Pole piece, battery cell and battery
By setting etching grooves and embedding parts on the composite foil tabs, the problem of ineffective conductivity between the conductive layers of the composite foil tabs is solved, thereby improving the energy density and safety performance of lithium-ion batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN HIGHPOWER TECH CO LTD
- Filing Date
- 2025-05-14
- Publication Date
- 2026-04-28
AI Technical Summary
The conductive layers of the composite foil tabs cannot conduct electricity effectively, affecting the energy density and safety performance of lithium-ion batteries.
Etching grooves and embedding portions are provided on the composite foil tabs, so that the conductive layers on both sides of the substrate layer of adjacent tabs are electrically connected through the etching grooves and embedding portions, thereby achieving effective conductivity.
This improves the energy density and safety performance of lithium-ion batteries. By setting etching grooves and embedding parts on the composite foil tabs of the electrode sheet, effective conductive connection between the conductive layers of the composite foil tabs is achieved.
Smart Images
Figure CN224177319U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of batteries, and in particular to an electrode, a cell, and a battery. Background Technology
[0002] In the new energy consumer market, lithium-ion batteries have rapidly occupied the 3C digital consumer market, the new energy vehicle market, and the energy storage application market due to their high energy density. With the development of the industry, the requirements for the electrical energy stored per unit mass of lithium-ion batteries are also getting higher and higher, that is, the requirements for the energy density of batteries are getting higher and higher.
[0003] To improve the energy density of lithium-ion batteries, composite current collectors are often used instead of traditional metal foil current collectors. Composite current collectors have a lower areal density, which reduces the weight of the current collector and thus increases the energy density of the battery. On the other hand, because polymer materials have high ductility, when a lithium-ion battery is impacted by a foreign object, the polymer material can wrap the fracture surface, thereby preventing the fracture from piercing the separator and causing a short circuit, reducing the risk of thermal runaway and improving the safety performance of lithium-ion batteries. However, due to the low conductivity of polymer materials, effective conductivity cannot be achieved between the conductive layers on both sides of the polymer material. Utility Model Content
[0004] To address the problem in related technologies that the conductive layers on both sides of the polymer material cannot effectively conduct electricity in composite foil electrode tabs, this invention provides an electrode sheet.
[0005] The electrode sheet of this utility model embodiment includes a composite foil electrode tab, which includes a substrate layer and conductive layers located on both sides of the substrate layer.
[0006] The composite foil tabs are provided with etching grooves and embedding portions;
[0007] The etching groove penetrates the conductive layer on one side of the substrate layer and the substrate layer, exposing the portion of the conductive layer on the other side of the substrate layer corresponding to the etching groove.
[0008] This utility model embodiment provides etching grooves on the composite foil tabs of the electrode sheet. After the electrode sheet is wound or stacked, the composite foil tabs can be arranged sequentially in its thickness direction, so that the etching grooves and embedding portions in adjacent composite foil tabs correspond to each other. The embedding portion of one composite foil tab can be embedded in the etching groove of another composite foil tab, so that the conductive layer on one side of the substrate layer of one composite foil tab is electrically connected to the conductive layer on the other side of the substrate layer of the other composite foil tab. At the same time, the conductive layer on one side of the substrate layer of one composite foil tab is electrically connected to the conductive layer on one side of the substrate layer of the other composite foil tab. That is, the conductive layers on both sides of the substrate layer of the other composite foil tab are electrically connected to the conductive layer on one side of the substrate layer of one composite foil tab, so that the conductive layers on both sides of the substrate layer of the other composite foil tab are electrically connected.
[0009] The embedding portion of one of the composite foil tabs can be embedded in the etching groove of one of the composite foil tabs, so that the conductive layer on one side of the substrate layer of the other composite foil tab is electrically connected to the conductive layer on the other side of the substrate layer of the first composite foil tab. At the same time, the conductive layer on one side of the substrate layer of the other composite foil tab is electrically connected to the conductive layer on one side of the substrate layer of the first composite foil tab. That is, the conductive layers on both sides of the substrate layer of one composite foil tab are electrically connected to the conductive layer on one side of the substrate layer of the other composite foil tab, so that the conductive layers on both sides of the substrate layer of the first composite foil tab are electrically connected.
[0010] This enables the conductive layers on both sides of the composite foil tab substrate layer to be electrically connected, thereby allowing effective conductivity between the conductive layers on both sides of the composite foil tab substrate layer.
[0011] In some embodiments, the etching groove extends along the length direction of the composite foil tab;
[0012] One end of the etching groove extends through the composite foil tab and its corresponding side edge.
[0013] In some embodiments, the ratio between the width of the etching groove and the width of the composite foil tab is 0.1-0.9.
[0014] In some embodiments, the ratio between the length of the etching groove and the length of the composite foil tab is 0.1-0.9.
[0015] In some embodiments, the etching groove extends along the width direction of the composite foil tab, and at most one of the two ends of the etching groove penetrates the composite foil tab and its corresponding side edge.
[0016] In some embodiments, the ratio between the width of the etching groove and the length of the composite foil tab is 0.1-0.9.
[0017] In some embodiments, the ratio between the length of the etching groove and the width of the composite foil tab is 0.1-0.9.
[0018] In some embodiments, there are multiple etching grooves.
[0019] This utility model also provides a battery cell.
[0020] The battery cell of this embodiment includes the electrode sheet described in the above embodiment, and the electrode sheet has multiple composite foil tabs. The electrode sheet is wound so that the multiple composite foil tabs are arranged sequentially in its thickness direction; or...
[0021] The battery cell includes a plurality of electrode sheets as described in the above embodiments, and the plurality of electrode sheets are stacked so that a plurality of composite foil tabs are arranged sequentially in their thickness direction;
[0022] The adjacent composite foil tabs are respectively the first tab and the second tab;
[0023] The first electrode includes a first conductive layer, a first substrate layer, and a second conductive layer stacked together.
[0024] The second electrode includes a stacked third conductive layer, a second substrate layer, and a fourth conductive layer;
[0025] The second conductive layer and the third conductive layer abut against each other;
[0026] The first electrode tab is provided with a first etching groove and a first embedding portion. The first etching groove penetrates the second conductive layer and the first substrate layer, so that the portion of the first conductive layer corresponding to the first etching groove is exposed.
[0027] The second electrode tab is provided with a second etching groove and a second embedding part. The second etching groove penetrates the third conductive layer and the second substrate layer, so that the portion of the fourth conductive layer corresponding to the second etching groove is exposed.
[0028] The first embedding portion is adapted to be embedded in the second etching groove so that the second conductive layer is electrically connected to the fourth conductive layer;
[0029] The second embedding portion is adapted to be embedded in the first etched groove so that the third conductive layer is electrically connected to the first conductive layer.
[0030] This utility model also provides a battery.
[0031] The battery of this utility model embodiment includes wound cells or stacked cells as described in the above embodiments. Attached Figure Description
[0032] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 This is one of the structural schematic diagrams of the electrode sheet in an embodiment of this utility model;
[0034] Figure 2 This is the second schematic diagram of the structure of the electrode sheet in an embodiment of this utility model;
[0035] Figure 3 This is the third schematic diagram of the electrode sheet in this embodiment of the present invention;
[0036] Figure 4 This is the fourth schematic diagram of the electrode sheet in an embodiment of this utility model;
[0037] Figure 5 This is the fifth schematic diagram of the electrode sheet in this embodiment of the present invention;
[0038] Figure 6 This is one of the partial cross-sectional views of the electrode sheet in an embodiment of this utility model;
[0039] Figure 7 This is a second partial cross-sectional view of the electrode sheet in an embodiment of this utility model;
[0040] Figure 8 This is the sixth schematic diagram of the electrode sheet in an embodiment of this utility model.
[0041] In the picture:
[0042] 1. First tab; 101. First conductive layer; 102. Second conductive layer; 103. First substrate layer;
[0043] 2. Second tab; 201. Third conductive layer; 202. Fourth conductive layer; 203. Second substrate layer;
[0044] 3. First etching groove; 4. First embedding part;
[0045] 5. Second etching groove; 6. Second embedding part;
[0046] 7. Positive electrode plate;
[0047] 8. Negative electrode plate;
[0048] 9. Substrate layer;
[0049] 10. Conductive layer;
[0050] 11. Etching grooves;
[0051] 12. Embedded part;
[0052] 13. Electrode;
[0053] 14. Composite foil tabs; Detailed Implementation
[0054] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0055] In the description of this utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0056] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal encapsulation of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0057] To address the problem in related technologies where the conductive layers on both sides of the polymer material cannot effectively conduct electricity in composite foil tabs.
[0058] This utility model provides an electrode 13.
[0059] like Figure 8 As shown, the electrode 13 of this utility model embodiment includes a composite foil electrode tab 14, which includes a substrate layer 9 and conductive layers 10 located on both sides of the substrate layer 9.
[0060] The composite foil tab 14 is provided with an etching groove 11 and an embedding part 12;
[0061] The etching groove 11 penetrates the conductive layer 10 and the substrate layer 9 on one side of the substrate layer 9, exposing the portion of the conductive layer 10 on the other side of the substrate layer 9 corresponding to the etching groove 11.
[0062] This embodiment of the invention provides etching grooves 11 on the composite foil tabs 14 of the electrode sheet 13. After the electrode sheet 13 is wound or stacked, the composite foil tabs 14 can be sequentially arranged in its thickness direction, so that the etching grooves 11 and the embedding portions 12 in adjacent composite foil tabs 14 correspond to each other. The embedding portion 12 of one composite foil tab 14 can be embedded into the etching groove 11 of another composite foil tab 14, so that the conductive layer 10 on the substrate layer 9 side of one composite foil tab 14 is connected to the other... The conductive layer 10 on the other side of the substrate layer 9 of one composite foil tab 14 is electrically connected. At the same time, the conductive layer 10 on one side of the substrate layer 9 of one composite foil tab 14 is electrically connected to the conductive layer 10 on one side of the substrate layer 9 of the other composite foil tab 14. That is, the conductive layers 10 on both sides of the substrate layer 9 of the other composite foil tab 14 are electrically connected to the conductive layer 10 on one side of the substrate layer 9 of one composite foil tab 14, so that the conductive layers 10 on both sides of the substrate layer 9 of the other composite foil tab 14 are electrically connected.
[0063] The embedding portion 12 of one of the composite foil tabs 14 can be embedded in the etching groove 11 of one of the composite foil tabs 14, so that the conductive layer 10 on one side of the substrate layer 9 of the other composite foil tab 14 is electrically connected to the conductive layer 10 on the other side of the substrate layer 9 of the first composite foil tab 14. At the same time, the conductive layer 10 on one side of the substrate layer 9 of the other composite foil tab 14 is electrically connected to the conductive layer 10 on one side of the substrate layer 9 of the first composite foil tab 14. That is, the conductive layers 10 on both sides of the substrate layer 9 of one composite foil tab 14 are electrically connected to the conductive layer 10 on one side of the substrate layer 9 of the other composite foil tab 14, so that the conductive layers 10 on both sides of the substrate layer 9 of the first composite foil tab 14 are electrically connected.
[0064] This makes the conductive layers 10 on both sides of the substrate layer 9 of the composite foil tab 14 electrically connected, thereby enabling effective conductivity between the conductive layers 10 on both sides of the substrate layer 9 of the composite foil tab 14.
[0065] It is understood that, in order for the etching grooves 11 and the inserts 12 of the adjacent composite foil tabs 14 to engage with each other, the shape of the inserts 12 should be at least partially the same as the shape of the etching grooves 11.
[0066] In some embodiments, the etching groove 11 extends along the length direction of the composite foil tab 14;
[0067] One end of the etching groove 11 penetrates the composite foil tab 14 and its corresponding side edge.
[0068] Furthermore, the ratio between the width of the etching groove 11 and the width of the composite foil tab 14 is 0.1-0.9.
[0069] It is understood that the width of the etching groove 11 here is the dimension of the etching groove 11 in the width direction of the composite foil tab 14, and the width of the composite foil tab 14 is the dimension of the composite foil tab 14 in its width direction.
[0070] Optionally, the ratio between the width of the etching groove 11 and the width of the composite foil tab 14 is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.
[0071] Furthermore, the ratio between the length of the etching groove 11 and the length of the composite foil tab 14 is 0.1-0.9.
[0072] It is understandable that the length of the etching groove 11 here is the dimension of the etching groove 11 in the length direction of the composite foil tab 14, and the length of the composite foil tab 14 is the dimension of the composite foil tab 14 in its length direction.
[0073] Optionally, the ratio between the width of the etching groove 11 and the width of the composite foil tab 14 is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.
[0074] In some embodiments, the etching groove 11 extends along the width direction of the composite foil tab 14, and at most one of the two ends of the etching groove 11 penetrates the composite foil tab 14 and its corresponding side edge.
[0075] Furthermore, the ratio between the width of the etching groove 11 and the length of the composite foil tab 14 is 0.1-0.9.
[0076] It is understood that the width of the etching groove 11 here is the dimension of the etching groove 11 in the length direction of the composite foil tab 14, and the length of the composite foil tab 14 is the dimension of the composite foil tab 14 in its length direction.
[0077] Optionally, the ratio between the width of the etching groove 11 and the length of the composite foil tab 14 is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.
[0078] Furthermore, the ratio between the length of the etching groove 11 and the width of the composite foil tab 14 is 0.1-0.9.
[0079] It is understood that the length of the etching groove 11 here is the dimension of the etching groove 11 in the width direction of the composite foil tab 14, and the width of the composite foil tab 14 is the dimension of the composite foil tab 14 in its width direction.
[0080] Optionally, the ratio between the length of the etching groove 11 and the width of the composite foil tab 14 is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.
[0081] In some embodiments, there are multiple etching grooves 11.
[0082] It is understandable that the number of etching grooves 11 should be determined based on the ratio between the size of the etching grooves 11 and the composite foil tabs 14.
[0083] The following is in conjunction with the appendix Figure 1-8 The electrode sheet of this utility model is further described below.
[0084] The electrode sheet of this utility model embodiment includes a plurality of composite foil electrode tabs, wherein the electrode sheet is wound or stacked so that the plurality of composite foil electrode tabs are arranged sequentially in its thickness direction;
[0085] The adjacent composite foil tabs are the first tab 1 and the second tab 2, respectively;
[0086] For example, there are an even number of composite foil tabs, and two adjacent composite foil tabs form a group. Each group of composite foil tabs consists of the first tab 1 and the second tab 2.
[0087] The first electrode 1 includes a first conductive layer 101, a first substrate layer 103, and a second conductive layer 102 stacked together;
[0088] The second electrode 2 includes a stacked third conductive layer 201, a second substrate layer 203, and a fourth conductive layer 202;
[0089] The second conductive layer 102 and the third conductive layer 201 abut against each other, so that the second conductive layer 102 and the third conductive layer 201 are connected.
[0090] The first electrode 1 is provided with a first etching groove 3 and a first embedding part 4. The first etching groove 3 penetrates the second conductive layer 102 and the first substrate layer 103, so that the portion of the first conductive layer 101 corresponding to the first etching groove 3 is exposed.
[0091] The second electrode 2 is provided with a second etching groove 5 and a second embedding portion 6. The second etching groove 5 penetrates the third conductive layer 201 and the second substrate layer 203, so that the portion of the fourth conductive layer 202 corresponding to the second etching groove 5 is exposed.
[0092] The first embedding part 4 is adapted to be embedded in the second etching groove 5 so that the second conductive layer 102 abuts against the fourth conductive layer 202. It is understood that the second conductive layer 102 and the fourth conductive layer 202 are connected.
[0093] The second embedding portion 6 of the second tab 2 is adapted to be embedded in the first etching groove 3 so that the third conductive layer 201 abuts against the first conductive layer 101. It is understood that the third conductive layer 201 and the first conductive layer 101 are connected.
[0094] Thus, the second conductive layer 102 is connected to the third conductive layer 201, the second conductive layer 102 is connected to the fourth conductive layer 202, and the third conductive layer 201 is connected to the first conductive layer 101, thereby achieving a conductive connection between the first conductive layer 101, the second conductive layer 102, the third conductive layer 201, and the fourth conductive layer 202.
[0095] The electrode sheet of this utility model is provided with a first etching groove 3, a first embedding part 4, a second etching groove 5, and a second embedding part 6 respectively on adjacent first electrode tabs 1 and second electrode tabs 2. The second conductive layer 102 and the third conductive layer 201 are connected, the second conductive layer 102 and the fourth conductive layer 202 are connected, and the third conductive layer 201 and the first conductive layer 101 are connected, thereby achieving conductive connection between the first conductive layer 101, the second conductive layer 102, the third conductive layer 201, and the fourth conductive layer 202.
[0096] Therefore, the electrode sheet of this utility model embodiment can connect the two conductive layers of the composite foil electrode tab, thereby enabling the two conductive layers of the composite foil electrode tab to conduct electricity.
[0097] In some embodiments, such as Figure 1 As shown, there are multiple first etching grooves 3 and multiple first embedding parts 4, and multiple second etching grooves 5 and multiple second embedding parts 6;
[0098] Multiple first etching grooves 3 and multiple first embedding portions 4 are alternately arranged in the width direction of the first electrode tab 1;
[0099] Multiple second etching grooves 5 and multiple second embedding portions 6 are alternately arranged in the width direction of the second tab 2.
[0100] Furthermore, the first etching groove 3 extends along the length direction of the first electrode 1, and one end of the first etching groove 3 penetrates the first electrode 1 and its corresponding side edge.
[0101] The second etching groove 5 extends along the length of the second electrode 2, and one end of the second etching groove 5 penetrates the second electrode 2 and its corresponding side edge.
[0102] It is understood that the first embedding portion 4 is formed between adjacent first etching grooves 3, and the second embedding portion 6 is formed between adjacent second etching grooves 5. Simultaneously, by pressing the first tab 1 and the second tab 2, the first embedding portion 4 of the first tab 1 is embedded into the second etching groove 5, and the second embedding portion 6 of the second tab 2 is embedded into the first etching groove 3, thereby enabling the first conductive layer 101 and the second conductive layer 102 of the first tab 1, and the third conductive layer 201 and the fourth conductive layer 202 of the second tab 2 to be connected.
[0103] In some embodiments, such as Figure 2-3 As shown, there are multiple first etching grooves 3 and multiple embedding parts, and multiple second etching grooves 5 and multiple second embedding parts 6;
[0104] Multiple first etching grooves 3 and multiple first embedding portions 4 are alternately arranged along the length direction of the first electrode tab 1;
[0105] Multiple second etching grooves 5 and multiple second embedding portions 6 are alternately arranged in the width direction of the second tab 2.
[0106] Furthermore, the first etching groove 3 extends along the width direction of the first electrode 1, and at most one of the two ends of the first etching groove 3 penetrates the first electrode 1 and its corresponding side edge. In other words, one of the two ends of the first etching groove 3 can penetrate the first electrode 1 and its corresponding side edge, or neither end of the first etching groove 3 can penetrate its corresponding side edge.
[0107] The second etching groove 5 extends along the width direction of the second electrode 2. At most one of the two ends of the second etching groove 5 penetrates the second electrode 2 and its corresponding side edge. In other words, one of the two ends of the second etching groove 5 can penetrate the second electrode 2 and its corresponding side edge, or neither end of the second etching groove 5 can penetrate its corresponding side edge.
[0108] It is understood that the first embedding part 4 is formed between adjacent first etching grooves 3, and the second embedding part 6 is formed between adjacent second etching grooves 5.
[0109] Simultaneously, by squeezing the first tab 1 and the second tab 2, the first embedding part 4 of the first tab 1 is embedded into the second etching groove 5, and the second embedding part 6 of the second tab 2 is embedded into the first etching groove 3, thereby enabling the first conductive layer 101 and the second conductive layer 102 of the first tab 1, and the third conductive layer 201 and the fourth conductive layer 202 of the second tab 2 to be connected.
[0110] In some embodiments, such as Figure 4-5 As shown, the first etching groove 3 and the first embedding part 4 are both single, and the second etching groove 5 and the second embedding part 6 are both single.
[0111] It is understood that by squeezing the first tab 1 and the second tab 2, the first embedding part 4 of the first tab 1 is embedded into the second etching groove 5, and the second embedding part 6 of the second tab 2 is embedded into the first etching groove 3, thereby enabling the first conductive layer 101 and the second conductive layer 102 of the first tab 1, and the third conductive layer 201 and the fourth conductive layer 202 of the second tab 2 to be connected.
[0112] This utility model also provides a battery cell.
[0113] The battery cell of this utility model embodiment is a wound battery cell, and the wound battery cell includes a positive electrode 7 and a negative electrode 8, at least one of the positive electrode 7 and the negative electrode 8 being the electrode described in the above embodiment.
[0114] This utility model also provides a battery cell.
[0115] The battery cell of this utility model embodiment is a laminated battery cell, and the laminated battery cell includes a positive electrode 7 and a negative electrode 8, at least one of the positive electrode 7 and the negative electrode 8 is the electrode described in the above embodiment.
[0116] This utility model also provides a battery.
[0117] The battery of this utility model embodiment includes stacked cells or wound cells as described in the above embodiments.
[0118] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.
Claims
1. An electrode sheet, characterized in that, It includes a composite foil tab (14), which includes a substrate layer (9) and conductive layers (10) located on both sides of the substrate layer (9). The composite foil tab (14) is provided with an etching groove (11) and an embedding part (12). The etching groove (11) penetrates the conductive layer (10) on one side of the substrate layer (9) and the substrate layer (9), so that the conductive layer (10) on the other side of the substrate layer (9) is partially exposed corresponding to the etching groove (11).
2. The electrode sheet according to claim 1, characterized in that, The etching groove (11) extends along the length direction of the composite foil tab (14); One end of the etching groove (11) extends through the composite foil tab (14) and its corresponding side edge.
3. The electrode sheet according to claim 1, characterized in that, The ratio between the width of the etching groove (11) and the width of the composite foil tab (14) is 0.1-0.
9.
4. The electrode sheet according to claim 1, characterized in that, The ratio between the length of the etching groove (11) and the length of the composite foil tab (14) is 0.1-0.
9.
5. The electrode sheet according to claim 1, characterized in that, The etching groove (11) extends along the width direction of the composite foil tab (14), and at most one of the two ends of the etching groove (11) penetrates the composite foil tab (14) and its corresponding side edge.
6. The electrode sheet according to claim 1, characterized in that, The ratio between the width of the etching groove (11) and the length of the composite foil tab (14) is 0.1-0.
9.
7. The electrode sheet according to claim 1, characterized in that, The ratio between the length of the etching groove (11) and the width of the composite foil tab (14) is 0.1-0.
9.
8. The electrode sheet according to claim 1, characterized in that, There are several etching grooves (11).
9. A battery cell, characterized in that, The battery cell includes an electrode sheet as described in any one of claims 1-8, and the electrode sheet has multiple composite foil tabs (14), the electrode sheet being wound so that the multiple composite foil tabs (14) are arranged sequentially in its thickness direction; or, The battery cell includes an electrode as described in any one of claims 1-8, wherein a plurality of the electrode sheets are stacked together so that a plurality of the composite foil tabs (14) are arranged sequentially in their thickness direction; The adjacent composite foil tabs (14) are the first tab (1) and the second tab (2), respectively. The first electrode (1) includes a first conductive layer (101), a first substrate layer (103), and a second conductive layer (102) stacked together. The second electrode (2) includes a stacked third conductive layer (201), a second substrate layer (203) and a fourth conductive layer (202). The second conductive layer (102) and the third conductive layer (201) abut against each other; The first electrode (1) is provided with a first etching groove (3) and a first embedding part (4). The first etching groove (3) penetrates the second conductive layer (102) and the first substrate layer (103), so that the part of the first conductive layer (101) corresponding to the first etching groove (3) is exposed. The second electrode (2) is provided with a second etching groove (5) and a second embedding part (6). The second etching groove (5) penetrates the third conductive layer (201) and the second substrate layer (203), so that the part of the fourth conductive layer (202) corresponding to the second etching groove (5) is exposed. The first embedding part (4) is adapted to be embedded in the second etching groove (5) so that the second conductive layer (102) is electrically connected to the fourth conductive layer (202); The second embedding part (6) is adapted to be embedded in the first etched groove (3) so that the third conductive layer (201) is electrically connected to the first conductive layer (101).
10. A battery, characterized in that, Includes the battery cell as described in claim 9.