal direction of the plurality of fillers is parallel to the protruding direction of the protruding piece portion.

[0009] Preferably, the insulating substrate includes a main body on which an active material layer is laminated, and a protruding piece connected to the main body and projecting outward from the main body. The plurality of fillers have an longitudinal shape. In the protruding piece, the longitudinal direction of the plurality of fillers intersects with the protruding direction of the protruding piece.

[0010] Preferably, the insulating substrate includes a main body portion on which an active material layer is laminated, and a protruding portion connected to the main body portion and projecting outward from the main body portion. The plurality of fillers have an longitudinal shape. In a wound body formed by winding the insulating substrate, the longitudinal direction of the plurality of fillers provided in the main body portion is along the winding direction of the insulating substrate. [Effects of the Invention]

[0011] According to this disclosure, peeling of the conductive layer in the electrode member can be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view showing a battery including the electrode members in this embodiment. [Figure 2] Figure 1 is a cross-sectional view of the electrode body 10 as seen in the direction of the arrow line II-II. [Figure 3] This is a cross-sectional view of the electrode body 10 shown in Figure 1, viewed in the direction of the arrow III-III. [Figure 4] This is a partial cross-sectional view showing an enlarged view of region IV of the first electrode in Figure 3. [Figure 5] Figure 4 is an unfolded view of the insulating substrate 110. [Figure 6] This is an unfolded view of the insulating substrate in a modified example. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments and modifications of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

[0014] [Embodiment] FIG. 1 is a perspective view showing a battery including an electrode member in the present embodiment. As shown in FIG. 1, the battery 1 including the electrode member in the present embodiment is a so-called rectangular battery. The battery 1 may be a secondary battery configured to be chargeable and dischargeable, such as a lithium-ion battery or a nickel-hydrogen battery. The battery 1 can be used, for example, as a cell included in a power storage module mounted on an electric vehicle.

[0015] The battery 1 includes an electrode body 10, a case 20, a first external terminal 30A, a second external terminal 30B, a first connecting member (not shown), a second connecting member (not shown), and an insulating member (not shown). First, the components of the battery 1 other than the electrode body 10 will be described.

[0016] The case 20 has conductivity. The conductive portion of the case 20 is made of a metal such as aluminum. The case 20 houses the electrode body 10. The case 20 also houses an electrolytic solution (not shown).

[0017] The case 20 includes a case body 21 and a lid 22. The case body 21 includes a bottom wall 21a and a peripheral wall 21b standing up from the bottom wall 21a.

[0018] A pressure release valve (not shown) is provided on the bottom wall 21a. The bottom wall 21a and the pressure release valve are made of a metal such as aluminum.

[0019] An opening is formed at the upper end of the peripheral wall 21b. The peripheral wall 21b has a substantially rectangular outer shape when viewed from the opening direction of the opening. The opening and the bottom wall 21a are arranged in the first direction D1. The first direction D1 may be the height direction or the vertical direction of the battery 1. In the present embodiment, the direction from the bottom wall 21a toward the lid 22 is referred to as "upward", and the direction from the lid 22 toward the bottom wall 21a is referred to as "downward". The peripheral wall 21b is made of a metal such as aluminum.

[0020] The lid 22 includes a lid body 22a and an insulating cover 22d. The lid body 22a is joined to the peripheral wall 21b by welding or the like so as to close the opening of the peripheral wall 21b. A liquid injection hole (not shown) is formed in the lid body 22a. The liquid injection hole is a through hole for injecting an electrolytic solution into the case body 21 during the manufacturing process of the battery 1. The liquid injection hole is sealed by a sealing plug. The insulating cover 22d covers the liquid injection hole and the sealing plug.

[0021] The lid 22 is provided with a first external terminal 30A and a second external terminal 30B. The first external terminal 30A and the second external terminal 30B are provided so as to be exposed to the outside in the battery 1.

[0022] The first external terminal 30A is electrically connected to the electrode body 10 through a first connecting member. More specifically, the first external terminal 30A and the first connecting member are joined to each other. The first connecting member is joined to a plurality of tabs 150A of the electrode body 10.

[0023] The second external terminal 30B is electrically connected to the electrode body 10 through a second connecting member. More specifically, the second external terminal 30B and the second connecting member are joined to each other. The second connecting member is joined to a plurality of tabs 150B of the electrode body 10.

[0024] In the present embodiment, the first external terminal 30A is a positive electrode terminal, and the second external terminal 30B is a negative electrode terminal. The first external terminal 30A and the second external terminal 30B are arranged in the second direction D2. The second direction D2 is a direction orthogonal to the first direction D1.

[0025] The insulating member has electrical insulating properties. The insulating member is placed between the electrode body 10 and the case 20. The insulating member electrically insulates the electrode body 10 and the case 20 from each other.

[0026] As shown in Figure 1, the battery 1 according to this embodiment comprises a plurality of electrode bodies 10. Typically, the battery 1 comprises two electrode bodies 10. These electrode bodies 10 are aligned in a third direction D3. The third direction D3 is perpendicular to both the first direction D1 and the second direction D2.

[0027] In the following description, one of the multiple electrode bodies 10 will be explained. Note that each of the multiple electrode bodies 10 may have the configuration shown below.

[0028] Figure 2 is a cross-sectional view of the electrode body 10 shown in Figure 1, viewed in the direction of the arrow II-II. Figure 3 is a cross-sectional view of the electrode body 10 shown in Figure 1, viewed in the direction of the arrow III-III. Referring to Figures 2 and 3, the electrode body 10 includes a first electrode 11A, a second electrode 11B, a separator 12, and a tape member 13. The electrode body 10 is wound such that the first electrode 11A, the second electrode 11B, and the separator 12 surround the winding axis Z. Thus, in this embodiment, the electrode body 10 is a so-called wound electrode body. However, the electrode body 10 may also be a laminated electrode body in which the first electrode 11A, the second electrode 11B, and the separator 12 are stacked in one direction (for example, a third direction D3). In Figures 2 and 3, the separator 12 is schematically shown by a dashed line.

[0029] The first electrode 11A and the second electrode 11B have a sheet-like outer shape. The electrode body 10 is composed of a group of electrode plates in which the first electrode 11A and the second electrode 11B are wound with one or more separators 12 in between.

[0030] In this embodiment, the first electrode 11A is the positive electrode and the second electrode 11B is the negative electrode. However, the first electrode 11A may be the negative electrode and the second electrode 11B may be the positive electrode.

[0031] The first electrode 11A includes a first current collector 100A and a first active material layer 200A. The first current collector 100A is an example of an "electrode member" in this disclosure. The first active material layer 200A is an example of an "active material layer" in this disclosure. The first active material layer 200A includes an inner active material layer 210A and an outer active material layer 220A. The second electrode 11B includes a second current collector 100B and a second active material layer 200B. The first active material layer 200A is a positive electrode active material layer, and the second active material layer 200B is a negative electrode active material layer. However, the first active material layer 200A may be a negative electrode active material layer and the second active material layer 200B may be a positive electrode active material layer.

[0032] The separator 12 is provided between the first electrode 11A and the second electrode 11B. The separator 12 is laminated on the first active material layer 200A in the radial direction centered on the winding axis Z. The separator 12 is laminated on the inner active material layer 210A in the same radial direction. The separator 12 is also laminated on the outer active material layer 220A in the same radial direction.

[0033] The second electrode 11B is laminated in the first active material layer 200A with a separator 12 in between in the radial direction. More specifically, the second electrode 11B is laminated in the inner active material layer 210A with a separator 12 in between, and is also laminated in the outer active material layer 220A with a separator 12 in between.

[0034] The separator 12 separates the first electrode 11A and the second electrode 11B while allowing ions to pass between them. These ions are, for example, lithium ions. The separator 12 has electrical insulating properties.

[0035] Of the first electrode 11A, the second electrode 11B, and the separator 12, the separator 12 is located on the innermost side with respect to the winding axis Z. Also, of the first electrode 11A, the second electrode 11B, and the separator 12, the separator 12 is located on the outermost side with respect to the winding axis Z. The outer edge of the separator 12 in the winding direction DR is fixed by a tape member 13 placed on the outer surface of the separator 12.

[0036] The separator 12 may contain, for example, a polyolefin resin. The separator 12 may be substantially made of a polyolefin resin. The polyolefin resin may contain, for example, at least one selected from the group consisting of polyethylene (PE) and polypropylene (PP).

[0037] The detailed configuration of the first electrode 11A will be described with reference to Figures 4 and 5. Figure 4 is a partial cross-sectional view showing an enlarged view of region IV of the first electrode in Figure 3. The first electrode 11A includes a first current collector 100A, a first active material layer 200A, and a protective portion 300.

[0038] The first current collector 100A includes an insulating substrate 110, a first conductive layer 120, a second conductive layer 130, and a tab 150A. Each of the first conductive layer 120 and the second conductive layer 130 is an example of a “conductive layer” in this disclosure.

[0039] The insulating substrate 110 is made of an electrically insulating resin composition. Therefore, the first current collector 100A is a composite current collector consisting of a conductive member and an electrically insulating member. Furthermore, the insulating substrate 110 is made of a material with higher rigidity than the separator 12 (see Figure 2). The insulating substrate 110 is made of a resin composition containing, for example, a polyamide resin, a polyester resin (e.g., polyethylene terephthalate), a polyolefin resin (e.g., polypropylene), polyethylene, PEEK, polycarbonate, or ABS. This makes it possible to increase the rigidity of the first current collector 100A while maintaining the electrical insulating properties of the insulating substrate 110. Consequently, the insulating substrate 110 can be made relatively thin.

[0040] The thickness direction DT of the insulating substrate 110 is substantially parallel to the third direction D3. The orthogonal direction DO, perpendicular to the thickness direction DT of the insulating substrate 110, is substantially parallel to the first direction D1. The insulating substrate 110 extends substantially parallel to the first direction D1. The insulating substrate 110 includes a first surface 111 and a second surface 112 that are spaced apart in the thickness direction DT. The first surface 111 is provided with a first conductive layer 120, and the second surface 112 is provided with a second conductive layer 130.

[0041] The thickness of the insulating substrate 110 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less, in order to reduce the overall thickness of the electrode body 10. The thickness of the insulating substrate 110 is not particularly limited as long as it has the desired rigidity. The thickness of the insulating substrate 110 may be, for example, 2 μm or more.

[0042] The insulating substrate 110 includes a main body portion 118 on which the first active material layer 200A is laminated, and a protruding piece portion 119 connected to the main body portion 118 and protruding from the main body portion 118 to the outside. The protruding direction DP of the protruding piece portion 119 is along the orthogonal direction DO. The protruding piece portion 119 protrudes upward from the upper side of the main body portion 118 along the orthogonal direction DO. That is, the protruding piece portion 119 protrudes upward from the upper side of the main body portion 118 along the first direction D1.

[0043] Here, the insulating substrate 110 will be described in more detail with reference to Figure 5. Figure 5 is an unfolded view of the insulating substrate 110 shown in Figure 4. Figure 5 shows the insulating substrate 110 before it is wound. The insulating substrate 110 has a sheet-like outer shape.

[0044] Multiple fillers 180 are dispersed inside the insulating substrate 110 to reduce the difference in the coefficient of thermal expansion between the insulating substrate 110 and the first conductive layer 120 (see Figure 4). The difference between the coefficient of thermal expansion of the insulating substrate 110 with the multiple fillers 180 dispersed and the coefficient of thermal expansion of the first conductive layer 120 is within ±20% of the coefficient of thermal expansion of the first conductive layer 120. Because the difference between the coefficient of thermal expansion of the insulating substrate 110 with the multiple fillers 180 dispersed and the coefficient of thermal expansion of the first conductive layer 120 is within ±20% of the coefficient of thermal expansion of the first conductive layer 120, peeling of the first conductive layer 120 in the first current collector 100A (see Figure 4) is suppressed.

[0045] Preferably, the difference between the coefficient of thermal expansion of the insulating substrate 110 in which multiple fillers 180 are dispersed and the coefficient of thermal expansion of the first conductive layer 120 is within ±10% of the coefficient of thermal expansion of the first conductive layer 120. The central part of the electrode body 10 (see Figure 1) in the first direction D1 tends to become hotter than the edges of the electrode body 10 in the first direction D1. By keeping the difference between the coefficient of thermal expansion of the insulating substrate 110 in which multiple fillers 180 are dispersed and the coefficient of thermal expansion of the first conductive layer 120 within ±10% of the coefficient of thermal expansion of the first conductive layer 120, peeling of the first conductive layer 120 is suppressed in the central part of the electrode body 10 in the first direction D1 (i.e., the high-temperature part).

[0046] It is more preferable that the difference between the coefficient of thermal expansion of the insulating substrate 110 in which the multiple fillers 180 are dispersed and the coefficient of thermal expansion of the first conductive layer 120 is within ±5% of the coefficient of thermal expansion of the first conductive layer 120. When the electrode body 10 (see Figure 2) is viewed from above, the electrode body 10 has arc portions E1 and E2 (see Figure 2) spaced apart in the second direction D2 and flat portions H1 and H2 (see Figure 2) spaced apart in the third direction D3. By keeping the difference between the coefficient of thermal expansion of the insulating substrate 110 in which the multiple fillers 180 are dispersed and the coefficient of thermal expansion of the first conductive layer 120 within ±5% of the coefficient of thermal expansion of the first conductive layer 120, peeling of the first conductive layer 120 is suppressed in the arc portions E1 and E2.

[0047] The multiple fillers 180 reduce the difference in the coefficient of thermal expansion between the insulating substrate 110 and the second conductive layer 130 (see Figure 4). The difference between the coefficient of thermal expansion of the insulating substrate 110 with the multiple fillers 180 dispersed and the coefficient of thermal expansion of the second conductive layer 130 is within ±20% of the coefficient of thermal expansion of the second conductive layer 130. Because the difference between the coefficient of thermal expansion of the insulating substrate 110 with the multiple fillers 180 dispersed and the coefficient of thermal expansion of the second conductive layer 130 is within ±20% of the coefficient of thermal expansion of the second conductive layer 130, peeling of the second conductive layer 130 in the first current collector 100A (see Figure 4) is suppressed.

[0048] Preferably, the difference between the coefficient of thermal expansion of the insulating substrate 110 in which the multiple fillers 180 are dispersed and the coefficient of thermal expansion of the second conductive layer 130 is within ±10% of the coefficient of thermal expansion of the second conductive layer 130. By keeping the difference between the coefficient of thermal expansion of the insulating substrate 110 in which the multiple fillers 180 are dispersed and the coefficient of thermal expansion of the second conductive layer 130 within ±10% of the coefficient of thermal expansion of the second conductive layer 130, peeling of the second conductive layer 130 is suppressed in the central part (i.e., the high-temperature part) of the electrode body 10 (see Figure 1) in the first direction D1.

[0049] It is more preferable that the difference between the coefficient of thermal expansion of the insulating substrate 110 in which the multiple fillers 180 are dispersed and the coefficient of thermal expansion of the second conductive layer 130 is within ±5% of the coefficient of thermal expansion of the second conductive layer 130. By keeping the difference between the coefficient of thermal expansion of the insulating substrate 110 in which the multiple fillers 180 are dispersed and the coefficient of thermal expansion of the second conductive layer 130 within ±5% of the coefficient of thermal expansion of the second conductive layer 130, peeling of the second conductive layer 130 is suppressed in the arc-shaped portions E1 and E2 (see Figure 2).

[0050] In this embodiment, the multiple fillers 180 reduce the difference in the coefficient of linear expansion between the insulating substrate 110 and each of the first conductive layer 120 and the second conductive layer 130. However, the multiple fillers 180 may also reduce the difference in the coefficient of linear expansion between the insulating substrate 110 and at least one of the first conductive layer 120 and the second conductive layer 130.

[0051] The multiple fillers 180 are, for example, glass fibers. By having the multiple fillers 180 be glass fibers, the coefficient of linear expansion of the insulating substrate 110 can be more favorably controlled.

[0052] The multiple fillers 180 may also be conductive. If the insulating substrate 110 is made of a resin composition containing polyethylene terephthalate, the multiple fillers 180 may be, for example, aluminum. If the multiple fillers 180 are conductive, the electrical resistance of the first current collector 100A (see Figure 4) can be reduced.

[0053] The multiple fillers 180 have a longitudinal shape. In the protruding portion 119, the longitudinal direction DQ of the multiple fillers 180 is parallel to the protruding direction DP of the protruding portion 119. That is, the longitudinal direction DQ of the multiple fillers 180 is parallel to the orthogonal direction DO. Also, the longitudinal direction DQ of the multiple fillers 180 is approximately parallel to the first direction D1. Because the longitudinal direction DQ of the multiple fillers 180 is parallel to the protruding direction DP of the protruding portion 119, the protruding portion 119 is prevented from tearing in a direction intersecting the protruding direction DP (for example, the winding direction DR of the insulating substrate 110).

[0054] In the main body portion 118, the longitudinal direction DQ of the multiple fillers 180 is parallel to the protruding direction DP of the protruding piece portion 119. In a wound body in which an insulating substrate 110 is wound, the longitudinal direction DQ of the multiple fillers 180 provided in the main body portion 118 may be aligned with the winding direction DR of the insulating substrate 110. Generally, resin compositions tend to shrink with heat. However, by aligning the longitudinal direction DQ of the multiple fillers 180 provided in the main body portion 118 with the winding direction DR of the insulating substrate 110, the insulating substrate 110 becomes less prone to shrinkage relative to the first conductive layer 120 and the second conductive layer 130 (see Figure 4).

[0055] Referring again to Figure 4, the first conductive layer 120 is laminated on the first surface 111 of the insulating substrate 110. The first conductive layer 120 is in contact with the insulating substrate 110 on one side in the thickness direction DT. In this embodiment, the first conductive layer 120 is located on the side of the winding axis Z (see Figure 3) when viewed from the insulating substrate 110. The first conductive layer 120 is in contact with the insulating substrate 110 over its entire surface on one side in the thickness direction DT.

[0056] The second conductive layer 130 is laminated on the second surface 112 of the insulating substrate 110. The second conductive layer 130 is in contact with the insulating substrate 110 on the other side in the thickness direction DT. In this embodiment, the second conductive layer 130 is located on the side opposite to the winding axis Z (see Figure 3) when viewed from the insulating substrate 110. The second conductive layer 130 is in contact with the insulating substrate 110 over its entire surface on the other side in the thickness direction DT.

[0057] The first conductive layer 120 and the second conductive layer 130 are each made of a metal. In this embodiment, the first conductive layer 120 and the second conductive layer 130 are made of a metal containing aluminum. As a result, the first current collector 100A can be suitably used as a positive electrode current collector. The first current collector 100A may also be a negative electrode current collector, and the first conductive layer 120 and the second conductive layer 130 may be made of a metal containing copper.

[0058] The thickness of the first conductive layer 120 and the second conductive layer 130 is thinner than the thickness of the insulating substrate 110. The thickness of the first conductive layer 120 and the second conductive layer 130 is, for example, 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less, in order to reduce the overall thickness of the electrode body 10 (see Figure 2). The thickness of the first conductive layer 120 and the second conductive layer 130 is, for example, 0.1 μm or more, in order to prevent the electrical resistance of the first conductive layer 120 and the second conductive layer 130 from becoming too high.

[0059] The first conductive layer 120 and the second conductive layer 130 are provided, for example, by depositing a metal containing aluminum onto the insulating substrate 110. The first conductive layer 120 and the second conductive layer 130 may each be film-like members bonded to the insulating substrate 110.

[0060] Tab 150A is bonded to the first conductive layer 120 and the second conductive layer 130, for example, by ultrasonic welding. Tab 150A extends upward from the insulating substrate 110 toward the battery 1 (see Figure 1). The extension direction of tab 150A is along the orthogonal direction DO.

[0061] Tab 150A is joined to the first connecting member described above, for example, by ultrasonic welding. Tab 150A includes a first foil portion 151 and a second foil portion 152. The first foil portion 151 is located on the side opposite to the insulating substrate 110 when viewed from the first conductive layer 120. The first foil portion 151 is joined to the first conductive layer 120. The first foil portion 151 and the first conductive layer 120 are joined to each other, for example, by ultrasonic welding. The second foil portion 152 is located on the side opposite to the insulating substrate 110 when viewed from the second conductive layer 130. The second foil portion 152 is joined to the second conductive layer 130. The second foil portion 152 and the second conductive layer 130 are joined to each other, for example, by ultrasonic welding. On the side opposite to the main body portion 118 when viewed from the protruding piece portion 119, the second foil portion 152 is joined to the first foil portion 151. The first foil portion 151 and the second foil portion 152 are joined to each other, for example, by ultrasonic welding.

[0062] In this embodiment, the length of the first foil portion 151 in the orthogonal direction DO, which is perpendicular to the thickness direction DT, is longer than the length of the second foil portion 152 in the orthogonal direction DO. The first foil portion 151 is joined to the first connecting member described above, while the second foil portion 152 is not joined to the first connecting member described above. However, the configuration of the tab 150A is not limited thereto. The first foil portion 151 or the second foil portion 152 may be joined to the first connecting member. The length of the second foil portion 152 in the orthogonal direction DO may be longer than the length of the first foil portion 151 in the orthogonal direction DO.

[0063] The first active material layer 200A is laminated on the first conductive layer 120. The first active material layer 200A is the positive electrode active material layer. In this embodiment, the first active material layer 200A is also laminated on the second conductive layer 130. The first active material layer 200A includes an inner active material layer 210A and an outer active material layer 220A. The inner active material layer 210A is laminated on the first conductive layer 120. The outer active material layer 220A is laminated on the second conductive layer 130.

[0064] The upper edge of the first active material layer 200A is separated from the tab 150A. More specifically, the upper edge of the inner active material layer 210A is separated from the first foil portion 151. The upper edge of the outer active material layer 220A is separated from the second foil portion 152.

[0065] The protective part 300 has electrical insulating properties and is made of, for example, ceramic. The protective part 300 covers the upper part of the first active material layer 200A. The protective part 300 further covers the first current collector 100A between the tab 150A and the first active material layer 200A.

[0066] The protective portion 300 includes an inner protective portion 310 and an outer protective portion 320. The inner protective portion 310 covers the upper part of the inner active material layer 210A. The inner protective portion 310 covers the first conductive layer 120 between the first foil portion 151 and the inner active material layer 210A. The outer protective portion 320 covers the upper part of the outer active material layer 220A. The outer protective portion 320 covers the second conductive layer 130 between the second foil portion 152 and the outer active material layer 220A.

[0067] As described above, the first current collector 100A (electrode member) in this embodiment comprises an insulating substrate 110 and a conductive layer (for example, a first conductive layer 120) provided on the surface of the insulating substrate 110. Multiple fillers 180 are dispersed inside the insulating substrate 110 to reduce the difference in the coefficient of linear expansion between the insulating substrate 110 and the conductive layer. The difference between the coefficient of linear expansion of the insulating substrate 110 with the multiple fillers 180 dispersed and the coefficient of linear expansion of the conductive layer is within ±20% of the coefficient of linear expansion of the conductive layer. As a result, the difference in the coefficient of linear expansion between the insulating substrate 110 and the conductive layer is reduced. Therefore, according to the first current collector 100A (electrode member) in this embodiment, peeling of the conductive layer in the electrode member can be suppressed.

[0068] Furthermore, in this embodiment, the multiple fillers 180 are glass fibers. Therefore, the first current collector 100A (electrode member) in this embodiment allows for more favorable control of the linear expansion coefficient of the insulating substrate 110.

[0069] Furthermore, in this embodiment, the longitudinal direction DQ of the multiple fillers 180 in the protruding piece 119 is parallel to the protruding direction DP of the protruding piece 119. Therefore, according to the first current collector 100A (electrode member) in this embodiment, the protruding piece 119 is prevented from tearing in a direction intersecting the protruding direction DP (for example, the winding direction DR of the insulating substrate 110).

[0070] [Differentiation] Referring to Figure 6, the insulating substrate in the modified example will be described. Figure 6 is an exploded view of the insulating substrate in the modified example. Figure 6 shows the state of the insulating substrate 110A in the modified example before it is wound. The difference between the insulating substrate 110A and the insulating substrate 110 (see Figure 5) described above is the orientation of the multiple fillers 180.

[0071] More specifically, in the protruding portion 119 of the insulating substrate 110A, the longitudinal direction DQ of the multiple fillers 180 intersects with the protruding direction DP of the protruding portion 119 of the insulating substrate 110A. In the main body portion 118 of the insulating substrate 110A, the longitudinal direction DQ of the multiple fillers 180 also intersects with the protruding direction DP of the protruding portion 119. More specifically, in a wound body formed by winding the insulating substrate 110A, the longitudinal direction DQ of the multiple fillers 180 provided on the main body portion 118 of the insulating substrate 110A is aligned with the winding direction DR of the insulating substrate 110A. In other respects, the insulating substrate 110A is the same as the insulating substrate 110.

[0072] In the protruding portion 119, the longitudinal direction DQ of the multiple fillers 180 intersects with the protruding direction DP of the protruding portion 119, thereby suppressing the tearing of the protruding portion 119 in the protruding direction DP. Furthermore, when the first current collector 100A (see Figure 4) includes an insulating base 110A instead of the insulating base 110, the longitudinal direction DQ of the multiple fillers 180 provided on the main body portion 118 is aligned with the winding direction DR of the insulating base 110A, making it less likely for the insulating base 110A to shrink relative to the first conductive layer 120 and the second conductive layer 130 (see Figure 4).

[0073] In addition, in the main body portion 118 of the insulating substrate 110A, the longitudinal direction DQ of the multiple fillers 180 may be parallel to the protruding direction DP of the protruding piece portion 119.

[0074] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0075] 1 Battery, 10 Electrode body, 11A First electrode, 11B Second electrode, 12 Separator, 13 Tape material, 20 Case, 21 Case body, 21a Bottom wall, 21b Peripheral wall, 22 Lid, 22a Lid body, 22d Insulating cover, 30A First external terminal, 30B Second external terminal, 100A First current collector, 100B Second current collector, 110, 110A Insulating substrate, 111 First surface, 112 Second surface, 118 Main body, 119 Protruding piece, 120 First conductive layer, 130 Second conductive layer, 150A, 150B Tab, 151 First foil part, 152 Second foil part, 180 Filler, 200A First active material layer, 200B Second active material layer, 210A Inner active material layer, 220A Outer active material layer, 300 protective section, 310 inner protective section, 320 outer protective section, D1 first direction, D2 second direction, D3 third direction, DO orthogonal direction, DP protruding direction, DQ longitudinal direction, DR winding direction, DT thickness direction, E1, E2 arc portion, H1, H2 flat portion, Z winding axis.

Claims

1. Insulating substrate and, The insulating substrate comprises a conductive layer provided on its surface, Multiple fillers are dispersed inside the insulating substrate to reduce the difference in the coefficient of linear expansion between the insulating substrate and the conductive layer. An electrode member wherein the difference between the coefficient of thermal expansion of the insulating substrate in which the plurality of fillers are dispersed and the coefficient of thermal expansion of the conductive layer is within ±20% of the coefficient of thermal expansion of the conductive layer.

2. The electrode member according to claim 1, wherein the plurality of fillers are glass fibers.

3. The insulating substrate includes a main body portion on which an active material layer is laminated, and a protruding piece portion connected to the main body portion and protruding from the main body portion to the outside. The aforementioned plurality of fillers have an elongated shape, The electrode member according to claim 1, wherein in the protruding portion, the longitudinal direction of the plurality of fillers is parallel to the protruding direction of the protruding portion.

4. The insulating substrate includes a main body portion on which an active material layer is laminated, and a protruding piece portion connected to the main body portion and protruding from the main body portion to the outside. The aforementioned plurality of fillers have an elongated shape, The electrode member according to claim 1, wherein in the protruding portion, the longitudinal direction of the plurality of fillers intersects with the protruding direction of the protruding portion.

5. The insulating substrate includes a main body portion on which an active material layer is laminated, and a protruding piece portion connected to the main body portion and protruding from the main body portion to the outside. The aforementioned plurality of fillers have an elongated shape, The electrode member according to claim 1, wherein in a wound body formed by winding the insulating substrate, the longitudinal direction of the plurality of fillers provided in the main body is aligned with the winding direction of the insulating substrate.

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