Bipolar electrode sheet, battery cell, battery and electrical device

Abstract

Provided in the present disclosure are a bipolar electrode sheet, a battery cell, a battery and an electrical device. The bipolar electrode sheet comprises a current collector, a positive electrode coating and a negative electrode coating. The current collector has a first end face and a second end face, and in the direction of thickness of the current collector, the first end face and the second end face are arranged opposite each other; the positive electrode coating is coated on the first end face; the negative electrode coating is coated on the second end face; and in the direction of thickness of the current collector, the positive electrode coating and the negative electrode coating are arranged in a staggered manner. The problem of the low production efficiency of bipolar battery cells caused by the high processing difficulty and low processing yield of bipolar electrode sheets can be solved.

Description

Bipolar electrodes, cells, batteries and electrical equipment

[0001] This disclosure claims priority to Chinese Patent Application No. 202411748914.6, filed on November 28, 2024, entitled "Bipolar Electrode, Cell, Battery and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of battery technology, and in particular to a bipolar electrode, a battery cell, a battery, and an electrical device. Background Technology

[0003] Batteries are power sources that provide power to tools, often referring to rechargeable batteries that power electric vehicles, electric trains, electric bicycles, and golf carts.

[0004] In related technologies, a bipolar cell is provided inside the battery. Positive electrode material and negative electrode material are coated on the upper and lower surfaces of the composite foil, respectively. The positive electrode material and negative electrode material are rolled and pressed to form bipolar electrode sheets. Multiple bipolar electrode sheets are connected to form a bipolar cell.

[0005] When the positive electrode coating and the negative electrode coating are subjected to the same force during rolling, it will lead to greater processing difficulty and lower yield of bipolar electrode sheets, resulting in low production efficiency of bipolar cells. Summary of the Invention

[0006] This disclosure provides a bipolar electrode, a battery cell, a battery, and an electrical device, which addresses the problem of low production efficiency of bipolar battery cells due to the high processing difficulty and low yield of bipolar electrode.

[0007] The embodiments disclosed herein provide the following technical solutions:

[0008] A first aspect of this disclosure provides a bipolar electrode, comprising:

[0009] The current collector has a first end face and a second end face, which are arranged opposite to each other along the thickness direction of the current collector.

[0010] Positive electrode dressing is applied to the first end face;

[0011] A negative electrode dressing is applied to the second end face;

[0012] Along the thickness direction of the current collector, the positive electrode dressing and the negative electrode dressing are staggered.

[0013] In one embodiment, the orthographic projection of the positive electrode dressing on the first end face and the orthographic projection of the negative electrode dressing on the first end face are spaced apart.

[0014] In one embodiment, the orthographic projection of the positive electrode dressing on the first end face is adjacent to the orthographic projection of the negative electrode dressing on the first end face.

[0015] In one embodiment, the current collector is conductively connected to the positive electrode dressing and the negative electrode dressing.

[0016] In one embodiment, the current collector has a first length L1 along its extending direction;

[0017] Along the extension direction of the current collector, the negative electrode dressing has a second length L2;

[0018] Along the extension direction of the current collector, the positive electrode dressing has a third length L3;

[0019] The first length L1, the second length L2, and the third length L3 satisfy the following condition: 1 / 2 * L1 > L2 > L3.

[0020] In one implementation, the second length L2 satisfies: 20mm ≤ L2 ≤ 1500mm;

[0021] And / or, the third length L3 satisfies: 20mm≤L3≤1500mm.

[0022] In one embodiment, the current collector includes a first connecting portion, a second connecting portion, and a third connecting portion connected in sequence;

[0023] The second connecting part is set at an angle to the first connecting part and the third connecting part, respectively;

[0024] The negative electrode dressing is at least partially coated on the first connection portion, and the positive electrode dressing is at least partially coated on the third connection portion.

[0025] In one embodiment, the current collector has a first thickness H1, which satisfies: 0.002 mm ≤ H1 ≤ 0.3 mm;

[0026] And / or along the thickness direction of the current collector, the negative electrode dressing has a second thickness H2, the second thickness H2 satisfying: 0.04mm≤H2≤0.9mm;

[0027] And / or along the thickness direction of the current collector, the positive electrode dressing has a third thickness H3, the third thickness H3 satisfying: 0.04mm≤H3≤0.9mm.

[0028] A second aspect of this disclosure provides a battery cell including a bipolar electrode, wherein multiple bipolar electrodes are disposed and stacked.

[0029] In one embodiment, among a plurality of bipolar electrodes, the positive electrode dressing of one of two adjacent bipolar electrodes is positioned opposite the negative electrode dressing of the other.

[0030] Alternatively, the negative electrode dressing of one of two adjacent bipolar electrodes is positioned opposite the positive electrode dressing of the other.

[0031] In one embodiment, at least three current collectors are provided along the stacking direction of the bipolar electrode. Among the three adjacent current collectors, the current collector in the middle is the first current collector, and the current collectors on both sides are the second and third current collectors, respectively.

[0032] The positive electrode dressing of the first current collector is positioned opposite the negative electrode dressing of the second current collector;

[0033] The negative electrode dressing of the first current collector is positioned opposite the positive electrode dressing of the third current collector.

[0034] In one embodiment, along the stacking direction of the bipolar electrodes, the positive electrode dressing, in the orthogonal projection of the first current collector, is located inside the negative electrode dressing, in the orthogonal projection of the first current collector.

[0035] In one embodiment, when the positive electrode dressing of the first current collector is disposed opposite to the negative electrode dressing of the second current collector, there is a difference between the extension length of the negative electrode dressing and the extension length of the positive electrode dressing along the extension direction of the current collector, and the difference is greater than 0.1 mm.

[0036] In one implementation, it further includes:

[0037] The first gasket surrounds the outer ring of the positive electrode dressing and is sealed to the first end face of the current collector.

[0038] The second gasket surrounds the outer ring of the negative electrode dressing and is sealed to the second end face of the current collector.

[0039] In one embodiment, in two adjacent current collectors, a first gasket of the first current collector and a second gasket of the second current collector are sealed together, and the first gasket, the second gasket, the first current collector and the second current collector together enclose a containment chamber for containing electrolyte.

[0040] In one implementation, it further includes:

[0041] The diaphragm, along the stacking direction of the bipolar electrodes, is at least partially located between the positive electrode dressing and the negative electrode dressing.

[0042] In one embodiment, at least part of the diaphragm is disposed within the containment chamber.

[0043] In one implementation, it further includes:

[0044] The negative current collector is a current collector connected to the outermost end of one side along the stacking direction of the bipolar electrodes;

[0045] The negative electrode lead-out terminal is formed on the side of the negative current collector away from the current collector.

[0046] In one embodiment, when a negative electrode lead-out end is formed on the side of the negative electrode current collector away from the current collector, a negative electrode dressing is coated on the side of the negative electrode current collector close to the current collector, and the negative electrode dressing of the negative electrode current collector and the positive electrode dressing of the adjacent current collector located at the far end are arranged opposite each other.

[0047] In one implementation, it further includes:

[0048] The positive current collector is connected to another current collector at the very end of the other side along the stacking direction of the bipolar electrode.

[0049] The positive electrode lead-out terminal is formed on the side of the positive current collector away from the current collector.

[0050] In one embodiment, when a positive electrode lead is formed on the side of the positive current collector away from the current collector, a positive electrode dressing is coated on the side of the positive current collector close to the current collector, and the positive electrode dressing of the positive current collector and the negative electrode dressing of the adjacent current collector located at the far end are arranged opposite to each other.

[0051] In one embodiment, along the stacking direction of the bipolar electrode, the first gasket has a fourth thickness H4, the fourth thickness H4 satisfying: 0.04mm≤H4≤1mm;

[0052] And / or, along the stacking direction of the bipolar electrode, the second gasket has a fifth thickness H5, the fifth thickness H5 satisfying: 0.04mm≤H5≤1mm;

[0053] And / or, along the stacking direction of the bipolar electrodes, the diaphragm has a sixth thickness H6, which satisfies: 0.003mm≤H6≤0.04mm.

[0054] A third aspect of this disclosure provides a battery, including a bipolar electrode or a battery cell.

[0055] A fourth aspect of this disclosure provides an electrical device, including an electrical appliance and a battery cell or a battery, wherein the battery cell or battery is used to provide electrical energy to the electrical appliance.

[0056] The bipolar electrode provided in the embodiments of this disclosure includes a current collector, a positive electrode dressing, and a negative electrode dressing. The current collector has a first end face and a second end face, which are arranged opposite to each other along the thickness direction of the current collector. The positive electrode dressing is coated on the first end face; the negative electrode dressing is coated on the second end face; and the positive and negative electrode dressings are staggered along the thickness direction of the current collector.

[0057] In this bipolar electrode structure, the current collector is used to conductively connect the positive and negative electrode materials to reduce the space occupied by the bipolar electrode, thereby increasing the energy density of the bipolar electrode. The first end face is used to support the positive electrode material, and the second end face is used to support the negative electrode material. Along the thickness direction of the current collector, the positive and negative electrode materials are staggered. Different pressures can be used for rolling according to the different positive and negative electrode materials to reduce the processing difficulty of the bipolar electrode, thereby improving the processing yield of the bipolar electrode and the production efficiency of the bipolar battery cell.

[0058] Therefore, the bipolar electrode provided by the embodiments of this disclosure can solve the problem of high processing difficulty and low processing yield of bipolar electrode, which leads to low production efficiency of bipolar cells.

[0059] In addition to the technical problems solved by the embodiments of this disclosure, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the bipolar electrode, cell, battery, and electrical equipment provided by the embodiments of this disclosure, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific implementation methods. Attached Figure Description

[0060] Figure 1 is a schematic diagram of the main structure of a bipolar electrode provided in an embodiment of this disclosure;

[0061] Figure 2 is a schematic diagram of one of the main structures of the current collector provided in an embodiment of this disclosure;

[0062] Figure 3 is a schematic diagram of the connection structure between the positive electrode dressing and the first gasket provided in an embodiment of this disclosure;

[0063] Figure 4 is a schematic diagram of the connection structure of the negative electrode dressing and the second gasket provided in the embodiments of this disclosure;

[0064] Figure 5 is a schematic diagram of the main structure of the negative electrode lead provided in an embodiment of this disclosure;

[0065] Figure 6 is a schematic diagram of the main structure of the positive lead-out terminal provided in an embodiment of this disclosure;

[0066] Figure 7 is a schematic diagram of the main structure of the current collector provided in an embodiment of this disclosure (second example).

[0067] Figure 8 is a schematic diagram of the main structure of the bipolar electrode provided in the embodiments of this disclosure.

[0068] Explanation of reference numerals in the attached drawings: 100 - Current collector; 101 - First end face; 102 - Second end face; 103 - First connecting part; 104 - Second connecting part; 105 - Third connecting part; 200 - Positive electrode dressing; 300 - Negative electrode dressing; 400 - First gasket; 500 - Second gasket; 600 - Receiving chamber; 700 - Diaphragm; 800 - Negative electrode current collector; 900 - Positive electrode current collector; L1 - First length; L2 - Second length; H1 - First thickness; H2 - Second thickness; H3 - Third thickness; H4 - Fourth thickness; H5 - Fifth thickness; H6 - Sixth thickness. Detailed Implementation

[0069] It should be noted that a positive electrode dressing and a negative electrode dressing are coated on the upper and lower surfaces of the current collector, respectively. The positive electrode dressing and the negative electrode dressing are respectively located on the two surfaces of the current collector. The current collector, the positive electrode dressing and the negative electrode dressing are connected to form a bipolar electrode.

[0070] In related technologies, the positive electrode coating and the negative electrode coating on the current collector are subjected to the same force during rolling, which leads to high processing difficulty and low yield of the bipolar electrode sheets formed, resulting in low production efficiency of bipolar cells.

[0071] The bipolar electrode sheet provided in the embodiments of this disclosure has a current collector used for conductive connection between the positive electrode material and the negative electrode material to reduce the space occupation of the bipolar electrode sheet, thereby increasing the energy density of the bipolar electrode sheet. The first end face is used to support the positive electrode material, and the second end face is used to support the negative electrode material. The positive electrode material and the negative electrode material are staggered along the thickness direction of the current collector. Different pressures can be used for rolling according to the different positive and negative electrode materials to reduce the processing difficulty of the bipolar electrode sheet, thereby improving the processing yield of the bipolar electrode sheet and the production efficiency of the bipolar battery cell.

[0072] As shown in Figure 1, the bipolar electrode sheet provided in the embodiments of this disclosure includes: a current collector 100, a positive electrode dressing 200, and a negative electrode dressing 300. The current collector 100 has a first end face 101 and a second end face 102, which are arranged opposite to each other along the thickness direction of the current collector 100. The positive electrode dressing 200 is coated on the first end face 101; the negative electrode dressing 300 is coated on the second end face 102; and the positive electrode dressing 200 and the negative electrode dressing 300 are staggered along the thickness direction of the current collector 100.

[0073] It should be noted that the current collector 100 can be a conductive foil, the first end face 101 can be one side surface of the conductive foil, and the second end face 102 can be the other side surface of the conductive foil. Along the thickness direction of the conductive foil, one side surface and the other side surface of the conductive foil are arranged opposite to each other.

[0074] Preferably, the current collector 100 can be a composite foil, such as a copper-aluminum composite foil. The copper-aluminum composite foil includes copper foil and aluminum foil stacked together. Along the stacking direction of the copper-aluminum composite foil, a negative electrode coating 300 is disposed on the copper foil side and a positive electrode coating 200 is disposed on the aluminum foil side.

[0075] As shown in Figures 3 and 4, it should be noted that the positive electrode dressing 200 and the negative electrode dressing 300 are staggered. There are several different ways to set them up. The following are examples of the specific ways to set the positive electrode dressing 200 and the negative electrode dressing 300 to be staggered.

[0076] In one embodiment, along the extending direction of the current collector 100, the positive electrode dressing 200 and the negative electrode dressing 300 are spaced apart, that is, the positive electrode dressing 200 is spaced apart from the positive projection of the first end face 101 and the negative electrode dressing 300 is spaced apart from the positive projection of the first end face 101.

[0077] It is understandable that the positive electrode dressing 200 and the negative electrode dressing 300 are spaced apart on the first end face 101, and different pressures can be used to roll the positive electrode dressing 200 and the negative electrode dressing 300 to reduce the processing difficulty of the bipolar electrode sheet. Furthermore, the positive electrode dressing 200 and the negative electrode dressing 300 can be rolled separately to improve the processing yield of the bipolar electrode sheet and the production efficiency of the bipolar battery cell.

[0078] In another embodiment, the orthographic projection of the positive electrode dressing 200 onto the first end face 101 is adjacent to the orthographic projection of the negative electrode dressing 300 onto the first end face 101.

[0079] It is understandable that the orthographic projection of the positive electrode dressing 200 on the first end face 101 is adjacent to the orthographic projection of the negative electrode dressing 300 on the first end face 101. Different pressures can be used to roll the positive electrode dressing 200 and the negative electrode dressing 300 to reduce the processing difficulty of the bipolar electrode sheet and reduce the space occupied by the positive electrode dressing 200 and the negative electrode dressing 300, thereby increasing the energy density of the bipolar electrode sheet.

[0080] It is understandable that there are no restrictions on the specific setting method of the positive electrode dressing 200 and the negative electrode dressing 300 being set separately, and the selection can be made according to the actual usage requirements.

[0081] It should be noted that the current collector 100 is electrically connected to the positive electrode dressing 200 and the negative electrode dressing 300.

[0082] It is understandable that the current collector 100 conductively connects the positive electrode dressing 200 and the negative electrode dressing 300, allowing one current collector 100 of the bipolar electrode to be connected in series with a positive electrode dressing 200 and a negative electrode dressing 300 on an adjacent side, and to be connected in series with a positive electrode dressing 200 and a negative electrode dressing 300 on the other adjacent side, thereby increasing the voltage of the bipolar electrode and thus improving the fast charging performance of the bipolar electrode.

[0083] As shown in Figure 2, it should be noted that the current collector 100 has a first length L1 along the extension direction of the current collector 100, the negative electrode dressing 300 has a second length L2 along the extension direction of the current collector 100, and the positive electrode dressing 200 has a third length L3 along the extension direction of the current collector 100. The first length L1, the second length L2 and the third length L3 satisfy the following relationship: 1 / 2 * L1 > L2 > L3.

[0084] It is understandable that the first length L1, the second length L2, and the third length L3 satisfy the following condition: 1 / 2 * L1 > L2 > L3. This optimizes the space occupied by the positive electrode dressing 200 and the negative electrode dressing 300, and allows the positive electrode dressing 200 and the negative electrode dressing 300 on one current collector 100 of the bipolar electrode sheet to be installed correspondingly with the positive electrode dressing 200 and the negative electrode dressing 300 on the two adjacent current collectors 100. Furthermore, it allows the extension length of the negative electrode dressing 300 to be greater than the extension length of the positive electrode dressing 200, thereby reducing the occurrence of edge failure of the negative electrode dressing 300 and extending the service life of the bipolar electrode sheet.

[0085] It should be noted that the positive electrode dressing 200 and negative electrode dressing 300 on one current collector 100 of the bipolar electrode sheet can be installed in correspondence with the positive electrode dressing 200 and negative electrode dressing 300 on two adjacent current collectors 100. The corresponding installation is as follows: the positive electrode dressing 200 on one current collector 100 is set opposite to the negative electrode dressing 300 on the first adjacent current collector 100, and the negative electrode dressing 300 on the same current collector 100 is set opposite to the positive electrode dressing 200 on the second adjacent current collector 100.

[0086] It should be noted that if the first length L1, the second length L2, and the third length L3 satisfy the condition 1 / 2 * L1 < L2 < L3, the positive electrode dressing 200 and the negative electrode dressing 300 will overlap along the thickness direction of the current collector 100, resulting in greater processing difficulty and lower yield of the bipolar electrode sheet; if the first length L1, the second length L2, and the third length L3 satisfy the condition 1 / 2 * L1 = L2 = L3, the negative electrode dressing 300 will experience edge failure, resulting in a reduced service life of the bipolar electrode sheet.

[0087] It should be noted that the first length L1 of the current collector 100 can be obtained by measuring the length of the current collector 100 along the arrangement direction from the positive electrode dressing 200 to the negative electrode dressing 300; the second length L2 of the negative electrode dressing 300 can be obtained by measuring the length of the negative electrode dressing 300 along the arrangement direction from the positive electrode dressing 200 to the negative electrode dressing 300; and the third length L3 of the positive electrode dressing 200 can be obtained by measuring the length of the positive electrode dressing 200 along the arrangement direction from the positive electrode dressing 200 to the negative electrode dressing 300.

[0088] It should be noted that the second length L2 satisfies: 20mm≤L2≤1500mm.

[0089] It is understandable that the second length L2 satisfies: 20mm≤L2≤1500mm, which can improve the energy density of the bipolar electrode and reduce the heat generation of the bipolar electrode.

[0090] It should be noted that if the second length L2 is less than 20 mm, the length of the negative electrode dressing 300 will be shorter, resulting in a lower energy density of the bipolar electrode; if the second length L2 is greater than 1500 mm, the length of the negative electrode dressing 300 will be longer, resulting in a greater heat generation of the bipolar electrode.

[0091] It should be noted that the third length L3 satisfies: 20mm≤L3≤1500mm.

[0092] It is understandable that the third length L3 satisfies: 20mm≤L3≤1500mm, which can improve the energy density of the bipolar electrode and reduce the heat generation of the bipolar electrode.

[0093] It should be noted that if the third length L3 is less than 20 mm, the length of the positive electrode dressing 200 will be shorter, resulting in a lower energy density of the bipolar electrode; if the third length L3 is greater than 1500 mm, the length of the positive electrode dressing 200 will be longer, resulting in a greater heat generation of the bipolar electrode.

[0094] It should be noted that the current collector 100 has a variety of different configuration shapes, and the configuration shapes of the current collector 100 will be illustrated with examples below.

[0095] In one embodiment, the current collector 100 is a square foil, the positive electrode dressing 200 is located on one side of the center of symmetry of the square foil, and the negative electrode dressing 300 is located on the other side of the center of symmetry of the square foil.

[0096] It is understandable that the current collector 100 is a square foil. The square foil setting can increase the coating area of ​​the positive electrode coating 200 and the negative electrode coating 300, thereby improving the current carrying capacity of the bipolar electrode.

[0097] In another embodiment, the current collector 100 is a circular foil, the positive electrode dressing 200 is located on one side of the center of symmetry of the circular foil, and the negative electrode dressing 300 is located on the other side of the center of symmetry of the circular foil.

[0098] It is understandable that the current collector 100 is a circular foil. The circular foil can improve the heat dissipation of the bipolar electrode, thereby reducing the surface temperature of the bipolar electrode.

[0099] As shown in Figures 7 and 8, in another embodiment, the current collector 100 includes a first connecting portion 103, a second connecting portion 104, and a third connecting portion 105 connected in sequence; the second connecting portion 104 is arranged at an angle to the first connecting portion 103 and the third connecting portion 105 respectively.

[0100] It is understandable that the first connecting part 103, the second connecting part 104 and the third connecting part 105 are connected in sequence to form a stepped current collector.

[0101] It should be noted that the negative electrode dressing 300 is at least partially coated on the first connecting part 103, the positive electrode dressing 200 is at least partially coated on the third connecting part 105, and the two ends of the second connecting part 104 are electrically connected to the first connecting part 103 and the third connecting part 105, respectively.

[0102] It is understandable that the arrangement of the first connecting part 103, the second connecting part 104 and the third connecting part 105 can reduce the space occupied by the positive electrode dressing 200 and the negative electrode dressing 300 on the current collector 100 in the thickness direction of the current collector 100, so as to reduce the volume of the bipolar electrode and thereby improve the energy density of the bipolar electrode.

[0103] It is understandable that the specific shape of the current collector 100 is not limited and can be selected according to actual usage requirements.

[0104] It should be noted that when the second connecting part 104 is set at an angle to the first connecting part 103 and the third connecting part 105 respectively, the second connecting part 104 has a variety of different angles with the first connecting part 103 and the third connecting part 105 respectively. The angles between the second connecting part 104 and the first connecting part 103 and the third connecting part 105 will be illustrated with examples below.

[0105] In one embodiment, the second connecting portion 104 is arranged at a 90-degree angle to the first connecting portion 103 and the third connecting portion 105, that is, the second connecting portion 104 is perpendicularly connected to the first connecting portion 103 and the third connecting portion 105.

[0106] It is understandable that the second connecting part 104 is set at a 90-degree angle to the first connecting part 103 and the third connecting part 105 respectively, which can reduce the space occupied between the second connecting part 104 and the first connecting part 103 and the third connecting part 105, thereby reducing the space occupied by the bipolar electrode.

[0107] In another embodiment, the second connecting portion 104 is arranged at an 88-degree angle with the first connecting portion 103 and the third connecting portion 105, respectively.

[0108] It is understandable that the second connecting part 104 is set at an 88-degree angle to the first connecting part 103 and the third connecting part 105 respectively, which can reduce the processing difficulty between the second connecting part 104 and the first connecting part 103 and the third connecting part 105, thereby reducing the processing difficulty of the bipolar electrode.

[0109] It is understandable that the angles between the second connecting part 104 and the first connecting part 103 and the third connecting part 105 are not limited and can be selected according to actual usage requirements.

[0110] It should be noted that the current collector 100 has a first thickness H1, which satisfies the following condition: 0.002mm ≤ H1 ≤ 0.3mm.

[0111] It should be noted that the first thickness H1 satisfies 0.002mm≤H1≤0.3mm, which can improve the strength of the current collector 100, thereby improving the safety performance of the current collector 100, and can also reduce the space occupied by the bipolar electrode, thereby increasing the energy density of the bipolar electrode.

[0112] It should be noted that if the first thickness H1 is less than 0.002 mm, the current collector 100 will experience stress concentration and fatigue damage when coated with positive electrode material 200 and negative electrode material 300. If the first thickness H1 is greater than 0.3 mm, the space occupied by the current collector 100 will increase, thereby reducing the energy density of the bipolar electrode and increasing the heating of the bipolar electrode.

[0113] It should be noted that, along the thickness direction of the current collector 100, the negative electrode dressing 300 has a second thickness H2, which satisfies the following condition: 0.04mm≤H2≤0.9mm.

[0114] It is understandable that the second thickness H2 satisfies: 0.04mm≤H2≤0.9mm, which can reduce the internal resistance of the negative electrode dressing 300, thereby reducing the heat generation of the negative electrode dressing 300 and thus providing safety protection for the bipolar electrode.

[0115] It should be noted that if the second thickness H2 is less than 0.04 mm, the battery capacity of the bipolar electrode will decrease; if the second thickness H2 is greater than 0.9 mm, the internal resistance of the negative electrode coating 300 will increase, and the heat generation of the negative electrode coating 300 will also increase.

[0116] It should be noted that, along the thickness direction of the current collector 100, the positive electrode dressing 200 has a third thickness H3, which satisfies the following condition: 0.04mm≤H3≤0.9mm.

[0117] It is understandable that the third thickness H3 satisfies: 0.04mm≤H3≤0.9mm, which can reduce the internal resistance of the positive electrode dressing 200, thereby reducing the heat generation of the positive electrode dressing 200 and thus providing safety protection for the bipolar electrode.

[0118] It should be noted that if the third thickness H3 is less than 0.04 mm, the battery capacity of the bipolar electrode will decrease; if the third thickness H3 is greater than 0.9 mm, the internal resistance of the positive electrode coating 200 will increase, and the heat generation of the positive electrode coating 200 will also increase.

[0119] The embodiments of this disclosure provide a battery cell including bipolar electrodes provided in any of the above embodiments, wherein multiple bipolar electrodes are provided and the multiple bipolar electrodes are stacked.

[0120] It is understandable that multiple current collectors 100 are stacked sequentially, and multiple current collectors 100 in the battery cell can be connected in series to improve the fast charging performance of the battery cell.

[0121] It should be noted that a bipolar electrode includes a current collector 100. In the case of multiple bipolar electrodes stacked together, the multiple current collectors 100 are stacked sequentially along the thickness direction of the current collector 100.

[0122] It should be noted that multiple bipolar electrodes can be installed in various ways. The specific installation methods of multiple bipolar electrodes will be illustrated below.

[0123] In one embodiment, among a plurality of bipolar electrodes, the positive electrode dressing 200 of one of two adjacent bipolar electrodes is disposed opposite to the negative electrode dressing 300 of the other.

[0124] It is understandable that the positive electrode dressing 200 of one of the two adjacent bipolar electrodes is positioned opposite the negative electrode dressing 300 of the other, which allows the two adjacent bipolar electrodes to be electrically connected and reduces the space occupied by the two adjacent bipolar electrodes.

[0125] In another embodiment, among a plurality of bipolar electrodes, the negative electrode dressing 300 of one of two adjacent bipolar electrodes is disposed opposite to the positive electrode dressing 200 of the other.

[0126] It is understandable that the negative electrode dressing 300 of one of the two adjacent bipolar electrodes is positioned opposite to the positive electrode dressing 200 of the other, which allows the two adjacent bipolar electrodes to be electrically connected and reduces the space occupied by the two adjacent bipolar electrodes.

[0127] Understandably, there are no restrictions on the specific installation method of multiple bipolar electrodes; the method can be selected according to actual usage requirements.

[0128] It should be noted that the positive electrode dressing 200 on one current collector 100 is arranged opposite to the negative electrode dressing 300 on the adjacent first current collector 100, and the negative electrode dressing 300 on the same current collector 100 is arranged opposite to the positive electrode dressing 200 on the adjacent second current collector 100.

[0129] It should be noted that in the battery cell provided in the embodiments of this disclosure, at least three current collectors 100 are provided along the stacking direction of the bipolar electrodes. Among the three adjacent current collectors 100, the current collector 100 located in the middle is the first current collector 100, and the current collectors 100 located on both sides are the second current collector 100 and the third current collector 100, respectively. The positive electrode dressing 200 of the first current collector 100 is disposed opposite to the negative electrode dressing 300 of the second current collector 100. The negative electrode dressing 300 of the first current collector 100 is disposed opposite to the positive electrode dressing 200 of the third current collector 100.

[0130] It is understandable that the positive electrode coating 200 of the first current collector 100 is arranged opposite to the negative electrode coating 300 of the second current collector 100, and the negative electrode coating 300 of the first current collector 100 is arranged opposite to the positive electrode coating 200 of the third current collector 100. This allows the bipolar electrode to be used normally and reduces the space occupied by the three adjacent bipolar electrodes, thereby improving the energy density of the battery cell.

[0131] In the battery cell provided in the embodiments of this disclosure, along the stacking direction of the bipolar electrodes, the positive electrode dressing 200, in the orthogonal projection of the first current collector 100, is located inside the negative electrode dressing 300, in the orthogonal projection of the first current collector 100.

[0132] It is understandable that, along the stacking direction of the bipolar electrode, the positive electrode dressing 200, in the orthogonal projection of the first current collector 100, is located inside the orthogonal projection of the negative electrode dressing 300. This can reduce the occurrence of edge failure in the negative electrode dressing 300, thereby extending the service life of the negative electrode dressing 300 and thus extending the service life of the bipolar electrode.

[0133] It should be noted that when the positive electrode dressing 200 of the first current collector 100 is arranged opposite to the negative electrode dressing 300 of the second current collector 100, there is a difference between the extension length of the negative electrode dressing 300 and the extension length of the positive electrode dressing 200 along the extension direction of the current collector 100, and the difference is greater than 0.1 mm.

[0134] Understandably, a difference greater than 0.1 mm can reduce the occurrence of edge failure of the negative electrode dressing 300, thereby extending the service life of the bipolar electrode or the battery cell.

[0135] It should be noted that if the difference is less than or equal to 0.1 mm, it will cause edge failure of the negative electrode coating 300, resulting in a lower energy density and lifespan of the battery cell.

[0136] It should be noted that the difference between the extension length of the negative electrode dressing 300 and the extension length of the positive electrode dressing 200 can be measured in various ways. Examples of the measurement methods for the difference between the extension length of the negative electrode dressing 300 and the extension length of the positive electrode dressing 200 will be given below.

[0137] In one embodiment, the difference between the extension length of the negative electrode dressing 300 and the extension length of the positive electrode dressing 200 can be the average value of the difference between the outermost edge of the negative electrode dressing 300 of the second current collector 100 and the outermost edge of the positive electrode dressing 200 of the first current collector 100 along the extension direction of the current collector 100.

[0138] In another embodiment, the difference between the extension length of the negative electrode dressing 300 and the extension length of the positive electrode dressing 200 can be the difference between the outer periphery of the negative electrode dressing 300 of the second current collector 100 and the outer periphery of the positive electrode dressing 200 of the first current collector 100 along the extension direction of the current collector 100.

[0139] Understandably, there are no restrictions on the method of measuring the difference between the extension length of the negative electrode dressing 300 and the extension length of the positive electrode dressing 200; the method can be selected according to actual usage requirements.

[0140] As shown in Figures 5 and 6, the battery cell provided in the embodiments of this disclosure further includes: a first washer 400 and a second washer 500. The first washer 400 is disposed around the outer ring of the positive electrode dressing 200 and is sealed to the first end face 101 of the current collector 100. The second washer 500 is disposed around the outer ring of the negative electrode dressing 300 and is sealed to the second end face 102 of the current collector 100.

[0141] Understandably, the first gasket 400 is used to isolate the positive electrode dressing 200 from direct contact with the external environment in order to protect the positive electrode dressing 200, and the second gasket 500 is used to isolate the negative electrode dressing 300 from direct contact with the external environment in order to protect the negative electrode dressing 300.

[0142] It should be noted that the first washer 400 is insulated from the first end face 101 of the current collector 100 to reduce the occurrence of short circuits in the current collector 100; the second washer 500 is insulated from the second end face 102 of the current collector 100 to reduce the occurrence of short circuits in the battery cell.

[0143] It should be noted that at least one of the first gasket 400 and the second gasket 500 can provide an electrolyte injection hole. After the electrolyte injection is completed, the injection hole on at least one of the first gasket 400 and the second gasket 500 can be resealed.

[0144] It is understandable that having the electrolyte injection hole located in at least one of the first gasket 400 and the second gasket 500 can reduce the difficulty of electrolyte injection, thereby improving the processing efficiency of the battery cell. After the electrolyte injection is completed, resealing the injection hole can reduce the occurrence of electrolyte leakage from the injection hole, thereby improving the safety performance of the battery cell.

[0145] It should be noted that the first washer 400 has a variety of different configuration shapes, and the configuration shapes of the first washer 400 will be illustrated with examples below.

[0146] In one embodiment, the first washer 400 is a first square insulating ring, which is sealed to the first end face 101, and the positive electrode dressing 200 is located in the inner ring of the first square insulating ring.

[0147] Understandably, the first square insulating ring can reduce the installation difficulty with the current collector 100 and has the advantage of easy installation.

[0148] In another embodiment, the first washer 400 is a first circular insulating ring, which is sealed to the first end face 101, and the positive electrode dressing 200 is located in the inner ring of the first circular insulating ring.

[0149] Understandably, the first circular insulating ring has the advantage of being easy to process, which can improve the processing efficiency of the first washer 400, thereby improving the processing efficiency of the bipolar electrode.

[0150] It is understandable that the shape of the first washer 400 is not limited and can be selected according to actual usage requirements, as long as the first washer 400 is sealed to the first end face 101.

[0151] It should be noted that the second washer 500 has a variety of different configuration shapes, and the configuration shapes of the second washer 500 will be illustrated with examples below.

[0152] In one embodiment, the second washer 500 is a second square insulating ring, which is sealed to the second end face 102, and the negative electrode dressing 300 is located in the inner ring of the second square insulating ring.

[0153] Understandably, the second square insulating ring can reduce the installation difficulty with the current collector 100 and has the advantage of easy installation.

[0154] In another embodiment, the second washer 500 is a second circular insulating ring, which is sealed to the second end face 102, and the negative electrode dressing 300 is located in the inner ring of the second circular insulating ring.

[0155] Understandably, the second circular insulating ring has the advantage of being easy to process, which can improve the processing efficiency of the second washer 500, thereby improving the processing efficiency of the bipolar electrode.

[0156] It is understandable that the shape of the second washer 500 is not limited and can be selected according to actual usage requirements, as long as the second washer 500 is sealed to the second end face 102.

[0157] It should be noted that in two adjacent current collectors 100, the first gasket 400 of the first current collector 100 and the second gasket 500 of the second current collector 100 are sealed together. The first gasket 400, the second gasket 500, the first current collector 100 and the second current collector 100 together enclose and form a receiving chamber 600, which is used to contain electrolyte.

[0158] Understandably, the first gasket 400 of the first current collector 100 and the second gasket 500 of the second current collector 100 are sealed together, which can isolate the containment chamber 600 from direct contact with the external environment and can seal and protect the electrolyte to reduce the occurrence of electrolyte leakage. The first gasket 400, the second gasket 500, the first current collector 100 and the second current collector 100 together enclose the containment chamber 600, which can reduce the volatilization of electrolyte, extend the service life of the bipolar electrode, and reduce the maintenance difficulty of the bipolar electrode.

[0159] It should be noted that the electrolyte can be either a liquid electrolyte or a gel electrolyte. The specific materials used in the electrolyte can be selected based on actual application requirements and are not limited here.

[0160] The bipolar electrode provided in the embodiments of this disclosure further includes a diaphragm 700, which is located between the positive electrode dressing 200 and the negative electrode dressing 300 along the stacking direction of the bipolar electrode.

[0161] Understandably, the diaphragm 700 is used to isolate the positive electrode dressing 200 and the negative electrode dressing 300 from direct contact, thereby preventing short circuits inside the cell and improving the cell's safety performance.

[0162] It should be noted that, in the embodiments of this disclosure, at least a portion of the diaphragm 700 is disposed within the receiving chamber 600.

[0163] Understandably, the diaphragm located within the housing 600 is used to isolate the positive electrode dressing 200 and the negative electrode dressing 300 from direct contact, thereby preventing short circuits inside the cell and improving the cell's safety performance. It also reduces the space occupied by the cell, thus increasing its energy density.

[0164] It should be noted that the diaphragm 700 has a variety of different installation positions, and the installation positions of the diaphragm 700 will be illustrated with examples below.

[0165] In the first embodiment, the diaphragm 700 is disposed on the first gasket 400 of the first current collector 100, and the positive electrode dressing 200, the diaphragm 700 and the negative electrode dressing 300 are arranged in sequence at intervals along the stacking direction of the bipolar electrode sheets.

[0166] Understandably, the separator 700 is placed on the first gasket 400 of the first current collector 100, which can reduce the installation difficulty of the separator 700 while isolating the direct contact between the positive electrode dressing 200 and the negative electrode dressing 300, thereby improving the installation efficiency of the battery cell.

[0167] In the second embodiment, the diaphragm 700 is disposed on the second gasket 500 of the second current collector 100, and the positive electrode dressing 200, the diaphragm 700, and the negative electrode dressing 300 are arranged alternately along the stacking direction of the bipolar electrode sheets.

[0168] Understandably, the separator 700 is placed on the second gasket 500 of the second current collector 100, which can reduce the installation difficulty of the separator 700 while isolating the direct contact between the positive electrode dressing 200 and the negative electrode dressing 300, thereby improving the installation efficiency of the battery cell.

[0169] In the third embodiment, a portion of the surface of the diaphragm 700 is connected to the first gasket 400 of the first current collector 100, and another portion of the surface of the diaphragm 700 is connected to the second gasket 500 of the second current collector 100. Along the stacking direction of the bipolar electrode sheets, the positive electrode dressing 200, the diaphragm 700, and the negative electrode dressing 300 are arranged in sequence at intervals.

[0170] Understandably, the diaphragm 700 is positioned between the first gasket 400 of the first current collector 100 and the second gasket 500 of the second current collector 100. This allows for adjustment of the diaphragm 700's installation position and improves its installation strength, thus providing safe protection for the battery cell.

[0171] In the fourth embodiment, the diaphragm 700 is disposed on the first end face 101 of the first current collector 100, and the diaphragm 700 surrounds the outer periphery of the positive electrode dressing 200 of the first current collector 100. Along the stacking direction of the bipolar electrode sheets, the positive electrode dressing 200, the diaphragm 700, and the negative electrode dressing 300 are arranged in sequence at intervals.

[0172] It is understandable that the diaphragm 700 is disposed on the first end face 101 of the first current collector 100, and the diaphragm 700 surrounds the outer periphery of the positive electrode dressing 200 of the first current collector 100, which can improve and extend the service life of the diaphragm 700, thereby improving the safety performance and service life of the battery cell.

[0173] In the fifth embodiment, the diaphragm 700 is disposed on the second end face 102 of the second current collector 100, and the diaphragm 700 surrounds the outer periphery of the negative electrode dressing 300 of the second current collector 100. Along the stacking direction of the bipolar electrode sheets, the positive electrode dressing 200, the diaphragm 700, and the negative electrode dressing 300 are arranged in sequence at intervals.

[0174] It is understandable that the diaphragm 700 is disposed on the second end face 102 of the second current collector 100, and the diaphragm 700 surrounds the outer periphery of the negative electrode dressing 300 of the second current collector 100, which can improve and extend the service life of the diaphragm 700, thereby improving the safety performance and service life of the battery cell.

[0175] Understandably, there are no restrictions on the specific installation position of the diaphragm 700. It can be selected according to actual usage requirements. It is only necessary to ensure that the positive electrode dressing 200, the diaphragm 700, and the negative electrode dressing 300 are set in sequence at intervals along the thickness direction of the current collector 100.

[0176] It should be noted that, along the stacking direction of the bipolar electrode, multiple current collectors 100 are stacked sequentially to form two end points.

[0177] As shown in Figure 8, the battery cell provided in the embodiments of this disclosure further includes: a negative current collector 800, which is connected to a current collector 100 at the far end of one side along the stacking direction of the bipolar electrode sheets; a negative lead-out terminal is formed on the side of the negative current collector 800 away from the current collector 100.

[0178] Understandably, the negative terminal is used to form the negative terminal of the battery cell so that the battery cell can be used normally.

[0179] It should be noted that when a negative electrode lead-out end is formed on the side of the negative electrode current collector 800 away from the current collector 100, a negative electrode dressing 300 is coated on the side of the negative electrode current collector 800 close to the current collector 100, and the negative electrode dressing 300 and the positive electrode dressing 200 of the adjacent current collector 100 located at the far end of one side are arranged opposite each other.

[0180] It is understandable that the negative electrode dressing 300 on the negative electrode current collector 800 and the positive electrode dressing 200 of the adjacent current collector 100 located at the far end on one side are arranged opposite each other, so that the negative electrode current collector 800 can be electrically connected to the adjacent current collector 100 located at the far end; the arrangement of the negative electrode lead-out end can increase the area of ​​the negative electrode on the battery cell, thereby improving the current carrying capacity of the battery cell.

[0181] The battery cell provided in the embodiments of this disclosure further includes: a positive current collector 900, which is connected to another current collector 100 at the far end of the other side along the stacking direction of the bipolar electrode; a positive lead-out terminal is formed on the side of the positive current collector 900 away from the current collector 100.

[0182] Understandably, the positive terminal is used to form the positive terminal of the battery cell so that the battery cell can be used normally.

[0183] It should be noted that when a positive electrode lead-out end is formed on the side of the positive current collector 900 away from the current collector 100, a positive electrode dressing 200 is coated on the side of the positive current collector 900 close to the current collector 100, and the positive electrode dressing 200 and the negative electrode dressing 300 of the adjacent current collector 100 located at the far end are arranged opposite each other.

[0184] It is understandable that the positive electrode dressing 200 on the positive current collector 900 and the negative electrode dressing 300 of the adjacent current collector 100 located at the other end on the other side are arranged opposite each other, so that the positive current collector 900 can be electrically connected to the adjacent current collector 100 located at the other end on the other side; the arrangement of the positive electrode lead can increase the area of ​​the positive electrode on the battery cell, thereby improving the current carrying capacity of the battery cell.

[0185] It should be noted that, along the stacking direction of the bipolar electrode, the first gasket 400 has a fourth thickness H4, which satisfies the following condition: 0.04mm≤H4≤1mm.

[0186] It is understandable that the fourth thickness H4 satisfies: 0.04mm≤H4≤1mm, which allows the first gasket 400 to accommodate the positive electrode dressing 200 along the thickness direction of the current collector 100, so as to provide safe protection for the positive electrode dressing 200, and can reduce the space occupied by the cell, thereby increasing the energy density of the cell.

[0187] It should be noted that if the fourth thickness H4 is less than 0.04 mm, part of the positive electrode coating 200 will be exposed in the stacking direction of the bipolar electrode, resulting in a short circuit or leakage in the cell; if the fourth thickness H4 is greater than 1 mm, the space occupied by the first gasket 400 will increase, resulting in a larger space occupied by the cell, thereby reducing the energy density of the cell.

[0188] It should be noted that, along the stacking direction of the bipolar electrode, the second gasket 500 has a fifth thickness H5, which satisfies the following condition: 0.04mm≤H5≤1mm.

[0189] It is understandable that the fifth thickness H5 satisfies: 0.04mm≤H5≤1mm, which allows the second gasket 500 to accommodate the negative electrode dressing 300 along the stacking direction of the bipolar electrode sheets, so as to provide safety protection for the negative electrode dressing 300, and can reduce the space occupied by the cell, thereby increasing the energy density of the cell.

[0190] It should be noted that if the fifth thickness H5 is less than 0.04 mm, part of the negative electrode coating 300 will be exposed in the stacking direction of the bipolar electrode, resulting in a short circuit or leakage in the cell; if the fifth thickness H5 is greater than 1 mm, the space occupied by the second gasket 500 will increase, resulting in a larger space occupied by the cell, thereby reducing the energy density of the cell.

[0191] It should be noted that, along the stacking direction of the bipolar electrodes, the separator 700 has a sixth thickness H6, which satisfies the following condition: 0.003mm ≤ H6 ≤ 0.04mm.

[0192] It is understandable that the sixth thickness H6 satisfies: 0.003mm≤H6≤0.04mm, which can provide safety protection for the inside of the cell and reduce the space occupied by the thin film, thereby improving the energy density of the cell.

[0193] It should be noted that if the sixth thickness H6 is less than 0.003 mm, the film thickness will be reduced, causing a short circuit inside the cell and resulting in abnormal internal heating. If the sixth thickness H6 is greater than 0.04 mm, the space occupied by the film will be increased, which will increase the space occupied by the cell and reduce the energy density of the cell.

[0194] Embodiments of this disclosure provide a battery, including a bipolar electrode or a cell provided in any of the above embodiments.

[0195] This disclosure also provides an electrical device, including an electrical device and a battery cell or battery as described in any of the above embodiments, wherein the battery cell or battery is used to provide electrical energy to the electrical device.

[0196] The electrical equipment in this embodiment can be a vehicle, such as a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle, and a new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. Accordingly, the electrical device can be the vehicle's drive mechanism or the vehicle's control system.

[0197] In addition, electrical equipment can also serve as other energy storage devices, such as mobile phones, portable devices, laptops, electric toys, power tools, ships, and spacecraft. Among these, spacecraft can include airplanes, rockets, space shuttles, or spacecraft.

[0198] Since the electrical device in this embodiment includes the battery cell or battery described in any of the above embodiments, the structure and beneficial effects of the electrical device including the battery cell or battery will not be described in detail here.

[0199] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0200] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0201] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A bipolar electrode, characterized in that, include: A current collector (100) having a first end face (101) and a second end face (102), wherein the first end face (101) and the second end face (102) are arranged opposite to each other along the thickness direction of the current collector (100); Positive electrode dressing (200) is applied to the first end face (101); A negative electrode dressing (300) is applied to the second end face (102); Along the thickness direction of the current collector (100), the positive electrode dressing (200) and the negative electrode dressing (300) are staggered.

2. The bipolar electrode according to claim 1, characterized in that, The positive electrode dressing (200) and the negative electrode dressing (300) are positioned at an interval on the first end face (101).

3. A bipolar electrode according to claim 1, characterized in that, The orthographic projection of the positive electrode dressing (200) on the first end face (101) is adjacent to the orthographic projection of the negative electrode dressing (300) on the first end face (101).

4. A bipolar electrode according to claim 1, characterized in that, The current collector (100) is electrically connected to the positive electrode dressing (200) and the negative electrode dressing (300).

5. A bipolar electrode according to claim 1, characterized in that, Along the extending direction of the current collector (100), the current collector (100) has a first length L1; Along the extending direction of the current collector (100), the negative electrode dressing (300) has a second length L2; Along the extending direction of the current collector (100), the positive electrode dressing (200) has a third length L3; The first length L1, the second length L2, and the third length L3 satisfy the following: 1 / 2 * L1 > L2 > L3.

6. A bipolar electrode according to claim 5, characterized in that, The second length L2 satisfies: 20mm ≤ L2 ≤ 1500mm; And / or, the third length L3 satisfies: 20mm≤L3≤1500mm.

7. A bipolar electrode sheet according to any one of claims 1-6, characterized in that, The current collector (100) includes a first connecting part (103), a second connecting part (104) and a third connecting part (105) connected in sequence; The second connecting part (104) is arranged at an angle to the first connecting part (103) and the third connecting part (105); The negative electrode dressing (300) is at least partially coated on the first connecting portion (103), and the positive electrode dressing (200) is at least partially coated on the third connecting portion (105).

8. A bipolar electrode sheet according to any one of claims 1-6, characterized in that, The current collector (100) has a first thickness H1, which satisfies: 0.002mm ≤ H1 ≤ 0.3mm; And / or along the thickness direction of the current collector (100), the negative electrode dressing (300) has a second thickness H2, the second thickness H2 satisfying: 0.04mm≤H2≤0.9mm; And / or along the thickness direction of the current collector (100), the positive electrode dressing (200) has a third thickness H3, the third thickness H3 satisfying: 0.04mm≤H3≤0.9mm.

9. A battery cell, characterized in that, The invention includes a bipolar electrode sheet according to any one of claims 1-8, wherein multiple bipolar electrodes are provided, and the multiple bipolar electrodes are stacked.

10. A battery cell according to claim 9, characterized in that, In the plurality of bipolar electrodes, the positive electrode dressing (200) of one of two adjacent bipolar electrodes is disposed opposite to the negative electrode dressing (300) of the other. Alternatively, the negative electrode dressing (300) of one of the two adjacent bipolar electrodes is positioned opposite the positive electrode dressing (200) of the other.

11. A battery cell according to claim 10, characterized in that, Along the stacking direction of the bipolar electrode, at least three current collectors (100) are provided. Among the three adjacent current collectors (100), the current collector (100) located in the middle is the first current collector (100), and the current collectors (100) located on both sides are the second current collector (100) and the third current collector (100), respectively. The positive electrode dressing (200) of the first current collector (100) is disposed opposite to the negative electrode dressing (300) of the second current collector (100); The negative electrode dressing (300) of the first current collector (100) is disposed opposite to the positive electrode dressing (200) of the third current collector (100).

12. A battery cell according to claim 11, characterized in that, Along the stacking direction of the bipolar electrodes, the positive electrode dressing (200), in the orthogonal projection of the first current collector (100), is located inside the negative electrode dressing (300), in the orthogonal projection of the first current collector (100).

13. A battery cell according to claim 11, characterized in that, When the positive electrode dressing (200) of the first current collector (100) is disposed opposite to the negative electrode dressing (300) of the second current collector (100), there is a difference between the extension length of the negative electrode dressing (300) and the extension length of the positive electrode dressing (200) along the extension direction of the current collector (100), and the difference is greater than 0.1 mm.

14. A battery cell according to claim 9, characterized in that, Also includes: The first gasket (400) surrounds the outer ring of the positive electrode dressing (200) and is sealed to the first end face (101) of the current collector (100); The second gasket (500) surrounds the outer ring of the negative electrode dressing (300) and is sealed to the second end face (102) of the current collector (100).

15. A battery cell according to claim 14, characterized in that, In two adjacent current collectors (100), the first gasket (400) of the first current collector (100) and the second gasket (500) of the second current collector (100) are sealed together, and the first gasket (400), the second gasket (500), the first current collector (100) and the second current collector (100) together enclose a receiving chamber (600) for containing electrolyte.

16. A battery cell according to claim 15, characterized in that, Also includes: A diaphragm (700) is located, at least partially, between the positive electrode dressing (200) and the negative electrode dressing (300) along the stacking direction of the bipolar electrode sheets.

17. A battery cell according to claim 16, characterized in that, At least a portion of the diaphragm (700) is disposed within the receiving chamber (600).

18. A battery cell according to any one of claims 9-17, characterized in that, Also includes: A negative current collector (800) is connected to one of the current collectors (100) at the far end of one side along the stacking direction of the bipolar electrode. The negative electrode current collector (800) forms a negative electrode lead-out terminal on the side away from the current collector (100).

19. A battery cell according to claim 18, characterized in that, When a negative electrode lead-out end is formed on the side of the negative electrode current collector (800) away from the current collector (100), a negative electrode dressing (300) is coated on the side of the negative electrode current collector (800) close to the current collector (100), and the negative electrode dressing (300) of the negative electrode current collector and the positive electrode dressing (200) of the adjacent, most end current collector (100) are arranged opposite each other.

20. A battery cell according to any one of claims 9-17, characterized in that, Also includes: A positive current collector (900) is connected to another current collector (100) at the other end along the stacking direction of the bipolar electrode. The positive electrode current collector (900) forms a positive electrode lead-out terminal on the side away from the current collector (100).

21. A battery cell according to claim 20, characterized in that, When a positive electrode lead-out terminal is formed on the side of the positive current collector (900) away from the current collector (100), a positive electrode dressing (200) is coated on the side of the positive current collector (900) close to the current collector (100), and the positive electrode dressing (200) of the positive current collector and the negative electrode dressing (300) of the adjacent, end-positioned current collector (100) are arranged opposite each other.

22. A battery cell according to claim 16, characterized in that, Along the stacking direction of the bipolar electrode, the first gasket (400) has a fourth thickness H4, which satisfies: 0.04mm≤H4≤1mm; And / or, along the stacking direction of the bipolar electrode, the second gasket (500) has a fifth thickness H5, the fifth thickness H5 satisfying: 0.04mm≤H5≤1mm; And / or, along the stacking direction of the bipolar electrode, the separator (700) has a sixth thickness H6, the sixth thickness H6 satisfying: 0.003mm≤H6≤0.04mm.

23. A battery, characterized in that, It includes a bipolar electrode sheet according to any one of claims 1-8 or a battery cell according to any one of claims 9-22.

24. An electrical appliance, characterized in that... The device includes an electrical appliance and a battery cell as described in any one of claims 9-22 or a battery as described in claim 23, wherein the battery cell or the battery is used to provide electrical energy to the electrical appliance.

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