Battery

Abstract

The utility model relates to the field of electric energy storage, in particular to a battery, which comprises a first pole piece, a diaphragm and a second pole piece which are laminated and wound, the first pole piece comprises a first tab, a first current collector and a first active layer coated on the surface of at least one side of the first current collector; a first groove for exposing the first current collector is formed in the surface of the first active layer, and an area between the first groove and the side edge closest to the current collector is an edge paste coating area of the first active layer; one end of the first tab is electrically connected with the first current collector in the first groove, and the other end of the first tab extends to the outer side of the first pole piece towards the direction of the edge paste coating area; the second pole piece is provided with an avoiding groove opposite to the edge pasting area, the surface, facing the first tab, of the second pole piece is provided with a second insulating layer, and the second insulating layer covers the avoiding groove. According to the lithium ion battery, the energy density and the cycle performance of the lithium ion battery are improved, and the use safety of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the field of electric energy storage, in particular to a battery. Background Art

[0002] Lithium-ion batteries, due to their high energy density, have been widely used in consumer electronics. As consumer electronics demand ever-increasing charging speeds for lithium-ion batteries, fast-charging technology has become a key development direction for lithium-ion batteries.

[0003] Conventional wound lithium-ion battery tabs are located at the head of the battery pole piece. This type of battery structure has a large internal resistance problem and cannot meet the performance requirements of lithium-ion battery fast charging.

[0004] Setting the tab in the middle of the lithium-ion battery electrode, that is, the central tab structure, is equivalent to dividing the battery electrode into two, and connecting the electrodes on both sides of the tab in parallel, which can significantly reduce the internal resistance of the lithium-ion battery. However, this structure easily leads to poor flatness of the battery.

[0005] Therefore, how to improve the flatness of lithium-ion batteries, and thereby enhance the energy density, cycle performance, and insulation stability of lithium-ion batteries, is an urgent problem to be solved by those skilled in the art. Utility Model Content

[0006] The purpose of the utility model is to provide a battery to solve the problems of poor flatness, low battery energy density and cycle performance, and poor insulation stability of lithium-ion batteries in the prior art.

[0007] In order to solve the above technical problems, the present invention provides a battery, comprising a first pole piece, a separator and a second pole piece that are stacked and wound, wherein the polarities of the first pole piece and the second pole piece are opposite;

[0008] The first pole piece includes a first pole tab, a first current collector, and a first active layer coated on at least one side of the first current collector;

[0009] A first groove is formed on the surface of the first active layer, exposing the first current collector, and the area between the first groove and the side closest to the current collector is the edge paste coating area of ​​the first active layer;

[0010] One end of the first electrode tab is electrically connected to the first current collector in the first slot, and the other end extends toward the edge paste coating area to the outside of the first electrode sheet;

[0011] The second pole piece is provided with an avoidance groove arranged opposite to the edge paste coating area, and the surface of the second pole piece facing the first pole ear is provided with a second insulating layer, and the second insulating layer covers the avoidance groove.

[0012] Optionally, in the battery, the second pole piece includes a second current collector and a second active layer coated on a surface of the second current collector facing the first pole tab, and the second active layer is arranged around the avoidance groove;

[0013] The second active layer is provided with a glue embedding groove communicating with the avoidance groove, the depth of the glue embedding groove is smaller than the depth of the avoidance groove, and the edge of the second insulating layer is located in the glue embedding groove.

[0014] Optionally, in the battery, the avoidance groove is a through hole on the second pole piece.

[0015] Optionally, the battery further comprises a third insulating layer;

[0016] The third insulating layer is disposed on a surface of the second pole piece facing away from the first pole tab and covers an opening of the avoidance groove.

[0017] Optionally, the battery further includes a first insulating layer;

[0018] The first insulating layer is disposed on the surface of the first active layer and covers the first electrode tab.

[0019] Optionally, in the battery, a ratio of a width of the avoidance groove to a width of the first insulating layer ranges from 0.5 to 1.0.

[0020] Optionally, the battery further includes a fourth insulating layer;

[0021] The first active layer is coated on both side surfaces of the first current collector;

[0022] A second groove and the first groove exposing the first current collector are respectively formed on the first active layer on both side surfaces of the first current collector, and a projection of the first groove on the first current collector overlaps with a projection of the second groove on the first current collector;

[0023] The fourth insulating layer covers the opening of the second groove.

[0024] Optionally, in the battery, a projection of the second groove of the first electrode sheet on the first current collector completely covers a projection of the first groove on the first current collector, and an edge of the second groove does not overlap with an edge of the first groove;

[0025] And / or the projection of the avoidance groove on the first pole piece completely covers the projection of the first pole tab on the first pole piece.

[0026] Optionally, in the battery, in the extension direction of the first electrode tab, a projected length of the first electrode tab in the first groove is greater than a projected length of the first electrode tab on the edge paste coating area.

[0027] Optionally, in the battery, the width of the avoidance groove is smaller than the width of the first groove.

[0028] The battery provided by the present invention includes a first electrode piece, a diaphragm and a second electrode piece which are stacked and wound, and the polarity of the first electrode piece and the second electrode piece are opposite; the first electrode piece includes a first electrode ear, a first current collector and a first active layer coated on at least one side of the surface of the first current collector; a first groove is formed on the surface of the first active layer to expose the first current collector, and the area between the first groove and the side of the current collector closest to the first active layer is the edge paste area of ​​the first active layer; one end of the first electrode ear is electrically connected to the first current collector in the first groove, and the other end extends to the outside of the first electrode piece in the direction of the edge paste area; the second electrode piece is provided with an avoidance groove arranged opposite to the edge paste area, and the surface of the second electrode piece facing the first electrode ear is provided with a second insulating layer, and the second insulating layer covers the avoidance groove. The utility model grooves the surface of the negative electrode sheet that will be pressed on the positive electrode tab (that is, sets a glue embedding groove), so that the positive electrode tab located at the edge of the positive electrode sheet and arranged on the edge paste coating area is accommodated in the glue embedding groove, thereby avoiding the edge of the lithium-ion battery electrode sheet with a central tab being padded by the positive electrode tab, resulting in poor flatness, thereby improving the energy density and battery cycle performance of the lithium-ion battery. In addition, it is further defined that the second insulating layer between the second electrode sheet and the first electrode sheet is arranged on the surface of the second electrode sheet and covers the avoidance groove. Burrs will be formed on the surface during the formation of the avoidance groove (scraping with a scraper, laser cleaning), and the common second insulating layer material has stronger adhesion on the second electrode sheet that is flatter than the first electrode sheet, thereby reducing the probability of displacement of the second insulating layer during the battery falling process, thereby greatly improving the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic structural diagram of a specific embodiment of the battery provided by the utility model;

[0031] Figure 2A schematic cross-sectional view of a specific embodiment of the battery provided by the present invention;

[0032] Figure 3-1 、 Figure 3-2 Schematic diagrams of cross-sectional structures of two specific embodiments of the battery provided by the present invention;

[0033] Figure 4 A schematic diagram of a top view of a partial structure of a specific embodiment of a battery provided by the present invention;

[0034] Figure 5 A schematic cross-sectional view of a specific embodiment of the battery provided by the present invention;

[0035] Figure 6 A schematic structural diagram of another specific embodiment of the battery provided by the present invention;

[0036] Figure 7 A schematic structural diagram of another specific embodiment of the battery provided by the present utility model;

[0037] Figure 8 This is a structural schematic diagram of another specific embodiment of the battery provided by the utility model.

[0038] In the figure, it includes 01-first insulating layer, 02-second insulating layer, 03-third insulating layer, 04-fourth insulating layer, 10-first pole piece, 11-first current collector, 12-first active layer, 12A-first groove, 12B-edge paste coating area, 12C-second groove, 20-second pole piece, 21-second current collector, 22-second active layer, 23-avoidance groove, 24-embedded glue groove, 30-diaphragm. DETAILED DESCRIPTION

[0039] To help those skilled in the art better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a portion of the present invention, not all of the embodiments. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0040] It should be noted that during the production process of lithium-ion batteries with a center-tab structure, the paste in the area where the electrode is connected to the current collector needs to be removed for welding the electrode. However, due to the center-tab, the location where the paste is removed is not at the edge of the electrode, but rather at a distance from the edge of the electrode. After welding the electrode at the location where the paste is removed from the electrode, the electrode will inevitably overlap with the paste reserved at the edge in order to extend the electrode and facilitate connection with the external circuit, resulting in the thickness of this location being thicker than other locations of the battery, affecting the flatness of the lithium-ion battery. On the one hand, it will affect the energy density of the lithium-ion battery, and on the other hand, it will affect the cycle performance of the lithium-ion battery. In addition, poor flatness will cause the insulation measures of the protruding electrode part to be more prone to insulation failure with the increase of usage time and the influence of external impact, causing accidental short circuits and reducing the safety of battery use.

[0041] The core of the present invention is to provide a battery, a structural diagram of a specific embodiment of which is shown in FIG. Figures 1 to 5 As shown, it is called specific embodiment 1, including a first pole piece 10, a diaphragm 30 and a second pole piece 20 that are wound in layers, and the polarities of the first pole piece 10 and the second pole piece 20 are opposite;

[0042] The first pole piece 10 includes a first pole tab 13, a first current collector 11, and a first active layer 12 coated on at least one side of the first current collector 11.

[0043] A first groove 12A is formed on the surface of the first active layer 12, exposing the first current collector 11. The area between the first groove 12A and the side closest to the current collector is the edge paste area 12B of the first active layer 12.

[0044] One end of the first electrode tab 13 is electrically connected to the first current collector 11 in the first groove 12A, and the other end extends toward the edge paste coating area 12B to the outside of the first electrode sheet 10;

[0045] The second pole piece 20 is provided with an avoidance groove 23 arranged opposite to the edge paste coating area 12B. The surface of the second pole piece 20 facing the first pole tab 13 is provided with a second insulating layer 02 , and the second insulating layer 02 covers the avoidance groove 23 .

[0046] The first electrode sheet 10 and the second electrode sheet 20 in the present invention represent the positive electrode sheet and the negative electrode sheet in the battery, respectively. Of course, whether the first electrode sheet 10 is the positive electrode sheet or the second electrode sheet 20 is the negative electrode sheet can be determined according to actual needs. The second electrode sheet 20 is also composed of a corresponding current collector and an active layer applied to at least one side of the current collector. Figure 1 、 Figure 2 The long dashed line in the figure is the separator 30 in the battery, and the dotted line frame is the avoidance groove 23.

[0047] As a specific embodiment, the second pole piece 20 includes a second current collector 21 and a second active layer 22 coated on a surface of the second current collector 21 facing the first pole tab 13 , and the second active layer 22 is arranged around the avoidance groove 23 ;

[0048] The second active layer 22 is provided with a glue embedding groove 24 communicating with the avoidance groove 23 . The depth of the glue embedding groove 24 is smaller than that of the avoidance groove 23 . The edge of the second insulating layer 02 is located in the glue embedding groove 24 .

[0049] In this preferred embodiment, a glue embedding groove 24 whose depth is less than that of the avoidance groove 23 is provided at the edge of the avoidance groove 23, so that the edge of the second insulating layer 02 can be placed in the glue embedding groove 24, so that the second insulating layer 02 no longer protrudes from the surface of the second active layer 22, further improving the surface flatness of the second pole piece 20 and reducing the thickness of the battery.

[0050] In addition, the avoidance groove 23 is a through hole on the second pole piece 20 .

[0051] In this specific embodiment, the position of the second pole piece 20 corresponding to the edge paste area 12B is directly hollowed out, leaving a through hole as the avoidance groove 23. By directly using the through hole as the avoidance groove 23, there is no need to consider the depth of the avoidance groove 23, which increases the versatility of the process, greatly simplifies the process, and improves the production efficiency of the battery.

[0052] Furthermore, the battery further includes a third insulating layer 03;

[0053] The third insulating layer 03 is disposed on a surface of the second electrode piece 20 facing away from the first electrode tab 13 and covers the opening of the avoiding groove 23 .

[0054] When the avoidance groove 23 is a through hole, openings will be left on both the front and back sides of the second pole piece 20. In this specific embodiment, the opening away from the first pole ear 13 is also covered with an insulating layer to prevent other unexpected structures from accidentally extending into the through hole and causing short circuits and other faults, thereby further improving the working stability of the battery.

[0055] Furthermore, it also includes a first insulating layer 01;

[0056] The first insulating layer 01 is disposed on the surface of the first active layer 12 and covers the first electrode tab 13 .

[0057] In other words, in this specific embodiment, the insulation between the first pole ear 13 and the adjacent second pole piece 20 is achieved by the first insulating layer. The first insulating layer 01 greatly improves the setting stability of the first insulating layer 01 through the larger connection area with the surface of the first active layer, reduces the possibility of the first insulating layer 01 falling off, and improves the working stability of the battery.

[0058] Furthermore, the ratio of the width of the avoidance groove 23 to the width of the first insulating layer 01 ranges from 0.5 to 1.0, including endpoints such as 0.50, 0.77, or 1.00. "Width" in this utility model refers to the dimension perpendicular to the extension direction of the first tab 13. A ratio of the width of the avoidance groove 23 to the width of the first insulating layer 01 of less than 1 ensures that the first insulating layer 01 can fully cover the avoidance groove 23 in the width direction, improving insulation performance. A smaller ratio reduces the alignment requirements for the first and second pole pieces 10 and 20, improving process yield. However, if the ratio is too small, it will waste the raw materials of the first insulating layer 01, increase battery production costs, and reduce battery energy density. Therefore, the above ratio range is the optimal range based on extensive theoretical calculations and practical tests, balancing high process yield and low cost. Of course, the ratio can be adjusted according to actual conditions, and this utility model is not limited here.

[0059] An elastic second insulating layer 02 is added to the opening of the avoidance groove 23 of the second pole piece 20 toward the first pole ear 13, and the insulation between the second pole piece 20 and the first pole ear 13 is achieved by the second insulating layer 02. During the pressing process of the first pole piece 10 and the second pole piece, the first pole ear 13 presses the second insulating layer 02, causing the second insulating layer 02 to deform and sink into the avoidance groove 23, while allowing the first pole ear 13 to enter the avoidance groove 23. In this way, the first pole ear 13 is in close contact with the second insulating layer 02, and in the process of achieving the insulation between the second pole piece 20 and the first pole ear 13, it plays an auxiliary fixing role for the first pole ear 13, thereby improving the working stability of the battery.

[0060] Furthermore, the battery further includes a fourth insulating layer 04;

[0061] The first active layer 12 is coated on both sides of the first current collector 11;

[0062] The first active layer 12 on both sides of the first current collector 11 is respectively formed with a second groove 12C and a first groove 12A exposing the first current collector 11 , wherein the projection of the first groove 12A on the first current collector 11 overlaps with the projection of the second groove 12C on the first current collector 11 ;

[0063] The fourth insulating layer 04 covers the opening of the second groove 12C.

[0064] To facilitate welding of the first electrode tab 13, on the first electrode piece 10, in addition to the need to remove the corresponding first active layer 12 on the surface where the first electrode tab 13 is set to leave the first groove 12A, the corresponding position of the first active layer 12 on the different side of the first electrode tab 13 also needs to be removed, and the remaining groove is the second groove 12C. In this specific embodiment, an insulating layer is also provided at the opening of the second groove 12C, namely the fourth insulating layer 04. This is because the first electrode 13 will leave a weld mark during the welding process, and the weld mark will extend from the second groove 12C in some cases, which may cause an electrical connection outside the design, leading to faults such as short circuits. Therefore, in this specific embodiment, the opening of the second groove 12C is sealed with the fourth insulating layer 04, which avoids the occurrence of unexpected faults and improves the operating stability of the battery.

[0065] Preferably, the insulating layer in the battery is an insulating tape layer. In this preferred embodiment, the insulating tape layer serves as the insulating layer. Because the tape is flexible, thin, and inherently sticky, it can be directly bonded to the corresponding surface, significantly improving production efficiency while not affecting the battery's energy density and operational stability. Of course, the "insulating layer in the battery" herein includes at least one of the first insulating layer 01, the second insulating layer 02, the third insulating layer, and the fourth insulating layer 04. Figure 1 and Figure 2 This is a side view of a specific embodiment of the present invention, for clarity, Figure 1 The various insulating layers are not drawn. Figure 2 The insulation layer is drawn in, but other structures are not marked. Figure 3-1 It is a cross-sectional view in another direction, and the direction perpendicular to the paper surface is the extending direction of the first electrode tab 13 . Figure 4 It is a partial top view of the second pole piece 20 .

[0066] As a preferred embodiment, the projection of the second groove 12C of the first pole piece 10 on the first current collector 11 completely covers the projection of the first groove 12A on the first current collector 11, and the edge of the second groove 12C does not overlap with the edge of the first groove 12A;

[0067] And / or the projection of the avoidance groove 23 on the first pole piece 10 completely covers the projection of the first pole tab 13 on the first pole piece 10 .

[0068] In other words, the first groove 12A is framed inside by the projection of the second groove 12C on the first pole piece 10. The larger second groove 12C can bring greater tolerance for the welding of the first pole ear 13, improve the process window, and thus improve the yield of the finished product. At the same time, in this preferred embodiment, it is stipulated that the edge of the second groove 12C does not overlap with the edge of the first groove 12A, thereby avoiding the overlap of the scraper edge on the first current collector 11 when removing the first active layer 12 on both sides of the first pole piece 10, resulting in damage to the first current collector 11, and further improving the process stability and the yield of the finished product.

[0069] Also, please refer to Figure 7 In this preferred embodiment, it is taken into consideration that in some cases, the thickness of the first pole tab 13 is greater than the first active layer 12 on one side of the first pole piece 10, which will cause the top height of the first pole tab 13 arranged in the first groove 12A to be higher than the first active layer 12 in other areas. In this case, the avoidance groove 23 is directly set in the corresponding area of ​​the entire first pole tab 13 to avoid the first pole tab 13 in the first groove 12A lifting the second pole piece 20 at the corresponding position, causing a decrease in battery energy density, thereby greatly improving the versatility of the technical solution of the utility model and ensuring high battery energy density and high cycle performance under extreme conditions.

[0070] As another preferred embodiment, in the extension direction of the first electrode tab 13 , the projected length of the first electrode tab 13 in the first groove 12A is greater than the projected length of the first electrode tab 13 on the edge paste coating area 12B.

[0071] Please refer to Figure 5 The length referred to here is the length of the first tab 13 in the extending direction, corresponding to Figure 5 L1 and L2 in the figure, and this preferred embodiment further limits L1 to be greater than L2. In other words, most of the first electrode tab 13 is placed in the first groove 12A, and a small part crosses the edge paste area 12B. This ensures that in the subsequent lamination process and folding process, the first electrode tab 13 and the first current collector 11 of the first electrode sheet 10 are always firmly connected, thereby improving the working stability of the battery.

[0072] The battery provided by the present invention includes a first electrode sheet 10, a separator 30 and a second electrode sheet 20 that are stacked and wound, wherein the polarities of the first electrode sheet 10 and the second electrode sheet 20 are opposite; the first electrode sheet 10 includes a first electrode tab 13, a first current collector 11 and a first active layer 12 coated on at least one side of the first current collector 11; a first groove 12A is formed on the surface of the first active layer 12 to expose the first current collector 11, and the area between the first groove 12A and the side closest to the current collector is an edge paste area 12B of the first active layer 12; one end of the first electrode tab 13 is electrically connected to the first current collector 11 in the first groove 12A, and the other end extends to the outside of the first electrode sheet 10 in the direction of the edge paste area 12B; the second electrode sheet 20 is provided with an avoidance groove 23 arranged opposite to the edge paste area 12B, and the surface of the second electrode sheet 20 facing the first electrode tab 13 is provided with a second insulating layer 02, and the second insulating layer 02 covers the avoidance groove 23. The utility model grooves the surface of the negative electrode sheet that will be pressed on the positive electrode tab (i.e., sets the glue embedding groove 24), so that the positive electrode tab located at the edge of the positive electrode sheet and arranged on the edge paste coating area 12B is accommodated in the glue embedding groove 24, avoiding the situation where the edge of the lithium-ion battery electrode sheet with the middle tab is padded by the positive electrode tab and the flatness is poor, thereby improving the energy density and battery cycle performance of the lithium-ion battery. Figure 3-2 In addition, it is further defined that the second insulating layer 02 between the second pole piece 20 and the first pole ear 13 is provided on the surface of the second pole piece 20 and covers the avoidance groove 23. During the formation process of the avoidance groove 23 (scraping with a scraper, laser cleaning), burrs will be formed on the surface, and the common second insulating layer 02 material has stronger adhesion on the second pole piece 20 which is flatter than the first pole piece 10, thereby reducing the probability of displacement of the second insulating layer 02 during the battery falling process, thereby greatly improving the safety of the battery.

[0073] On the basis of the specific embodiment 1, the avoidance groove 23 is further limited to obtain the specific embodiment 2, and its corresponding structural diagram is as follows: Figure 6 As shown, it includes a first pole piece 10, a diaphragm 30 and a second pole piece 20 that are wound in layers, and the polarities of the first pole piece 10 and the second pole piece 20 are opposite;

[0074] The first pole piece 10 includes a first pole tab 13, a first current collector 11, and a first active layer 12 coated on at least one side of the first current collector 11.

[0075] A first groove 12A is formed on the surface of the first active layer 12, exposing the first current collector 11. The area between the first groove 12A and the side closest to the current collector is the edge paste area 12B of the first active layer 12.

[0076] One end of the first electrode tab 13 is electrically connected to the first current collector 11 in the first groove 12A, and the other end extends toward the edge paste coating area 12B to the outside of the first electrode sheet 10;

[0077] The second pole piece 20 is provided with an avoidance groove 23 arranged opposite to the edge paste coating area 12B. The surface of the second pole piece 20 facing the first pole tab 13 is provided with a second insulating layer 02, and the second insulating layer 02 covers the avoidance groove 23;

[0078] The avoidance groove 23 is a leaking foil slot;

[0079] The bottom surface of the drain foil slot is the second current collector 21 of the second pole piece 20 .

[0080] The difference between this embodiment and the above embodiment is that the avoidance groove 23 in this embodiment is a foil-leaking groove, and the remaining structures are the same as those in the above embodiment, which will not be described in detail in this utility model.

[0081] In this preferred embodiment, the avoidance groove 23 is defined as the leakage foil groove, that is, the second active layer 22 on the side of the second electrode sheet 20 facing the first electrode tab 13 is removed to leak the second current collector below to form the leakage foil groove. Figure 6 This is the corresponding side cross-sectional view. This structure has a simple processing technology and can retain the complete energy storage structure on the other side of the second current collector 21, further improving the energy density of the battery.

[0082] On the basis of the specific embodiment 1, the relationship between the avoidance groove 23 and the first groove 12A is further defined to obtain the specific embodiment 3, and its corresponding structural diagram is as follows: Figure 8 As shown, it includes a first pole piece 10, a diaphragm 30 and a second pole piece 20 that are wound in layers, and the polarities of the first pole piece 10 and the second pole piece 20 are opposite;

[0083] The first pole piece 10 includes a first pole tab 13, a first current collector 11, and a first active layer 12 coated on at least one side of the first current collector 11.

[0084] A first groove 12A is formed on the surface of the first active layer 12, exposing the first current collector 11. The area between the first groove 12A and the side closest to the current collector is the edge paste area 12B of the first active layer 12.

[0085] One end of the first electrode tab 13 is electrically connected to the first current collector 11 in the first groove 12A, and the other end extends toward the edge paste coating area 12B to the outside of the first electrode sheet 10;

[0086] The second pole piece 20 is provided with an avoidance groove 23 arranged opposite to the edge paste coating area 12B. The surface of the second pole piece 20 facing the first pole tab 13 is provided with a second insulating layer 02, and the second insulating layer 02 covers the avoidance groove 23;

[0087] The width of the avoidance groove 23 is smaller than the width of the first groove 12A.

[0088] The difference between this specific embodiment and the above specific embodiment is that this specific embodiment defines the relationship between the width of the avoidance groove 23 and the width of the first groove 12A, and the remaining structures are the same as the above specific embodiment, which will not be repeated in this utility model.

[0089] In this preferred embodiment, the width of the avoidance groove 23 is limited to be smaller than the width of the first groove 12A. The width here still refers to the length in the direction perpendicular to the extension direction of the first tab 13. Figure 8 , Figure 8 The direction perpendicular to the paper is the extension direction of the first pole ear 13. The width of the avoidance groove 23 is smaller than the width of the first groove 12A. In order for the first pole ear 13 to be embedded in the avoidance groove 23, the width of the first pole ear 13 must be smaller than the width of the avoidance groove 23. In this way, in addition to accommodating the first pole ear 13, the avoidance groove 23 can also limit the movement of the first pole ear 13, thereby improving the working stability of the subsequent battery.

[0090] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the methods.

[0091] It should be noted that, in this specification, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0092] The battery provided by the present invention has been introduced in detail above. The principles and implementation methods of the present invention are illustrated herein using specific examples. The description of the above examples is intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A battery, characterized in that: It includes a first pole piece, a diaphragm and a second pole piece that are stacked and wound, and the polarities of the first pole piece and the second pole piece are opposite; The first pole piece includes a first pole tab, a first current collector, and a first active layer coated on at least one side of the first current collector; A first groove is formed on the surface of the first active layer, exposing the first current collector, and the area between the first groove and the side closest to the current collector is the edge paste coating area of ​​the first active layer; One end of the first electrode tab is electrically connected to the first current collector in the first slot, and the other end extends toward the edge paste coating area to the outside of the first electrode sheet; The second pole piece is provided with an avoidance groove arranged opposite to the edge paste coating area, and a second insulating layer is provided on the surface of the second pole piece facing the first pole ear, and the second insulating layer covers the avoidance groove.

2. The battery according to claim 1, wherein The second pole piece includes a second current collector and a second active layer coated on a surface of the second current collector facing the first pole tab, wherein the second active layer is arranged around the avoidance groove; The second active layer is provided with a glue embedding groove communicating with the avoidance groove, the depth of the glue embedding groove is smaller than the depth of the avoidance groove, and the edge of the second insulating layer is located in the glue embedding groove.

3. The battery according to claim 1, wherein The avoidance groove is a through hole on the second pole piece.

4. The battery according to claim 3, wherein Also comprising a third insulating layer; The third insulating layer is disposed on a surface of the second pole piece facing away from the first pole tab and covers an opening of the avoidance groove.

5. The battery according to claim 1, wherein Also comprising a first insulating layer; The first insulating layer is disposed on the surface of the first active layer and covers the first electrode tab.

6. The battery according to claim 5, wherein A ratio of a width of the avoiding groove to a width of the first insulating layer is in a range of 0.5 to 1.

0.

7. The battery according to claim 1, wherein Also comprising a fourth insulating layer; The first active layer is coated on both side surfaces of the first current collector; A second groove and the first groove exposing the first current collector are respectively formed on the first active layer on both side surfaces of the first current collector, and a projection of the first groove on the first current collector overlaps with a projection of the second groove on the first current collector; The fourth insulating layer covers the opening of the second groove.

8. The battery according to claim 7, wherein The projection of the second groove of the first pole piece on the first current collector completely covers the projection of the first groove on the first current collector, and the edge of the second groove does not overlap with the edge of the first groove; And / or the projection of the avoidance groove on the first pole piece completely covers the projection of the first pole tab on the first pole piece.

9. The battery according to claim 1, wherein In the extension direction of the first electrode tab, a projected length of the first electrode tab in the first groove is greater than a projected length of the first electrode tab on the edge paste coating area.

10. The battery according to claim 1, wherein The width of the avoidance groove is smaller than the width of the first groove.

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