Battery and electric equipment

Abstract

The utility model provides a battery and electric equipment, and the battery comprises a pole piece which comprises a main body, and the main body is provided with a first tab and a second tab along the edge of the first main body; after the winding body is formed by winding the pole piece, the orthographic projection of the first tab on the second tab is at least partially overlapped with the second tab along the radial direction of the winding body; a first insulating layer is arranged at the root, close to the main body, of the first tab, and a second insulating layer is arranged at the root of the second tab; in the first direction, the distance between the edge of the first insulating layer and the edge of the first body is a, the distance between the edge of the second insulating layer and the edge of the first body is b, and b is larger than a. According to the battery and the electric equipment provided by the invention, the second insulating layer is arranged at the root part of the second tab, and the distance b between the edge of the second insulating layer and the edge of the first main body is relatively large, so that the root part of the second tab has relatively high bending resistance, and the second tab is more easily bent in an arc shape when being bent; therefore, the condition of inverted insertion of the tabs is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery and an electrical device using the same. Background Art

[0002] A battery may include a single or several bare battery cells (JR). Each bare battery cell may include a cathode plate, a separator, and an anode plate stacked in sequence. Each cathode plate may lead out a cathode tab, and each anode plate may lead out an anode tab. After the stacked cathode plates, separators, and anode plates are wound, the cathode tab and the anode tab are respectively connected to the adapter plates of the top cover.

[0003] During the battery assembly process, the cathode tab and the anode tab may be bent, and there may be a situation where the tabs are inserted in the reverse direction, affecting the battery performance. Summary of the Utility Model

[0004] In view of this, an object of the present application is to provide a battery and an electrical device using the same, so as to at least partially solve the problem that the battery performance is affected due to the reverse insertion of the tabs.

[0005] Based on the above object, a first aspect of the present application provides a battery, including: a pole piece, the pole piece includes a main body, and an edge of the main body along the winding direction is defined as a first main body edge; at least two tabs are arranged along the first main body edge of the main body, and the at least two tabs include a first tab and a second tab; after the pole piece is wound to form a winding body, along the radial direction of the winding body, the orthographic projection of the first tab on the second tab at least partially coincides with the second tab; a first insulating layer is arranged at the root of the first tab close to the main body, and a second insulating layer is arranged at the root of the second tab; along a first direction, the distance between the edge of the first insulating layer away from the main body and the adjacent first main body edge is a, and the distance between the edge of the second insulating layer away from the main body and the adjacent first main body edge is b, and b is greater than a; the first direction is perpendicular to the winding direction.

[0006] Optionally, the dimension of the tab along the winding direction is defined as the width of the tab; the width of at least a part of the first tab is greater than the width of the second tab.

[0007] Optionally, the difference between b and a is 2 mm to 7 mm.

[0008] Optionally, along the thickness direction of the pole piece, the orthographic projection of the second tab is a rectangle, and one of the short sides of the rectangle is close to the main body.

[0009] Optionally, along the thickness direction of the pole piece, the orthographic projection of the first tab is a trapezoid, and the upper base of the trapezoid is away from the main body.

[0010] Optionally, along the first direction, the second insulating layer includes an equal-height region and a guiding region. The distance between the edge of the equal-height region away from the main body and the adjacent first main body edge is b1, and b1 is equal to a. In the second insulating layer, at least the materials of the equal-height region and the first insulating layer are the same.

[0011] Optionally, the materials of the first insulating layer and the second insulating layer both include ceramic materials.

[0012] Optionally, at least two first tab groups are arranged at intervals along the first main body edge of the main body, and at least one second tab is arranged at intervals between two adjacent first tab groups. Each first tab group includes at least one first tab.

[0013] Optionally, along the radial direction of the winding body, the tab located in the outermost layer is the first tab.

[0014] Based on the same inventive concept, the second aspect of the present application also provides an electrical device, including the battery as described in the first aspect.

[0015] As can be seen from the above, in the battery and the electrical device provided by the present application, the first tab and the second tab are arranged along the winding direction on the main body of the electrode sheet, the second insulating layer is arranged at the root of the second tab, and the distance b between the edge of the second insulating layer away from the main body and the adjacent first main body edge is relatively large, so that the root of the second tab has strong anti-bending ability, and the second tab is more likely to form an arc-shaped bend when bent, thereby avoiding the situation of the tab being inserted backwards.

[0016] At the same time, when the first tab is bent, since the first tab and the second tab at least partially overlap, the second tab can play a guiding role for the first tab, so that the first tab also forms an arc-shaped bend. At the same time, the first insulating layer is arranged at the root of the first tab, and the distance a between the edge of the first insulating layer away from the main body and the adjacent first main body edge is relatively small, which helps to reduce the gap between the tabs on both sides of the first insulating layer, thereby avoiding the situation of delamination of the connected tabs. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0018] Figure 1 It is a partial schematic diagram of the electrode sheet of the battery in the embodiment of the present application when unfolded;

[0019] Figure 2 This is a partial schematic view of the wound body formed after winding the electrode sheet of the battery according to the embodiment of the present application;

[0020] Figure 3 This is a partial schematic view of the first structure of the electrode sheet of the battery according to the embodiment of the present application;

[0021] Figure 4 is Figure 3 an enlarged schematic view of part A in

[0022] Figure 5 This is a partial schematic view of the second structure of the electrode sheet of the battery according to the embodiment of the present application;

[0023] Figure 6 This is a partial schematic view of the third structure of the electrode sheet of the battery according to the embodiment of the present application.

[0024] Explanation of reference numerals:

[0025] 100, electrode sheet; 10, main body; 11, first main body edge; 20, tab; 21, first tab; 22, second tab; 23, first tab group; 30, first insulating layer; 40, second insulating layer; 41, equal height region; 42, guiding region;

[0026] 200, wound body. Detailed implementation manners

[0027] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0028] It should be noted that: unless otherwise specifically stated, the relative arrangements, numerical expressions and numerical values of the components described in these embodiments do not limit the scope of the present application.

[0029] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0030] The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present application and its application or use.

[0031] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the ordinary meanings understood by those of ordinary skill in the art to which the present application belongs. The "first", "second" and similar terms used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0032] In some embodiments, taking the negative electrode tab of the battery as an example, a negative electrode tab is led out from one side edge of the negative electrode along the length direction. When the positive electrode tab, the separator and the negative electrode tab are stacked and wound to form a bare cell winding body, the negative electrode tabs can be connected to each other by ultrasonic welding, and the negative electrode tabs connected to each other are then laser welded to the adapter plate. However, as the capacity of the energy storage wound square shell battery gradually increases, the number of layers of the cell electrode tabs (including the positive electrode tab and the negative electrode tab) included in the bare cell in the battery and the number of cell electrode tabs (including the positive electrode tab and the negative electrode tab) led out from the cell electrode tabs increase. During the battery assembly process, it is very likely that the electrode tab will be inserted backwards among a large number of cell electrode tabs, that is, the cell electrode tab will be inserted into the end face of the bare cell winding body, which may cause an internal short circuit of the battery and thus trigger a safety accident.

[0033] The applicant's research found that when the negative electrode tab is inserted backwards, the negative electrode tab often bends reversely at its root. If the bending of the negative electrode tab at the root can be prevented, the problem of internal short circuit of the battery caused by the reverse insertion of the electrode tab can be avoided.

[0034] In view of this, as Figure 1 , Figure 1 shows a partial schematic view of the electrode tab 100 of the battery when unfolded. The embodiments of the present application provide a battery, including: an electrode tab 100, the electrode tab 100 includes a main body 10, and an edge of the main body 10 along the winding direction (such as Figure 1 the V direction in

[0035] is defined as the first main body edge 11; at least two electrode tabs 20 are arranged along the first main body edge 11 of the main body 10, and the at least two electrode tabs 20 include a first electrode tab 21 and a second electrode tab 22. Figure 2 , Figure 2It shows a partial schematic view of the electrode tab 100 of the battery forming a wound body 200 after winding. After winding the electrode tab 100 to form the wound body 200, along the radial direction of the wound body 200 (such as Figure 2 the W direction in

[0036] ), the positive projection of the first electrode tab 21 on the second electrode tab 22 coincides with at least a part of the second electrode tab 22. Figure 3 , Figure 3 It shows a partial schematic view of the first structure of the electrode tab 100 of the battery. A first insulating layer 30 is provided at the root of the first electrode tab 21 close to the main body 10, and a second insulating layer 40 is provided at the root of the second electrode tab 22; along the first direction (such as Figure 3 the U direction in

[0037] ), the distance between the edge of the first insulating layer 30 far from the main body 10 and the adjacent first main body edge 11 (that is, the height of the first insulating layer 30 extending from the root of the first electrode tab 21 to the end, hereinafter referred to as the extension height of the first insulating layer 30) is a, and the distance between the edge of the second insulating layer 40 far from the main body 10 and the adjacent first main body edge 11 (that is, the extension height of the second insulating layer 40) is b, and b is greater than a; the first direction is perpendicular to the winding direction.

[0038] Exemplarily, the first main body edge 11 can be the long side edge of the main body 10.

[0039] Exemplarily, the foil thickness of the main body 10, the foil thickness of the first electrode tab 21, and the foil thickness of the second electrode tab 22 are the same.

[0040] Exemplarily, the main body 10 and the electrode tab 20 can be integrally formed and connected, and the electrode tab 100 can be an integrally punched and formed structure.

[0041] Exemplarily, along the thickness direction of the electrode tab 100, the electrode tab 100 can include a foil (for example, a conductive metal layer) and a structural layer formed on the surface of the foil (for example, the first insulating layer 30 and the second insulating layer 40).

[0042] Exemplarily, the current-carrying capacities of the first electrode tab 21 and the second electrode tab 22 both meet the operating conditions.

[0043] It can be understood that when the thickness of the material layer increases, its bending resistance ability also increases accordingly. In this embodiment, the regions of the pole piece 100 covered by the first insulating layer 30 and the second insulating layer 40 have a larger thickness, so the bending resistance ability is stronger. When assembling the pole piece 100, since the root of the pole ear 20 is covered by the first insulating layer 30 and the second insulating layer 40, the root region of the pole ear 20 is not easily bent, which can reduce the occurrence of reverse insertion of the pole ear, thereby preventing internal short circuit of the battery and avoiding potential safety hazards of the battery.

[0044] Combined with Figure 3 It can be known that along the first direction, the higher the extension height of the first insulating layer 30 and the second insulating layer 40, the smaller the probability of reverse insertion of the pole ear. However, combined with the foregoing content, it can be seen that a plurality of corresponding pole ears 20 need to be welded to form a whole, and the regions of the pole ear 20 covered by the first insulating layer 30 or the second insulating layer 40 cannot be welded. Therefore, in order to ensure reliable connection between a plurality of corresponding pole ears 20, in this embodiment, both the first insulating layer 30 and the second insulating layer 40 are provided at the root of the pole ear 20.

[0045] At the same time, since both the first insulating layer 30 and the second insulating layer 40 have a certain thickness, if the extension heights of both the first insulating layer 30 and the second insulating layer 40 are relatively high, then after the pole piece 100 is wound, there will be a large gap between adjacent pole ears 20 along the radial direction of the winding body 200, which is not conducive to maintaining reliable connection between the pole ears 20 and is prone to pole ear delamination. Therefore, in this embodiment, making the extension height of the first insulating layer 30 on the first pole ear 21 relatively low helps to reduce the interval gap between adjacent pole ears 20 on both sides in the thickness direction of the first insulating layer 30, so as to reduce the probability of pole ear delamination. At the same time, after the pole piece 100 forms the winding body 200, when the first pole ear 21 is bent, since the first pole ear 21 and the second pole ear 22 at least partially overlap, the second pole ear 22 can guide the bending of the first pole ear 21, so that the first pole ear 21 also forms an arc-shaped bend, which helps to avoid the occurrence of reverse insertion of the first pole ear 21.

[0046] Such as Figure 4 , Figure 4 shows Figure 3 an enlarged schematic view of part C in Figure 4 . In some embodiments, the dimension of the pole ear 20 along the winding direction (such as Figure 4 the V direction in

[0047] is defined as the width of the pole ear 20; the width of at least part of the first pole ear 21 is greater than the width of the second pole ear 22.

[0047] Exemplarily, the width of the first pole ear 21 along the first direction (such as Figure 4The width of the first pole lug 21 at different positions (in the U direction) is different, wherein the width of some positions of the first pole lug 21 may be less than or equal to the width of the second pole lug 22, and the width of other positions may be greater than the width of the second pole lug 22; or, the width of each position of the first pole lug 21 may be greater than the width of the second pole lug 22.

[0048] Designing the width of the first pole lug 21 to be larger can, on the one hand, further improve the current flow capacity of the first pole lug 21, that is, the flow area of the first pole lug 21 is larger than the flow area of the second pole lug 22; on the other hand, it can also increase the weldable area between the first pole lug 21 and the second pole lug 22, which helps to achieve a reliable connection between the first pole lug 21 and the second pole lug 22, and further avoid stratification of the connected pole lugs 20.

[0049] It should also be noted that the reason why the width of the first pole tab 21 is designed to be greater than the width of the second pole tab 22 in the present application is that the first pole tab 21 is easier to bend along the first direction due to the low extension height of the first insulating layer 30. Therefore, even if the width of the first pole tab 21 is large, the first pole tab 21 will not be difficult to bend. As for the second pole tab 22, since the extension height of the second insulating layer 40 is high, if the width of the second pole tab 22 is large, the second pole tab 22 may not be easy to bend in an arc shape, which may have an adverse effect on the subsequent battery assembly.

[0050] In some embodiments, the difference between b and a is 2 mm to 7 mm.

[0051] Exemplarily, the size of a may range from 1 mm to 3 mm, and the size of b may range from 5 mm to 8 mm.

[0052] If the difference between b and a is too large, that is, the size of b is too large, the second insulating layer 40 may extend too high on the second pole tab 22, which may result in a smaller weldable area between different second pole tabs 22 or between the second pole tab 22 and the first pole tab 21, which may have an adverse effect on the connection reliability between the pole tabs 20. If the difference between b and a is too small, in one case, the size of b is too small, which may cause the second pole tab 22 to be bent near the root, and the pole tab may be easily inserted upside down; in another case, the size of a is too large, which may cause a larger gap between adjacent pole tabs 20 on both sides of the thickness direction of the first insulating layer 30, and the pole tabs may be easily delaminated.

[0053] Therefore, in this embodiment, the difference between b and a is limited to avoid the above situation.

[0054] In addition to the different widths of the first electrode tab 21 and the second electrode tab 22 , the shapes of the first electrode tab 21 and the second electrode tab 22 may also be different.

[0055] As Figure 4 , in some embodiments, along the thickness direction of the electrode tab 100 (such as the W direction in Figure 4 ), the orthographic projection of the second tab 22 is a rectangle, and one of the short sides of the rectangle is close to the main body 10.

[0056] Exemplarily, the length H of the short side of the rectangle is:

[0057] H = Q * C * Z1 / (T * Y);

[0058] Wherein, Q is the capacity of the battery, C is the test rate, Z1 is the first modification coefficient (Z1 can be 1.5 to 2), T is the foil thickness of the electrode tab 100, and Y is the overcurrent coefficient.

[0059] Exemplarily, the end of the second tab 22 is provided with a chamfered corner (that is, the angle formed by the short side and the long side of the rectangle far from the main body 10 is a chamfered corner), and the radius of the chamfered corner is 1 mm to 3 mm.

[0060] Exemplarily, the root of the second tab 22 is provided with a chamfered corner (that is, the angle formed by the long side of the rectangle and the first main body edge 11 is a chamfered corner), and the radius of the chamfered corner is 1 mm to 3 mm.

[0061] In this embodiment, designing the second tab 22 as a rectangle with a uniform width and the long side parallel to the first direction can make the second tab 22 have a smaller width. Combining with the second insulating layer 40 with a relatively high extension height provided at the root of the second tab 22, the second tab 22 can be more easily formed into an arc-shaped bend when bent.

[0062] As Figure 4 , in some embodiments, along the thickness direction of the electrode tab 100, the orthographic projection of the first tab 21 is a trapezoid, and the upper base of the trapezoid is far from the main body 10.

[0063] Exemplarily, the orthographic projection of the first tab 21 is an isosceles trapezoid.

[0064] Exemplarily, the length A of the upper base of the trapezoid is:

[0065] A = H * Z2

[0066] Wherein, H is the length of the short side of the above rectangle, and Z2 is the second modification coefficient (Z2 can be 0.8 to 1.2).

[0067] The length B of the lower base of the trapezoid is:

[0068] B = A * Z3

[0069] Wherein, A is the length of the upper base of the above trapezoid, and Z3 is the third modification coefficient (Z3 can be 1.1 to 2.5).

[0070] Exemplarily, the end of the first tab 21 is provided with a chamfer (i.e., the angle between the upper base of the trapezoid and the waist is a rounded angle), and the radius of the chamfer is 1 mm to 3 mm.

[0071] Exemplarily, the root of the first tab 21 is provided with a chamfer (i.e., the angle between the waist of the trapezoid and the edge of the first main body 11 is a rounded angle), and the radius of the chamfer is 1 mm to 3 mm.

[0072] In this embodiment, the first tab 21 is designed as a trapezoid with a larger width at the root and a smaller width at the top. On the one hand, it helps to increase the current-carrying area of the first tab 21. On the other hand, it can also reduce the possibility of the first tab 21 being bent from the root and avoid the situation of the tab being inserted backwards.

[0073] Such as Figure 4 , in some embodiments, along the first direction (such as Figure 4 the U direction in

[0074] Exemplarily, the materials of the equal-height region 41 and the guiding region 42 can be the same or different.

[0075] Exemplarily, the material of the guiding region 42 can be a ceramic material or a hot melt adhesive.

[0076] In this embodiment, since the extension height b1 of the equal-height region 41 is the same as the extension height a of the first insulating layer 30, when preparing the electrode sheet 100, the equal-height region 41 and the first insulating layer 30 can be formed simultaneously on the foil of the electrode sheet 100, that is, the equal-height region 41 and the first insulating layer 30 are formed by using the same material and process.

[0077] After forming the equal-height region 41, the guiding region 42 is formed on the second tab 22, so that the equal-height region 41 and the guiding region 42 form the second insulating layer 40.

[0078] Of course, the equal-height region 41, the guiding region 42 and the first insulating layer 30 can also be formed simultaneously, that is, the equal-height region 41, the guiding region 42 and the first insulating layer 30 are formed by using the same material and process, which is not limited herein.

[0079] In some embodiments, the materials of the first insulating layer 30 and the second insulating layer 40 both include ceramic materials.

[0080] Exemplarily, the materials of the first insulating layer 30 and the second insulating layer 40 can both be ceramic materials.

[0081] The ceramic material not only has strong insulating ability, but also can make the area covered by the ceramic material have greater rigidity, which can effectively avoid the situation of reverse insertion of the tab.

[0082] Such as Figure 3 , in some embodiments, at least two first tab groups 23 are arranged at intervals along the first body edge 11 of the main body 10, at least one second tab 22 is arranged at intervals between two adjacent first tab groups 23, and each first tab group 23 includes at least one first tab 21.

[0083] Figure 3 It is the structure of the electrode sheet 100 when the first tab group 23 includes one first tab 21 and one second tab 22 is arranged at intervals between two adjacent first tab groups 23.

[0084] Such as Figure 5 , Figure 5 Shows a partial schematic diagram of the second structure of the electrode sheet 100 of the battery, that is, the structure of the electrode sheet 100 when the first tab group 23 includes one first tab 21 and two second tabs 22 are arranged at intervals between two adjacent first tab groups 23.

[0085] Such as Figure 6 , Figure 6 Shows a partial schematic diagram of the third structure of the electrode sheet 100 of the battery, that is, the structure of the electrode sheet 100 when the first tab group 23 includes two first tabs 21 and two second tabs 22 are arranged at intervals between two adjacent first tab groups 23.

[0086] According to different winding methods and structural requirements, the first tabs 21 and the second tabs 22 of the electrode sheet 100 are arranged in a staggered manner in different orders, so that after the electrode sheet 100 is wound to form the winding body 200, each first tab 21 can at least partially coincide with the corresponding second tab 22, so that the first tab 21 can form an arc-shaped bend under the guiding action of the second tab 22, so as to avoid the situation of reverse insertion of the tabs 20 on the electrode sheet 100.

[0087] Such as Figure 2 , in some embodiments, along the radial direction of the winding body 200, the tab 20 located in the outermost layer is the first tab 21.

[0088] After the pole piece 100 is wound to form the wound body 200, if the first pole ear 21 is located on the outermost layer, the first pole ear 21 can be welded to the adapter piece. Since the extension height of the first insulating layer 30 on the first pole ear 21 is relatively low, that is, the first pole ear 21 has a large weldable area, the connection between the first pole ear 21 and the adapter piece can be made more reliable, which helps to improve the battery performance. At the same time, since the weldable area of the first pole ear 21 is large, the welding difficulty between the first pole ear 21 and the adapter piece can also be reduced, facilitating the welding operation.

[0089] Based on the same inventive concept, in combination with the descriptions of the batteries in the above various embodiments, this embodiment provides an electrical device, which has the corresponding technical effects of the batteries in the above various embodiments, and will not be elaborated herein.

[0090] An electrical device includes the battery as described in the above various embodiments.

[0091] It should be noted that some embodiments of the present application are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the above embodiments and still achieve the desired results. Additionally, the processes depicted in the figures do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0092] The various embodiments in the present application are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0093] The description of the present application is given for purposes of illustration and description, and is not intended to be exhaustive or to limit the present application to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The selection and description of embodiments are for the purpose of better illustrating the principles and practical applications of the present application, and enabling those of ordinary skill in the art to understand the present application and thus design various embodiments with various modifications suitable for specific purposes.

[0094] Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is only exemplary, and is not intended to imply that the scope of the present application is limited to these examples; under the concept of the present application, the technical features between the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

[0095] Although the present application has been described in connection with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description.

[0096] Embodiments of the present application are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the present application. Accordingly, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. A battery, characterized in that, Comprising: A pole piece, the pole piece includes a main body, and an edge of the main body along the winding direction is defined as a first main body edge; At least two tabs are arranged along the first main body edge of the main body, and the at least two tabs include a first tab and a second tab; after winding the pole piece to form a wound body, along the radial direction of the wound body, the orthographic projection of the first tab on the second tab at least partially coincides with the second tab; A first insulating layer is arranged at the root of the first tab close to the main body, and a second insulating layer is arranged at the root of the second tab; Along a first direction, the distance between the edge of the first insulating layer away from the main body and the adjacent first main body edge is a, and the distance between the edge of the second insulating layer away from the main body and the adjacent first main body edge is b, and b is greater than a; The first direction is perpendicular to the winding direction.

2. The battery according to claim 1, wherein, The dimension of the tab along the winding direction is defined as the width of the tab; the width of at least a part of the first tab is greater than the width of the second tab.

3. The battery according to claim 1, characterized in that, The difference between b and a is 2 mm to 7 mm.

4. The battery according to claim 1, characterized in that, Along the thickness direction of the pole piece, the orthographic projection of the second tab is a rectangle, and one of the short sides of the rectangle is close to the main body.

5. The battery according to claim 1, characterized in that, Along the thickness direction of the pole piece, the orthographic projection of the first tab is a trapezoid, and the upper base of the trapezoid is away from the main body.

6. The battery according to claim 1, characterized in that, Along the first direction, the second insulating layer includes an equal-height region and a guiding region, and the distance between the edge of the equal-height region away from the main body and the adjacent first main body edge is b1, and b1 is equal to a; In the second insulating layer, at least the material of the equal-height region is the same as the material of the first insulating layer.

7. The battery according to claim 1, characterized in that, The materials of the first insulating layer and the second insulating layer both include ceramic materials.

8. The battery according to claim 1, wherein, At least two first tab groups are arranged at intervals along the first main body edge of the main body, and at least one second tab is arranged at intervals between adjacent two first tab groups, and each first tab group includes at least one first tab.

9. The battery according to claim 1, wherein Along the radial direction of the wound body, the tab located in the outermost layer is the first tab.

10. An electrical device, characterized in that, Including the battery according to any one of claims 1 to 9.

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