Power storage cell

Abstract

The positive electrode sheet (first electrode sheet) of the capacitor cell includes a long side (first long side) located at the end of the Z1 side (one side in the axial direction). The negative electrode sheet (second electrode sheet) includes a long side (second long side) located at the end of the Z1 side. The positive electrode sheet includes a positive electrode current collector (first current collector) and a positive electrode composite layer (first electrode material layer). The positive electrode uncoated portion of the positive electrode current collector is formed on the long side and includes a plurality of flat portions (first flat portions) arranged in the X direction (winding direction). An insulating portion (first insulating portion, insulating member) is formed on the long side of the negative electrode sheet.

Description

Technology Field

[0001] The present disclosure relates to a capacitor cell. Background Technology

[0002] U.S. Patent Application Publication No. 2016 / 0104875 discloses a battery cell having an electrode body in which electrode sheets (positive electrode sheet and negative electrode sheet) are wound in a swirling shape. The electrode sheets are wound in a state in which the positive electrode sheet and the negative electrode sheet are overlapped with a separator interposed therebetween.

[0003] Here, although not specified in the above U.S. Patent Application Publication No. 2016 / 0104875, there may be cases where a plurality of pieces (metal pieces) are provided at the axial end of the electrode sheet. For example, there may be cases where a plurality of pieces of a positive electrode sheet (first electrode sheet) are folded so that a plurality of pieces come into contact with a negative electrode sheet (second electrode sheet).

[0004] The present disclosure is made to solve the above problem, and the purpose is to provide a capacitor cell capable of preventing a plurality of portions provided at the axial end of a first electrode sheet from contacting a second electrode sheet.

[0005] A capacitor cell related to one aspect of the present disclosure comprises a wound electrode body including a first electrode sheet, a second electrode sheet, and a separator disposed between the first electrode sheet and the second electrode sheet, and an insulating member. Each of the first electrode sheet and the second electrode sheet is formed as a long length in the winding direction of the wound electrode body. The first electrode sheet includes a first long side located at one end in the axial direction in which the winding axis of the wound electrode body extends. The second electrode sheet includes a second long side located at one end in the axial direction. The first electrode sheet includes a first electrode material layer, a first coated portion in which the first electrode material layer is formed, and a first uncoated portion in which the first electrode material layer is not coated. The first uncoated portion is formed on the first long side and includes a plurality of first portions arranged in the winding direction. The insulating member includes a first insulating portion formed on the second long side.

[0006] In a capacitor cell related to one aspect of the present disclosure, as described above, a plurality of flat portions are provided on a first long side located at an axial end of a first electrode sheet, and a first insulating portion is formed on a second long side located at an axial end of a second electrode sheet. Accordingly, even if the plurality of first flat portions are folded toward the second electrode sheet, contact (conduction) between the plurality of first flat portions and the second electrode sheet can be suppressed by the first insulating portion.

[0007] In the capacitor cell associated with the above-mentioned phase, preferably, the first electrode sheet includes a third longitudinal side located at the other end in the axial direction. The second electrode sheet includes a fourth longitudinal side located at the other end in the axial direction. The second electrode sheet includes a second electrode material layer, a second coated portion on which the second electrode material layer is formed, and a second uncoated portion on which the second electrode material layer is not coated. The second uncoated portion includes a plurality of second strips arranged in the winding direction, which are formed on the fourth longitudinal side. The insulating member includes a second insulating portion formed on the third longitudinal side. By configuring in this way, even if the plurality of second strips are folded toward the first electrode sheet, contact (conduction) between the plurality of second strips and the first electrode sheet can be suppressed by the second insulating portion.

[0008] In the capacitor cell associated with the above-mentioned phase, preferably, the insulating member is formed of a porous material. With this configuration, when the electrolyte is injected into the wound electrode body from one side in the axial direction, the electrolyte can be introduced into the interior of the wound electrode body through the insulating member, which is a porous material.

[0009] In this case, preferably, the insulating member is formed continuously along the winding direction. By configuring it in this way, contact between the electrode sheet and the flat portion can be more reliably suppressed.

[0010] In the capacitor cell associated with the above-mentioned phase, preferably, the insulating member is formed intermittently along the winding direction. With this configuration, a gap is created between the insulating members, so when the electrolyte is injected into the wound electrode body from one side in the axial direction, the entry of the electrolyte can be easily suppressed by the insulating member.

[0011] According to the present disclosure, a plurality of portions provided at the axial end of the first electrode sheet can be prevented from contacting the second electrode sheet. Brief explanation of the drawing

[0012] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements. FIG. 1 is a cross-sectional view showing the configuration of a capacitor cell according to one embodiment. FIG. 2 is a schematic perspective view showing the configuration of a wound electrode body according to one embodiment. FIG. 3 is a plan view showing the configuration of a positive electrode current collector plate according to one embodiment. FIG. 4 is a plan view showing the configuration of a negative electrode collector plate according to one embodiment. Figure 5 is a magnified view of the area near the positive electrode collector plate of Figure 1. Figure 6 is a magnified view of the area near the negative electrode collector plate of Figure 1. FIG. 7 is a diagram showing the configuration of the positive electrode sheet and the negative electrode sheet in an unwound state according to one embodiment. FIG. 8 is a drawing showing the configuration of the positive electrode sheet and the negative electrode sheet in an unwound state according to a modified example of one embodiment. Specific details for implementing the invention

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, the same or substantial parts in the drawings are denoted by the same reference numerals, and their descriptions are not repeated.

[0014] The capacitor cell (100) comprises a wound electrode body (1), a case (2), a positive electrode terminal (3), a positive electrode collector plate (4), an outer gasket (5), an inner gasket (6), a negative electrode collector plate (7), a polymer ring (8), and a sealing plug (9).

[0015] The wound electrode body (1) is housed in a case (2). The case (2) has a cylindrical shape. The wound electrode body (1) is wound to form a cylindrical shape, just like the case (2). That is, the capacitor cell (100) is a cylindrical battery. In addition, the case (2) is formed of copper or aluminum, etc.

[0016] The case (2) includes a top plate (2a), a main wall (2c), and a sealing plate (2d). The main wall (2c) is provided on the outer periphery of the wound electrode body (1) and has a cylindrical shape. The top plate (2a) is connected to the end on the Z1 side of the main wall (2c). The top plate (2a) is formed integrally with the main wall (2c). The sealing plate (2d) is connected to the end on the Z2 side of the main wall (2c). The sealing plate (2d) covers the opening on the Z2 side of the main wall (2c). At the end on the Z2 side of the main wall (2c), a crimped portion (2e) formed on the outer periphery of the sealing plate (2d) is formed. The crimping portion (2e) is formed in an annular shape.

[0017] The wound electrode body (1) includes a positive electrode sheet (10), a negative electrode sheet (20), and a separator (30). The separator (30) is provided between the positive electrode sheet (10) and the negative electrode sheet (20). The separator (30) separates the positive electrode sheet (10) and the negative electrode sheet (20) while enabling the movement of ions (e.g., lithium ions) between the positive electrode sheet (10) (positive electrode active material) and the negative electrode sheet (20) (negative electrode active material). The wound electrode body (1) is composed of a group of electrode plates in which the positive electrode sheet (10) and the negative electrode sheet (20) are wound with the separator (30) interposed. Additionally, the positive electrode sheet (10) and the negative electrode sheet (20) are each examples of the "first electrode sheet" and "second electrode sheet" of the present disclosure.

[0018] As shown in FIG. 2, the wound electrode body (1) is wound such that the positive electrode sheet (10), the negative electrode sheet (20), and the separator (30) surround the winding axis (α). In FIG. 2, the wound state of the wound electrode body (1) is shown with the winding slightly unwound so that the wound state of the wound electrode body (1) is easily understood.

[0019] Referring again to FIG. 1, the positive terminal (3) includes a disk portion (3a) and a rivet portion (3b). The disk portion (3a) is exposed as it is provided on the outside of the case (2). The rivet portion (3b) is connected to the disk portion (3a). The rivet portion (3b) is provided to extend from the center of the disk portion (3a) toward the Z2 side. Additionally, the positive terminal (3) is formed of aluminum.

[0020] The disk part (3a) is of the case (2). Top plate It is positioned in (2a). The top plate (2a) is provided at the end of the Z1 side of the case (2). Top plate (2a) is arranged to be orthogonal to the Z direction. Top plate (2a) is provided with a through hole (2b) (see FIG. 5). The rivet portion (3b) extends from the disk portion (3a), which is positioned outside the case (2), through the through hole (2b) to the inside of the case (2). Also, the Z direction is an example of the “axial direction” of the present disclosure.

[0021] The positive electrode collector plate (4) is housed in the case (2). The positive electrode collector plate (4) (part (4d) described later) is welded to the positive electrode uncoated portion (11b) described later of the positive electrode sheet (10). Accordingly, the positive electrode collector plate (4) is positively charged. The positive electrode collector plate (4) is welded to the end (3c) on the Z2 side of the rivet portion (3b). Accordingly, the positive electrode terminal (3) is positively charged.

[0022] The external gasket (5) is provided on the outside of the case (2). Specifically, the external gasket (5) is positioned between the disk portion (3a) of the positive terminal (3) and the top plate portion (2a) of the case (2). Accordingly, the positive terminal (3) and the case (2) are insulated.

[0023] The inner gasket (6) is provided inside the case (2). Specifically, the inner gasket (6) is positioned between the case (2) and the positive electrode collector plate (4). Accordingly, the case (2) and the positive electrode collector plate (4) are insulated. Additionally, the rivet portion (3b) is in contact with the positive electrode collector plate (4) by penetrating the inner gasket (6).

[0024] The negative electrode collector plate (7) is housed in the case (2). The negative electrode collector plate (7) (part (7d) described later) is welded to the negative electrode uncoated portion (21b) described later of the negative electrode sheet (20). Accordingly, the negative electrode collector plate (7) is charged negatively. Additionally, the negative electrode collector plate (7) is in contact with the case (2). Accordingly, the case (2) is charged negatively.

[0025] The polymer ring (8) is provided between the outer circumference of the sealing plate (2d) and the crimping portion (2e) formed on the main wall portion (2c). The polymer ring (8) has a circular shape.

[0026] The sealing plug (9) blocks the through hole (2f) provided in the center of the sealing plate (2d). The sealing plug (9) passes through the through hole (7g) provided in the center of the negative electrode collector plate (7) together with the through hole (2f).

[0027] FIG. 3 is a plan view of a positive electrode collector plate (4). The positive electrode collector plate (4) has a circular shape. The positive electrode collector plate (4) includes a central part (4a), a spoke (4b), an outer periphery part (4c), and a flat part (4d).

[0028] The central portion (4a) is provided in the center of the positive electrode collector plate (4). The rivet portion (3b) is joined to the central portion (4a). The spokes (4b) are provided to extend outward in the radial direction from the central portion (4a). Six spokes (4b) are provided at equal intervals centered on the central portion (4a) of the positive electrode collector plate (4).

[0029] The outer periphery (4c) is provided on the outer periphery of the positive electrode collector plate (4). Each of the six spokes (4b) connects the outer periphery (4c) and the central part (4a). The spokes (4b) are formed to bend in the Z direction. In addition, the central part (4a) of the positive electrode collector plate (4) moves (displaces) the most in the Z direction.

[0030] Through holes (4e) are formed between adjacent spokes (4b) in the circumferential direction. That is, six through holes (4e) are formed. A portion (4d) is provided on the inner side of each of the six through holes (4e). Each of the six portions (4d) is connected to the outer circumference portion (4c) by a connecting portion (4f). Additionally, each of the six portions (4d) has a tapered shape toward the inner side in the radial direction.

[0031] FIG. 4 is a plan view of a negative electrode collector plate (7). The negative electrode collector plate (7) has a circular shape. The negative electrode collector plate (7) includes a central part (7a), a spoke (7b), an outer circumference part (7c), and a flat part (7d).

[0032] The central portion (7a) is provided in the center of the negative electrode collector plate (7). The spokes (7b) are provided to extend outward in the radial direction from the central portion (7a). Six spokes (7b) are provided at equal angular intervals centered on the central portion (7a) of the negative electrode collector plate (7).

[0033] The outer periphery (7c) is provided on the outer periphery of the negative electrode collector plate (7). Each of the six spokes (7b) connects the outer periphery (7c) and the central part (7a). Each spoke (7b) is formed to bend in the Z direction. The outer periphery (7c) of the negative electrode collector plate (7) moves (displaces) the most in the Z direction.

[0034] Through holes (7e) are formed between adjacent spokes (7b) in the circumferential direction. That is, six through holes (7e) are formed. A section (7d) is provided at a position corresponding to each of the six through holes (7e). Specifically, each of the six sections (7d) is positioned inside the corresponding through hole (7e). Each of the six sections (7d) is connected to the central section (7a) by a connecting section (7f). Additionally, each of the six sections (7d) has a tapered shape toward the inner side in the radial direction.

[0035] As shown in FIG. 5, the positive electrode sheet (10) includes a positive electrode current collector (11) and a positive electrode composite layer (12). The positive electrode composite layer (12) is coated on both sides in the diameter direction (R direction) of the positive electrode current collector (11) (positive electrode coating portion (11a) described later). The positive electrode composite layer (12) is in close contact with the separator (30). In addition, the positive electrode current collector (11) and the positive electrode composite layer (12) are each examples of a "first current collector" and a "first electrode material layer."

[0036] The positive electrode current collector (11) is formed from, for example, aluminum, etc. The positive electrode composite layer (12) is formed by coating a positive electrode slurry onto the surface of the positive electrode current collector (11) and drying it. The positive electrode slurry is a slurry prepared by mixing a solvent with a material of the positive electrode composite layer (12) (positive electrode active material, binder, etc.). The positive electrode composite layer (12) is in close contact with the separator (30). The thickness of the positive electrode composite layer (12) is, for example, 0.1 μm or more and 1000 μm or less.

[0037] The positive electrode current collector (11) includes a positive electrode coated portion (11a) and a positive electrode uncoated portion (11b). The positive electrode coated portion (11a) is a portion of the positive electrode current collector (11) where the positive electrode composite layer (12) is coated. In other words, the positive electrode coated portion (11a) is a portion that is not exposed because it is covered by the positive electrode composite layer (12). Furthermore, the positive electrode coated portion (11a) and the positive electrode uncoated portion (11b) are, respectively, examples of the “first coated portion” and “first uncoated portion” of the present disclosure.

[0038] The positive electrode uncoated portion (11b) is a portion of the positive electrode current collector (11) that is not covered by the positive electrode composite layer (12) and the insulating portion (15) described later, and is exposed. The positive electrode uncoated portion (11b) is located on the Z1 side compared to the positive electrode coated portion (11a). Specifically, the positive electrode uncoated portion (11b) protrudes from the positive electrode coated portion (11a) toward the Z1 side. Furthermore, the Z1 side is an example of the "axial side" of the present disclosure.

[0039] The positive electrode uncoated portion (11b) is bent inward in the diameter direction by coming into contact with the positive electrode collector plate (4) positioned on the Z1 side. Accordingly, the positive electrode collector plate (4) is positively charged. Additionally, the positive electrode uncoated portion (11b) is joined to the positive electrode collector plate (4) by welding.

[0040] The positive electrode mid-coating unit (11b) includes a plurality of portions (11c). The plurality of portions (11c) are arranged along the winding direction of the wound electrode body (1). Additionally, the portion (11c) is an example of the “first portion” of the present disclosure.

[0041] The negative electrode sheet (20) includes a negative electrode current collector (21) and a negative electrode composite layer (22). The negative electrode composite layer (22) is coated on both sides in the diameter direction (R direction) of the negative electrode current collector (21) (negative electrode coating portion (21a) described later). The negative electrode composite layer (22) is in close contact with the separator (30). Additionally, the negative electrode current collector (21) and the negative electrode composite layer (22) are each examples of the “second current collector” and “second electrode material layer” of the present disclosure.

[0042] The negative electrode current collector (21) is formed, for example, by copper, etc. The negative electrode composite layer (22) is formed by coating a negative electrode slurry onto the surface of the negative electrode current collector (21) and drying it. The negative electrode slurry is a slurry prepared by mixing a solvent with a material of the negative electrode composite layer (22) (such as a negative electrode active material or a binder). The thickness of the negative electrode composite layer (22) is, for example, 0.1 μm or more and 1000 μm or less.

[0043] As shown in FIG. 6, the negative electrode current collector (21) includes a negative electrode coated portion (21a) and a negative electrode uncoated portion (21b). The negative electrode coated portion (21a) is a portion of the negative electrode current collector (21) where the negative electrode composite layer (22) is coated. In other words, the negative electrode coated portion (21a) is a portion that is not exposed because it is covered by the negative electrode composite layer (22). Additionally, the negative electrode coated portion (21a) and the negative electrode uncoated portion (21b) are, respectively, examples of the “second coated portion” and “second uncoated portion” of the present disclosure.

[0044] The negative electrode uncoated portion (21b) is a portion of the negative electrode current collector (21) that is not covered by the negative electrode composite layer (22) and the insulating portion (25) described later, and is exposed. The negative electrode uncoated portion (21b) is located on the Z2 side from the negative electrode coated portion (21a). Specifically, the negative electrode uncoated portion (21b) protrudes from the negative electrode coated portion (21a) toward the Z2 side. Furthermore, the Z2 side is an example of the "other side in the axial direction" of the present disclosure.

[0045] The negative electrode uncoated portion (21b) is bent inward in the diameter direction by contacting the negative electrode collector plate (7) positioned on the Z2 side. Accordingly, the negative electrode collector plate (7) is charged negatively. Additionally, the negative electrode uncoated portion (21b) is joined to the negative electrode collector plate (7) by welding.

[0046] The negative electrode uncoated portion (21b) includes a plurality of portions (21c). The plurality of portions (21c) are arranged along the winding direction of the wound electrode body (1). Additionally, the portion (21c) is an example of the “second portion” of the present disclosure.

[0047] As shown in FIG. 7, each of the positive electrode sheet (10) (positive electrode current collector (11)) and the negative electrode sheet (20) (negative electrode current collector (21)) is formed in a long length in the winding direction of the wound electrode body (1). In addition, the winding direction of the wound electrode body (1) is the extension direction (X direction in FIG. 7) of the positive electrode sheet (10) (negative electrode sheet (20)) in the unwound and unfolded state.

[0048] The positive electrode sheet (10) includes a long side (13) and a long side (14). The long side (13) is located at the end on the Z1 side of the positive electrode sheet (10). The long side (14) is located at the end on the Z2 side of the positive electrode sheet (10). The positive electrode uncoated portion (11b) (a plurality of uncoated portions (11c)) is provided on the long side (13). The plurality of uncoated portions (11c) are arranged in a line along the X direction. Additionally, the long side (13) and the long side (14) are each examples of the “first long side” and “third long side” of the present disclosure.

[0049] The negative electrode sheet (20) includes a long side (23) and a long side (24). The long side (23) is located at the end on the Z1 side of the negative electrode sheet (20). The long side (24) is located at the end on the Z2 side of the negative electrode sheet (20). A negative electrode uncoated portion (21b) (a plurality of uncoated portions (21c)) is provided on the long side (24). The plurality of uncoated portions (21c) are arranged in a line along the X direction. Additionally, the long side (23) and the long side (24) are each examples of the “second long side” and “fourth long side” of the present disclosure.

[0050] Here, in the configuration of a conventional capacitor cell, for example, there are cases where multiple parts of a positive electrode sheet are folded so that multiple parts come into contact with a negative electrode sheet.

[0051] Accordingly, in the present embodiment, the capacitor cell (100) has an insulating portion (25) formed on the long side (23) of the negative electrode sheet (20). The insulating portion (25) has an insulating material coated on a portion (25a) (see FIG. 5) of the negative electrode current collector (21) where the negative electrode composite layer (22) is not coated. The portion (25a) is a portion corresponding to the long side (23) and is a portion provided at the end on the Z1 side of the negative electrode current collector (21). In addition, the insulating portion (25) is an example of the “first insulating portion” and “insulating member” of the present disclosure.

[0052] Additionally, the capacitor cell (100) has an insulating portion (15) formed on the long side (14) of the positive electrode sheet (10). The insulating portion (15) has an insulating material coated on a portion (15a) (see FIG. 6) of the positive electrode current collector (11) where the positive electrode composite layer (12) is not coated. The portion (15a) is a portion corresponding to the long side (14) and is a portion provided at the end on the Z2 side of the positive electrode current collector (11). Additionally, the insulating portion (15) is an example of the “second insulating portion” and “insulating member” of the present disclosure.

[0053] As shown in FIG. 5, the insulating portion (25) covers the portion (25a) so that the portion (25a) is not exposed. Specifically, the insulating portion (25) is formed to cover the portion (25a) from both sides in the diameter direction and from the Z1 side. Accordingly, the positive electrode uncoated portion (11b) (part (11c)) and the portion (25a) are reliably insulated.

[0054] In addition, as described above, the insulating portion (25) is coated on the portion (25a) of the negative current collector (21) where the negative electrode composite layer (22) is not coated. Accordingly, the occurrence of a step difference at the boundary between the portion (25a) coated with the insulating portion (25) and the portion (21a) coated with the negative electrode composite layer (22) is suppressed. As a result, it is possible to suppress the application of stress to the negative electrode sheet (20) during the expansion and contraction of the wound electrode body (1).

[0055] As shown in FIG. 6, the insulating portion (15) covers the portion (15a) so that the portion (15a) is not exposed. Specifically, the insulating portion (15) is formed to cover the portion (15a) from both sides in the diameter direction and from the Z2 side. Accordingly, the negative electrode uncoated portion (21b) (part (21c)) and the portion (15a) are insulated.

[0056] In addition, as described above, the insulating portion (15) is coated on the portion (15a) of the positive electrode current collector (11) where the positive electrode composite layer (12) is not coated. Accordingly, the occurrence of a step difference at the boundary between the portion (15a) coated with the insulating portion (15) and the portion (11a) coated with the positive electrode composite layer (12) is suppressed. As a result, it is possible to suppress the application of stress to the positive electrode sheet (10) during the expansion and contraction of the wound electrode body (1).

[0057] As shown in FIG. 7, the insulating portion (15) is formed continuously in the X direction. That is, the insulating portion (15) is composed of a single member extending in the X direction. Likewise, the insulating portion (25) is formed continuously in the X direction. That is, the insulating portion (25) is composed of a single member extending in the X direction.

[0058] Specifically, the insulating portion (15) is formed to extend from the X1 side end (11d) of the positive electrode sheet (10) (e.g., the winding start portion) to the X2 side end (11e) of the positive electrode sheet (10) (the winding end portion). The insulating portion (25) is formed to extend from the X1 side end (21d) of the negative electrode sheet (20) (the winding start portion) to the X2 side end (21e) of the negative electrode sheet (20) (the winding end portion).

[0059] In addition, in this embodiment, each of the insulating part (15) and the insulating part (25) is formed by a porous material. Specifically, each of the insulating part (15) and the insulating part (25) is formed by alumina. In FIG. 7, pores (16) contained in the alumina are indicated by dots to show that each of the insulating part (15) and the insulating part (25) is a porous material.

[0060] Accordingly, each of the insulating part (15) and the insulating part (25) can allow gas and liquid to pass through. As a result, the main flow of the electrolyte can be prevented from being obstructed by each of the insulating part (15) and the insulating part (25).

[0061] In addition, since alumina has heat resistance, heat can be suppressed from being applied to a separator, etc. by each of the insulating part (15) and the insulating part (25). Therefore, heat can be suppressed from being applied to a separator, etc. when welding the flat part (11c) with the positive electrode collector plate (4), and when welding the flat part (21c) with the negative electrode collector plate (7).

[0062] As described above, in this embodiment, the insulating portion (25) is formed on the long side (23) of the negative electrode sheet (20). Accordingly, the insulating portion (25) can electrically isolate the positive electrode uncoated portion (11b) (partial portion (11c)) of the positive electrode sheet (10) and the long side (23) of the negative electrode sheet (20). As a result, it is possible to prevent the positive electrode sheet (10) and the negative electrode sheet (20) from being electrically connected.

[0063] FIG. 8 is a drawing showing a variation of the above embodiment. As shown in FIG. 8, the positive electrode sheet (110) includes a positive electrode current collector (111), a long side (113), and a long side (114). The long side (113) is located at the end on the Z1 side of the positive electrode sheet (110). The long side (114) is located at the end on the Z2 side of the positive electrode sheet (110). A plurality of flat sections (11c) are provided on the long side (113). An insulating section (115) (the diagonal section in FIG. 8) is formed on the long side (114). Additionally, the positive electrode sheet (110) and the positive electrode current collector (111) are each examples of the "first electrode sheet" and "first current collector" of the present disclosure. Additionally, the long side (113) and the long side (114) are each examples of the “first long side” and the “second long side” of the present disclosure. Additionally, the insulating part (115) is an example of the “second insulating part” and the “insulating member” of the present disclosure.

[0064] The insulating portion (115) is formed intermittently along the X direction. The distance (D1) between the insulating portions (115) is greater towards the X2 side (the end of winding side). Additionally, the width (W1) of the insulating portion (115) in the X direction is greater towards the X2 side (the end of winding side). Accordingly, when the positive electrode sheet (110) is wound, layers in which the insulating portion (115) is formed and layers in which the insulating portion (115) is not formed are arranged alternately. Furthermore, the width (W1) and distance (D1) may be constant regardless of the position of the insulating portion (115) in the X direction.

[0065] The negative electrode sheet (120) includes a negative electrode current collector (121), a long side (123), and a long side (124). The long side (123) is located at the end on the Z1 side of the negative electrode sheet (120). The long side (124) is located at the end on the Z2 side of the negative electrode sheet (120). A plurality of flat sections (21c) are provided on the long side (124). An insulating section (125) (the diagonal section in FIG. 8) is formed on the long side (123). Additionally, the negative electrode sheet (120) and the negative electrode current collector (121) are each examples of the "second electrode sheet" and "second current collector" of the present disclosure. Additionally, the long side (123) and the long side (124) are each examples of the "first long side" and "second long side" of the present disclosure. In addition, the insulating part (125) is an example of the “first insulating part” and “insulating member” of the present disclosure.

[0066] The insulating portion (125) is formed intermittently along the X direction. The distance (D2) between the insulating portions (125) is greater towards the X2 side (the end of winding side). Additionally, the width (W2) of the insulating portion (125) in the X direction is greater towards the X2 side (the end of winding side). Accordingly, when the negative electrode sheet (120) is wound, layers in which the insulating portion (125) is formed and layers in which the insulating portion (125) is not formed are arranged alternately. Furthermore, the width (W2) and distance (D2) may be constant regardless of the position of the insulating portion (125) in the X direction.

[0067] Additionally, each of the insulating part (115) and the insulating part (125) does not have to be formed from a porous material as in the above embodiment. For example, the insulating part (115) may be formed from polypropylene. Also, the insulating part (125) may be formed from polyethylene, for example. Additionally, each of the insulating part (115) and the insulating part (125) may be formed from a porous material. Furthermore, one of the insulating part on the positive electrode side and the insulating part on the negative electrode side may be formed continuously in the X direction, and the other of the insulating part on the positive electrode side and the insulating part on the negative electrode side may be formed intermittently in the X direction.

[0068] In the above embodiment, an example is shown in which an insulating portion is formed on each of the positive electrode sheet (10) and the negative electrode sheet (20), but the present disclosure is not limited thereto. An insulating portion may be formed on only one of the positive electrode sheet (10) and the negative electrode sheet (20).

[0069] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

Claim 1 A wound electrode body comprising a first electrode sheet, a second electrode sheet, and a separator disposed between the first electrode sheet and the second electrode sheet, an insulating member, an external terminal, and a current collector plate electrically connected to the external terminal, wherein each of the first electrode sheet and the second electrode sheet is formed as a long length in the winding direction of the wound electrode body, wherein the first electrode sheet includes a first long side located at one end in the axial direction in which the winding axis of the wound electrode body extends, and the second electrode sheet includes a second long side located at the one end in the axial direction, and wherein the first electrode sheet includes a first electrode material layer, a first coated portion in which the first electrode material layer is formed, and a first uncoated portion in which the first electrode material layer is not coated, and wherein the first uncoated portion is on the first long side A capacitor cell comprising a plurality of first portions arranged in the winding direction, wherein the plurality of first portions are welded to the current collector plate, and the insulating member is not formed on the first long side and includes a first insulating portion formed on the second long side. Claim 2 A capacitor cell according to claim 1, wherein the first electrode sheet comprises a third longitudinal side located at the other end in the axial direction, the second electrode sheet comprises a fourth longitudinal side located at the other end in the axial direction, the second electrode sheet comprises a second electrode material layer, a second coated portion formed thereon, and a second uncoated portion where the second electrode material layer is not coated, the second uncoated portion comprises a plurality of second portions arranged in the winding direction and formed on the fourth longitudinal side, and the insulating member comprises a second insulating portion formed on the third longitudinal side. Claim 3 In claim 1 or 2, the insulating member is a capacitor cell formed by a porous material. Claim 4 In claim 3, the insulating member is a capacitor cell that is continuously formed along the winding direction. Claim 5 In claim 1 or 2, the insulating member is a capacitor cell that is intermittently formed along the winding direction. Claim 6 In claim 2, the first insulating part is a capacitor cell covering the end of the second current collector. Claim 7 In claim 2, the second insulating part is a capacitor cell covering the end of the first current collector. Claim 8 In claim 2, the second insulating part is a capacitor cell that is not formed on the fourth long side.

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