Diaphragm, battery and electric equipment

Abstract

The utility model relates to a diaphragm, a battery and electric equipment, the diaphragm is applied to the battery, the diaphragm comprises a diaphragm body, the diaphragm body comprises a flat area and a non-flat area located on at least one side of the flat area in a first direction; an extension layer is arranged on the non-flat area and is used for filling a gap between a positive plate and a negative plate in a battery cell of the battery. The gaps between the battery pole pieces are filled with the diaphragm, so that more electrolyte can be accommodated, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of battery equipment, and in particular to a diaphragm, a battery and an electrical device. Background Art

[0002] At present, the diaphragm is an important component in lithium batteries. The diaphragm is placed between the positive and negative electrodes of lithium batteries to isolate the positive and negative electrodes and prevent the risk of short circuit. During the production process, the diaphragm is put into the winding or lamination process. The positive and negative electrodes are placed on both sides of the diaphragm respectively, and then the winding or lamination process is carried out. The pores in the diaphragm can be used to store electrolyte.

[0003] In the related art, the battery diaphragm mostly adopts a flat diaphragm, and as the battery energy density requirements become higher and higher, the thickness of the diaphragm as an auxiliary material is getting thinner and thinner, which will lead to a weakening of the diaphragm's liquid storage capacity, thereby affecting the battery's cycle life. Utility Model Content

[0004] The present application is proposed to solve the above problems. According to one aspect of the present application, a diaphragm is provided. The diaphragm includes a diaphragm body, the diaphragm body includes a flat region and a non-flat region located on at least one side of a first direction of the flat region; an extension layer is provided on the non-flat region, and the extension layer is used to fill the gap between the positive electrode sheet and the negative electrode sheet in the battery cell of the battery.

[0005] Exemplarily, the uneven region includes a first uneven region and a second uneven region respectively arranged on both sides of the flat region in a first direction; the extension layer includes a first extension layer arranged on the first uneven region and a second extension layer arranged on the second uneven region, and the first extension layer and the second extension layer are both used to fill the gap between the positive electrode sheet and the negative electrode sheet in the battery cell of the battery.

[0006] Exemplarily, the first extension layer includes a first positive extension layer and a first negative extension layer, and the first positive extension layer and the first negative extension layer are respectively located on both sides of the thickness direction of the first non-flat region; the second extension layer includes a second positive extension layer and a second negative extension layer, and the second positive extension layer and the second negative extension layer are respectively located on both sides of the first direction of the second non-flat region.

[0007] Exemplarily, the widths of the first positive extension layer, the first negative extension layer, the second positive extension layer, and the second negative extension layer are all greater than 0.1 mm.

[0008] Exemplarily, the thickness of the first positive extension layer, the first negative extension layer, the second positive extension layer, and the second negative extension layer is greater than 10 um.

[0009] Exemplarily, the membrane body, the first extension layer and the second extension layer are made of polyolefin porous material.

[0010] According to another aspect of the present application, a battery is provided, which includes a plurality of battery cells, each of which includes a positive electrode sheet, a negative electrode sheet and the above-mentioned separator, wherein the separator is located between the positive electrode sheet and the negative electrode sheet; the width of the separator is greater than the width of the negative electrode sheet, and the width of the negative electrode sheet is greater than the width of the positive electrode sheet.

[0011] Exemplarily, the positive electrode sheet includes a positive electrode active coating and a positive electrode current collector, and the positive electrode active coating is arranged on both sides of the thickness direction of the positive electrode current collector; the negative electrode sheet includes a negative electrode active coating and a negative electrode current collector, and the negative electrode active coating is arranged on both sides of the thickness direction of the negative electrode current collector; the two sides of the flat area of ​​the diaphragm in the thickness direction are in contact with the positive electrode active coating and the negative electrode active coating, respectively.

[0012] Exemplarily, the first negative electrode extension layer and the second negative electrode extension layer of the separator are respectively filled on both sides of the width direction of the negative electrode sheet, and the first positive electrode extension layer and the second positive electrode extension layer of the separator are respectively filled on both sides of the width direction of the positive electrode sheet.

[0013] Exemplarily, the battery cell also includes a positive electrode filling layer and a negative electrode filling layer, the positive electrode filling layer is filled between two adjacent first positive extension layers and two adjacent second positive extension layers, and the positive electrode filling layer is in contact with the positive electrode sheet; the negative electrode filling layer is filled between two adjacent first negative extension layers and two adjacent second negative extension layers, and the negative electrode filling layer is in contact with the negative electrode sheet.

[0014] Exemplarily, the thickness of the positive electrode filling layer is greater than the thickness of the negative electrode filling layer.

[0015] According to another aspect of the present application, there is provided an electrical device, the electrical device comprising the above-mentioned battery.

[0016] The diaphragm in the present application is provided with a flat area and a non-flat area, and the non-flat area is thickened by the first extension layer and the second extension layer. The first extension layer and the second extension layer of the thickened part fill the gap between the positive and negative electrodes of the battery. After the diaphragm is wound, more electrolyte can be stored. Compared with the flat diaphragm, the liquid storage capacity can be improved, thereby improving the cycle life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0018] Figure 1 A schematic diagram of a flat diaphragm after unfolding in the related art is shown.

[0019] Figure 2 A schematic diagram of the membrane after unfolding in an embodiment of the present application is shown.

[0020] FIG. 3( a ) and FIG. 3( b ) are schematic diagrams showing a cross section of a diaphragm in the first embodiment of the present application.

[0021] Figure 4 A cross-sectional schematic diagram of the separator and the positive and negative electrodes of the battery after winding in Example 1 of the present application is shown.

[0022] Figure 5 A cross-sectional schematic diagram of the separator and the positive and negative electrodes of the battery after winding in Example 2 of the present application is shown.

[0023] Figure numerals: 1. diaphragm body; 11. flat area; 12. first non-flat area; 13. second non-flat area; 2. first extension layer; 21. first positive electrode extension layer; 22. first negative electrode extension layer; 3. second extension layer; 31. second positive electrode extension layer; 32. second negative electrode extension layer; 4. positive electrode sheet; 41. positive electrode current collector; 42. positive electrode active coating; 5. negative electrode sheet; 51. negative electrode current collector; 52. negative electrode active coating; 6. positive electrode filling layer; 7. negative electrode filling layer. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0025] like Figure 1 As shown, the diaphragm used in the related art is a flat diaphragm. As the battery energy density requirement becomes higher and higher, the thickness of the diaphragm as an auxiliary material is getting thinner and thinner. When the battery thickness is insufficient, the flat diaphragm has limited liquid storage capacity during use, which will affect the cycle life of the battery.

[0026] Embodiment 1

[0027] like Figure 2 As shown in Figure 3, an embodiment of the present application provides a diaphragm for use in a battery, wherein the diaphragm includes a diaphragm body 1, wherein the diaphragm body 1 includes a flat region 11 and a non-flat region located on at least one side of the first direction of the flat region 11; an extension layer is provided on the non-flat region, and the extension layer is used to fill the gap between the positive electrode sheet and the negative electrode sheet in the battery cell.

[0028] Exemplarily, the uneven region includes a first uneven region 12 and a second uneven region 13 respectively arranged on both sides of the flat region in a first direction. The extension layer includes a first extension layer 2 arranged on the first uneven region 12 and a second extension layer 3 arranged on the second uneven region 13, and the first extension layer 2 and the second extension layer 3 are used to fill the gap between the positive electrode sheet and the negative electrode sheet in the battery cell.

[0029] The diaphragm in the present application is provided with a flat area 11 and a non-flat area. The non-flat area is thickened by the first extension layer 2 and the second extension layer 3. The thickened first extension layer 2 and the second extension layer 3 fill the gap between the positive and negative electrodes of the battery. After winding or lamination, more electrolyte can be stored. Compared with a flat diaphragm, the liquid storage capacity can be improved, thereby improving the cycle life of the battery.

[0030] Exemplarily, the total width of the diaphragm body 1 is w, and the widths of the first uneven region 12 and the second uneven region 13 are a and b, respectively, wherein a and b may be the same or different in size.

[0031] As shown in FIG. 3( a ), illustratively, the first extension layer 2 includes a first positive extension layer 21 and a first negative extension layer 22 , and the first positive extension layer 21 and the first negative extension layer 22 are respectively located on both sides of the first uneven region 12 in the thickness direction.

[0032] As shown in FIG3(b), exemplarily, the second extension layer 3 includes a second positive extension layer 31 and a second negative extension layer 32, and the second positive extension layer 31 and the second negative extension layer 32 are respectively located on both sides of the first direction of the second uneven region 13. The total width of the diaphragm body 1 is H, wherein the thickness of the first positive extension layer 21 and the second positive extension layer 31 is c, and the thickness of the first negative extension layer 22 and the second negative extension layer 32 is d, wherein the sizes of c and d may be the same or different. Exemplarily, the width of the first positive extension layer 21 and the first negative extension layer 22 is less than or equal to a, and the width of the second positive extension layer 31 and the second negative extension layer 32 is less than or equal to b.

[0033] For example, the edges of the first extension layer 2 and the second extension layer 3 in the first direction may be flush with the edge of the diaphragm body 1 , or may not be flush with each other, and both can achieve filling of the above-mentioned gap.

[0034] The first direction in the embodiment of the present application is the width direction of the flat area 11, that is, the width direction of the unfolded opening of the diaphragm in the embodiment of the present application. The first extension layer 2 and the second extension layer 3 can be integrated with the diaphragm body 1, and the first extension layer 2 and the second extension layer 3 can also be added to the original flat diaphragm by bonding, coating, etc. The first extension layer 2, the second extension layer 3 and the diaphragm body 1 are prepared by sampling the same material, or different materials can be used. However, the first extension layer 2, the second extension layer 3 and the diaphragm body 1 are all polyolefin porous materials. Specifically, it can be selected according to actual conditions, such as polyethylene porous materials and polypropylene porous materials, etc. In addition, porous ceramic materials can also be used as the materials of the first extension layer 2, the second extension layer 3 and the diaphragm body 1.

[0035] Exemplarily, the width of the first positive extension layer 21 is greater than the width of the first negative extension layer 22, and the width of the second positive extension layer 31 is greater than the width of the second negative extension layer 32. And the widths of the first positive extension layer 21, the first negative extension layer 22, the second positive extension layer 31, and the second negative extension layer 32 are all greater than 0.1 mm. The widths of the first positive extension layer 21 and the second positive extension layer 31 can be the same or different, and the widths of the first negative extension layer 22 and the second negative extension layer 32 can be the same or different. A suitable width can be set according to the actual needs of the battery.

[0036] The widths of the positive and negative electrodes in the battery are inconsistent. Generally speaking, the width of the negative electrode is greater than that of the positive electrode. In some cases, the length of the negative electrode is also greater than that of the positive electrode. The portion of the negative electrode that is beyond the positive electrode in the length and width directions will produce a gap during the winding process, which is generally referred to as an overhang gap. This design is mainly to ensure the safety of lithium deposition in the battery. Therefore, in this case, the portion that needs to be filled in the width direction of the positive electrode is also wider. Therefore, in the embodiment of the present application, the width of the first positive extension layer 21 is greater than the width of the first negative extension layer 22, and the width of the second positive extension layer 31 is greater than the width of the second negative extension layer 32. The width is limited to be greater than 0.1 mm in order to ensure that the first extension layer 2 and the second extension layer 3 have sufficient volume, so as to have the effect of indicating the liquid storage capacity. Preferably, the thickness of the first extension layer 2 and the second extension layer 3 is greater than or equal to 0.3 mm.

[0037] Exemplarily, the thickness of the first positive extension layer 21, the first negative extension layer 22, the second positive extension layer 31 and the second negative extension layer 32 is greater than 10um. The first extension layer 2 and the second extension layer 3 have sufficient thickness to fill the gaps at the edges of the positive and negative electrode sheets. Preferably, the thickness of the first positive extension layer 21, the first negative extension layer 22, the second positive extension layer 31 and the second negative extension layer 32 is greater than or equal to 40um.

[0038] The positive electrode sheet, negative electrode sheet and diaphragm in the battery are wound or stacked when in use, so that the first extension layer 2 and the second extension layer 3 in the uneven area of ​​the diaphragm fill the gap between the positive and negative electrodes of the battery, which can store more electrolyte. Compared with a flat diaphragm, the liquid storage capacity can be improved, thereby increasing the cycle life of the battery.

[0039] The embodiment of the present application further provides a battery, the battery comprising a plurality of battery cells, the battery cells comprising a positive electrode sheet 4, a negative electrode sheet 5 and the above-mentioned diaphragm, the diaphragm being located between the positive electrode sheet 4 and the negative electrode sheet 5. The width of the diaphragm is greater than the width of the negative electrode sheet 5, and the width of the negative electrode sheet 5 is greater than the width of the positive electrode sheet 4.

[0040] Among them, the part of the negative electrode sheet 5 that exceeds the positive electrode sheet 4 in the length and width directions will produce a gap during the winding or stacking process. The gap is filled by the first extension layer 2 and the second extension layer 3 in the above-mentioned diaphragm, which can improve the storage capacity of the electrolyte and thus improve the cycle life of the battery.

[0041] like Figure 4 As shown, a schematic cross-sectional view of the separator and the positive and negative electrodes of the battery after winding in the embodiment of the present application. For example, the positive electrode sheet 4 includes a positive electrode active coating 42 and a positive electrode collector 41, and the positive electrode active coating 42 is arranged on both sides of the thickness direction of the positive electrode collector 41. The negative electrode sheet 5 includes a negative electrode active coating 52 and a negative electrode collector 51, and the negative electrode active coating 52 is arranged on both sides of the thickness direction of the negative electrode collector 51. The two sides of the flat region 11 of the separator in the thickness direction are in contact with the positive electrode active coating 42 and the negative electrode active coating 52 respectively. Among them, the positive electrode collector 41 and the negative electrode collector 51 are aluminum foil and copper foil respectively, and the positive electrode active coating 42 can be arranged on both sides of the positive electrode collector 41 by coating, and the negative electrode active coating 52 can be arranged on both sides of the negative electrode collector 51 by coating, thereby forming the above-mentioned positive electrode sheet 4 and negative electrode sheet 5.

[0042] In the figure, direction A is the first direction, that is, the width direction of the separator. After winding or lamination, the width directions of the separator, the positive electrode sheet 4 and the negative electrode sheet 5 are consistent. The first negative extension layer 22 and the second negative extension layer 32 on the separator are respectively filled on both sides of the width direction of the negative electrode sheet 5, and the first positive extension layer 21 and the second positive extension layer 31 of the separator are respectively filled on both sides of the width direction of the positive electrode sheet 4. Among them, the first negative extension layer 22 and the second negative extension layer 32 are in contact with the negative electrode sheet 5 on one side close to the edge of the negative electrode sheet 5, and the first positive extension layer 21 and the second positive extension layer 31 are in contact with the positive electrode sheet 4 on one side close to the edge of the positive electrode sheet 4, thereby realizing the filling of the gap at the edge of the positive and negative electrodes by the extension layer.

[0043] The first positive extension layer 21, the first negative extension layer 22, the second positive extension layer 31 and the second negative extension layer 32 are used to fill the gaps between the positive and negative electrodes of the battery, and can store more electrolyte. Compared with the flat diaphragm, the liquid storage capacity can be improved, thereby improving the cycle life of the battery.

[0044] like Figure 4 As shown, in an embodiment of the present application, in addition to filling the gap between the positive and negative electrodes by the first extension layer 2 and the second extension layer 3, a filling layer is also provided in the gap. Exemplarily, the battery cell also includes a positive filling layer 6 and a negative filling layer 7, and the positive filling layer 6 is filled between two adjacent first positive extension layers 21 and two adjacent second positive extension layers 31, and the positive filling layer 6 is in contact with the positive electrode sheet 4. The negative filling layer 7 is filled between two adjacent first negative extension layers 22 and two adjacent second negative extension layers 32, and the negative filling layer 7 is in contact with the negative electrode sheet 5. The edges of the positive electrode sheet 4 and the negative electrode sheet 5 in the width direction are filled by the structure of the first extension layer 2, the second extension layer 3, the positive filling layer 6 and the negative extension layer, and the electrolyte can also be stored by fillers in the gap, thereby further improving the battery's liquid storage capacity. It should be noted that, Figure 4 What is shown in FIG. 1 is a partial cross section of the interior of the battery cell after winding or stacking, and a separator and a positive electrode sheet 4 not shown are also arranged on the left and right sides of the figure.

[0045] Exemplarily, the thickness of the positive electrode filling layer 6 is greater than that of the negative electrode filling layer 7, and the thicknesses of the positive electrode filling layer 6 and the negative electrode filling layer 7 are both arranged along the first direction. Because the width of the positive electrode sheet 4 in the first direction is smaller, the gap formed at its edge is correspondingly larger, so the positive electrode filling layer 6 has a greater thickness. Similarly, the width of the first positive electrode extension layer 21 in the first direction is greater than that of the first negative electrode extension layer 22, and the width of the second positive electrode extension layer 31 in the first direction is greater than that of the second negative electrode extension layer 32.

[0046] Exemplarily, the positive electrode filling layer 6 and the negative electrode filling layer 7 are both porous materials, such as PE (polyethylene) film, PP (polypropylene) film, etc., and other porous materials such as non-woven fabrics, etc. can also be used. The material can be the same as or different from the separator. In addition, the positive electrode filling layer 6 and the negative electrode filling layer 7 can be a coating, such as a ceramic porous coating, a polymer material coating, etc.

[0047] The battery in the embodiment of the present application fills the gap between the positive and negative electrodes of the battery through the first extension layer 2 and the second extension layer 3 on the diaphragm, and can store more electrolyte after winding or lamination; and through the structure of the positive electrode filling layer 6 and the negative electrode filling layer 7, the liquid storage capacity can be further improved, thereby effectively improving the cycle life of the battery.

[0048] An embodiment of the present application further provides an electrical device, wherein the electrical device includes the above-mentioned battery.

[0049] Embodiment 2

[0050] The present application provides a battery comprising a plurality of cells, each of which comprises a positive electrode sheet 4 (such as Figure 5 As shown in the figure), the negative electrode sheet 5 and the above-mentioned separator are located between the positive electrode sheet 4 and the negative electrode sheet 5. The width of the separator is greater than the width of the negative electrode sheet 5, and the width of the negative electrode sheet 5 is greater than the width of the positive electrode sheet 4.

[0051] Please refer to Figure 5 , which is different from the above-mentioned embodiment 1 in that no filling layer is provided in the battery in the embodiment of the present application, and the gap between the positive and negative electrodes is filled only by the first extension layer 2 and the second extension layer 3. The two adjacent first positive extension layers 21 are in contact with each other, and the two adjacent second positive extension layers 31 are in contact with each other, thereby achieving the filling of the gaps on both sides of the positive electrode sheet 4 of the battery cell. Similarly, the two adjacent first negative extension layers 22 are in contact with each other, and the two adjacent second negative extension layers 32 are in contact with each other, thereby achieving the filling of the gaps on both sides of the negative electrode sheet 5 of the battery cell. Exemplarily, the width of the first positive extension layer 21 in the first direction is greater than that of the first negative extension layer 22, and the width of the second positive extension layer 31 in the first direction is greater than that of the second negative extension layer 32.

[0052] It should be noted that Figure 5What is shown in the figure is a partial cross-section of the battery cell after winding or lamination. On the left and right sides of the figure, there are also diaphragms and positive electrode sheets 4 that are not shown. In order to better show the first extension layer 2 and the second extension layer 3 in the figure, the thickness ratio is adjusted. The figure does not show the actual ratio between the first extension layer 2, the second extension layer 3 and the diaphragm body 1. The battery in the embodiment of the present application fills the gap between the positive and negative electrodes of the battery through the first extension layer 2 and the second extension layer 3 on the diaphragm. After winding or lamination, more electrolyte can be stored, thereby effectively improving the cycle life of the battery.

[0053] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0054] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0055] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0056] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0057] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0058] The above is only a specific implementation or description of a specific implementation of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A separator used in a battery, characterized in that: The diaphragm comprises a diaphragm body, wherein the diaphragm body comprises a flat region and a non-flat region located at least on one side of the flat region in a first direction; An extension layer is arranged on the uneven area, and the extension layer is used to fill the gap between the positive electrode sheet and the negative electrode sheet in the battery cell of the battery.

2. The diaphragm according to claim 1, characterized in that The uneven area includes a first uneven area and a second uneven area respectively arranged on both sides of the flat area in a first direction; The extension layer includes a first extension layer disposed on the first uneven area and a second extension layer disposed on the second uneven area. Both the first extension layer and the second extension layer are used to fill the gap between the positive electrode sheet and the negative electrode sheet in the battery cell.

3. The diaphragm according to claim 2, characterized in that The first extension layer includes a first positive extension layer and a first negative extension layer, and the first positive extension layer and the first negative extension layer are respectively located on both sides of the first uneven region in a thickness direction; The second extension layer includes a second positive extension layer and a second negative extension layer, and the second positive extension layer and the second negative extension layer are respectively located at two sides of the second uneven region in the first direction.

4. The diaphragm according to claim 3, characterized in that The widths of the first positive extension layer, the first negative extension layer, the second positive extension layer, and the second negative extension layer are all greater than 0.1 mm.

5. The diaphragm according to claim 3, characterized in that The thickness of the first positive extension layer, the first negative extension layer, the second positive extension layer and the second negative extension layer is greater than 10 um.

6. The diaphragm according to any one of claims 2 to 5, characterized in that The membrane body, the first extension layer and the second extension layer are made of polyolefin porous material.

7. A battery, characterized in that: The battery comprises a plurality of cells, each of which comprises a positive electrode sheet, a negative electrode sheet, and a separator according to any one of claims 1 to 6, wherein the separator is located between the positive electrode sheet and the negative electrode sheet; The width of the separator is greater than the width of the negative electrode sheet, and the width of the negative electrode sheet is greater than the width of the positive electrode sheet.

8. The battery according to claim 7, characterized in that The positive electrode sheet includes a positive electrode active coating and a positive electrode current collector, and the positive electrode active coating is arranged on both sides of the positive electrode current collector in the thickness direction; the negative electrode sheet includes a negative electrode active coating and a negative electrode current collector, and the negative electrode active coating is arranged on both sides of the negative electrode current collector in the thickness direction; the two sides of the flat area of ​​the diaphragm in the thickness direction are in contact with the positive electrode active coating and the negative electrode active coating respectively.

9. The battery according to claim 7, characterized in that The first negative electrode extension layer and the second negative electrode extension layer of the separator are respectively filled on both sides of the negative electrode sheet in the width direction, and the first positive electrode extension layer and the second positive electrode extension layer of the separator are respectively filled on both sides of the positive electrode sheet in the width direction.

10. The battery according to claim 9, characterized in that The battery cell also includes a positive electrode filling layer and a negative electrode filling layer, the positive electrode filling layer is filled between two adjacent first positive extension layers and two adjacent second positive extension layers, and the positive electrode filling layer is in contact with the positive electrode sheet; the negative electrode filling layer is filled between two adjacent first negative extension layers and two adjacent second negative extension layers, and the negative electrode filling layer is in contact with the negative electrode sheet.

11. The battery according to claim 10, characterized in that The thickness of the positive electrode filling layer is greater than the thickness of the negative electrode filling layer.

12. An electrical equipment, characterized in that: The electrical device comprises the battery according to any one of claims 7 to 11.

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