Battery and electronic equipment

Abstract

The utility model relates to the technical field of batteries, in particular to a battery and electronic equipment. The battery comprises a battery cell, and the battery cell comprises a positive plate which comprises a positive current collector, a positive lug and positive active coatings arranged on the two sides of the positive current collector; the negative plate comprises a negative current collector, a negative tab and negative active coatings arranged on the two sides of the negative current collector, a tab groove is formed in the first side of the negative plate, and the negative tab is arranged in the tab groove; the diaphragm is arranged between the positive plate and the negative plate, and the positive plate, the negative plate and the diaphragm are wound; wherein the positive active layer adjacent to the second side of the negative plate is provided with a first area, the projection of the tab groove on the positive plate is located in the first area, and the first area is provided with a concave part. By applying the technical scheme provided by the invention, the problem that lithium is easy to separate out in the battery in the related technology can be effectively solved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery and an electronic device. Background Art

[0002] With the rapid development of lithium-ion battery technology, people have put forward higher requirements on the energy density, fast charging capability and charge and discharge rate of lithium-ion batteries. Fast-charging lithium batteries are also the development trend of consumer lithium-ion batteries.

[0003] In the related art, the tabs on the pole pieces are generally connected by welding.

[0004] This setting method is likely to destroy the activity of the active material coated on the electrode, causing the battery to produce lithium deposition problems, affecting the safety of the lithium-ion battery. Utility Model Content

[0005] The present application provides a battery and an electronic device to solve the problem of easy lithium deposition in batteries in the related art.

[0006] In one aspect, the present application provides a battery, including a battery cell, wherein the battery cell includes:

[0007] A positive electrode sheet, comprising a positive electrode current collector, a positive electrode ear, and a positive electrode active coating disposed on both sides of the positive electrode current collector;

[0008] A negative electrode sheet, comprising a negative electrode current collector, a negative electrode ear and a negative electrode active coating disposed on both sides of the negative electrode current collector, wherein a first side of the negative electrode current collector is provided with an electrode ear groove, and the negative electrode ear is disposed in the electrode ear groove;

[0009] The separator is arranged between the positive electrode sheet and the negative electrode sheet, and the positive electrode sheet, the negative electrode sheet and the separator are wound;

[0010] The positive electrode active layer adjacent to the second side of the negative electrode current collector has a first region, the projection of the tab groove on the positive electrode sheet is located in the first region, and the positive electrode active layer has a concave portion in the first region.

[0011] In some embodiments, the recessed portion includes an opening and / or a groove disposed on the positive electrode active coating.

[0012] In some embodiments, the negative electrode tab is connected to the negative electrode current collector by welding to form a welding area on the negative electrode tab, wherein the welding area has a plurality of welding points, and the plurality of welding points are arranged in an array, and the number of the welding points is between 32 and 175.

[0013] In some embodiments, the height of each of the welding points protruding from the surface of the negative electrode ear is between 20 μm and 30 μm.

[0014] In some embodiments, the sum of the areas of the plurality of welding points accounts for 75% to 90% of the total area of ​​the welding region.

[0015] In some embodiments, the length of the first region in the first direction is L1, the length of the negative electrode ear in the first direction is L2, and L1 and L2 satisfy: 0 mm ≤ L1 - L2 ≤ 4 mm;

[0016] and / or,

[0017] The negative electrode ear is welded to the negative electrode collector and a welding area is formed on the negative electrode collector, the length of the first area in the second direction is W1, the length of the welding area in the second direction is W2, W1 and W2 satisfy: 0mm≤W1-W2≤4mm, wherein the first direction is parallel to the width direction of the negative electrode ear, and the second direction is parallel to the length direction of the negative electrode ear.

[0018] In some embodiments, the battery further includes a protection structure, which is bonded to the tab groove and covers a portion of the negative electrode active coating to connect the negative tab and the negative electrode active coating.

[0019] In some embodiments, the protective structure includes protective tape, the size of the protective tape in the first direction is L3, the size of the pole tab groove in the first direction is L4, L3 and L4 satisfy: 2mm≤L3-L4≤4mm, and in the first direction, the minimum distance between the edge of the protective tape and the edge of the pole tab groove is greater than or equal to 1mm, wherein the first direction is parallel to the width direction of the negative pole tab.

[0020] In some embodiments, the dimension of the protective tape in the second direction is W3, and the dimension of the tab groove in the second direction is W4, W3 and W4 satisfy: 2mm≤W3-W4≤6mm, and in the second direction, the minimum distance between the edge of the protective tape and the tab groove is greater than or equal to 1mm, wherein the second direction is parallel to the length direction of the negative tab.

[0021] In some embodiments, the negative electrode ear is provided with an ear glue, and the protective structure includes a protective adhesive paper, and the protective adhesive paper at least partially overlaps with the ear glue;

[0022] In the first direction, the size of the overlapping portion of the protective tape and the tab adhesive is between 1 mm and 4 mm;

[0023] and / or,

[0024] In the second direction, the size of the overlapping portion between the protective tape and the tab glue is between 0.5 mm and 1.5 mm, wherein the first direction is parallel to the width direction of the negative tab.

[0025] In some embodiments, the tab is provided with tab glue, the protective structure includes protective adhesive tape, and in the second direction, there is a gap between the protective structure and the tab glue, and the distance of the gap is between 0 mm and 0.5 mm.

[0026] On the other hand, the present application provides an electronic device, comprising the above-mentioned battery.

[0027] The battery provided in the present application includes a battery cell, and the battery cell includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet, the negative electrode sheet and the separator are wound. The positive electrode sheet includes a positive current collector and a positive electrode active coating coated on both sides of the positive current collector; the first side of the negative electrode sheet is provided with a pole ear groove and a negative electrode ear, and the positive electrode active coating adjacent to the second side of the negative electrode sheet has a first region. Due to the welding of the negative electrode ear and the negative current collector, the activity of the negative electrode active coating on the second side of the negative current collector is affected, thereby resulting in a decrease in the CB value between the first region and the negative electrode active coating on the second side of the negative current collector. Therefore, a recess is provided in the first region, and part of the positive electrode active material is excavated by the recess, thereby reducing the capacity of the positive electrode active material per unit area in the first region, thereby increasing the CB value at the first region, improving the lithium precipitation phenomenon here, and improving the performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0030] Figure 2 A top view of the positive electrode sheet and the negative electrode sheet of the battery provided in the embodiment of the present application;

[0031] Figure 3 A top view of the positive electrode sheet of the battery provided in an embodiment of the present application;

[0032] Figure 4 A front view of the positive electrode sheet of the battery provided in an embodiment of the present application;

[0033] Figure 5 A top view of the negative electrode sheet of the battery provided in an embodiment of the present application;

[0034] Figure 6 A front view of the negative electrode sheet of the battery provided in an embodiment of the present application;

[0035] Figure 7 A front view of another embodiment of the negative electrode sheet of the battery provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 10. Battery cells;

[0038] 100, positive electrode sheet; 110, positive electrode current collector; 120, positive electrode active coating; 130, first region; 131, recess;

[0039] 200, negative electrode sheet; 210, negative electrode current collector; 220, negative electrode active coating; 230, welding area;

[0040] 310, pole ear slot; 320, negative pole ear; 330, pole ear glue;

[0041] 400. Protective tape. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] With the rapid development of lithium-ion battery technology, the industry has higher and higher requirements for the performance of lithium-ion batteries, such as high energy density, super fast charging, high safety, etc. This also puts higher requirements on R&D personnel when designing lithium-ion batteries, and also puts higher requirements on the production and manufacturing of lithium-ion batteries to meet the performance requirements of high energy density, super fast charging, high safety, etc. of lithium-ion batteries. Although more extreme production and manufacturing can improve the high energy density and super fast charging performance of lithium-ion batteries, their safety performance cannot be effectively guaranteed; because of its extreme manufacturing, it will cause the following problems:

[0044] In order to pursue higher energy density, the pole ear is single-sided laser welded, leaving the other side of the pole ear coated with paste to allow it to fully utilize its capacity. However, since some active materials will be destroyed during welding, some active materials in this position will fail during charging and discharging, causing black spot lithium problems, affecting the safety performance of lithium-ion batteries.

[0045] Specifically, the existing lithium-ion battery core adopts a winding structure, and the positive and negative electrodes are coated with paste on both sides. When the positive and negative electrode tabs are connected, the paste can be scraped off by digging a single-sided tab groove to expose the current collector, and the tabs are connected to the current collector by welding. In other words, when welding the tabs, there are active materials on the back of the tabs, but during the welding process, the high temperature generated by the welding equipment, sound waves, etc. will destroy the active materials in the coating, reducing the CB value (the ratio of the negative electrode capacity per unit area to the positive electrode capacity per unit area) here, which will easily lead to the phenomenon of lithium precipitation here, affecting the performance of the battery.

[0046] In view of this, the present application provides a battery, which improves the CB value at the tab by improving the positive electrode sheet in the battery cell. The present application divides a first area at the positive electrode sheet adjacent to the negative tab, and reduces the surface capacity of the positive electrode active material in the first area by digging out the paste in the first area, thereby improving the CB value at this position, and at the same time increasing the potential of the negative electrode sheet at this position, improving the lithium deposition condition at the tab.

[0047] The battery provided in the embodiment of the present application is described below in conjunction with the accompanying drawings. It should be noted that the battery provided in the embodiment of the present application can be a secondary battery, that is, the battery in the embodiment of the present application can be charged and discharged and recycled, and the specific type of the battery can include but is not limited to lithium batteries, etc., and the battery can be used in scenarios including but not limited to electronic products, energy storage devices, transportation vehicles and other electronic devices, such as mobile communication equipment, new energy vehicles, drones, etc., which are not specifically limited in the embodiment of the present application.

[0048] Figure 1 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application; Figure 2 A top view of the positive electrode sheet and the negative electrode sheet of the battery provided in the embodiment of the present application; Figure 3 A top view of the positive electrode sheet of the battery provided in an embodiment of the present application; Figure 4 A front view of the positive electrode sheet of the battery provided in an embodiment of the present application; Figure 5 A top view of the negative electrode sheet of the battery provided in an embodiment of the present application.

[0049] like Figures 1 to 5 As shown, the battery of this embodiment includes a battery cell 10, and the battery cell 10 includes a positive electrode sheet 100, a negative electrode sheet 200 and a separator.

[0050] The positive electrode sheet 100 includes a positive electrode current collector 110, positive and negative electrode ears 320, and a positive electrode active coating 120 disposed on both sides of the positive electrode current collector 110; the negative electrode sheet 200 includes a negative electrode current collector 210, a negative electrode ear 320, and a negative electrode active coating 220 disposed on both sides of the negative electrode current collector 210, a first side of the negative electrode current collector 210 is provided with an electrode ear groove 310, and the negative electrode ear 320 is disposed in the electrode ear groove 310; the diaphragm is disposed between the positive electrode sheet 100 and the negative electrode sheet 200, and the positive electrode sheet 100, the negative electrode sheet 200, and the diaphragm are wound;

[0051] The positive electrode active layer adjacent to the second side of the negative electrode current collector 210 has a first region 130 , the projection of the tab groove 310 on the positive electrode sheet 100 is located in the first region 130 , and the positive electrode active layer in the first region 130 has a recess 131 .

[0052] Applying the technical solution of this embodiment, the battery cell 10 includes a positive electrode sheet 100, a negative electrode sheet 200 and a separator. The positive electrode sheet 100, the negative electrode sheet 200 and the separator are wound. The positive electrode sheet 100 includes a positive electrode collector 110 and a positive electrode active coating 120 coated on both sides of the positive electrode collector 110; the first side of the negative electrode sheet 200 is provided with a pole ear groove 310 and a negative electrode ear 320, and the positive electrode active coating 120 adjacent to the second side of the negative electrode sheet 200 has a first region 130. Due to the welding of the negative electrode ear 320 and the negative electrode collector 210, the activity of the negative electrode active coating 220 on the second side of the negative electrode collector 210 is affected, thereby resulting in a decrease in the CB value (ratio of the negative electrode capacity per unit area to the positive electrode capacity per unit area) between the first region 130 and the negative electrode active coating 220 on the second side of the negative electrode collector 210. Therefore, the recess 131 is provided in the first region 130 , thereby reducing the capacity of the positive electrode active material per unit area in the first region 130 , thereby increasing the CB value in the first region 130 , improving the lithium deposition phenomenon there, and improving the battery performance.

[0053] It should be noted that the above-mentioned “first side of the negative electrode sheet” and “second side of the negative electrode sheet” refer to the two sides in the thickness direction of the negative electrode sheet, rather than the two ends in the length direction or the two ends in the width direction of the negative electrode sheet.

[0054] In addition, the above-mentioned “positive electrode active coating 120 adjacent to the second side of the negative electrode sheet 200” refers to the positive electrode active coating 120 separated from the second side of the negative electrode sheet 200 by only a separator. It should also be noted that the recess 131 is formed by digging out part of the positive electrode active coating in the first area 130.

[0055] Specifically, in some embodiments, the recess includes an opening and / or a groove provided on the positive electrode active coating. The opening or the groove can reduce the amount of the positive electrode active coating 120 in the first region 130, thereby reducing the CB value at the first region 130.

[0056] Furthermore, the recess 131 penetrates the opposite sides of the positive electrode active coating in the thickness direction of the positive electrode sheet, that is, the recess 131 is formed by digging out the positive electrode active coating 120 until the positive electrode current collector 110 is exposed. There may be multiple recesses 131, and the multiple recesses 131 are evenly spaced in the first area.

[0057] For example, when the groove is an opening, there may be a plurality of openings, and the plurality of openings may be arranged in an array. The cross section of the opening may be circular, polygonal, etc., which is not limited in this embodiment.

[0058] For example, when the groove is a slot, there may be a plurality of slots, and the plurality of slots may be arranged at intervals in the first direction. The cross section of the slot may be circular, polygonal, etc., which is not limited in this embodiment.

[0059] In other embodiments, the recess may also include an opening or a groove.

[0060] In other embodiments, the recess may also be formed by digging out all the positive electrode active coating in the first region.

[0061] Furthermore, in some embodiments, the negative electrode tab and the negative electrode current collector are connected by welding, thereby ensuring the stability of the connection between the negative electrode tab and the negative electrode current collector.

[0062] In addition, after the negative electrode ear 320 and the negative electrode current collector 210 are welded, a welding area is formed on the negative electrode ear, and a plurality of welding points are arranged in an array so that there is a spacing between the welding points, reducing the risk of leakage caused by the welding points being too close. At the same time, the number of welding points can be set between 32 and 175. Too few welding points can easily lead to poor welding of the negative electrode ear 320 and the negative electrode current collector 210, which can easily cause a cold weld; too many welding points can easily lead to a large area of ​​damage to the foil at the welding position, which can also easily cause a cold weld. Therefore, the number of welding points can be set between 32 and 175.

[0063] In some embodiments, the height of each welding spot protruding from the surface of the negative electrode ear is between 20 μm and 30 μm, so as to prevent the welding spot from protruding too high and increasing the risk of puncturing the diaphragm.

[0064] In some embodiments, the areas of the multiple welding points account for 75% to 90% of the total area of ​​the welding region, so that the negative electrode tab 320 and the negative electrode collector 210 can be welded firmly and the probability of poor welding between the negative electrode tab 320 and the negative electrode collector 210 can be reduced.

[0065] Figure 6 A front view of the negative electrode sheet of the battery provided in an embodiment of the present application; Figure 7 A front view of another embodiment of the negative electrode sheet of the battery provided in an embodiment of the present application.

[0066] Furthermore, if Figures 2 to 5 As shown, in some embodiments, the first area is in the first direction (the first direction is Figure 2 The x direction in the x direction, that is, the first direction is parallel to the width direction of the negative electrode ear, wherein the width direction of the negative electrode ear refers to the direction in which the two shorter opposite sides of the negative electrode ear are located) is L1, and the length of the negative electrode ear 320 in the first direction is L2, and L1 and L2 satisfy: 0mm≤L1-L2≤4mm, that is, the difference between L1 and L2 is between 0mm-4mm.

[0067] The above structure enables the damaged area of ​​the negative electrode active coating 220 to be covered in the first region 130, thereby ensuring the performance of the battery.

[0068] Exemplarily, specific values ​​that can be used for L1-L2 include but are not limited to 0mm, 1mm, 1.5mm, 2mm, 3mm, 4mm, etc.

[0069] like Figures 2 to 5 As shown, in some embodiments, the negative electrode ear 320 is welded to the negative electrode collector 210 and forms a welding area 230 on the negative electrode collector 210, and the first area is in the second direction (the second direction is Figure 2 The length of the welding area 230 in the y direction, that is, the second direction is parallel to the length direction of the negative electrode ear. ) is W1, and the length of the welding area 230 in the second direction is W2, and W1 and W2 satisfy: 0mm≤W1-W2≤4mm. That is, the difference between W1 and W2 is between 0mm-4mm.

[0070] The above structure enables the damaged area of ​​the negative electrode active coating 220 to be covered in the first region 130, thereby ensuring the performance of the battery.

[0071] Exemplarily, specific values ​​that W1-W2 may adopt include but are not limited to 0 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, etc.

[0072] It should also be noted that in other embodiments not shown in the application, the activity of the positive electrode active coating can also be reduced by pasting protective tape in the first area, thereby increasing the CB value at the pole ear. The size of the protective tape in the first direction is D1, and the length of the pole ear in the first direction is L2. D1 and L2 can satisfy 0mm≤D1-L2≤4mm. The size of the protective tape in the second direction is D2, and the length of the welding area of ​​the pole ear in the second direction is W2. D2 and W2 can satisfy: 0mm≤D2-W2≤4mm. The difference between this embodiment and the above embodiment is that if the protective tape is pasted, the positive electrode active material covered by it will not exert any capacity. Although the above-mentioned lithium plating problem can be solved, it loses the capacity and loses the original meaning of improving the energy density of single-sided laser welding.

[0073] Furthermore, if Figure 6 and Figure 7 As shown, in some embodiments, the battery further includes a protection structure, which is bonded to the tab groove 310 and covers a portion of the negative electrode active coating 220 to connect the negative tab 320 and the negative electrode active coating 220 .

[0074] In the above structure, the protective structure can cover the pole ear groove 310, and then can cover the negative pole ear 320, thereby reducing the probability of the protruding welding point generated by the pole ear welding piercing the diaphragm. The protective structure can also reduce the probability of the active material particles protruding from the edge of the pole ear groove piercing the diaphragm. The protective structure fixes the negative pole ear 320, the negative electrode current collector 210 and the negative electrode active coating 220 together, reducing the probability of the negative pole ear 320 detaching from the negative electrode current collector 210, and at the same time makes the negative pole ear 320 and the negative electrode current collector 210 contact more closely, reducing the contact impedance. The protective structure also avoids friction between the unwelded part of the negative pole ear 320 and the negative electrode current collector 210, and avoids the problem of tearing due to shaking friction at the junction of the pole ear and the negative electrode current collector 210.

[0075] For example, in some embodiments, the protection structure includes a protective tape 400 , and the protective tape 400 is sticky on one side and can bond and fasten the negative electrode ear 320 to the negative electrode active coating 220 .

[0076] like Figure 6 and Figure 7 As shown, the dimension of the protective tape 400 in the first direction is L3, the dimension of the tab groove 310 in the first direction is L4, L3 and L4 satisfy: 2mm≤L3-L4≤4mm, and in the first direction, the minimum distance between the edge of the protective tape 400 and the tab groove 310 is greater than or equal to 1mm.

[0077] The above structure enables the protective tape 400 to cover the tab groove 310, thereby playing a protective role. At the same time, it also avoids the protective tape 400 covering too large an area and covering too much area of ​​the negative electrode active coating 220, thereby affecting the performance of the battery.

[0078] Exemplarily, specific values ​​that can be used for L3-L4 include but are not limited to 2mm, 2.5mm, 3mm, 3.5mm, 4mm, etc.

[0079] In some embodiments, the dimension of the protective tape 400 in the second direction is W3, and the dimension of the tab groove 310 in the second direction is W4, W3 and W4 satisfy: 2mm≤W3-W4≤6mm, and in the second direction, the minimum distance between the edge of the protective tape 400 and the tab groove 310 is greater than or equal to 1mm.

[0080] The above structure enables the protective tape 400 to cover the tab groove 310, thereby playing a protective role. At the same time, it also avoids the protective tape 400 covering too large an area and covering too much area of ​​the negative electrode active coating 220, thereby affecting the performance of the battery.

[0081] Exemplarily, specific values ​​that W3-W4 may adopt include but are not limited to 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, etc.

[0082] like Figure 7 As shown, in some embodiments, a negative electrode ear 320 is provided with an ear glue 330, and the protective structure includes a protective tape 400, which at least partially overlaps with the ear glue 330; in the first direction, the size of the overlapping portion of the protective tape and the ear glue is between 1 mm and 4 mm; in the second direction, the size of the overlapping portion of the protective tape and the ear glue is between 0.5 mm and 1.5 mm.

[0083] In the above structure, the protective structure can fix the negative electrode ear 320 and the ear glue 330, and avoid the problem of tearing due to shaking and friction at the intersection of the negative electrode ear 320 and the negative electrode current collector 210. In addition, the protective structure can protect and fix the right angles on the left and right sides of the ear glue 330, avoid shaking of the ear glue 330 during the production process, and reduce the probability of the ear glue 330 piercing the diaphragm and causing fire.

[0084] It should be noted that the protective structure can be a protective tape 400, and the portion of the protective tape not blocked by the negative electrode tab 320 and the tab glue 330 can be bonded to the diaphragm, thereby reducing the probability of friction between the negative electrode sheet 200 and the diaphragm.

[0085] For example, in the first direction, the size of the protective structure covering the tab glue 330 may include, but is not limited to, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc. In the second direction, the size of the protective structure covering the tab glue 330 may include, but is not limited to, 0.5 mm, 1 mm, 1.5 mm, etc.

[0086] Of course, in some embodiments, the protective structure may not cover the tab glue 330, that is, in the second direction, there is a gap between the protective structure and the tab glue, and the distance of the gap is between 0 mm and 0.5 mm. The above structure can also fix the diaphragm and the negative tab 320 together.

[0087] It should be noted that, in some embodiments, a positive electrode tab may also be provided on the positive electrode sheet 100, and the arrangement of the positive electrode tab may be the same as that of the negative electrode tab. In addition, the positive electrode tab may also be pasted with protective tape to enhance the protection of the positive electrode tab.

[0088] On the other hand, the present application provides an electronic device (not shown in the figure), comprising the above-mentioned battery. Since the battery of the present application has the advantages of low probability of lithium plating and good performance, the electronic device having the battery also has the above-mentioned advantages.

[0089] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0090] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0091] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0092] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0093] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned implementation modes, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned implementation modes can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation modes of the present application.

Claims

1. A battery, characterized in that: The invention comprises a battery cell, wherein the battery cell comprises: A positive electrode sheet, comprising a positive electrode current collector, a positive electrode ear, and a positive electrode active coating disposed on both sides of the positive electrode current collector; A negative electrode sheet, comprising a negative electrode current collector, a negative electrode ear and a negative electrode active coating disposed on at least one side of the negative electrode current collector, wherein a first side of the negative electrode sheet is provided with an electrode ear groove, and the negative electrode ear is disposed in the electrode ear groove; A separator is arranged between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode sheet, the negative electrode sheet and the separator are wound; The positive electrode active coating layer adjacent to the second side of the negative electrode sheet has a first region, the projection of the electrode tab groove on the positive electrode sheet is located within the first region, and the first region has a concave portion.

2. The battery according to claim 1, characterized in that The recess includes an opening and / or a groove.

3. The battery according to claim 1, characterized in that The length of the first region in the first direction is L1, the length of the negative electrode ear in the first direction is L2, and L1 and L2 satisfy: 0mm≤L1-L2≤4mm; and / or, The negative electrode ear is located on the negative electrode collector and forms a welding area on the negative electrode collector, the length of the first area in the second direction is W1, the length of the welding area in the second direction is W2, W1 and W2 satisfy: 0mm≤W1-W2≤4mm, wherein the first direction is parallel to the width direction of the negative electrode ear, and the second direction is parallel to the length direction of the negative electrode ear.

4. The battery according to claim 1, characterized in that The negative electrode ear is connected to the negative electrode sheet by welding to form a welding area on the negative electrode ear. The welding area has a plurality of welding points, which are arranged in an array. The number of the welding points is between 32 and 175.

5. The battery according to claim 4, characterized in that The height of each welding point protruding from the surface of the negative electrode ear is between 20 μm and 30 μm.

6. The battery according to claim 4, characterized in that The total area of ​​the plurality of welding points accounts for 75% to 90% of the total area of ​​the welding region.

7. The battery according to any one of claims 1 to 6, characterized in that The battery further comprises a protection structure, wherein the protection structure is bonded to the tab groove and to a portion of the negative electrode active coating.

8. The battery according to claim 7, characterized in that The protection structure includes protective tape, the size of the protective tape in the first direction is L3, the size of the pole lug groove in the first direction is L4, L3 and L4 satisfy: 2mm≤L3-L4≤4mm, and in the first direction, the minimum distance between the edge of the protective tape and the edge of the pole lug groove is greater than or equal to 1mm, wherein the first direction is parallel to the width direction of the negative pole lug.

9. The battery according to claim 8, characterized in that The size of the protective tape in the second direction is W3, and the size of the tab groove in the second direction is W4, W3 and W4 satisfy: 2mm≤W3-W4≤6mm, and in the second direction, the minimum distance between the edge of the protective tape and the tab groove is greater than or equal to 1mm, wherein the second direction is parallel to the length direction of the negative tab.

10. The battery according to claim 7, characterized in that The negative electrode ear is provided with an ear glue, and the protection structure includes a protective adhesive paper, and the protective adhesive paper at least partially overlaps with the ear glue; In the first direction, the size of the overlapping portion between the protective adhesive tape and the tab adhesive is between 1 mm and 4 mm; and / or, In the second direction, the size of the overlapping portion of the protective tape and the tab glue is between 0.5 mm and 1.5 mm, wherein the first direction is parallel to the width direction of the negative tab.

11. The battery according to claim 7, characterized in that The tab is provided with tab glue, the protection structure includes protective adhesive paper, and in the second direction, there is a gap between the protection structure and the tab glue, and the distance of the gap is between 0 mm and 0.5 mm.

12. An electronic device, characterized in that: A battery comprising any one of claims 1 to 11.

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