Electrode plate for power storage device, and power storage device

Abstract

The disclosed electrode plate (21) for a power storage device is provided with: a long sheet-shaped current collector (22) having a first main surface (23) and a second main surface (25); and a first active material layer (27) provided on the first main surface (23). The first main surface (23) has at least one first uncoated section (24) in which the first active material layer (27) is not provided at one end of the collector (22) in the width direction. The first uncoated section (24) includes a first longitudinal edge (24a) that coincides with a part of the outer edge of the collector (22), a pair of first width-direction edges (24b) that extend in the width direction from both ends of the first longitudinal edge (24a), and a first connecting edge (24c) that connects the ends of the pair of first width-direction edges (24b). Half or more of the first connection edge (24c) extends obliquely with respect to the longitudinal direction of the current collector (22). This makes it possible to suppress the occurrence of wrinkles in the uncoated portion.

Description

Technical Field

[0001] The present disclosure relates to an electrode plate for a power storage device and a power storage device. Background Art

[0002] In the past, an electrode plate for a storage device used in a storage device such as a secondary battery is known (for example, Patent Document 1). The electrode plate for a storage device of Patent Document 1 includes a substantially rectangular collector and an active material layer provided on at least one surface of the collector, and the surface has an uncoated portion (uncoated portion) where the active material layer is not provided at one end in the width direction of a portion of the longitudinal direction of the collector. The uncoated portion includes an outer edge that coincides with a portion of the outer edge of the collector, two width-direction extending edges connected to both ends of the outer edge, and an inner edge connected to the two width-direction extending edges.

[0003] Prior Art Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-206465 Summary of the invention

[0005] Problems to be solved by the invention

[0006] As described in Patent Document 1 Figure 3 As shown in FIG. 1 , the active material layer is adjacent to the inner edge of the uncoated portion. In the process of compressing the active material layer along the length direction of the current collector, a difference in elongation occurs between the uncoated portion and the active material layer adjacent thereto, and wrinkles may occur in the uncoated portion. If wrinkles occur in the uncoated portion, it is difficult to properly attach the electrode tab to the uncoated portion. Under such circumstances, one of the purposes of the present disclosure is to suppress the generation of wrinkles in the uncoated portion.

[0007] Means for solving problems

[0008] One aspect of the present disclosure relates to an electrode plate for a power storage device. The electrode plate for a power storage device comprises a long sheet-shaped current collector having a first main surface and a second main surface, and a first active material layer provided on the first main surface, the first main surface having at least one first uncoated portion at one end in the width direction of the current collector where the first active material layer is not provided, the first uncoated portion comprising a first longitudinal edge consistent with a portion of the outer edge of the current collector, a pair of first width edges extending along the width direction from both ends of the first longitudinal edge, and a first connecting edge connecting the ends of the pair of first width edges, wherein more than half of the first connecting edge extends obliquely relative to the longitudinal direction of the current collector.

[0009] Another aspect of the present disclosure relates to an electric storage device. The electric storage device comprises: an electrode body formed by winding a first electrode plate and a second electrode plate with a separator interposed therebetween; a bottomed cylindrical shell housing the electrode body and having an opening at one end; and a sealing body sealing the opening of the shell, wherein the first electrode plate is the above-mentioned electrode plate for the electric storage device, and the electric storage device further comprises a first electrode tab mounted on the first uncoated portion and electrically connecting the first electrode plate to the sealing body.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to suppress the occurrence of wrinkles in the uncoated portion.

[0012] The novel features of the present invention are set forth in the appended claims, both as to structure and content, and together with other objects and features of the present application, the present invention will be better understood from the following detailed description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a longitudinal sectional view schematically showing the power storage device according to the first embodiment.

[0014] Figure 2 1 and 2 are views showing the periphery of the uncoated portion of the positive electrode plate of Embodiment 1, wherein (a) is a plan view, (b) is a cross-sectional view taken along line IIB-IIB, (c) is a cross-sectional view taken along line IIC-IIC, and (d) is a cross-sectional view taken along line IID-IID.

[0015] Figure 3 The figures show the periphery of the uncoated portion of the positive electrode plate of Embodiment 2, (a) is a top view, (b) is a cross-sectional view taken along line IIIB-IIIB, (c) is a cross-sectional view taken along line IIIC-IIIC, and (d) is a cross-sectional view taken along line IIID-IIID. DETAILED DESCRIPTION

[0016] The following examples are used to illustrate the embodiments of the electrode plate for a storage device and the storage device involved in the present disclosure. However, the present disclosure is not limited to the examples described below. In the following description, specific values ​​or materials are sometimes cited, but other values ​​or materials may also be applied as long as the effects of the present disclosure can be obtained.

[0017] (Electrode plates for power storage devices)

[0018] The electrode plate for a power storage device disclosed in the present disclosure can be used as a positive electrode plate or a negative electrode plate of a power storage device. The electrode plate for a power storage device disclosed in the present disclosure comprises a current collector and a first active material layer. The type of power storage device is not particularly limited, and the following mainly takes the case of a lithium ion secondary battery as an example for explanation.

[0019] The current collector is formed into a long sheet having a first main surface and a second main surface. When used as a positive electrode current collector of a lithium ion secondary battery, the current collector can be composed of aluminum foil or aluminum alloy foil. When used as a negative electrode current collector of a lithium ion secondary battery, the current collector can be composed of copper foil or copper alloy foil.

[0020] The first active material layer is provided on the first main surface. In the case of a positive electrode active material layer of a lithium ion secondary battery, the first active material layer may contain, for example, a positive electrode active material (e.g., a transition metal oxide containing lithium), a conductive agent, and a binder. In the case of a negative electrode active material layer of a lithium ion secondary battery, the first active material layer may contain, for example, a negative electrode active material (a carbonaceous material, a silicon-containing material, etc.), a conductive agent, and a binder.

[0021] The first main surface of the current collector has at least one first uncoated portion. The first uncoated portion is a region where the first active material layer is not provided, and is disposed at one end portion in the width direction of the current collector. The first uncoated portion can also be said to be a region where the first main surface of the current collector is exposed. The first uncoated portion can be formed by intermittently applying a paste-like active material slurry to the first main surface.

[0022] The first uncoated portion includes a first longitudinal edge, a pair of first widthwise edges, and a first connecting edge. The first longitudinal edge coincides with a portion of the outer edge of the current collector (the outer edge extending in the longitudinal direction of the current collector). A pair of first widthwise edges extend from both ends of the first longitudinal edge along the width direction of the current collector. The lengths of the pair of first widthwise edges may be different from each other. The first connecting edge connects the ends of a pair of first widthwise edges. The first connecting edge may extend in a straight line or in a non-linear shape (e.g., an arch or a curve).

[0023] More than half (or more than 50%) of the first connecting edge extends obliquely with respect to the length direction of the current collector. Here, in the process of forming the first active material layer, a step of compressing it along the length direction of the current collector is included (for example, a calendering roller can be used). If most of the first connecting edge extends along the length direction of the current collector, the strain caused by the difference in elongation between the first uncoated portion and the first active material layer is accumulated in the compression process, resulting in the possibility of wrinkles on the first uncoated portion. In contrast, since more than half of the first connecting edge of the present invention extends obliquely with respect to the length direction of the current collector, the strain caused by the difference in elongation is dispersed, resulting in wrinkles that are less likely to occur on the first uncoated portion. Furthermore, the first connecting edge may extend obliquely with respect to the length direction of the current collector by more than 60%, more than 70%, more than 80%, or more than 90%.

[0024] The electrode plate for the storage device may also have a second active material layer arranged on the second main surface. The second main surface may have at least one second uncoated portion arranged on the back side of the first uncoated portion and not provided with a second active material layer. The second uncoated portion may have a second longitudinal edge consistent with a portion of the outer edge of the collector, a pair of second width edges extending along the width direction from both ends of the second longitudinal edge, and a second connecting edge connecting the ends of the pair of second width edges. More than half of the second connecting edge may extend obliquely relative to the longitudinal direction. The composition of the second active material layer may be the same as or different from that of the first active material layer. The lengths of a pair of second width edges may be different from each other. The second connecting edge may extend in a straight line or in a non-linear shape (for example, an arch or a curve). In this structure, as in the case of the first uncoated portion, the generation of wrinkles in the second uncoated portion can be suppressed.

[0025] The inclination direction of the first connecting edge and the inclination direction of the second connecting edge may be opposite to each other. In the present specification, the inclination directions of the two connecting edges refer to the inclination directions when observed from the first main surface side of the collector. Observed from the normal direction of the first main surface, the first connecting edge and the second connecting edge may intersect with each other. Such a first connecting edge and a second connecting edge can be formed by making the coating direction of the active material slurry of the first active material layer opposite to the coating direction of the active material slurry of the second active material layer. According to this structure, in the compression process of each active material layer, the strain of the first uncoated portion and the strain of the second uncoated portion will not overlap and accumulate, so the generation of wrinkles in each uncoated portion can be further suppressed.

[0026] The inclination direction of the first connecting edge and the inclination direction of the second connecting edge may be the same as each other. When viewed from the normal direction of the first main surface, the first connecting edge and the second connecting edge may overlap each other at least in part, or may be staggered as a whole. Such a first connecting edge and a second connecting edge may be formed by simultaneously applying an active material slurry of the first active material layer and an active material slurry of the second active material layer. Thus, in this structure, the electrode plate for the storage device involved in the present disclosure can be efficiently manufactured.

[0027] The end of the first width-direction edge on one side and the end of the first width-direction edge on the other side can be staggered in the width direction of the collector. The maximum dimension of the first uncoated portion in the width direction of the collector is set to L1 [mm], and the distance between the end of the first width-direction edge on one side and the end of the first width-direction edge on the other side in the width direction of the collector is set to D1 [mm], and 0.025≤D1 / L1≤0.17 can be established. By establishing 0.025≤D1 / L1, the generation of wrinkles in the first uncoated portion can be effectively suppressed. By establishing D1 / L1≤0.17, the capacity performance function of the electrode plate for the storage device can be highly maintained.

[0028] The inclination angle of the first connecting edge relative to the length direction of the collector can be greater than 0.5° and less than 35°. In this specification, the inclination angle of the first connecting edge (or the second connecting edge) refers to the angle (acute angle) formed by a straight line connecting a pair of connecting parts between a pair of first width-direction edges and the first connecting edge, and a straight line extending along the length direction of the collector. By making the inclination angle greater than 0.5°, the generation of wrinkles in the first uncoated portion can be effectively suppressed. By making the inclination angle less than 35°, the capacity performance function of the electrode plate for the storage device can be highly maintained.

[0029] The inclination angle of the second connecting edge relative to the longitudinal direction of the current collector can be 0.5° or more and 35° or less. By setting the inclination angle to be 0.5° or more, the wrinkles of the second uncoated portion can be effectively suppressed. By setting the inclination angle to be 35° or less, the capacity performance function of the electrode plate for the power storage device can be highly maintained.

[0030] The inclination angle of the first connecting edge with respect to the longitudinal direction of the current collector and the inclination angle of the second connecting edge with respect to the longitudinal direction of the current collector may be the same as or different from each other.

[0031] (Electricity storage device)

[0032] The power storage device involved in the present disclosure may be a battery or a capacitor. The battery may be a primary battery such as a lithium primary battery, or a non-aqueous electrolyte secondary battery such as an alkaline storage battery (nickel-metal hydride battery, nickel-cadmium battery, etc.), a lithium-ion secondary battery, a lithium metal secondary battery, or an all-solid battery. The power storage device involved in the present disclosure includes an electrode body, a housing, a sealing body, and a first electrode tab.

[0033] The electrode body is formed by winding the first electrode plate and the second electrode plate with a separator between them. The outer shape of the electrode body can be, for example, cylindrical or prismatic. One of the first electrode plate and the second electrode plate is a positive electrode plate, and the other of the first electrode plate and the second electrode plate is a negative electrode plate. The first electrode plate is an electrode plate for the storage device involved in the present disclosure. The separator can be composed of a porous sheet having ion permeability and insulation. Examples of the porous sheet include thin films, woven fabrics, non-woven fabrics, etc. having micropores.

[0034] The shell is formed into a bottomed cylinder with an opening at one end to accommodate the electrode body. The shell can be, for example, a bottomed cylindrical cylinder or a bottomed square cylindrical cylinder. The shell can be made of a conductor (such as metal). The shell can be electrically connected to the second electrode plate of the electrode body. In this case, the shell functions as an external terminal of the power storage device.

[0035] The sealing body seals the opening of the shell. At least a portion of the sealing body is made of a conductor (such as metal). The outer shape of the sealing body can be, for example, a circular plate or a square plate. The sealing body can have an explosion-proof mechanism that works when the internal pressure of the shell exceeds a predetermined value.

[0036] The first electrode contact is mounted on the first uncoated portion of the first electrode plate. The first electrode contact may be made of a conductor (e.g., metal). The first electrode contact electrically connects the first electrode plate to the sealing body. Thus, the sealing body functions as another external terminal of the power storage device. One first electrode plate may have more than two first uncoated portions, or more than three. The number of first electrode contacts may be the same as the number of first uncoated portions. That is, the first electrode plate may be a multi-connector type electrode plate.

[0037] As described above, according to the present disclosure, since more than half of the first connecting edge extends obliquely with respect to the longitudinal direction of the current collector (compression direction of the first active material layer), the generation of wrinkles in the first uncoated portion can be suppressed.

[0038] Hereinafter, an example of an electrode plate for a power storage device and a power storage device involved in the present disclosure will be specifically described with reference to the accompanying drawings. The above-mentioned components can be applied to the components of the electrode plate for a power storage device and the power storage device of the example described below. The components of the electrode plate for a power storage device and the power storage device of the example described below can be changed based on the above description. In addition, the matters described below can be applied to the above-mentioned embodiment. Regarding the components of the electrode plate for a power storage device and the power storage device of the example described below, the components that are not essential for the electrode plate for a power storage device and the power storage device involved in the present disclosure can be omitted. In addition, the drawings shown below are schematic and do not accurately reflect the actual shape or number of components.

[0039] Implementation Method 1

[0040] Embodiment 1 of the present disclosure will be described. The power storage device 10 of this embodiment is configured as a lithium ion secondary battery, but is not limited thereto. Figure 1 As shown, the power storage device 10 includes an electrode body 20 , a case 40 , a sealing body 50 , a positive electrode tab 61 , and a negative electrode tab 62 .

[0041] The electrode body 20 has a positive electrode plate 21, a negative electrode plate 29 and a separator 31. The positive electrode plate 21, the negative electrode plate 29 and the separator 31 are all in the form of long strips (or strips). The positive electrode plate 21 and the negative electrode plate 29 are wound into a spiral shape with the separator 31 sandwiched therebetween in such a way that the width direction of the long strips of positive electrode plate 21 and negative electrode plate 29 is parallel to the winding axis. The first insulating plate 71 and the second insulating plate 72 are respectively arranged on both sides of the axial direction of the electrode body 20. The positive electrode plate 21 is an example of a first electrode plate, and the negative electrode plate 29 is an example of a second electrode plate. The structure of the positive electrode plate 21 will be described in detail later.

[0042] The housing 40 is configured as one end ( Figure 1 The housing 40 contains the electrode body 20 and the electrolyte (not shown). The housing 40 has a step portion 41 formed by partially punching the side wall of the housing 40 from the outside. The step portion 41 can be formed in a ring shape on the side wall of the housing 40 along the circumferential direction of the housing 40. In this case, the sealing body 50 can be supported on the surface of the opening side of the step portion 41.

[0043] The sealing body 50 seals the opening of the shell 40. An insulating gasket 81 is arranged between the sealing body 50 and the shell 40, thereby ensuring the airtightness of the shell 40. The sealing body 50 has a filter 51, a lower valve body 52, an insulating component 53, an upper valve body 54 and a cover 55. In the sealing body 50, these components are stacked in sequence. The sealing body 50 is installed at the opening of the shell 40 in a manner that the cover 55 is located on the outside of the shell 40 and the filter 51 is located on the inside of the shell 40. The above-mentioned components constituting the sealing body 50 are, for example, in the shape of a disc or a ring. The components except the insulating component 53 are electrically connected to each other.

[0044] The positive electrode tab 61 is mounted on the first uncoated portion 24 (described later) of the positive electrode plate 21 to electrically connect the positive electrode plate 21 to the sealing body 50. Specifically, one end of the positive electrode tab 61 is connected to the first uncoated portion 24, and the other end thereof is connected to the cover 55 of the sealing body 50. The positive electrode tab 61 passes through a through hole formed in the first insulating plate 71. Thus, the cover 55 of the sealing body 50 functions as an external positive terminal. Only one positive electrode tab 61 may be provided, or a plurality of positive electrode tabs may be provided. The positive electrode tab 61 is an example of a first electrode tab.

[0045] The negative electrode tab 62 is mounted on the negative electrode plate 29 to electrically connect the negative electrode plate 29 to the housing 40. Specifically, one end of the negative electrode tab 62 is connected to the negative electrode plate 29, and the other end is connected to the inner bottom surface of the housing 40. Thus, the housing 40 functions as an external negative electrode terminal. Only one negative electrode tab 62 may be provided, or a plurality of negative electrode tabs 62 may be provided.

[0046] Next, refer to Figure 2 , the structure of the positive electrode plate 21 is described in detail.

[0047] like Figure 2 As shown, the positive electrode plate 21 includes a long sheet-shaped current collector 22 having a first main surface 23 and a second main surface 25 , a first active material layer 27 provided on the first main surface 23 , and a second active material layer 28 provided on the second main surface.

[0048] The current collector 22 is made of, for example, aluminum foil or aluminum alloy foil. Figure 2 In the left-right direction in (a), the width direction of the current collector 22 is Figure 2 (a) The longitudinal direction of the current collector 22 coincides with the winding direction of the electrode body 20 , and the width direction of the current collector 22 coincides with the axial direction of the electrode body 20 .

[0049] The first active material layer 27 includes, for example, a transition metal oxide containing lithium, a conductive agent, a binder, etc. The second active material layer 28 has, for example, the same composition as that of the first active material layer 27 .

[0050] The first main surface 23 of the current collector 22 has an end portion ( Figure 2 (a) The first uncoated portion 24 in which the first active material layer 27 is not provided (the upper end portion in FIG. 1 ). Only one first uncoated portion 24 may be provided, or a plurality of first uncoated portions 24 may be provided. The first uncoated portion 24 includes a first longitudinal edge 24a that coincides with a portion of the outer edge of the current collector 22, a pair of first widthwise edges 24b extending from both ends thereof in the widthwise direction, and a first connecting edge 24c connecting their ends. More than half of the first connecting edge 24c extends obliquely relative to the longitudinal direction of the current collector 22. The inclination angle θ1 of the first connecting edge 24c relative to the longitudinal direction is greater than 0.5° and less than 35°.

[0051] The end of the first width direction edge 24b on one side and the end of the first width direction edge 24b on the other side are staggered in the width direction of the current collector 22. The maximum dimension of the first uncoated portion 24 in the width direction is set to L1 [mm], and the distance between the end of the first width direction edge 24b on one side and the end of the first width direction edge on the other side in the width direction is set to D1 [mm], and 0.025≤D1 / L1≤0.17 holds.

[0052] The second main surface 25 of the current collector 22 has a second uncoated portion 26 which is arranged on the back side of the first uncoated portion 24b and is not provided with the second active material layer 28. The second uncoated portion 26 can be provided in the same number as the first uncoated portion 24. The second uncoated portion 26 includes a second longitudinal edge 26a that coincides with a portion of the outer edge of the current collector 22, a pair of second widthwise edges 26b extending from both ends thereof in the width direction, and a second connecting edge 26c connecting their ends. More than half of the second connecting edge 26c extends obliquely relative to the longitudinal direction of the current collector 22. The inclination angle θ2 of the second connecting edge 26c relative to the longitudinal direction is greater than or equal to 0.5° and less than or equal to 35°.

[0053] The end of the second width direction edge 26b on one side and the end of the second width direction edge 26b on the other side are arranged to be staggered with each other in the width direction of the current collector 22. The maximum dimension of the second uncoated portion 26 in the width direction is set to L2 [mm], and the distance between the end of the second width direction edge 26b on one side and the end of the second width direction edge on the other side in the width direction is set to D2 [mm], and 0.04≤D2 / L2≤0.25 is established.

[0054] In the present embodiment, the first connecting edge 24c and the second connecting edge 26c are inclined in opposite directions to each other. When viewed from the normal direction of the first main surface 23, the first connecting edge 24c and the second connecting edge 26c intersect each other.

[0055] Implementation Method 2

[0056] Embodiment 2 of the present disclosure will be described. In the power storage device 10 of this embodiment, the structure of the positive electrode plate 21 is different from that of the above-mentioned Embodiment 1. Hereinafter, mainly the differences from the above-mentioned Embodiment 1 will be described.

[0057] like Figure 3 As shown, in this embodiment, the inclination direction of the first connecting edge 24c and the inclination direction of the second connecting edge 26c are the same. When viewed from the normal direction of the first main surface 23, the first connecting edge 24c and the second connecting edge 26c overlap each other, but the present invention is not limited thereto.

[0058] Postscript

[0059] Based on the description of the above embodiments, the following technical solutions are disclosed.

[0060] (Technical Solution 1)

[0061] An electrode plate for a storage device comprises a collector in the form of a long sheet having a first main surface and a second main surface, and a first active material layer arranged on the first main surface, the first main surface having at least one first uncoated portion at one end in the width direction of the collector where the first active material layer is not arranged, the first uncoated portion comprising a first length direction edge consistent with a portion of the outer edge of the collector, a pair of first width direction edges extending along the width direction from both ends of the first length direction edge, and a first connecting edge connecting the ends of the pair of first width direction edges, wherein more than half of the first connecting edge extends obliquely relative to the length direction of the collector.

[0062] (Technical Solution 2)

[0063] The electrode plate for a storage device according to Technical Solution 1 also has a second active material layer arranged on the second main surface, and the second main surface has at least one second uncoated portion arranged on the back side of the first uncoated portion and on which the second active material layer is not provided, and the second uncoated portion includes a second length direction edge consistent with a portion of the outer edge of the collector, a pair of second width direction edges extending along the width direction from both ends of the second length direction edge, and a second connecting edge connecting the ends of the pair of second width direction edges, and more than half of the second connecting edge extends obliquely relative to the length direction.

[0064] (Technical Solution 3)

[0065] According to the electrode plate for a power storage device according to claim 2, the inclination direction of the first connecting edge and the inclination direction of the second connecting edge are opposite to each other.

[0066] (Technical Solution 4)

[0067] According to the electrode plate for a power storage device according to claim 2, the inclination direction of the first connecting edge and the inclination direction of the second connecting edge are in the same direction.

[0068] (Technical Solution 5)

[0069] According to any one of technical solutions 1 to 4, for the electrode plate for a storage device, the end of the first width-direction edge on one side and the end of the first width-direction edge on the other side are staggered with each other in the width direction, the maximum dimension of the first uncoated portion in the width direction is set to L1 [mm], and the distance between the end of the first width-direction edge on one side and the end of the first width-direction edge on the other side in the width direction is set to D1 [mm], and 0.025≤D1 / L1≤0.17 holds.

[0070] (Technical Solution 6)

[0071] According to any one of claims 1 to 5 , the electrode plate for a power storage device has an inclination angle of the first connecting edge with respect to the longitudinal direction of 0.5° or more and 35° or less.

[0072] (Technical Solution 7)

[0073] A power storage device comprises: an electrode body formed by winding a first electrode plate and a second electrode plate with a separator therebetween; a bottomed cylindrical shell that accommodates the electrode body and has an opening at one end; and a sealing body that seals the opening of the shell, wherein the first electrode plate is an electrode plate for a power storage device according to any one of technical solutions 1 to 6, and the power storage device further comprises a first electrode tab that is mounted on the first uncoated portion and electrically connects the first electrode plate to the sealing body.

[0074] The present invention has been described in conjunction with the currently preferred embodiments, but this disclosure should not be interpreted as limiting. By reading the above disclosure, a person of ordinary skill in the art to which the present invention belongs can clearly understand various modifications and changes. Therefore, the appended claims should be interpreted as including all modifications and changes without departing from the true spirit and scope of the present invention.

[0075] Industrial Availability

[0076] The present disclosure can be utilized in an electrode plate for a power storage device and a power storage device.

[0077] Description of Reference Numerals

[0078] 10: Power storage device

[0079] 20: Electrode body

[0080] 21: Positive plate (first electrode plate)

[0081] 22: Current collector

[0082] 23: Main side 1

[0083] 24: 1st uncoated part

[0084] 24a: 1st longitudinal edge

[0085] 24b: 1st width direction edge

[0086] 24c: 1st connecting edge

[0087] 25: Second main side

[0088] 26: Second uncoated part

[0089] 26a: Second longitudinal edge

[0090] 26b: Second width direction edge

[0091] 26c: 2nd connecting edge

[0092] 27: 1st active material layer

[0093] 28: Second active material layer

[0094] 29: Negative plate (second electrode plate)

[0095] 31: Diaphragm

[0096] 40: Shell

[0097] 41: Step

[0098] 50: Sealing body

[0099] 51: Filter

[0100] 52: Lower valve body

[0101] 53: Insulation parts

[0102] 54: Upper valve body

[0103] 55: Cover

[0104] 61: Positive electrode contact (first electrode contact)

[0105] 62: Negative terminal

[0106] 71: 1st insulation board

[0107] 72: Second insulation board

[0108] 81: Gasket

[0109] D1: Difference in size between a pair of first widthwise edges

[0110] D2: Difference in size between a pair of second widthwise edges

[0111] L1: Maximum size of the first uncoated area

[0112] L2: Maximum size of the second uncoated area

[0113] θ1: Inclination angle of the first connecting edge

[0114] θ2: Inclination angle of the second connecting edge

Claims

1. An electrode plate for a power storage device, comprising a long sheet-shaped current collector having a first main surface and a second main surface, and a first active material layer provided on the first main surface, The first main surface has at least one first uncoated portion at one end portion in the width direction of the current collector where the first active material layer is not provided. The first uncoated portion includes a first longitudinal edge that coincides with a portion of an outer edge of the current collector, a pair of first widthwise edges extending from both ends of the first longitudinal edge along the widthwise direction, and a first connecting edge that connects ends of the pair of first widthwise edges. More than half of the first connecting edge extends obliquely with respect to the longitudinal direction of the current collector.

2. The electrode plate for a power storage device according to claim 1, further comprising a second active material layer provided on the second main surface, The second main surface has at least one second uncoated portion which is arranged on the back side of the first uncoated portion and on which the second active material layer is not provided. The second uncoated portion includes a second longitudinal edge that coincides with a portion of the outer edge of the current collector, a pair of second widthwise edges extending from both ends of the second longitudinal edge along the widthwise direction, and a second connecting edge that connects ends of the pair of second widthwise edges. More than half of the second connecting edge extends obliquely with respect to the longitudinal direction.

3. The electrode plate for a power storage device according to claim 2, The inclination direction of the first connecting edge and the inclination direction of the second connecting edge are opposite to each other.

4. The electrode plate for a power storage device according to claim 2, The inclination direction of the first connecting edge and the inclination direction of the second connecting edge are the same direction.

5. The electrode plate for a power storage device according to any one of claims 1 to 4, The end of the first width direction edge on one side and the end of the first width direction edge on the other side are arranged to be staggered with each other in the width direction. Let the maximum dimension of the first uncoated portion in the width direction be L1 in mm, and let the distance between the end of the first width edge on one side and the end of the first width edge on the other side in the width direction be D1 in mm, and 0.025≤D1 / L1≤0.17 holds.

6. The electrode plate for a power storage device according to any one of claims 1 to 4, The inclination angle of the first connecting edge with respect to the longitudinal direction is greater than or equal to 0.5° and less than or equal to 35°.

7. An electric storage device comprising: An electrode body formed by winding a first electrode plate and a second electrode plate with a separator interposed therebetween; a bottomed cylindrical casing that accommodates the electrode body and has an opening at one end; and A sealing body for sealing the opening of the housing, The first electrode plate is an electrode plate for a power storage device according to any one of claims 1 to 4, The power storage device further includes a first electrode tab that is mounted on the first uncoated portion and electrically connects the first electrode plate and the sealing body.

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