Electrode sheet and energy storage device

Abstract

The electrode sheet and the energy storage device provided by the embodiment of the present application are applied to the positive electrode sheet and the negative electrode sheet of the energy storage device, and comprise a base layer, wherein the base layer is provided with a conductive area, the conductive area is formed on one side of the base layer close to the length direction and extends along the length direction of the base layer, and the conductive area is formed with a notch arranged along the edge in the length direction of the base layer; based on the improvement of the existing electrode sheet, the end surface of the cylindrical battery cell naturally forms a sunken groove, liquid injection to the cylindrical battery cell through the sunken groove is facilitated, the electrolyte quickly penetrates into the cylindrical battery cell through the sunken groove, the liquid injection time is greatly reduced, the liquid injection cost is reduced, the difficulty of liquid injection operation is reduced, meanwhile, the consistency of electrolyte penetration in each cylindrical battery cell can be ensured, and the quality of the energy storage device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage devices, in particular to an electrode sheet and an energy storage device. BACKGROUND

[0002] Energy storage devices include lithium ion batteries, lead-acid batteries, cadmium-nickel batteries, nickel-hydrogen batteries, super capacitors, etc., and are widely used in electrically powered vehicles, medical devices, marine, aerospace, etc. as a kind of portable or temporary energy storage device.

[0003] In the existing energy storage device, the most widely used is a cylindrical energy storage device, and the cylindrical cell thereof is usually processed by a winding type manufacturing process. Specifically, the cylindrical cell of the energy storage device is sequentially stacked by a positive electrode sheet, a separator and a negative electrode sheet, and is wound layer by layer in the same direction, wherein the positive electrode sheet and the negative electrode sheet are alternately arranged and are arranged in a staggered manner along the width direction of the positive electrode sheet and the negative electrode sheet, the separator is located between the positive electrode sheet and the negative electrode sheet, the conductive area on the positive electrode sheet is gathered at one end of the cylindrical cell to form a positive current collector, and the conductive area on the negative electrode sheet is gathered at the other end of the cylindrical cell to form a negative current collector.

[0004] However, the shape of the existing positive and negative electrode sheets (referred to as electrode sheets) is too regular, and when winding the cylindrical cell, the electrode sheet is subjected to a large extrusion strength along the length direction of the edge, and the electrode sheet is prone to breakage. Moreover, due to the regularity of the edge of the electrode sheet, after the end of the cylindrical cell is flattened, the two ends of the cylindrical cell are usually close and lack gaps, making it difficult to inject liquid into the cylindrical cell. Not only does this result in a high difficulty in injection operation, a long injection time, and multiple injection equipment, which increases the cost, but also the electrolyte cannot uniformly penetrate into the cylindrical cell, and the consistency of the electrolyte penetration directly affects the consistency of the performance of the cylindrical cell, thereby greatly affecting the quality of the energy storage device. SUMMARY

[0005] The present application provides an electrode sheet and an energy storage device to solve the problem that the cylindrical cell formed by winding the positive and negative electrode sheets in the existing energy storage device is difficult to inject liquid.

[0006] The present application also provides an electrode sheet applied to the positive and negative electrode sheets of an energy storage device, which comprises a base layer, a conductive area is provided on the base layer, the conductive area is formed on one side edge close to the length direction of the base layer and extends along the length direction of the base layer, and the conductive area is formed with a notch arranged along the length direction of the base layer.

[0007] According to the electrode sheet of one embodiment of the present application, the notch is formed in a preset length section with the head end of the base layer as the starting point.

[0008] According to an electrode sheet of an embodiment of the present application, the gaps include a plurality of gaps arranged in sequence along the length direction of the base layer; the gaps are in any one of a rectangular shape, a triangular shape, a trapezoidal shape, a sector shape, and an arc shape; and the gaps formed by the conductive regions include a combination of at least one of the rectangular shape, the triangular shape, the trapezoidal shape, the sector shape, and the arc shape.

[0009] According to an electrode sheet of an embodiment of the present application, the gaps are formed in a continuous strip shape along the length direction of the base layer.

[0010] According to an electrode sheet of an embodiment of the present application, a coating region is further formed on the base layer, the coating region extends along the length direction of the base layer, the coating region and the conductive region are arranged along the width direction of the base layer, a coating layer is formed on the end surface of the base layer corresponding to the coating region, and a conductive layer is formed on the end surface of the base layer corresponding to the conductive region.

[0011] According to an electrode sheet of an embodiment of the present application, the electrode sheet further includes an insulating coating layer; the insulating coating layer is formed on the end surface of the base layer along the length direction of the base layer and arranged at the joint of the conductive region and the coating region, one side edge of the insulating coating layer along the length direction of the base layer is connected to the coating layer, and the other side edge of the insulating coating layer along the length direction of the base layer is connected to the conductive layer.

[0012] An energy storage device is also provided in an embodiment of the present application, including a cylindrical battery cell, the cylindrical battery cell including a positive electrode sheet, a separator, and a negative electrode sheet arranged in sequence and wound into one body, the positive electrode sheet and the negative electrode sheet using the electrode sheet described above.

[0013] According to an energy storage device of an embodiment of the present application, a sunken groove or a plurality of sunken points arranged discretely is formed in the central area of the end of the cylindrical battery cell.

[0014] According to an energy storage device of an embodiment of the present application, the energy storage device further includes a current collecting disc and a cylindrical shell; one end of the cylindrical battery cell forms a positive current collector, and the other end forms a negative current collector; the cylindrical battery cell is inserted into the cylindrical shell, the end surface of the positive current collector and / or the negative current collector is connected to one disc surface of the current collecting disc, and the other disc surface of the current collecting disc is connected to the end of the cylindrical shell.

[0015] According to an energy storage device of an embodiment of the present application, the energy storage device further includes a shell cover, the current collecting disc is connected to the shell cover, and the shell cover is connected to the end of the cylindrical shell, wherein the current collecting disc is connected to the shell cover in a surface contact manner, or the current collecting disc is connected to the shell cover through a conductive soft connection, or a nesting structure for conduction is formed between the current collecting disc and the shell cover.

[0016] The electrode sheet and the energy storage device provided by the embodiment of the present application have the following advantages: the electrode sheet is designed with a notch arranged along the length direction of the base layer at the conductive area of the base layer, so that when the positive electrode sheet and the negative electrode sheet adopting the structure are wound to form the cylindrical battery cell, a sunken groove is naturally formed on the end face of the cylindrical battery cell, liquid injection to the cylindrical battery cell through the sunken groove is facilitated, the electrolyte can quickly penetrate into the cylindrical battery cell through the sunken groove, the liquid injection time is greatly shortened, the liquid injection cost is reduced, the difficulty of liquid injection operation is reduced, meanwhile, the consistency of electrolyte penetration in each cylindrical battery cell is ensured, and the quality of the energy storage device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0018] Figure 1 is a first cross-sectional structure schematic diagram of an electrode sheet provided by the embodiment of the present application;

[0019] Figure 2 is a second cross-sectional structure schematic diagram of an electrode sheet provided by the embodiment of the present application;

[0020] Figure 3 is a third cross-sectional structure schematic diagram of an electrode sheet provided by the embodiment of the present application;

[0021] Figure 4 is a fourth cross-sectional structure schematic diagram of an electrode sheet provided by the embodiment of the present application;

[0022] Figure 5 is a plane expansion structure schematic diagram of a first structure form of an electrode sheet shown by the embodiment of the present application;

[0023] Figure 6 is a plane expansion structure schematic diagram of a second structure form of an electrode sheet shown by the embodiment of the present application;

[0024] Figure 7 is a plane expansion structure schematic diagram of a third structure form of an electrode sheet shown by the embodiment of the present application;

[0025] Figure 8 is a plane expansion structure schematic diagram of a fourth structure form of an electrode sheet shown by the embodiment of the present application;

[0026] Figure 9 is a first structure schematic diagram of an end face of a cylindrical battery cell wound and formed by an electrode sheet;

[0027] Figure 10 is a second structure diagram of an end surface of a cylindrical battery cell wound and formed by the electrode sheet shown in the embodiment of the present application;

[0028] Figure 11 is a first structure diagram of an energy storage device shown in the embodiment of the present application;

[0029] Figure 12 is a second structure diagram of an energy storage device shown in the embodiment of the present application;

[0030] Figure 13 is a third structure diagram of an energy storage device shown in the embodiment of the present application;

[0031] Figure 14 is a fourth structure diagram of an energy storage device shown in the embodiment of the present application;

[0032] Figure 15 is a fifth structure diagram of an energy storage device shown in the embodiment of the present application;

[0033] Figure 16 is a sixth structure diagram of an energy storage device shown in the embodiment of the present application;

[0034] Figure 17 is a seventh structure diagram of an energy storage device shown in the embodiment of the present application.

[0035] In the figure, 1, electrode sheet; 101, base layer; 102, coating layer; 103, conductive layer; 104, insulating coating layer; 110, conductive area; 111, coating area; 2, notch; 3, cylindrical battery cell; 31, sunken point; 32, circular sunken groove; 4, current collecting disc; 5, cylindrical shell; 6, shell cover; 61, end cover; 62, pole; 63, insulating pad. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] As Figures 1 to 8 The electrode sheet 1 provided by the embodiment is applied to the positive electrode sheet and the negative electrode sheet of the energy storage device, and includes a base layer 101 and a coating layer 102. The base layer 101 is provided with a conductive area 110 and a coating area 111 extending along the length direction thereof. The coating layer 102 is formed on the end surface of the base layer 101 corresponding to the coating area 111. The conductive area 110 is distributed on one side of the coating area 111 along the width direction of the base layer 101 and is formed close to one side of the base layer 101 along the length direction. The conductive area 110 is formed with a notch 2 arranged along the length direction of the base layer 101.

[0039] Specifically, by designing the notch 2 arranged along the length direction of the base layer 101 in the conductive area 110 of the base layer 101, when the positive electrode sheet and the negative electrode sheet adopting the structure are wound into a cylindrical battery cell, a sunken groove is naturally formed on the end surface of the cylindrical battery cell, which facilitates the injection of electrolyte into the end of the cylindrical battery cell, greatly reduces the injection time, and makes the electrolyte reach a consistent penetration effect in each battery cell, thereby ensuring the quality of the energy storage device. The energy storage device shown in the embodiment includes but is not limited to lithium ion batteries, lead-acid batteries, cadmium-nickel batteries, nickel-hydrogen batteries, supercapacitors, etc.

[0040] The electrode sheet 1 shown in the embodiment includes the positive electrode sheet and the negative electrode sheet of the corresponding cylindrical battery cell of the energy storage device. The material of the base layer 101 of the positive electrode sheet is copper foil, and the material of the base layer 101 of the negative electrode sheet is aluminum foil. Since the structure of the positive electrode sheet and the negative electrode sheet of the energy storage device is the same without considering the specific material, the electrode sheet 1 shown in the above embodiment can be applied to the positive electrode sheet and the negative electrode sheet of the energy storage device.

[0041] At the same time, the base layer 101 and the coating layer 102 shown in the embodiment and the insulating coating layer 104 shown in the following embodiment are all formed on the upper and lower end surfaces of the base layer 101, and the vertical projections on the upper and lower end surfaces of the base layer 101 coincide.

[0042] As Figure 1As shown, the electrode sheet 1 shown in the embodiment can also be provided with an insulating coating 104, which is formed on the end surface of the base layer 101 along the length direction of the base layer 101 and arranged at the joint of the conductive region 110 and the coating region 111, and the insulating coating 104 is connected to the coating layer 102 along one side of the length direction of the base layer 101.

[0043] Specifically, the thickness of the insulating coating 104 is equal to the thickness of the coating layer 102 in the embodiment shown in Figure 1 , and the thickness of the insulating coating 104 is greater than the thickness of the coating layer 102 in the embodiment shown in Figure 2 . By optimizing the thickness of the insulating coating 104, the two ends of the cylindrical battery can achieve good tightness when the electrode sheet 1 with the structure is used to wind the cylindrical battery.

[0044] As shown in Figures 3 to 4 , in order to further ensure that the two ends of the cylindrical battery achieve good tightness after being wound and formed, and to ensure that the two ends of the cylindrical battery achieve good conductivity, the embodiment can also be provided with a conductive layer 103 on the end surface of the base layer 101 corresponding to the conductive region 110, so that the other side of the insulating coating 104 along the length direction of the base layer 101 is connected to the conductive layer 103.

[0045] Specifically, the thickness of the conductive layer 103 is equal to the thickness of the coating layer 102 in the embodiment shown in Figure 3 , and the thickness of the conductive layer 103 is greater than the thickness of the coating layer 102 in the embodiment shown in Figure 4 . Of course, the thickness of the conductive layer 103 can also be less than the thickness of the coating layer 102, but in the process of winding the cylindrical battery, a conductive strip arranged along the length direction of the conductive layer 103 needs to be inserted between two adjacent positive electrode sheets or negative electrode sheets.

[0046] As shown in Figures 5 to 8 , the notch 2 shown in the embodiment is formed in a preset length section starting from the head end of the base layer 101, wherein the head end of the base layer 101 refers to the starting end of the electrode sheet corresponding to the layer-by-layer winding of the cylindrical battery. Therefore, by arranging the notch 2 distributed in the preset length section starting from the head end of the base layer 101 in the conductive region 110, the center area of the end portion of the cylindrical battery wound and formed can form a sunken groove corresponding to the notch 2. Since the sunken groove has a certain depth, the end portion of the cylindrical battery can be flattened without greatly affecting the sunken groove, which facilitates the liquid injection treatment of the cylindrical battery.

[0047] In one specific embodiment, the notch 2 shown in this embodiment includes multiple notches, which are arranged sequentially at intervals along the length direction of the base layer 101; the shape of the notch 2 is any one of rectangle, triangle, trapezoid, fan, and arc; the notch 2 formed by the conductive area 110 includes a combination of at least one of rectangle, triangle, trapezoid, fan and arc.

[0048] like Figure 5 As shown in the figure, the conductive area 110 in this embodiment has a plurality of notches 2 arranged sequentially at intervals along the length direction of the base layer 101, and each notch 2 is rectangular.

[0049] like Figure 6 As shown, the conductive area 110 in this embodiment has multiple notches 2 arranged sequentially at intervals along the length of the base layer 101, and each notch 2 is arc-shaped.

[0050] like Figure 7 As shown in the figure, the conductive area 110 in this embodiment has a plurality of notches 2 arranged sequentially at intervals along the length direction of the base layer 101, and each notch 2 is trapezoidal.

[0051] In another specific embodiment, the notch 2 shown in this embodiment is formed as a continuous strip along the length direction of the base layer 101. For example... Figure 8 As shown, the notch 2 in this embodiment is specifically rectangular, with the long side of the rectangle arranged along the length direction of the base layer 101.

[0052] like Figures 9 to 10 As shown, this embodiment also provides an energy storage device based on the electrode sheet shown above, the energy storage device including a cylindrical cell 3.

[0053] With multiple notches 2 provided and arranged at intervals along the length of the base layer 101, the central region of the end of the cylindrical cell 3 shown in this embodiment can be formed as follows: Figure 9 The diagram shows multiple discretely arranged sinking points 31. By setting the distance between the gaps 2, the multiple sinking points 31 can be arranged in different shapes in the central region of the end of the cylindrical cell 3. Figure 9 The diagram illustrates that multiple sinking points 31 are arranged in a radial pattern along the cylindrical cell 3.

[0054] When the notch 2 is formed as a continuous strip along the length of the base layer 101, the central region of the end of the cylindrical cell 3 shown in this embodiment can be formed as follows: Figure 10 The sinking trough shown can be a circular sinking trough 32.

[0055] like Figure 11As shown, this embodiment proposes a first structural form of energy storage device, which further includes a current collector 4 and a cylindrical shell 5; the conductive areas on the positive electrode plate are collected at one end of the cylindrical cell 3 to form a positive current collector, and the conductive areas on the negative electrode plate are collected at the other end of the cylindrical cell 3 to form a negative current collector; the cylindrical cell 3 is inserted into the cylindrical shell 5, and the end faces of the positive current collector and the negative current collector are connected to one of the disk faces of the current collector 4 in a one-to-one correspondence, and the other disk face of the current collector 4 is connected to the end of the cylindrical shell 5.

[0056] It should be noted that an insulating protective layer is formed on the side wall of the cylindrical cell 3 shown in this embodiment. The insulating protective layer is in contact with the inner side wall of the cylindrical shell 5 away from the wall of the cylindrical cell 3. The current collector 4 shown in this embodiment can be connected to the positive current collector and the negative current collector at both ends of the cylindrical cell 3 by welding. The current collector 4 connected to the positive current collector can be insulated from the cylindrical shell 5 through an insulating sleeve. The current collector 4 connected to the negative current collector can be insulated from the cylindrical shell 5 or directly contacted with the cylindrical shell 5. Furthermore, the edge of the cylindrical cell 3 can be pressed onto the other side of the current collector 4 by rolling and flanging using a tool, thereby fixing the current collector 4.

[0057] like Figure 12 As shown, based on the following Figure 11 The energy storage device shown in this embodiment is an improvement. This embodiment proposes a second structural form of the energy storage device, which can be a single-pole structure. The positive terminal of this energy storage device is also provided with a housing cover 6. The housing cover 6 includes an end cap 61, a pole 62, and an insulating pad 63. The pole 62 is located in the middle of the end cap 61, and the pole 62 and the end cap 61 are connected by the insulating pad 63. The side of the pole 62 has a limiting groove adapted to the assembly hole in the middle of the end cap 61, and the insulating pad 63 is embedded in the limiting groove. After assembling the housing cover 6 into a single unit, the pole 62 on the housing cover 6 can be clamped by a tool, bringing the pole 62 close to one end of the cylindrical cell 3 and abutting against the other surface of the current collector 4. After the surface of the current collector 4 contacts the end of the cylindrical cell 3, a sealing machine is used to seal the edge of the end cap 61 to the corresponding end of the cylindrical housing 5.

[0058] like Figure 13 As shown, based on the following Figure 12 The energy storage device shown is an improvement. This embodiment proposes a third structural form of energy storage device, which can also be a bipolar structure, with shell covers 6 installed at both ends of the energy storage device.

[0059] like Figure 14 As shown, based on the following Figure 11The energy storage device shown is an improvement. This embodiment proposes a fourth type of energy storage device. Both ends of the cylindrical cell 3 of this energy storage device can be connected to the current collector 4 by welding or extrusion. The current collector 4 is connected to one end of the conductive flexible connection, and the other end of the conductive flexible connection is connected to the shell cover 6. The shell cover 6 is connected to the port of the cylindrical shell 5.

[0060] like Figure 15 As shown, based on the following Figure 11 The energy storage device shown is an improvement. This embodiment proposes a fifth structural form of energy storage device. The positive terminal of the cylindrical cell 3 of this energy storage device is connected to the current collector 4 by welding or extrusion. The current collector 4 is connected to one end of a conductive flexible connection. The other end of the conductive flexible connection is connected to the shell cover 6. The shell cover 6 is connected to the port of the cylindrical shell 5. The negative terminal of the cylindrical cell 3 is directly connected to the cylindrical shell 5. The cylindrical shell 5 has an open end structure, and the open end of the cylindrical shell 5 faces the positive terminal of the cylindrical cell 3.

[0061] like Figure 16 As shown, based on the following Figure 11 The energy storage device shown is an improvement. This embodiment proposes a sixth structural form of the energy storage device. At the positive end of the energy storage device, the positive end of the cylindrical cell 3 can be connected to the current collector 4 by welding or extrusion. A first structure is formed in the middle of the current collector 4, and a second structure is provided on the shell cover 6 corresponding to the current collector 4. The first structure and the second structure form a nested structure for conducting electricity. At the negative end of the energy storage device, the negative end of the cylindrical cell 3 can be connected to the current collector 4 by welding or extrusion. The end face of the current collector 4 is directly electrically connected to the shell cover 6, and the shell cover 6 is connected to the corresponding port of the cylindrical shell 5.

[0062] like Figure 17 As shown, based on the following Figure 11 The energy storage device shown in this embodiment is an improvement. It proposes a seventh structural form of energy storage device. At both ends of the cylindrical cell 3 of the energy storage device, one end of the current collector 4 is connected to the edge of the cylindrical cell 3. The end face of one side of the current collector 4 can be folded and pressed against the end of the cylindrical cell 3. A pressing platform is provided on the shell cover 6. When the shell cover 6 is installed on the corresponding port of the cylindrical shell 5, the pressing platform on the shell cover 6 directly presses against the end face of the other side of the current collector 4, thereby realizing the conductive connection between the current collector 4 and the shell cover 6.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrode sheet, used in the positive and negative electrode sheets of a cylindrical battery cell that requires end flattening treatment, characterized in that, include: The base layer has a conductive area formed on one side near the length direction of the base layer and extending along the length direction of the base layer. The conductive area has notches arranged along the edge along the length direction of the base layer, and the notches are formed as continuous strips along the length direction of the base layer. The notch is formed within a predetermined length segment starting from the head end of the base layer, so that the central region of the end of the cylindrical cell formed by winding the electrode sheet forms a recessed groove corresponding to the notch. A coating area is also formed on the base layer, the coating area extends along the length direction of the base layer, the coating area and the conductive area are arranged along the width direction of the base layer, and a coating layer is formed on the end face of the base layer corresponding to the coating area; It also includes: an insulating coating; the insulating coating is formed on the end face of the base layer along the length direction of the base layer and arranged at the junction of the conductive area and the coating area; the thickness of the insulating coating is greater than the thickness of the coating layer.

2. The electrode sheet according to claim 1, characterized in that, A conductive layer is formed on the end face of the base layer corresponding to the conductive area.

3. The electrode sheet according to claim 2, characterized in that, The insulating coating is connected to the coating layer on one side along the length of the substrate, and the insulating coating is connected to the conductive layer on the other side along the length of the substrate.

4. An energy storage device, comprising a cylindrical battery cell, said cylindrical battery cell comprising a positive electrode, a separator, and a negative electrode arranged in sequence and wound together, characterized in that, The positive electrode and the negative electrode are electrode plates as described in any one of claims 1 to 3.

5. The energy storage device according to claim 4, characterized in that, It also includes a current collector and a cylindrical shell; one end of the cylindrical cell forms a positive current collector and the other end forms a negative current collector; the cylindrical cell is inserted into the cylindrical shell, the end face of the positive current collector and / or the negative current collector is connected to one of the disk faces of the current collector, and the other disk face of the current collector is connected to the end of the cylindrical shell.

6. The energy storage device according to claim 5, characterized in that, It also includes a housing cover, the collector plate is connected to the housing cover, and the housing cover is connected to the end of the cylindrical shell. The collector plate is connected to the housing cover in a surface contact manner, or the collector plate is connected to the housing cover through a conductive flexible connection, or a nested structure for conducting electricity is formed between the collector plate and the housing cover.

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