Composite electrode plate, battery cell and electric equipment

Abstract

The utility model discloses a composite electrode plate, a battery cell and electric equipment, and belongs to the technical field of batteries. The composite electrode plate can be a negative electrode plate or a positive electrode plate and comprises a current collector, an active layer is arranged on one surface of the current collector, and an insulating layer is arranged on the other surface of the current collector. Compared with an electrode plate which is only provided with an active layer on one surface of a current collector, the composite electrode plate disclosed by the utility model can alleviate the curl problem caused by uneven tension after cutting, is favorable for realizing large-scale production, can improve the space utilization rate of a battery, reduces the weight and the manufacturing cost of the battery, and is suitable for popularization and application. And the risk of short circuit can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a composite electrode sheet, a battery core and electrical equipment. Background Art

[0002] The electrode sheet usually contains a current collector and an active layer formed on the surface of the current collector. The electrode sheet can be obtained by preparing a functional layer such as an active layer only on one surface of the current collector, or by preparing a functional layer such as an active layer on both surfaces of the current collector. The electrode sheet with a functional layer prepared only on one surface of the current collector is prone to curling due to uneven tension after cutting and during assembly into a battery cell, which is not conducive to large-scale production.

[0003] The battery cell includes electrode sheets. The first electrode sheet and the last electrode sheet of the battery cell can be the electrode sheet with the functional layer prepared only on one surface of the current collector, or can be the electrode sheet with the functional layer prepared on both surfaces of the current collector. The first type of electrode sheet is prone to curling due to uneven tension. Therefore, the first electrode and the last electrode of the battery cell are usually selected as electrode sheets with functional layers prepared on both surfaces of the current collector. However, in this electrode sheet, the functional layers formed on both surfaces of the current collector are usually active layers, and the active layer facing outward relative to the center of the battery cell does not participate in the charging and discharging of the battery, which is a waste of the battery's space utilization, weight, and manufacturing cost. Utility Model Content

[0004] Based on the above-mentioned subject, the utility model mainly provides a composite electrode sheet and a battery cell.

[0005] To achieve the above objectives, the utility model provides a composite electrode sheet in a first aspect, the electrode sheet comprises a current collector, one surface of the current collector is an active layer, the other surface is an insulating layer, and the electrode sheet is a negative electrode sheet or a positive electrode sheet.

[0006] In some embodiments of the present invention, the thickness of the insulating layer ranges from 10 to 100 μm.

[0007] In some embodiments of the present invention, the electrode sheet is a negative electrode sheet, and the active layer is a negative electrode active layer.

[0008] In some embodiments of the present invention, the electrode sheet is a positive electrode sheet, and the active layer is a positive electrode active layer.

[0009] The second aspect of the utility model provides a battery cell, the battery cell having a layered structure, the battery cell comprising at least one positive electrode layer and at least one negative electrode layer, the positive electrode layers and the negative electrode layers are alternately stacked, and a separator is provided between any adjacent positive electrode layers and negative electrode layers;

[0010] The first layer and the last layer of the battery cell are the positive electrode layer or the negative electrode layer, and the first layer and the last layer are the electrode sheets of the utility model as described above;

[0011] The insulating layer in the electrode sheet faces outward relative to the center of the battery cell.

[0012] In some embodiments of the present invention, the first layer and the last layer of the battery cell are both negative electrode sheets, or the first layer and the last layer of the battery cell are both positive electrode sheets.

[0013] In some embodiments of the present invention, the first layer of the battery cell is a negative electrode sheet, and the last layer of the battery cell is a positive electrode sheet.

[0014] In some embodiments of the present invention, the battery cell contains two positive electrode layer layers and two negative electrode layer layers, and the two negative electrode layer layers are respectively the first layer and the last layer.

[0015] In some embodiments of the present invention, at least one negative electrode layer is contained between the first layer and the last layer of the battery cell, and the negative electrode layer includes a current collector, and negative electrode active layers are provided on both surfaces of the current collector.

[0016] In some embodiments of the present invention, at least one positive electrode layer is contained between the first layer and the last layer of the battery cell, and the positive electrode layer includes a current collector, and positive electrode active layers are provided on both surfaces of the current collector.

[0017] A third aspect of the present invention provides an electrical device, which includes the battery cell of the present invention as described above.

[0018] Beneficial effects that can be achieved by the utility model:

[0019] The composite electrode sheet of the utility model includes a current collector, one surface of the current collector is provided with an active layer, and the other surface is provided with an insulating layer. Compared with the electrode sheet obtained by only providing a functional layer on one surface of the current collector, the composite electrode sheet of the utility model can alleviate the curling problem of the electrode sheet due to uneven tension after cutting, which is conducive to large-scale production. The above-mentioned composite electrode sheet of the utility model is used as the first electrode sheet and the last electrode sheet of the battery cell, and the insulating layer in the composite electrode sheet is arranged outward relative to the center of the battery cell, which can not only alleviate the curling problem of the electrode sheet due to uneven tension. In the application of the battery cell, the active layer arranged outward relative to the center of the battery cell in the first electrode sheet and / or the last electrode sheet of the battery cell usually does not participate in charging and discharging. The composite electrode sheet of the utility model is used as the first electrode sheet and / or the last electrode sheet of the battery cell, and the insulating layer replaces the active layer arranged outward relative to the center of the battery cell, which is conducive to improving the space utilization of the battery, reducing the weight and manufacturing cost of the battery, and also because the insulating layer has an insulating effect, it can reduce the risk of short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 It is a cross-sectional view of a composite electrode sheet according to an embodiment of the present utility model.

[0022] Figure 2 It is a cross-sectional view of a battery cell according to an embodiment of the utility model.

[0023] Figure 3 It is a cross-sectional view of a battery cell according to another embodiment of the utility model.

[0024] Figure 4 This is a cross-sectional view of a battery cell according to another embodiment of the present utility model.

[0025] Figure 5 It is a cross-sectional view of an electrode sheet according to an embodiment of the present utility model.

[0026] Figure 6 This is a cross-sectional view of an electrode sheet according to another embodiment of the present invention.

[0027] Description of labels:

[0028] 100 Battery Cell 10 Electrode sheet 20 Diaphragm 11 Composite electrode sheet 111 current collector 112 Active layer 113 Insulation layer

[0029] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In the present utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0033] The electrode sheet usually contains a current collector and an active layer formed on the surface of the current collector. The electrode sheet can be obtained by preparing a functional layer such as an active layer on only one surface of the current collector, or by preparing functional layers on both surfaces of the current collector. The electrode sheet with a functional layer prepared on only one surface of the current collector is prone to curling due to uneven tension after cutting and during assembly into a battery cell, which is not conducive to large-scale production.

[0034] In view of this, the utility model provides a composite electrode sheet, referring to Figure 1 The composite electrode sheet 11 of the present invention comprises a current collector 111 , one surface of the current collector 111 is provided with an active layer 112 , and the other surface of the current collector 111 is provided with an insulating layer 113 .

[0035] Both surfaces of the current collector 111 of the composite electrode sheet 11 of the utility model are coated with functional layers, and the functional layers on the two surfaces of the current collector 111 are of different types, namely, an active layer 112 and an insulating layer 113. Compared with an electrode sheet in which a functional layer, such as an active layer 112, is provided on only one surface of the current collector 111, the composite electrode sheet 11 of the utility model is not easy to curl due to uneven tension after cutting or during the process of assembling the battery cell 100 and the battery, which is conducive to large-scale production.

[0036] The composite electrode sheet 11 of the utility model can be either a positive electrode sheet or a negative electrode sheet. The composite electrode sheet 11 of the utility model is used as the first electrode sheet and / or the last electrode sheet of the battery cell 100, and the insulating layer 113 in the composite electrode sheet 11 of the utility model is arranged outward relative to the center of the battery cell 100, and the outermost layer of the first electrode sheet and / or the last electrode sheet of the battery cell 100 is the insulating layer 113. In the application of the battery cell 100, the functional layer in the first electrode sheet and / or the last electrode sheet of the battery cell 100 that is arranged outward relative to the center of the battery cell 100 usually does not participate in charging and discharging. If the functional layer is the active layer 112, it will be unfavorable to control the weight and manufacturing cost of the battery, and it is also easy to reduce the space utilization rate of the battery. The composite electrode sheet 11 of the utility model is used as the first electrode sheet and / or the last electrode sheet of the battery cell 100, and the insulating layer 113 replaces the active layer 112 arranged outward from the center of the battery cell 100. Under the same membrane volume, the insulating layer 113 is usually lighter than the active layer 112, which is beneficial to reduce the weight and volume energy density of the battery, improve the space utilization rate of the battery, and has the advantages of low cost and strong operability. In addition, the insulating layer 113 has an insulating effect and can reduce the risk of short circuit. In general, compared with the electrode sheet with the active layer 112 arranged on both surfaces of the current collector 111, the battery cell 100 using the composite electrode sheet 11 of the utility model can not only reduce the risk of the electrode sheet being easily curled, but also help to reduce the weight and volume energy density of the battery, and has the advantages of low cost and strong operability. In addition, the insulating layer 113 has an insulating effect and can reduce the risk of short circuit.

[0037] It can be understood that the center of the battery cell 100 refers to the central position formed by alternately stacking all functional layers of the battery cell 100 , where the functional layers include the electrode sheets 10 and the separators 20 .

[0038] In the present invention, the active layer 112 in the composite electrode sheet 11 participates in the electrochemical reaction of the battery, and the active layer 112 usually contains active materials, and the active materials participate in the above electrochemical reaction. In addition, the active layer 112 may also contain a binder and / or a conductive agent. The binder can help the material to adhere to the surface of the current collector 111 to form an active layer with strong bonding force, and the conductive agent can play a role in conductivity. The above active materials, binders and conductive agents can be dissolved and mixed, and then coated on the surface of the current collector 111 by means commonly used in the art to form the active layer 112.

[0039] In some embodiments, when the composite electrode sheet 11 is a negative electrode sheet, the active layer 112 is a negative electrode active layer; when the composite electrode sheet 11 is a positive electrode sheet, the active layer 112 is a negative electrode active layer.

[0040] In some embodiments, the conductive agent in the active layer 112 includes at least one of conductive carbon black, Super P, KS6, VGCF, and carbon nanotubes.

[0041] In some embodiments, the binder in the active layer 112 includes at least one of sodium polymethylcellulose, lithium polymethylcellulose, styrene-butadiene rubber, polyacrylic acid, and polyacrylonitrile.

[0042] In some embodiments, when the active layer 112 is a positive electrode active layer, the binder includes polyvinylidene fluoride.

[0043] In some embodiments, when the active layer 112 is a negative electrode active layer, the active material includes a negative electrode active material, and the negative electrode active material includes at least one of artificial graphite, natural graphite, silicon carbon, lithium titanate, graphene, tin oxide, tin-based composite oxide, tin-based alloy, silicon-based alloy, germanium-based alloy, aluminum-based alloy, antimony-based alloy, and magnesium-based alloy.

[0044] In some embodiments, when the active layer 112 is a positive electrode active layer, the active material includes a positive electrode active material, and the positive electrode active material includes at least one of lithium cobalt oxide, lithium iron phosphate, lithium iron manganese phosphate, and a ternary positive electrode material.

[0045] In some embodiments, the thickness of the insulating layer 113 is in the range of 10 μm to 100 μm, and can be any value in the range of 10 μm to 100 μm, such as 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc.

[0046] In some embodiments, the insulating layer 113 is a PET film layer, a PP film layer or a PE film layer. The above types of insulating layers 113 are used to replace the active layer 112 facing outward relative to the center of the battery cell in the first electrode sheet and / or the last electrode sheet of the battery cell 100. This not only improves the problem of curling of the electrode sheet 10 due to uneven tension, but also has a lighter weight and lower cost, which is beneficial to improving the space utilization of the battery, reducing the weight and manufacturing cost of the battery, and reducing the risk of short circuit due to the insulating effect.

[0047] In some embodiments, the current collector 111 is a copper foil current collector, an aluminum foil current collector, an aluminum alloy foil current collector, or an organic layer composite current collector.

[0048] The battery cell includes electrode sheets. The first electrode sheet and the last electrode sheet of the battery cell can be electrode sheets with active layers prepared on one surface of the current collector, or electrode sheets with active layers prepared on both surfaces of the current collector. Electrode sheets with active layers prepared on only one surface of the current collector are prone to curling due to uneven tension. Therefore, the first electrode sheet and the last electrode sheet of the battery cell are usually selected to be electrode sheets with active layers prepared on both surfaces of the current collector. However, the active layers of the first electrode sheet and the last electrode sheet facing outward from the center of the battery cell do not participate in the charging and discharging of the battery, which is a waste of the battery's space utilization, weight, and manufacturing cost.

[0049] In view of this, refer to Figures 1 to 4 The utility model also provides a battery cell 100, which includes at least two layers of electrode sheets 10, at least one layer of electrode sheets 10 is a positive electrode sheet, and at least one layer of electrode sheets 10 is a negative electrode sheet, the positive electrode sheets and the negative electrode sheets are alternately stacked, and a layer of separator 20 is provided between any adjacent positive electrode sheets and negative electrode sheets; the first electrode sheet and the last electrode sheet of the battery cell are the composite electrode sheets 11 mentioned above in the utility model; the insulating layer 113 in the composite electrode sheet 11 is arranged outwardly relative to the center of the battery cell 100.

[0050] It can be understood that the center of the battery cell 100 refers to the central position formed by alternately stacking the functional layers of the battery cell 100 , where the functional layers include the electrode sheets 10 and the separators 20 .

[0051] It can be understood that the first layer and the last layer of the first electrode sheet and the last electrode sheet in the battery cell 100 are not specific. The first electrode sheet and the last electrode sheet are used to refer to the two outermost electrode sheets of the battery cell 100. When one of the outermost electrode sheets is defined as the first layer, the other outermost electrode sheet is defined as the last layer; and when one of the outermost electrode sheets is defined as the last layer, the other outermost electrode sheet is defined as the first layer.

[0052] The positive electrode sheet contained in the battery cell 100 of the present invention can be a positive electrode sheet provided by the present invention in which an active layer 112 and an insulating layer 113 are respectively arranged on both surfaces of the current collector 111, or can be a positive electrode sheet commonly used in the art, for example, referring to Figure 5 and Figure 6 In the art, the conventional positive electrode sheet contains at least a current collector 111, such as Figure 5 As shown, an active layer 112 is provided on one surface of the current collector 111, or, as Figure 6 As shown, active layers 112 are provided on both surfaces of the current collector 111. In this embodiment, the active layer 112 is a positive electrode active layer. In this embodiment, the positive electrode sheet in the composite electrode sheet 11 of the utility model can be used as the first electrode sheet and / or the last electrode sheet of the battery cell 100, and the electrode sheet between the first electrode sheet and the last electrode sheet can be selected as above. Figure 6 The electrode sheet 10 is shown.

[0053] The negative electrode sheet contained in the battery cell 100 of the present invention may be a negative electrode sheet provided by the present invention in which an active layer 112 and an insulating layer 113 are respectively arranged on both surfaces of the current collector 111, or may be a negative electrode sheet commonly used in the art. Figure 5 and Figure 6 The negative electrode sheet commonly used in the art at least contains a current collector 111, such as Figure 5 As shown, an active layer 112 is provided on one surface of the current collector 111, or, as Figure 6 As shown, active layers 112 are provided on both surfaces of the current collector. In this embodiment, the active layer 112 is a negative electrode active layer. In this embodiment, the negative electrode sheet in the composite electrode sheet 11 of the utility model can be used as the first electrode sheet and / or the last electrode sheet of the battery cell 100, and the electrode sheet between the first electrode sheet and the last electrode sheet can be selected as above. Figure 6 The electrode sheet 10 is shown.

[0054] In some embodiments, continue to refer to Figures 1 to 4 The first electrode sheet and the last electrode sheet of the battery cell 100 are both the composite electrode sheet 11 of the present invention, and the composite electrode sheet 11 is a negative electrode sheet. The first electrode sheet and the last electrode sheet of the battery cell 100 of this embodiment are both the composite electrode sheet 11 of the present invention coated with functional layers on both surfaces of the current collector, and the composite electrode sheet 11 is not easy to curl due to uneven tension after cutting and during the process of assembling the battery cell and the battery. Moreover, the insulating layer 113 in the first electrode sheet and the last electrode sheet of the battery cell 100 is arranged outward relative to the center of the battery cell 100. Compared with the electrode sheet in which the active layer 112 is arranged on both surfaces of the current collector 111, the present embodiment replaces the active layer 112 in the first electrode sheet and the last electrode sheet of the battery cell 100 that is outward relative to the center of the battery cell 100 with the insulating layer 113. Under the same membrane volume, the insulating layer 113 is usually lighter than the active layer 112, which is beneficial to reducing the weight and volume energy density of the battery, and has the advantages of low cost and strong operability. The insulating layer 113 can also reduce the risk of short circuit due to its insulating effect. In one embodiment, refer to Figure 3 to Figure 4 In addition to the first electrode sheet and the last electrode sheet, the battery cell 100 also includes at least one electrode sheet 10, which is a positive electrode sheet. The positive electrode sheet is disposed between the first electrode sheet and the last electrode sheet, and includes a current collector 111. An active layer 112 is disposed on both surfaces of the current collector 111. The active layer 112 is a positive electrode active layer. In another embodiment, at least one negative electrode sheet is disposed between the first electrode sheet and the last electrode sheet of the battery cell 100. The negative electrode sheet also includes a current collector 111. An active layer 112 is disposed on both surfaces of the current collector 111. The active layer 112 is a negative electrode active layer.

[0055] In some embodiments, continue to refer to Figures 1 to 4 The first electrode sheet and the last electrode sheet of the battery cell 100 are both the composite electrode sheet 11 of the present invention, and the composite electrode sheets are all positive electrode sheets. The first electrode sheet and the last electrode sheet of the battery cell 100 of this embodiment are both the composite electrode sheet 11 of the present invention with functional layers coated on both surfaces of the current collector. The composite electrode sheet 11 is not easy to curl due to uneven tension after cutting and during the process of assembling the battery cell and the battery. Moreover, the insulating layer 113 in the first electrode sheet and the last electrode sheet of this embodiment is arranged outward relative to the center of the battery cell 100. Compared with the electrode sheet in which the active layer 112 is arranged on both surfaces of the current collector 111, the insulating layer 113 in this embodiment replaces the active layer 112 in the first electrode sheet and the last electrode sheet of the battery cell 100 that is outward relative to the center of the battery cell 100. Under the same membrane volume, the insulating layer 113 is usually lighter than the active layer 112, which is beneficial to reducing the weight and volume energy density of the battery, and has the advantages of low cost and strong operability. The insulating layer 113 can also reduce the risk of short circuit due to its insulating effect. In one embodiment, refer to Figure 3 to Figure 4 In addition to the first electrode sheet and the last electrode sheet, the battery cell 100 also includes at least one electrode sheet 10, which is a negative electrode sheet. The negative electrode sheet is disposed between the first electrode sheet and the last electrode sheet, and includes a current collector 111. An active layer 112 is disposed on both surfaces of the current collector 111. The active layer 112 is a negative electrode active layer. In another embodiment, at least one positive electrode sheet is disposed between the first electrode sheet and the last electrode sheet of the battery cell 100. The positive electrode sheet also includes a current collector 111. An active layer 112 is disposed on both surfaces of the current collector 111. The active layer 112 is a positive electrode active layer.

[0056] In this embodiment, continue to refer to Figure 3 and Figure 4The battery cell 100 includes an electrode sheet 10 and a separator 20, which are alternately stacked, and the first electrode sheet and the last electrode sheet of the battery cell 100 are both composite electrode sheets 11. The first electrode sheet of the battery cell 100 is a negative electrode sheet, and an active layer 112 and an insulating layer 113 are respectively provided on both surfaces of the current collector 111, and the last electrode sheet of the battery cell 100 is a positive electrode sheet, and an active layer 112 and an insulating layer 113 are respectively provided on both surfaces of the current collector 111. In the present embodiment, the first electrode sheet and the last electrode sheet of the battery cell 100 are both the composite electrode sheets 11 provided by the present invention, and the active layer 112 and the insulating layer 123 are respectively provided on the two surfaces of the current collector. After cutting and in the process of assembling the battery cell and the battery, it is not easy to curl due to uneven tension. Moreover, the insulating layer 113 in the first electrode sheet and the last electrode sheet is arranged outward relative to the center of the battery cell 100. Compared with the electrode sheet in which the active layer 112 is provided on both surfaces of the current collector 111, the present invention replaces the active layer 112 with the insulating layer 113. Under the same membrane volume, the insulating layer 113 is generally lighter than the active layer 112, which is beneficial to reducing the weight and volume energy density of the battery, and has the advantages of low cost and strong operability. The insulating layer 113 can also reduce the risk of short circuit due to its insulating effect. In one embodiment, referring to Figure 3 and Figure 4 At least one electrode sheet 10 is provided between the first electrode sheet and the last electrode sheet of the battery cell 100 of this embodiment. Both surfaces of the current collector 111 of the electrode sheet 10 are coated with an active layer 112. The electrode sheet 10 is a negative electrode sheet or a positive electrode sheet. The battery cell 100 of this embodiment has multiple layers of electrode sheets 10, which is conducive to improving the capacity and energy density of the battery.

[0057] The battery cell 100 of the utility model has a layered structure and can be prepared into a laminated battery. In addition, the battery cell 100 with a layered structure can be wound to form a columnar battery, and a columnar battery can be prepared from the columnar battery. Both the laminated battery and the columnar battery of this embodiment can be applied to electrical equipment.

[0058] The third aspect of the present invention provides an electrical device, which includes the battery cell of the present invention and is at least used for all the above-mentioned beneficial effects of the battery cell, which will not be elaborated here.

[0059] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A composite electrode sheet, characterized in that: The composite electrode sheet (11) comprises a current collector (111), one surface of the current collector is provided with an active layer (112), and the other surface is provided with an insulating layer (113), and the composite electrode sheet is a negative electrode sheet or a positive electrode sheet.

2. The composite electrode sheet according to claim 1, characterized in that: The thickness of the insulating layer (113) ranges from 10 μm to 100 μm.

3. The composite electrode sheet according to claim 1, characterized in that: The insulating layer (113) is a PET film layer, a PP film layer or a PE film layer; and / or the current collector (111) is a copper foil current collector, an aluminum foil current collector, an aluminum alloy foil current collector or an organic layer composite current collector.

4. The composite electrode sheet according to claim 1, characterized in that: The composite electrode sheet (11) is a negative electrode sheet, and the active layer (112) is a negative electrode active layer; and / or the composite electrode sheet (11) is a positive electrode sheet, and the active layer (112) is a positive electrode active layer.

5. A battery cell, characterized in that: The battery cell (100) comprises at least two layers of electrode sheets (10), at least one layer of the electrode sheets is a positive electrode sheet, at least one layer of the electrode sheets (10) is a negative electrode sheet, the positive electrode sheets and the negative electrode sheets are alternately stacked, and a layer of separator (20) is provided between any adjacent positive electrode sheets and negative electrode sheets; The first electrode sheet and / or the last electrode sheet of the battery cell (100) is the composite electrode sheet (11) according to any one of claims 1 to 4; The insulating layer (113) in the composite electrode sheet (11) is arranged outwardly relative to the center of the battery core (100).

6. The battery cell according to claim 5, characterized in that: The first electrode sheet and the last electrode sheet of the battery cell (100) are both the composite electrode sheets (11), and the composite electrode sheets (11) are both negative electrode sheets.

7. The battery cell according to claim 5, characterized in that: The first electrode sheet and the last electrode sheet of the battery cell (100) are both the composite electrode sheets (11), and the composite electrode sheets (11) are both positive electrode sheets.

8. The battery cell according to claim 5, characterized in that: The first electrode sheet and the last electrode sheet of the battery cell (100) are both the composite electrode sheet (11), the first electrode sheet of the battery cell is a positive electrode sheet, and the last electrode sheet of the battery cell is a negative electrode sheet.

9. The battery cell according to claim 5, characterized in that: At least one negative electrode sheet is provided between the first electrode sheet and the last electrode sheet of the battery cell (100), the negative electrode sheet comprising a current collector (111), and active layers (112) are provided on both surfaces of the current collector (111); Alternatively, at least one positive electrode sheet is provided between the first electrode sheet and the last electrode sheet of the battery cell (100), and the positive electrode sheet comprises a current collector (111), and active layers (112) are provided on both surfaces of the current collector (111).

10. An electrical device, characterized in that: The electrical equipment comprises the battery cell according to any one of claims 5 to 9.

Images