Battery monomer, battery device and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises an electrode assembly, and the electrode assembly comprises a negative pole piece, a positive pole piece and an insulating layer. The first main body area of the negative pole piece is provided with a first edge. A positive current collector of the positive pole piece is provided with a second edge, and the second edge exceeds the first edge in the first direction. The insulating layer is arranged on one side, facing the negative pole piece, of the positive pole piece and is close to the second edge, on a projection plane perpendicular to the stacking direction of the positive pole piece and the negative pole piece, the orthographic projection of the first edge falls into the orthographic projection of the insulating layer, and the insulating layer exceeds the first edge in the direction from the first edge to the second edge. Wherein the size of the insulating layer along the first direction is d1, the minimum size of the insulating layer exceeding the first edge is d2, and the condition that 0.5 d1 < = d2 < d1 is satisfied. According to the technical scheme, the reliability of the battery device can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery production, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] In the development of battery device technology, how to improve the reliability of the battery device is a technical problem that needs to be solved in battery device technology. Practical new type content

[0004] The present application provides a battery monomer, a battery device and a power utilization device, which can improve the reliability of the battery device.

[0005] The present application is realized by the following technical solutions:

[0006] In a first aspect, the present application provides a battery monomer, which comprises an electrode assembly, the electrode assembly comprising a negative electrode sheet, a positive electrode sheet and an insulating layer. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, the negative electrode current collector comprising a first main body region and a negative electrode tab, the negative electrode active material layer being arranged in the first main body region, the first main body region having a first edge in the first direction, and the negative electrode tab extending from the first edge. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer arranged on the surface of the positive electrode current collector, the positive electrode sheet being arranged in a stack with the negative electrode sheet, the positive electrode current collector having a second edge on the same side as the first edge in the first direction, and the second edge exceeding the first edge in the first direction. The insulating layer is arranged on the side of the positive electrode sheet facing the negative electrode sheet and close to the second edge, the orthographic projection of the first edge falls within the orthographic projection of the insulating layer in the projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, and the insulating layer exceeds the first edge in the direction from the first edge to the second edge. The dimension of the insulating layer in the first direction is d1, the minimum dimension of the insulating layer exceeding the first edge is d2, and the condition 0.5d1≤d2

[0007] The technical scheme of the embodiment of the application is that the first edge can be the edge of the negative pole piece for cutting the negative pole lug, the orthographic projection of the first edge falls into the orthographic projection of the insulating layer on the projection plane perpendicular to the stacking direction of the positive pole piece and the negative pole piece, and the burr of the first edge can be blocked by the insulating layer after the burr pierces the isolation film, so that the risk of short circuit of the positive pole piece and the negative pole piece can be reduced, and the reliability of the battery monomer can be improved. Meanwhile, in the direction from the first edge to the second edge, the minimum size d2 of the insulating layer beyond the first edge meets the above condition, so that the size of the insulating layer beyond the first edge is relatively large. When the electrode assembly contacts the insulating piece arranged in the shell of the battery monomer, the insulating layer contacts and is deformed by the insulating piece. After the insulating layer pierces the isolation film, because the size of the insulating layer beyond the first edge is relatively large, the probability of contact between the insulating layer and the negative pole piece is reduced, that is, the probability of contact between the positive current collector provided with the insulating layer and the negative pole piece is reduced, which is beneficial to reducing the risk of short circuit of the positive pole piece and the negative pole piece, and further improving the reliability of the battery monomer.

[0008] In some embodiments, 0.7mm≤d2≤5mm.

[0009] The technical scheme of the embodiment of the application is that in the direction from the first edge to the second edge, the minimum size d2 of the insulating layer beyond the first edge meets the above condition, so that the size of the insulating layer beyond the first edge is further relatively large, which is further beneficial to reducing the risk of short circuit of the positive pole piece and the negative pole piece, and further improving the reliability of the battery monomer.

[0010] In some embodiments, the electrode assembly is of a winding type, and along the winding direction of the electrode assembly, the electrode assembly comprises an initial region, an intermediate region and a tail region connected in sequence, the winding number of the initial region is in the range of 1 to 3, the winding number of the tail region is in the range of 1 to 2, and the extension direction of the winding axis of the electrode assembly is parallel to the first direction. In the direction from the initial region to the tail region, the minimum size of the insulating layer of the initial region beyond the first edge gradually decreases, the minimum size of the insulating layer of the intermediate region beyond the first edge remains unchanged, and the minimum size of the insulating layer of the tail region beyond the first edge gradually increases.

[0011] The technical scheme of the embodiment of the application is that, from the direction of the initial area pointing to the tail area, the minimum size of the insulating layer of the initial area beyond the first edge is gradually reduced, the minimum size of the insulating layer of the intermediate area beyond the first edge remains unchanged, and the minimum size of the insulating layer of the tail area beyond the first edge is gradually increased, so that the size of the insulating layer of the initial area and the tail area beyond the first edge is large, the probability of the insulating layer of the initial area and the tail area contacting the negative pole piece is reduced, that is, the probability of the positive pole current collector provided with the insulating layer contacting the negative pole piece is reduced, the risk of the positive pole piece and the negative pole piece contacting and short-circuiting is reduced, and the reliability of the battery monomer is further improved.

[0012] In some embodiments, the battery monomer further includes a shell, a positive pole terminal and a negative pole terminal. The electrode assembly is arranged in the shell, and the shell includes a first wall, a thickness direction of the first wall being parallel to the first direction. The positive pole terminal is arranged on the first wall. The negative pole terminal is arranged on the first wall. The positive pole current collector includes a second main body area and a positive pole tab, the positive pole active material layer is arranged on the second main body area, the positive pole tab extends from the second edge and is electrically connected with the positive pole terminal, and the negative pole tab is electrically connected with the negative pole terminal.

[0013] The technical scheme of the embodiment of the application is that, the positive pole terminal is connected with the positive pole tab, and the negative pole terminal is connected with the negative pole tab, so that the charging and discharging of the battery monomer is facilitated.

[0014] In some embodiments, the electrode assembly is in a winding type structure, and the electrode assembly includes an initial area and a tail area. From the direction of the initial area pointing to the tail area, the distance between the first edge and the first wall in the first direction is gradually reduced, and the distance between the second edge and the first wall in the first direction is gradually reduced.

[0015] The technical scheme of the embodiment of the application is that, from the direction of the initial area pointing to the tail area, the distance between the first edge and the first wall in the first direction is gradually reduced, and the distance between the second edge and the first wall in the first direction is gradually reduced, so that the distance between the insulating layer of the initial area and the first wall in the first direction is large, and when the insulating layer contacts the insulating piece, the insulating layer of the tail area contacts the insulating piece first, the risk of the insulating layer of the initial area contacting and being extruded and deformed is reduced, that is, the risk of the positive pole piece and the negative pole piece of the initial area contacting and short-circuiting is reduced, and the reliability of the battery monomer is improved.

[0016] In some embodiments, the electrode assembly is in a winding type structure, and the electrode assembly includes an initial area and a tail area. From the direction of the initial area pointing to the tail area, the distance between the first edge and the first wall in the first direction is gradually increased, and the distance between the second edge and the first wall in the first direction is gradually increased.

[0017] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is gradually increased, and the distance between the second edge and the first wall in the first direction is gradually increased, so that the distance between the insulating layer of the tail area and the first wall in the first direction is relatively large, thereby reducing the risk that the insulating layer of the tail area is in contact with the insulating piece and is deformed by extrusion when the insulating layer is in contact with the insulating piece, that is, reducing the risk of contact short circuit of the positive pole piece and the negative pole piece of the tail area, and improving the reliability of the battery monomer.

[0018] In some embodiments, the electrode assembly is in a wound structure, and the electrode assembly includes an initial area and a tail area. In the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is gradually decreased, and the distance between the second edge and the first wall in the first direction is gradually increased.

[0019] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is gradually decreased, and the distance between the second edge and the first wall in the first direction is gradually increased, so that the size of the insulating layer of the initial area beyond the first edge is relatively large, thereby reducing the risk that the insulating layer of the initial area is in contact with the insulating piece and is deformed by extrusion, that is, reducing the risk of contact short circuit of the positive pole piece and the negative pole piece of the initial area, and improving the reliability of the battery monomer.

[0020] In some embodiments, the electrode assembly is in a wound structure, and the electrode assembly includes an initial area and a tail area. In the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is gradually increased, and the distance between the second edge and the first wall in the first direction is gradually decreased.

[0021] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is gradually decreased, and the distance between the second edge and the first wall in the first direction is gradually increased, so that the size of the insulating layer of the tail area beyond the first edge is relatively large, thereby reducing the risk that the insulating layer of the tail area is in contact with the insulating piece and is deformed by extrusion, that is, reducing the risk of contact short circuit of the positive pole piece and the negative pole piece of the tail area, and improving the reliability of the battery monomer.

[0022] In some embodiments, the electrode assembly is in a wound structure, and the electrode assembly includes an initial area and a tail area. In the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually decreased.

[0023] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually reduced, so that the size of the insulating layer of the tail area beyond the first edge is large, the risk that the insulating layer of the tail area contacts the insulating piece and is deformed by extrusion is reduced, that is, the risk that the positive pole piece and the negative pole piece of the tail area are in contact and short-circuit is reduced, and the reliability of the battery monomer is improved.

[0024] In some embodiments, the electrode assembly is in a jelly-roll structure, and the electrode assembly comprises an initial area and a tail area, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually increased.

[0025] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually increased, so that the size of the insulating layer of the tail area beyond the first edge is large, the risk that the insulating layer of the tail area contacts the insulating piece and is deformed by extrusion is reduced, that is, the risk that the positive pole piece and the negative pole piece of the tail area are in contact and short-circuit is reduced, and the reliability of the battery monomer is improved.

[0026] In some embodiments, the electrode assembly is in a jelly-roll structure, and the electrode assembly comprises an initial area and a tail area, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually increased.

[0027] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually increased, so that the size of the insulating layer of the tail area beyond the first edge is large, the risk that the insulating layer of the tail area contacts the insulating piece and is deformed by extrusion is reduced, that is, the risk that the positive pole piece and the negative pole piece of the tail area are in contact and short-circuit is reduced, and the reliability of the battery monomer is improved.

[0028] In some embodiments, the electrode assembly is in a jelly-roll structure, and the electrode assembly comprises an initial area and a tail area, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is kept unchanged, and the distance between the second edge and the first wall in the first direction is gradually increased.

[0029] The technical scheme of the embodiment of the application is that, in the direction from the initial area to the tail area, the distance between the first edge and the first wall in the first direction is gradually increased, and the distance between the second edge and the first wall in the first direction is kept unchanged, so that the size of the insulating layer of the tail area beyond the first edge is large, the risk of the insulating layer of the tail area being in contact with the insulating piece and being deformed by extrusion is reduced, that is, the risk of the positive electrode tab and the negative electrode tab of the tail area being in contact and short-circuiting is reduced, and the reliability of the battery monomer is improved.

[0030] In some embodiments, the first wall is configured to support the electrode assembly.

[0031] The technical scheme of the embodiment of the application is that the first wall supports the electrode assembly, and the battery monomer can be used in an inverted state, so as to improve the application range of the battery monomer.

[0032] In some embodiments, the electrode assembly includes a main body part, a positive electrode tab and a negative electrode tab, and the first main body area, the negative active material layer, the second main body area and the positive active material layer constitute the main body part. The battery monomer further includes an insulating piece and a support piece. The insulating piece is arranged on the side of the first wall facing the electrode assembly. The support piece is arranged between the insulating piece and the main body part and supports the main body part.

[0033] The technical scheme of the embodiment of the application is that the insulating piece can separate the first wall and the electrode assembly, so as to reduce the risk of positive and negative contact short-circuiting. The support piece supports the main body part, can limit the movement of the main body part towards the first wall, reduce the influence of the movement of the main body part on the connection stability of the positive electrode tab and the negative electrode tab to the corresponding components, and facilitate the improvement of the reliability of the battery monomer.

[0034] In the third aspect, the application further provides a battery device, which includes the battery monomer according to any one of the above embodiments.

[0035] In some embodiments, the battery device includes a box body, and the battery monomer is arranged in the box body. The battery monomer includes a shell, a positive electrode terminal and a negative electrode terminal, the electrode assembly is arranged in the shell, the shell includes a first wall, the positive electrode terminal and the negative electrode terminal are arranged on the first wall, the positive electrode tab of the electrode assembly is connected to the positive electrode terminal, the negative electrode tab of the electrode assembly is connected to the negative electrode terminal, and the first wall supports the electrode assembly.

[0036] The technical scheme of the embodiment of the application is that the first wall supports the electrode assembly, and the battery monomer can be used in an inverted state, so as to improve the application range of the battery monomer.

[0037] In the third aspect, the application further provides a battery device, which includes the battery monomer according to any one of the above embodiments.

[0038] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0041] Figure 2 This is an exploded view of the structure of a battery device provided in some embodiments of this application;

[0042] Figure 3 This is an exploded view of the structure of a battery cell provided in some embodiments of this application;

[0043] Figure 4 This is a schematic diagram of the winding structure of an electrode assembly provided in some embodiments of this application;

[0044] Figure 5 A schematic diagram showing the unfolded state of the positive electrode sheet provided in some embodiments of this application;

[0045] Figure 6 A schematic diagram showing the unfolded state of the negative electrode sheet provided for some embodiments of this application;

[0046] Figure 7 A schematic diagram illustrating the stacked state of positive and negative electrode sheets provided in some embodiments of this application;

[0047] Figure 8 for Figure 7 Enlarged view of point A in the image;

[0048] Figure 9 A cross-sectional view of a portion of the stacked structure of the positive and negative electrode sheets provided in the first embodiment of this application;

[0049] Figure 10 This is a cross-sectional view of a portion of the stacked structure of the positive and negative electrode sheets provided in the second embodiment of this application.

[0050] Figure 11 A cross-sectional view of a portion of the stacked structure of the positive and negative electrode sheets provided in the third embodiment of this application;

[0051] Figure 12A cross-sectional view of a partial structure of a stacked state of a positive electrode tab and a negative electrode tab according to the fourth embodiment of the present application;

[0052] Figure 13 A cross-sectional view of a partial structure of a stacked state of a positive electrode tab and a negative electrode tab according to the fifth embodiment of the present application;

[0053] Figure 14 A cross-sectional view of a partial structure of a stacked state of a positive electrode tab and a negative electrode tab according to the sixth embodiment of the present application;

[0054] Figure 15 A cross-sectional view of a partial structure of a stacked state of a positive electrode tab and a negative electrode tab according to the seventh embodiment of the present application;

[0055] Figure 16 A cross-sectional view of a partial structure of a stacked state of a positive electrode tab and a negative electrode tab according to the eighth embodiment of the present application;

[0056] Figure 17 A cross-sectional view of a partial structure of a stacked state of a positive electrode tab and a negative electrode tab according to the ninth embodiment of the present application;

[0057] Figure 18 A cross-sectional view of a battery cell according to some embodiments of the present application.

[0058] Figure: 1 - battery cell; 10 - electrode assembly; 11 - negative electrode tab; 111 - negative current collector; 1111 - first edge; 1112 - first main body region; 112 - negative active material layer; 113 - negative electrode tab winding start end; 114 - negative electrode tab winding end; 115 - negative electrode tab; 12 - positive electrode tab; 121 - positive current collector; 1211 - second edge; 1212 - second main body region; 122 - positive active material layer; 123 - positive electrode tab winding start end; 124 - positive electrode tab winding end; 125 - positive electrode tab; 13 - insulating layer; 14 - initial region; 15 - end region; 16 - intermediate region; 17 - main body portion; 18 - separator; 20 - case; 21 - first wall; 22 - housing; 23 - end cap; 30 - positive terminal; 40 - negative terminal; 50 - insulator; 60 - support; 100 - battery device; 110 - box; 120 - first sub-box; 130 - second sub-box; 1000 - vehicle; 1100 - controller; 1200 - motor; X - first direction; Y - stacking direction of positive electrode tab and negative electrode tab; Z - direction in which initial region points to end region; P - winding direction of electrode assembly. DETAILED DESCRIPTION

[0059] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0060] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0061] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiments, nor are they necessarily mutually exclusive or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0062] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0064] In the present application, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more groups (including two groups), and "multiple pieces" means two or more pieces (including two pieces).

[0065] The battery device mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0066] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0067] In some embodiments, the battery device can be a battery pack including a box and one or more battery cell assemblies accommodated in the box.

[0068] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box by fixing the battery module in the box.

[0069] As an example, the battery cell assembly can also be accommodated in the box by directly fixing a plurality of battery cells in the box.

[0070] As an example, the box can include a first sub-box and a second sub-box. The first sub-box and the second sub-box are coupled so that a closed space is formed inside the box to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or unsealed. The first sub-box can be a top cover or a bottom plate.

[0071] As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame so that a closed space is formed inside the box to accommodate the battery cell assembly.

[0072] As an example, the box can be part of the chassis structure of a vehicle. For example, the top cover of the box can be at least part of the floor of the vehicle, or the frame of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0073] In some embodiments, the battery device refers to an energy storage device, which includes a box, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0074] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging the battery cell.

[0075] The battery cell can be, but is not limited to, a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc.

[0076] The battery cell generally includes an electrode assembly. The electrode assembly includes a cathode, an anode, and a separator. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the cathode and the anode. The separator is disposed between the cathode and the anode, and can function to prevent short circuiting of the cathode and the anode while allowing the active ions to pass through.

[0077] In some embodiments, the cathode can be a cathode sheet, which can include a cathode current collector and a cathode active material disposed on at least one surface of the cathode current collector.

[0078] As an example, the cathode current collector has two surfaces opposite in the thickness direction thereof, and the cathode active material is disposed on either one or both of the two surfaces of the cathode current collector.

[0079] As an example, the cathode current collector can be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. with a silver plating treatment on the surface thereof can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0080] As an example, the cathode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a cathode active material for a battery can also be used.

[0081] In some embodiments, the anode can be an anode sheet, which can include an anode current collector.

[0082] As an example, the anode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver plating treatment on the surface thereof, stainless steel with a silver plating treatment on the surface thereof, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used.

[0083] In some embodiments, the anode current collector has two surfaces opposite in the thickness direction thereof, and the anode active material is disposed on either one or both of the two surfaces of the anode current collector.

[0084] As an example, the negative active material can employ a negative active material for a battery known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative active material for a battery can also be used.

[0085] These negative active materials can be used alone or in combination of two or more.

[0086] In some embodiments, the separator is a separator film. The present application does not have a particular limitation on the type of separator film, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0087] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a single member located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0088] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes, and functions to transport ions and separate the positive and negative electrodes.

[0089] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0090] In some embodiments, the electrode assembly is a stacked structure.

[0091] In some embodiments, the battery cell can include a case. The case is used to package the electrode assembly and other components such as the electrolyte. The case can be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., copper-aluminum composite case), or an aluminum-plastic film, etc.

[0092] In some embodiments, the case includes an end cap and a case body, and the case body is provided with an opening, and the end cap closes the opening to form a sealed space for accommodating the electrode assembly and the electrolyte, etc. The case body can be provided with one or more openings. The end cap can also be provided with one or more openings.

[0093] In some embodiments, at least one electrode terminal is arranged on the shell, and the electrode terminal is electrically connected with the tab of the electrode assembly. The electrode terminal can be directly connected with the tab, or indirectly connected with the tab through an adapter. The electrode terminal can be arranged on the end cover, or arranged on the shell.

[0094] In some embodiments, an explosion-proof valve is arranged on the shell. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0095] In some embodiments, the shell can be a sealed structure, or a non-sealed structure. As an example, when the shell is a sealed structure, the shell can protect the electrode assembly and prevent electrolyte leakage and the like. When the shell is a non-sealed structure, the shell can protect the electrode assembly, and a sealing bag can be further arranged between the shell and the electrode assembly, and the sealing bag is used to encapsulate the electrode assembly, electrolyte and the like. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum plastic film.

[0096] As an example, the battery cell can be a prismatic battery cell, a soft-pack battery cell, or a battery cell with other shapes, and the prismatic battery cell includes a square battery cell, a blade-shaped battery cell, a multi-prismatic battery cell, for example, a hexagonal battery cell, and the like.

[0097] At present, from the development of market situation, the battery has been widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as electric tools, unmanned aerial vehicles, energy storage equipment and other fields. With the continuous expansion of the field of battery, the demand for its market is also increasing.

[0098] The development of battery technology needs to consider many design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters. In addition, with the change of environmental conditions and / or internal conditions of the battery, the reliability of the battery is also one of the key factors to be considered.

[0099] Currently, an electrode assembly is arranged in a housing to form a battery cell. The electrode assembly includes a positive electrode sheet and a negative electrode sheet arranged in a stack. In order to reduce the risk of ion precipitation from the negative electrode sheet, the positive projection of the negative electrode sheet covers the positive projection of the positive electrode sheet in a projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet. Meanwhile, the negative electrode sheet includes a negative current collector having a first edge extending beyond the negative electrode tab, and the positive electrode sheet includes a positive current collector having a second edge extending beyond the positive electrode tab. In order to reduce the risk of the first edge of the negative electrode sheet piercing the separator and contacting the positive electrode sheet, an insulating layer can be arranged on the side of the positive current collector of the positive electrode sheet facing the negative electrode sheet. The insulating layer is arranged on the side close to the second edge, and the positive projection of the insulating layer covers the positive projection of the first edge of the negative electrode sheet in the projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, so as to separate the positive electrode sheet and the negative electrode sheet by the insulating layer.

[0100] The housing includes a first wall provided with an electrode terminal, and the tabs of the electrode assembly are electrically connected to the electrode terminal. The battery cell further includes an insulating member arranged between the positive current collector (and the negative current collector) and the first wall, to reduce the risk of contact between the positive electrode sheet and the negative electrode sheet.

[0101] However, the insulating layer and the insulating member are at risk of being deformed by extrusion. After deformation, the bent insulating layer pierces the separator and contacts the negative electrode sheet, and there is a risk of contact between the positive current collector and the negative electrode sheet, which leads to short circuit, affecting the reliability of the battery cell and the battery device.

[0102] Based on the above considerations, in order to reduce the risk of contact between the positive electrode sheet and the negative electrode sheet leading to short circuit and poor reliability of the battery cell and the battery, embodiments of the present application provide a battery cell including an electrode assembly. The electrode assembly includes a negative electrode sheet, a positive electrode sheet, and an insulating layer. The negative electrode sheet includes a negative current collector and a negative active material layer arranged on the surface of the negative current collector. In a first direction parallel to the width direction of the negative electrode sheet, the negative current collector has a first edge. The positive electrode sheet includes a positive current collector and a positive active material layer arranged on the surface of the positive current collector. The positive electrode sheet and the negative electrode sheet are arranged in a stack. In the first direction, the positive current collector has a second edge on the same side as the first edge, and the second edge exceeds the first edge in the first direction. The insulating layer is arranged on the side of the positive electrode sheet facing the negative electrode sheet, and is arranged close to the second edge. In a projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, the positive projection of the first edge falls within the positive projection of the insulating layer. In the direction from the first edge to the second edge, the insulating layer exceeds the first edge. The dimension of the insulating layer in the first direction is d1, the minimum dimension of the insulating layer exceeding the first edge in the direction from the first edge to the second edge is d2, and the condition 0.5d1≤d2

[0103] In the direction from the first edge to the second edge, the minimum size d2 of the insulating layer beyond the first edge satisfies the above condition, so that the size of the insulating layer beyond the first edge is large, when the electrode assembly contacts the insulating piece arranged in the shell of the battery monomer, the insulating layer contacts and is extruded by the insulating piece, after the insulating layer pierces the diaphragm, due to the large size of the insulating layer beyond the first edge, the probability of the contact between the insulating layer and the negative pole piece is reduced, that is, the probability of the contact between the positive pole current collector provided with the insulating layer and the negative pole piece is reduced, which is beneficial to reduce the risk of the contact short circuit between the positive pole piece and the negative pole piece, and further improve the reliability of the battery monomer.

[0104] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, an electric device such as a vehicle, a ship or an aircraft, and can also be used to form a power supply system of the electric device.

[0105] The embodiments of the present application provide an electric device using a battery as a power supply, and the electric device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric vehicle, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy and an electric aircraft toy, and the spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft.

[0106] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0107] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a vehicle provided by some embodiments of the present application is shown. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric vehicle, a hybrid electric vehicle or a range extended vehicle. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom, the head or the tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, the battery device 100 can be used as an operating power supply of the vehicle 1000, which is used for the working power demand of the circuit system of the vehicle 1000, for example, the working power demand during the starting, navigation and running of the vehicle 1000.

[0108] The vehicle 1000 can further include a controller 1100 and a motor 1200, and the controller 1100 is used to control the battery device 100 to supply power to the motor 1200, for example, the working power demand during the starting, navigation and running of the vehicle 1000.

[0109] In some embodiments of the present application, the battery device 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle 1000.

[0110] Please refer to Figure 2 , Figure 2 The structural exploded view of the battery device provided in some embodiments of the present application is shown in FIG. 1. The battery device 100 can further include a box body 110, in which the battery cells 1 are accommodated. The box body 110 is used to provide accommodation space for the battery cells 1, and the box body 110 can adopt various structures. In some embodiments, the box body 110 can include a first sub-box body 120 and a second sub-box body 130, the first sub-box body 120 and the second sub-box body 130 are mutually covered, and the first sub-box body 120 and the second sub-box body 130 jointly define an accommodation space for accommodating the battery cells 1. The second sub-box body 130 can be a hollow structure with one end open, and the first sub-box body 120 can be a plate-like structure, which is covered on the open side of the second sub-box body 130 to jointly define the accommodation space with the second sub-box body 130; the first sub-box body 120 and the second sub-box body 130 can also be hollow structures with one side open, and the open side of the first sub-box body 120 is covered on the open side of the second sub-box body 130.

[0111] In the battery device 100, the battery cells 1 can be multiple, and the multiple battery cells 1 can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the multiple battery cells 1 are connected in series and in parallel. The multiple battery cells 1 can be directly connected in series, in parallel, or in a mixed manner, and then the whole of the multiple battery cells 1 is accommodated in the box body 110; of course, the multiple battery cells 1 can be first connected in series, in parallel, or in a mixed manner to form a battery device 100 module, and then multiple battery device 100 modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box body 110. The battery device 100 can further include other structures, for example, the battery device 100 can further include a current collecting component for realizing the electrical connection between the multiple battery cells 1.

[0112] The battery cells 1 can be secondary batteries or primary batteries; the battery cells 1 can also be lithium-sulfur batteries, sodium-ion batteries, or magnesium-ion batteries, but are not limited thereto.

[0113] Please refer to Figure 3 , Figure 3 The structural exploded view of the battery cell provided in some embodiments of the present application is shown in FIG. 2. As shown in FIG. 2, the battery cell 1 can include a positive electrode 21, a negative electrode 22, and a separator 23 interposed between the positive electrode 21 and the negative electrode 22. Figure 3As shown, the battery cell 1 includes a housing 20, an electrode assembly 10, and two electrode terminals, which can include a positive electrode terminal 30 and a negative electrode terminal 40. The housing 20 includes a shell 22 having an opening and an end cap 23 closing the opening to isolate the internal environment of the battery cell 1 from the external environment.

[0114] The shell 22 is a component for cooperating with the end cap 23 to form the internal environment of the battery cell 1, in which the electrode assembly 10, electrolyte, and other components can be accommodated. The shell 22 and the end cap 23 can be independent components. The shell 22 can be of various shapes and sizes. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 10. The shell 22 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0115] The end cap 23 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 1 from the external environment. Without limitation, the shape of the end cap 23 can be adapted to the shape of the shell 22 to cooperate with the shell 22. Alternatively, the end cap 23 can be made of a material with certain hardness and strength (such as aluminum alloy), so that the end cap 23 is less likely to deform when subjected to extrusion and collision, allowing the battery cell 1 to have higher structural strength and improved reliability. The end cap 23 can be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect with the electrode assembly 10 for outputting or inputting the electrical energy of the battery cell 1. The material of the end cap 23 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not specially limited in the embodiments. In some embodiments, an insulating member 50 can also be provided on the inner side of the end cap 23, which can be used to isolate the electrical connection components in the shell 22 from the end cap 23 to reduce the risk of short circuit. Exemplarily, the insulating member 50 can be plastic, rubber, etc.

[0116] Please refer to Figure 3 , and refer to Figure 4 to Figure 8 , Figure 4 the winding structure schematic diagram of the electrode assembly provided by some embodiments of the present application, Figure 5 the unfolded state schematic diagram of the positive electrode tab provided by some embodiments of the present application, Figure 6 the unfolded state schematic diagram of the negative electrode tab provided by some embodiments of the present application, Figure 7 the schematic diagram of the stacked state of the positive electrode tab and the negative electrode tab provided by some embodiments of the present application, Figure 8 the Figure 7An enlarged view of A in FIG. 1. The embodiments of the present application provide a battery monomer 1, which includes an electrode assembly 10, the electrode assembly 10 includes a negative electrode tab 11, a positive electrode tab 12 and an insulation layer 13. The negative electrode tab 11 includes a negative electrode current collector 111 and a negative electrode active material layer 112, the negative electrode current collector 111 includes a first main area 1112 and a negative electrode lug 115, the negative electrode active material layer 112 is arranged on the first main area 1112, in the first direction X, the first main area 1112 has a first edge 1111, and the negative electrode lug 115 extends from the first edge 1111. The positive electrode tab 12 includes a positive electrode current collector 121 and a positive electrode active material layer 122 arranged on the surface of the positive electrode current collector 121, and the positive electrode tab 12 is arranged in a stack with the negative electrode tab 11, in the first direction X, the positive electrode current collector 121 has a second edge 1211 on the same side as the first edge 1111, and the second edge 1211 exceeds the first edge 1111 in the first direction X. The insulation layer 13 is arranged on the side of the positive electrode tab 12 facing the negative electrode tab 11 and close to the second edge 1211, in the projection plane perpendicular to the stacking direction of the positive electrode tab 12 and the negative electrode tab 11, the positive projection of the first edge 1111 falls within the positive projection of the insulation layer 13, and the insulation layer 13 exceeds the first edge 1111 in the direction from the first edge 1111 to the second edge 1211. Wherein, the size of the insulation layer 13 along the first direction X is d1, the minimum size of the insulation layer 13 exceeding the first edge 1111 is d2, and the condition is satisfied: 0.5d1≤d2<d1.

[0117] In some embodiments, the electrode assembly 10 can be a wound electrode assembly.

[0118] In some embodiments, the electrode assembly 10 can be a stacked electrode assembly.

[0119] In some embodiments, the negative electrode tab 11 can include a negative electrode current collector 111 and a negative electrode active material layer 112, and the negative electrode active material layer 112 can be arranged on both surfaces of the negative electrode current collector 111 in the thickness direction thereof.

[0120] In some embodiments, the positive electrode tab 12 can include a positive electrode current collector 121 and a positive electrode active material layer 122, and the positive electrode active material layer 122 can be arranged on both surfaces of the positive electrode current collector 121 in the thickness direction thereof.

[0121] In some embodiments, the negative electrode current collector 111 can have a first edge 1111, the first edge 1111 can be located on the side of the negative electrode current collector 111 extending out of the negative electrode lug 115, and the negative electrode active material layer 112 can extend to the first edge 1111.

[0122] In some embodiments, the positive current collector 121 can have a second edge 1211, the second edge 1211 can be located at a side of the positive current collector 121 extending out of the positive tab 125, the positive active material layer 122 extends along a direction close to the second edge 1211, the insulating layer 13 is arranged between the edge of the positive active material layer 122 close to the second edge 1211 and the second edge 1211, and the insulating layer 13 can extend to the second edge 1211.

[0123] It should be noted that the first edge 1111 here is the edge of the negative current collector 111 excluding the negative tab 115, and the second edge 1211 is the edge of the positive current collector 121 excluding the positive tab 125.

[0124] In some embodiments, the first direction can be represented by the direction indicated by the letter X in the figure.

[0125] In some embodiments, in the first direction X, the second edge 1211 is beyond the first edge 1111, the width of the negative active material layer 112 is set to be greater than the width of the positive active material layer 122 to form an OverHang, so as to reduce the risk of metal ions being precipitated on the surface of the negative electrode tab 11, and the insulating layer 13 is arranged on the positive current collector 121 where the positive active material layer 122 is not arranged.

[0126] In some embodiments, the insulating layer 13 can be arranged on the side of the positive electrode tab 12 facing the negative electrode tab 11, wherein the insulating layer 13 can be arranged on the side of the positive current collector 121 facing the negative electrode tab 11.

[0127] In some embodiments, the insulating layer 13 is arranged close to the second edge 1211, wherein the insulating layer 13 can be connected to the positive active material layer 122 or can not be connected to the positive active material layer 122.

[0128] In some embodiments, the stacking direction Y of the positive electrode tab and the negative electrode tab can be represented by the direction indicated by the letter Y in the figure. The stacking direction Y of the positive electrode tab and the negative electrode tab can be parallel to the thickness direction of the positive electrode tab 12, and the stacking direction Y of the positive electrode tab and the negative electrode tab can be parallel to the thickness direction of the negative electrode tab 11.

[0129] It should be noted that in a winding type electrode assembly, the electrode assembly 10 can include a flat area and a bending area, in the flat area the stacking direction Y of the positive electrode tab and the negative electrode tab remains unchanged, and in the bending area the stacking direction Y of the positive electrode tab and the negative electrode tab in each bending area is different.

[0130] In some embodiments, the positive electrode tab 12 and the negative electrode tab 11 are projected on a projection plane perpendicular to the stacking direction Y of the positive electrode tab and the negative electrode tab, to obtain a positive projection of the positive electrode tab 12 and a positive projection of the negative electrode tab 11, with the positive projection of the negative active material layer 112 covering the positive projection of the positive active material layer 122, i.e. the positive projection of the negative active material layer 112 covers the positive projection of the edge of the positive active material layer 122, a part of the positive projection of the insulating layer 13 overlaps with the positive projection of the negative active material layer 112, another part of the positive projection of the insulating layer 13 does not overlap with the positive projection of the negative active material layer 112, and the connection of the two parts of the positive projection of the insulating layer 13 corresponds to the overlap of the positive projection of the first edge 1111.

[0131] In some embodiments, the insulating layer 13 is an electrically insulating structure, and when the burr of the first edge 1111 passes through the isolation film 18, the burr can be blocked by the insulating layer 13.

[0132] In the stacking direction Y of the positive electrode tab and the negative electrode tab, the insulating layer 13 is located between the negative electrode tab 11 and the positive current collector 121, and the insulating layer 13 can block the burr of the first edge 1111 from contacting and short-circuiting the positive current collector 121.

[0133] The insulating layer 13 can be entirely coated on the surface of the positive current collector 121, or a part of the insulating layer 13 can be coated on the surface of the positive current collector 121, and another part of the insulating layer 13 can be coated on the surface of the positive active material layer 122. When a part of the insulating layer 13 is coated on the positive active material layer 122, the insulating layer 13 can also block the burr of the first edge 1111 from contacting and short-circuiting the positive active material layer 122.

[0134] In some embodiments, the insulating layer 13 can be made of an insulating material as an insulating paste, which is coated on the surface of the positive current collector 121 and solidified to form the insulating layer 13.

[0135] In some embodiments, the insulating layer 13 can be coated or pasted on the surface of the positive current collector 121 by mixing an insulating material with an adhesive.

[0136] In some embodiments, the material of the insulating layer 13 can be bormite, aluminum oxide, ceramic, polyvinylidene fluoride, or aramid.

[0137] In some embodiments, in the first direction X, the size of the insulating layer 13 can be d1.

[0138] In some embodiments, the direction from the first edge 1111 to the second edge 1211 can be parallel to the first direction X. In the direction from the first edge 1111 to the second edge 1211, the minimum size of the insulating layer 13 beyond the first edge 1111 can be d2, where the condition 0.5d1≤d2

[0139] In some embodiments, the measurement method of the minimum size d2 of the insulating layer 13 beyond the first edge 1111 can be as follows: the electrode assembly 10 in the battery monomer 1 is taken out, at this time the insulating layer 13 is deformed by extrusion, the main body part 17 is fixed in a pressing or clamping manner, the deformed insulating layer 13 is flattened to restore the original state as much as possible, and the minimum size d2 of the insulating layer 13 beyond the first edge 1111 is measured.

[0140] In some embodiments, the measurement method of the minimum size d2 of the insulating layer 13 beyond the first edge 1111 can also be battery CT detection, battery X-RAY detection, etc.

[0141] The technical scheme of the embodiments of the present application, the first edge 1111 can be the edge of the negative pole tab 115 cut from the negative pole piece 11, in the projection plane perpendicular to the stacking direction of the positive pole piece 12 and the negative pole piece 11, the normal projection of the first edge 1111 falls into the normal projection of the insulating layer 13, and the burr of the first edge 1111 can be blocked by the insulating layer 13 after piercing the isolation film 18, which can reduce the risk of contact short circuit of the positive pole piece 12 and the negative pole piece 11 and improve the reliability of the battery monomer 1. At the same time, in the direction from the first edge 1111 to the second edge 1211, the minimum size d2 of the insulating layer 13 beyond the first edge 1111 satisfies the above condition, so that the size of the insulating layer 13 beyond the first edge 1111 is large. When the electrode assembly 10 contacts the insulating part 50 arranged in the shell 20 of the battery monomer 1, the insulating layer 13 contacts and is deformed by extrusion, and after the insulating layer 13 pierces the diaphragm, due to the large size of the insulating layer 13 beyond the first edge 1111, the probability of contact between the insulating layer 13 and the negative pole piece 11 is reduced, that is, the probability of contact between the positive current collector 121 provided with the insulating layer 13 and the negative pole piece 11 is reduced, which is beneficial to reduce the risk of contact short circuit of the positive pole piece 12 and the negative pole piece 11 and further improve the reliability of the battery monomer 1.

[0142] Please refer to Figure 8 In some embodiments, 0.7mm≤d2≤5mm.

[0143] In some embodiments, the minimum size of the insulating layer 13 beyond the first edge 1111 in the direction from the first edge 1111 to the second edge 1211 can be d2, where the condition 0.7mm≤d2≤5mm is satisfied. That is, d2 can be any one of 0.7mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm or a value between any two of them. Correspondingly, d1 can be any one of 0.71mm, 1mm, 1.4mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or a value between any two of them.

[0144] The technical solution of the embodiments of the present application further satisfies the condition of the minimum size d2 of the insulating layer 13 beyond the first edge 1111 in the direction from the first edge 1111 to the second edge 1211, further makes the size of the insulating layer 13 beyond the first edge 1111 larger, and further helps to reduce the risk of short circuit between the positive electrode tab 12 and the negative electrode tab 11, and further improves the reliability of the battery monomer 1.

[0145] Please refer to Figure 9 , Figure 9 A cross-sectional view of a part of the structure of the stacking state of the positive electrode tab and the negative electrode tab provided by the first embodiment of the present application. In some embodiments, the electrode assembly 10 is a winding type structure, and along the winding direction P of the electrode assembly, the electrode assembly 10 includes an initial region 14, an intermediate region 16 and a tail region 15 connected in sequence, the winding number of the initial region 14 is in the range of 1 to 3 turns, the winding number of the tail region 15 is in the range of 1 to 2 turns, and the extension direction of the winding axis of the electrode assembly 10 is parallel to the first direction X. In the direction Z from the initial region to the tail region, the minimum size of the insulating layer 13 of the initial region 14 beyond the first edge 1111 gradually decreases, the minimum size of the insulating layer 13 of the intermediate region 16 beyond the first edge 1111 remains unchanged, and the minimum size of the insulating layer 13 of the tail region 15 beyond the first edge 1111 gradually increases.

[0146] In some embodiments, the winding direction of the electrode assembly can be represented by the direction indicated by the letter P in the figure.

[0147] In some embodiments, the initial region 14 and the tail region 15 are sequentially distributed along the winding direction, the initial region 14 can be the winding starting section of the electrode assembly 10, and the tail region 15 can be the winding ending section of the electrode assembly 10.

[0148] The initial region 14 can be one or more turns of structure of the positive electrode tab 12 close to the positive electrode tab winding starting end 123, and one or more turns of structure of the negative electrode tab 11 close to the negative electrode tab winding starting end 113.

[0149] The tail region 15 can be one or more turns of the positive electrode tab 12 near the positive electrode tab winding tail end 124, and one or more turns of the negative electrode tab 11 near the negative electrode tab winding tail end 114.

[0150] In some embodiments, the number of turns of the initial region 14 can be 1 turn, 2 turns, 3 turns.

[0151] In some embodiments, the number of turns of the tail region 15 can be 1 turn, 2 turns.

[0152] In some embodiments, the intermediate region 16 can be one or more turns of the positive electrode tab 12 connecting the initial region 14 and the tail region 15.

[0153] In some embodiments, the number of turns of the intermediate region 16 can be 1 turn, 2 turns, 3 turns, 4 turns, or 5 turns.

[0154] In some embodiments, in the wound electrode assembly, the direction from the initial region to the tail region can be represented by the direction indicated by the letter Z in the figure.

[0155] In some embodiments, the minimum size of the insulating layer 13 of each region exceeding the first edge 1111 can be different by changing the relative position of the insulating layer 13 and the first edge 1111 of each region, such as moving the second edge 1211 of the positive electrode tab 12 closer to the first edge 1111 along the first direction X, or moving the second edge 1211 of the positive electrode tab 12 away from the first edge 1111 along the first direction X. It should be noted that this method can be performed during the formation of the electrode assembly 10 through the winding process.

[0156] In some embodiments, the minimum size of the insulating layer 13 of each region exceeding the first edge 1111 can be different by keeping the relative position of the insulating layer 13 and the first edge 1111 unchanged, and changing the size d1 of the insulating layer 13 in the first direction X.

[0157] In some embodiments, the minimum size of the insulating layer 13 of each region exceeding the first edge 1111 can be different by changing the relative position of the insulating layer 13 and the first edge 1111 for a part of the insulating layer 13, and changing the size d1 of the insulating layer 13 in the first direction X for another part of the insulating layer 13.

[0158] In some embodiments, the dimension d2 of the insulating layer 13 of the initial region 14 beyond the first edge 1111 gradually decreases, which can be to keep the position of the positive electrode tab 12 of the initial region 14, i.e. the position of the insulating layer 13 of the initial region 14, unchanged, and by moving the negative electrode tab 11 in the first direction X in the direction Z from the initial region to the end region, the dimension between the first edge 1111 and the second edge 1211 gradually decreases.

[0159] Alternatively, the position of the negative electrode tab 11 of the initial region 14 can be kept unchanged, and by moving the positive electrode tab 12 in the first direction X in the direction Z from the initial region to the end region, the dimension between the first edge 1111 and the second edge 1211 gradually decreases.

[0160] Alternatively, by moving the positive electrode tab 12 and the negative electrode tab 11 in the first direction X in the direction Z from the initial region to the end region, and the moving directions of the positive electrode tab 12 and the negative electrode tab 11 are opposite, the dimension between the first edge 1111 and the second edge 1211 gradually decreases.

[0161] Similarly, in some embodiments, the dimension d2 of the insulating layer 13 of the end region 15 beyond the first edge 1111 gradually increases, which can be to keep the position of the positive electrode tab 12 of the initial region 14, i.e. the position of the insulating layer 13 of the initial region 14, unchanged, and by moving the negative electrode tab 11 in the first direction X in the direction Z from the initial region to the end region, the dimension between the first edge 1111 and the second edge 1211 gradually increases.

[0162] Alternatively, the position of the negative electrode tab 11 of the initial region 14 can be kept unchanged, and by moving the positive electrode tab 12 in the first direction X in the direction Z from the initial region to the end region, the dimension between the first edge 1111 and the second edge 1211 gradually increases.

[0163] Alternatively, by moving the positive electrode tab 12 and the negative electrode tab 11 in the first direction X in the direction Z from the initial region to the end region, and the moving directions of the positive electrode tab 12 and the negative electrode tab 11 are opposite, the dimension between the first edge 1111 and the second edge 1211 gradually increases.

[0164] The technical scheme of the embodiment of the application is that, in the direction Z from the initial area to the tail area, the size d2 of the insulating layer 13 of the initial area 14 is gradually reduced, the size d2 of the insulating layer 13 of the intermediate area 16 remains unchanged, and the size d2 of the insulating layer 13 of the tail area 15 is gradually increased, so that the size of the insulating layer 13 of the initial area 14 and the tail area 15 beyond the first edge 1111 is larger, the probability of the insulating layer 13 of the initial area 14 and the tail area 15 contacting the negative pole piece 11 is reduced, that is, the probability of the positive pole current collector 121 provided with the insulating layer 13 contacting the negative pole piece 11 is reduced, the risk of the positive pole piece 12 and the negative pole piece 11 contacting and short-circuiting is reduced, and the reliability of the battery monomer 1 is further improved.

[0165] Please refer to Figure 3 In some embodiments, the battery monomer 1 further includes a shell 20, a positive pole terminal 30 and a negative pole terminal 40. The electrode assembly 10 is arranged in the shell 20, and the shell 20 includes a first wall 21, and the thickness direction of the first wall 21 is parallel to the first direction X. The positive pole terminal 30 is arranged on the first wall 21. The negative pole terminal 40 is arranged on the first wall 21. The positive pole current collector 121 includes a second main body area 1212 and a positive pole lug 125, the positive pole active material layer 122 is arranged on the second main body area 1212, the positive pole lug 125 extends from the second edge 1211 and is electrically connected with the positive pole terminal 30, and the negative pole lug 115 is electrically connected with the negative pole terminal 40.

[0166] In some embodiments, the first wall 21 can be an end cover 23.

[0167] In some embodiments, the thickness direction of the first wall 21 can be parallel to the first direction X.

[0168] In some embodiments, the first direction X can be parallel to the height direction of the battery monomer 1.

[0169] In some embodiments, the positive pole terminal 30 and the negative pole terminal 40 are arranged on the first wall 21 respectively, the first wall 21 is provided with a first electrode lead-out hole corresponding to the positive pole terminal 30 and a second electrode lead-out hole corresponding to the negative pole terminal 40, the positive pole terminal 30 is electrically connected with the positive pole lug 125 through the first electrode lead-out hole, and the negative pole terminal 40 is electrically connected with the negative pole lug 115 through the second electrode lead-out hole.

[0170] The technical scheme of the embodiment of the application is that, by arranging the positive pole terminal 30 to be connected with the positive pole lug 125 and arranging the negative pole terminal 40 to be connected with the negative pole lug 115, the charging and discharging of the battery monomer 1 is facilitated.

[0171] Please refer to Figure 10 , Figure 10A cross-sectional view of a partial structure of a stack state of a positive electrode tab and a negative electrode tab provided by the second embodiment of the application. In order to facilitate the display of the structure of the electrode assembly, Figure 10 to Figure 17 The position of the first wall is not shown in the middle. The first wall is located on the side of the electrode assembly extending the tab. In some embodiments, the electrode assembly 10 is a wound structure, and the electrode assembly 10 includes an initial region 14 and a tail region 15. In the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually decreases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually decreases.

[0172] In some embodiments, in the first direction X, the first wall 21 is the wall closest to the first edge 1111 of the shell 20, and the first wall 21 is the wall closest to the second edge 1211 of the shell 20.

[0173] In some embodiments, in the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually decreases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually decreases, that is, the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually decreases.

[0174] In the direction Z from the initial region to the tail region, the size d2 of the insulating layer 13 beyond the first edge 1111 can be the same or different.

[0175] In some embodiments, in the direction Z from the initial region to the tail region, the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually decreases, that is, the insulating layer 13 of the tail region 15 is more likely to contact the insulating member 50 first.

[0176] The technical scheme of the embodiment of the application, in the direction Z from the initial region to the tail region, by gradually reducing the distance between the first edge 1111 and the first wall 21 in the first direction X, and gradually reducing the distance between the second edge 1211 and the first wall 21 in the first direction X, the distance between the insulating layer 13 and the first wall 21 in the first direction X is larger on the initial region 14, so that when the insulating layer 13 contacts the insulating member 50, the insulating layer 13 of the tail region 15 contacts the insulating member 50 first, reducing the risk of the insulating layer 13 of the initial region 14 contacting and being extruded and deformed by the insulating member 50, that is, reducing the risk of the positive electrode tab 12 and the negative electrode tab 11 of the initial region 14 contacting and short-circuiting, and improving the reliability of the battery monomer 1.

[0177] Please refer to Figure 11 , Figure 11A cross-sectional view of a partial structure of a stacking state of a positive electrode tab and a negative electrode tab provided by the third embodiment of the present application. In some embodiments, the electrode assembly 10 is a wound structure, and the electrode assembly 10 includes an initial region 14 and a tail region 15. In the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases.

[0178] In some embodiments, in the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases, i.e., the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually increases.

[0179] In some embodiments, in the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases, i.e., the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually increases.

[0180] In some embodiments, in the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases, i.e., the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually increases.

[0181] The technical scheme of the embodiments of the present application, in the direction Z from the initial region to the tail region, by gradually increasing the distance between the first edge 1111 and the first wall 21 in the first direction X, and gradually increasing the distance between the second edge 1211 and the first wall 21 in the first direction X, the distance between the insulating layer 13 and the first wall 21 in the first direction X is larger on the tail region 15, so that when the insulating layer 13 contacts the insulating member 50, the insulating layer 13 of the initial region 14 contacts the insulating member 50 first, reducing the risk of the insulating layer 13 of the tail region 15 contacting and being extruded and deformed by the insulating member 50, i.e., reducing the risk of the positive electrode tab 12 and the negative electrode tab 11 of the tail region 15 contacting and short-circuiting, improving the reliability of the battery monomer 1.

[0182] Please refer to Figure 12 , Figure 12 A cross-sectional view of a partial structure of a stacking state of a positive electrode tab and a negative electrode tab provided by the fourth embodiment of the present application. In some embodiments, the electrode assembly 10 is a wound structure, and the electrode assembly 10 includes an initial region 14 and a tail region 15. In the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually decreases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases.

[0183] In some embodiments, in the direction Z from the initial region to the closing region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually decreases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases. That is, the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually increases, thereby making the dimension d2 of the insulating layer 13 extending beyond the first edge 1111 gradually decrease. In other words, the dimension d2 of the insulating layer 13 extending beyond the first edge 1111 in the initial region 14 is greater than the dimension d2 of the insulating layer 13 extending beyond the first edge 1111 in the closing region 15. This makes the risk of short circuit between the positive electrode 12 and the negative electrode 11 after the insulating layer 13 in the initial region 14 is squeezed and deformed less.

[0184] The technical solution of this application embodiment, in the direction Z from the initial region to the terminal region, by setting the distance between the first edge 1111 and the first wall 21 in the first direction X to gradually decrease, and setting the distance between the second edge 1211 and the first wall 21 in the first direction X to gradually increase, makes the insulating layer 13 of the initial region 14 extend a larger dimension beyond the first edge 1111, reducing the risk of the insulating layer 13 of the initial region 14 contacting the insulating member 50 and being squeezed and deformed, that is, reducing the risk of short circuit between the positive electrode 12 and the negative electrode 11 of the initial region 14, and improving the reliability of the battery cell 1.

[0185] Please refer to Figure 13 , Figure 13 This is a cross-sectional view of a portion of the stacked structure of the positive and negative electrode sheets provided in the fifth embodiment of this application. In some embodiments, the electrode assembly 10 has a wound structure, and the electrode assembly 10 includes an initial region 14 and a terminal region 15. In the direction Z from the initial region to the terminal region, the distance between the first edge 1111 and the first wall 21 gradually increases in the first direction X, and the distance between the second edge 1211 and the first wall 21 gradually decreases in the first direction X.

[0186] In some embodiments, in the direction Z from the initial region to the closing region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually decreases. That is, the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually decreases, thereby making the dimension d2 of the insulating layer 13 extending beyond the first edge 1111 gradually increase. That is, the dimension d2 of the insulating layer 13 extending beyond the first edge 1111 in the initial region 14 is smaller than the dimension d2 of the insulating layer 13 extending beyond the first edge 1111 in the closing region 15. This makes the risk of short circuit between the positive electrode 12 and the negative electrode 11 after the insulating layer 13 in the closing region 15 is squeezed and deformed less.

[0187] The technical scheme of the embodiment of the present application is that, in the direction Z from the initial area to the tail area, the distance between the first edge 1111 and the first wall 21 in the first direction X is gradually increased, and the distance between the second edge 1211 and the first wall 21 in the first direction X is gradually decreased, so that the size of the insulating layer 13 of the tail area 15 beyond the first edge 1111 is large, the risk of the insulating layer 13 of the tail area 15 being in contact with the insulating piece 50 and being deformed by extrusion is reduced, that is, the risk of the positive electrode tab 12 and the negative electrode tab 11 of the tail area 15 being in contact and short-circuiting is reduced, and the reliability of the battery monomer 1 is improved.

[0188] Please refer to Figure 14 , Figure 14 The cross-sectional view of the partial structure of the stacking state of the positive electrode tab and the negative electrode tab provided by the sixth embodiment of the present application is shown in the figure. In some embodiments, the electrode assembly 10 is a winding type structure, and the electrode assembly 10 includes an initial area 14 and a tail area 15. In the direction Z from the initial area to the tail area, the distance between the first edge 1111 and the first wall 21 in the first direction X remains unchanged, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually decreases.

[0189] In some embodiments, in the direction Z from the initial area to the tail area, the distance between the first edge 1111 and the first wall 21 in the first direction X remains unchanged, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually decreases, that is, the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually decreases, so that the size d2 of the insulating layer 13 beyond the first edge 1111 gradually increases, that is, the size d2 of the insulating layer 13 of the initial area 14 beyond the first edge 1111 is smaller than the size d2 of the insulating layer 13 of the tail area 15 beyond the first edge 1111, so that the risk of the positive electrode tab 12 and the negative electrode tab 11 being short-circuited after the insulating layer 13 of the tail area 15 is deformed by extrusion is smaller.

[0190] The technical scheme of the embodiment of the present application is that, in the direction Z from the initial area to the tail area, the distance between the first edge 1111 and the first wall 21 in the first direction X remains unchanged, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually decreases, so that the size of the insulating layer 13 of the tail area 15 beyond the first edge 1111 is large, the risk of the insulating layer 13 of the tail area 15 being in contact with the insulating piece 50 and being deformed by extrusion is reduced, that is, the risk of the positive electrode tab 12 and the negative electrode tab 11 of the tail area 15 being in contact and short-circuiting is reduced, and the reliability of the battery monomer 1 is improved.

[0191] Please refer to Figure 15 , Figure 15A cross-sectional view of a partial structure of a stacking state of the positive electrode tab and the negative electrode tab provided by the seventh embodiment of the present application. In some embodiments, the electrode assembly 10 is a wound structure, and the electrode assembly 10 includes an initial region 14 and a tail region 15. In the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X remains unchanged, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases.

[0192] In some embodiments, in the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X remains unchanged, and the distance between the second edge 1211 and the first wall 21 in the first direction X gradually increases, i.e., the distance between the insulating layer 13 and the first wall 21 in the first direction X gradually increases, so that the size d2 of the insulating layer 13 beyond the first edge 1111 gradually decreases, i.e., the size d2 of the insulating layer 13 of the initial region 14 beyond the first edge 1111 is greater than the size d2 of the insulating layer 13 of the tail region 15 beyond the first edge 1111, so that the risk of the insulating layer 13 of the initial region 14 being deformed after being extruded to cause the positive electrode tab 12 and the negative electrode tab 11 to short circuit is smaller.

[0193] The technical scheme of the embodiments of the present application, in the direction Z from the initial region to the tail region, by setting the distance between the first edge 1111 and the first wall 21 in the first direction X to remain unchanged and setting the distance between the second edge 1211 and the first wall 21 in the first direction X to gradually increase, the size of the insulating layer 13 of the initial region 14 beyond the first edge 1111 is larger, reducing the risk of the insulating layer 13 of the initial region 14 being in contact with the insulating member 50 and being deformed after being extruded, i.e., reducing the risk of the positive electrode tab 12 and the negative electrode tab 11 of the initial region 14 being in contact and short circuit, improving the reliability of the battery monomer 1.

[0194] Please refer to Figure 16 , Figure 16 A cross-sectional view of a partial structure of a stacking state of the positive electrode tab and the negative electrode tab provided by the eighth embodiment of the present application. In some embodiments, the electrode assembly 10 is a wound structure, and the electrode assembly 10 includes an initial region 14 and a tail region 15. In the direction Z from the initial region to the tail region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually decreases, and the distance between the second edge 1211 and the first wall 21 in the first direction X remains unchanged.

[0195] In some embodiments, in the direction Z from the initial region to the ending region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually decreases, and the distance between the second edge 1211 and the first wall 21 in the first direction X remains unchanged, that is, the distance between the insulating layer 13 and the first wall 21 in the first direction X remains unchanged, so that the size d2 of the insulating layer 13 beyond the first edge 1111 gradually decreases, that is, the size d2 of the insulating layer 13 of the initial region 14 beyond the first edge 1111 is greater than the size d2 of the insulating layer 13 of the ending region 15 beyond the first edge 1111, so that the risk of the positive electrode tab 12 and the negative electrode tab 11 short-circuiting after the insulating layer 13 of the initial region 14 is deformed by extrusion is smaller.

[0196] The technical scheme of the embodiments of the present application is that, in the direction Z from the initial region to the ending region, the distance between the first edge 1111 and the first wall 21 in the first direction X is gradually decreased, and the distance between the second edge 1211 and the first wall 21 in the first direction X remains unchanged, so that the size of the insulating layer 13 of the initial region 14 beyond the first edge 1111 is larger, the risk of the insulating layer 13 of the initial region 14 contacting the insulating member 50 and being deformed by extrusion is reduced, that is, the risk of the positive electrode tab 12 and the negative electrode tab 11 of the initial region 14 contacting and short-circuiting is reduced, and the reliability of the battery monomer 1 is improved.

[0197] Please refer to Figure 17 , Figure 17 A partial structure cross-sectional view of the layering state of the positive electrode tab and the negative electrode tab provided by the ninth embodiment of the present application. In some embodiments, the electrode assembly 10 is a winding type structure, and the electrode assembly 10 includes an initial region 14 and an ending region 15. In the direction Z from the initial region to the ending region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X remains unchanged.

[0198] In some embodiments, in the direction Z from the initial region to the ending region, the distance between the first edge 1111 and the first wall 21 in the first direction X gradually increases, and the distance between the second edge 1211 and the first wall 21 in the first direction X remains unchanged, that is, the distance between the insulating layer 13 and the first wall 21 in the first direction X remains unchanged, so that the size d2 of the insulating layer 13 beyond the first edge 1111 gradually increases, that is, the size d2 of the insulating layer 13 of the initial region 14 beyond the first edge 1111 is smaller than the size d2 of the insulating layer 13 of the ending region 15 beyond the first edge 1111, so that the risk of the positive electrode tab 12 and the negative electrode tab 11 short-circuiting after the insulating layer 13 of the ending region 15 is deformed by extrusion is smaller.

[0199] The technical scheme of the embodiment of the application is that, in the direction Z from the initial area to the tail area, the distance between the first edge 1111 and the first wall 21 in the first direction X is gradually increased, and the distance between the second edge 1211 and the first wall 21 in the first direction X remains unchanged, so that the size of the insulating layer 13 of the tail area 15 beyond the first edge 1111 is large, the risk of the insulating layer 13 of the tail area 15 being in contact with and being deformed by the insulation piece 50 is reduced, that is, the risk of the positive electrode tab 12 and the negative electrode tab 11 of the tail area 15 being in contact and short-circuiting is reduced, and the reliability of the battery monomer 1 is improved.

[0200] Please refer to Figure 18 , Figure 18 A sectional view of a battery monomer provided by some embodiments of the application is shown. In some embodiments, the first wall 21 is configured to support the electrode assembly 10.

[0201] In some embodiments, during use of the battery monomer 1, the first wall 21 is located below the electrode assembly 10, the first wall 21 supports the electrode assembly 10, and bears at least part of the gravity of the electrode assembly 10.

[0202] In some embodiments, when the first wall 21 supports the electrode assembly 10, the insulating layer 13 is first in contact with the insulation piece 50, and at least part of the gravity of the electrode assembly 10 acts on the insulating layer 13, so that the insulating layer 13 is easily deformed by extrusion. Therefore, the size d2 of the insulating layer 13 beyond the first edge 1111 is set to be large, the probability of the insulating layer 13 being in contact with the negative electrode tab 11 is reduced, that is, the probability of the positive current collector 121 provided with the insulating layer 13 being in contact with the negative electrode tab 11 is reduced, the risk of the positive electrode tab 12 and the negative electrode tab 11 being in contact and short-circuiting is reduced, and the reliability of the battery monomer 1 is further improved.

[0203] The technical scheme of the embodiment of the application is that the first wall 21 supports the electrode assembly 10, and the battery monomer 1 can be used in an inverted state, so as to improve the application range of the battery monomer 1.

[0204] Please refer to Figure 18 In some embodiments, the electrode assembly 10 includes a main body part 17, a positive electrode tab 125, and a negative electrode tab 115, and the first main body area 1112, the negative active material layer 112, the second main body area 1212, and the positive active material layer 122 constitute the main body part 17. The battery monomer 1 further includes an insulation piece 50 and a support piece 60. The insulation piece 50 is arranged on the side of the first wall 21 facing the electrode assembly 10. The support piece 60 is arranged between the insulation piece 50 and the main body part 17, and supports the main body part 17.

[0205] In some embodiments, the positive electrode tab 12 and the negative electrode tab 11 have portions with active material constituting the main body part 17 of the electrode assembly 10, and the portions without active material of the positive electrode tab 12 and the negative electrode tab 11 each constitute the positive electrode tab 125 and the negative electrode tab 115.

[0206] The positive electrode tab 125 and the negative electrode tab 115 can be located at one end of the main body part 17.

[0207] In some embodiments, the support 60 is arranged in the casing 20 and between the insulating part 50 and the main body part 17, and the support 60 can bear at least part of the gravity of the main body part 17 to support the main body part 17.

[0208] The positive electrode tab 125 is electrically connected to the positive electrode terminal 30 after bypassing the support 60, and the negative electrode tab 115 is electrically connected to the negative electrode terminal 40 after bypassing the support 60.

[0209] In some embodiments, the positive electrode tab 125 is fixed to the support 60, and the negative electrode tab 115 is fixed to the support 60, so as to fix the positions of the positive electrode tab 125 and the negative electrode tab 115, so as to improve the connection reliability of the positive electrode tab 125 and the positive electrode terminal 30 and the connection reliability of the negative electrode tab 115 and the negative electrode terminal 40.

[0210] The technical scheme of the embodiments of the present application can separate the first wall 21 and the electrode assembly 10 by the insulating part 50, so as to reduce the risk of positive and negative contact short circuit. The support 60 supports the main body part 17, can limit the movement of the main body part 17 towards the first wall 21, reduce the influence of the movement of the main body part 17 on the connection stability of the positive electrode tab 125 and the negative electrode tab 115 and the corresponding components, and facilitate to improve the reliability of the battery monomer 1.

[0211] Please refer to Figure 2 The embodiments of the present application also provide a battery device 100, which comprises the battery monomer 1 according to any one of the above embodiments.

[0212] In some embodiments, the battery device 100 comprises a box body 110, and the battery monomer 1 is arranged in the box body 110. The battery monomer 1 comprises a casing 20, a positive electrode terminal 30 and a negative electrode terminal 40, the electrode assembly 10 is arranged in the casing 20, the casing 20 comprises a first wall 21, the positive electrode terminal 30 and the negative electrode terminal 40 are arranged on the first wall 21, the positive electrode tab 125 of the electrode assembly 10 is connected to the positive electrode terminal 30, the negative electrode tab 115 of the electrode assembly 10 is connected to the negative electrode terminal 40, and the first wall 21 supports the electrode assembly 10.

[0213] In some embodiments, the positive electrode terminal 30 can be electrically connected to the positive electrode tab 125, and the negative electrode terminal 40 can be electrically connected to the negative electrode tab 115.

[0214] In some embodiments, in the direction of gravity, the box 110 can include a bottom wall located below, the first wall 21 can be arranged opposite to the bottom wall, and the first wall 21 is located between the electrode assembly 10 and the bottom wall.

[0215] The technical scheme of the embodiments of the present application, the first wall 21 supports the electrode assembly 10, and the battery monomer 1 can be used in an inverted state, so as to improve the application range of the battery monomer 1.

[0216] Please refer to Figure 1 The embodiments of the present application also provide a power utilization device, which comprises the battery monomer 1 according to any one of the above embodiments or the battery device 100 according to any one of the above embodiments, and the battery monomer 1 or the battery device 100 is used to provide electric energy for the power utilization device.

[0217] Please refer to Figure 4 to Figure 8 In some embodiments, the battery monomer 1 comprises a shell 20 and an electrode assembly 10, and the electrode assembly 10 is arranged in the shell 20. The electrode assembly 10 comprises a main body part 17, a positive electrode tab 125 and a negative electrode tab 115, the shell 20 comprises an end cover 23, the end cover 23 is provided with a positive electrode terminal 30 and a negative electrode terminal 40, the positive electrode terminal 30 is electrically connected with the positive electrode tab 125, and the negative electrode terminal 40 is electrically connected with the negative electrode tab 115.

[0218] In some embodiments, the end cover 23 bears the main body part 17.

[0219] In some embodiments, the electrode assembly 10 comprises a positive electrode tab 12, a negative electrode tab 115 and an insulating layer 13. The negative electrode tab 11 comprises a negative electrode current collector 111 and a negative electrode active material layer 112 arranged on the surface of the negative electrode current collector 111, the positive electrode tab 12 comprises a positive electrode current collector 121 and a positive electrode active material layer 122 arranged on the surface of the positive electrode current collector 121, the part of the positive electrode tab 12 and the negative electrode tab 11 with active material constitutes the main body part 17 of the electrode assembly 10, and the part of the positive electrode tab 12 and the negative electrode tab 11 without active material respectively constitutes the positive electrode tab 125 and the negative electrode tab 115.

[0220] In the first direction X, the negative electrode current collector 111 has a first edge 1111 extending out of the negative electrode tab 115, the positive electrode current collector 121 has a second edge 1211 extending out of the positive electrode tab 125, and the first direction X is parallel to the width direction of the negative electrode tab 11.

[0221] The insulating layer 13 is arranged on the side of the positive electrode tab 12 facing the negative electrode tab 11 and close to the second edge 1211. In the projection plane perpendicular to the stacking direction of the positive electrode tab 12 and the negative electrode tab 11, the orthographic projection of the first edge 1111 falls within the orthographic projection of the insulating layer 13. In the direction from the first edge 1111 to the second edge 1211, the insulating layer 13 exceeds the first edge 1111. The dimension of the insulating layer 13 along the first direction X is d1, and in the direction from the first edge 1111 to the second edge 1211, the minimum dimension of the insulating layer 13 exceeding the first edge 1111 is d2, satisfying the condition: 0.5d1≤d2<d1.

[0222] The minimum dimension d2 of the insulating layer 13 exceeding the first edge 1111 in the direction from the first edge 1111 to the second edge 1211 satisfies the above condition, so that the dimension of the insulating layer 13 exceeding the first edge 1111 is large. When the electrode assembly 10 contacts the insulating member 50 arranged in the shell 20 of the battery cell 1, the insulating layer 13 contacts and is deformed by the insulating member 50. After the insulating layer 13 pierces the separator, because the dimension d2 of the insulating layer 13 exceeding the first edge 1111 is large, the probability of the insulating layer 13 contacting the negative electrode tab 11, i.e., the probability of the positive current collector 121 provided with the insulating layer 13 contacting the negative electrode tab 11, is reduced, which is beneficial to reducing the risk of the positive electrode tab 12 and the negative electrode tab 11 contacting and short-circuiting, and further improving the reliability of the battery cell 1.

[0223] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to the present application and equivalents thereof without departing from the scope of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, Includes an electrode assembly, the electrode assembly comprising: A negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode current collector includes a first main body region and a negative electrode tab. The negative electrode active material layer is disposed in the first main body region. In a first direction, the first main body region has a first edge, and the negative electrode tab extends from the first edge. A positive electrode sheet includes a positive current collector and a positive active material layer disposed on the surface of the positive current collector. The positive electrode sheet and the negative electrode sheet are stacked together. In the first direction, the positive current collector has a second edge on the same side as the first edge. Along the first direction, the second edge extends beyond the first edge. An insulating layer is disposed on the side of the positive electrode sheet facing the negative electrode sheet and close to the second edge. On a projection plane perpendicular to the stacking direction of the positive electrode sheet and the negative electrode sheet, the orthogonal projection of the first edge falls into the orthogonal projection of the insulating layer. In the direction from the first edge to the second edge, the insulating layer extends beyond the first edge. Wherein, the dimension of the insulating layer along the first direction is d1, and the minimum dimension of the insulating layer extending beyond the first edge is d2, satisfying the condition: 0.5d1≤d2<d1.

2. The battery cell according to claim 1, characterized in that, 0.7mm≤d2≤5mm.

3. The battery cell according to claim 1, characterized in that, The electrode assembly has a wound structure. Along the winding direction of the electrode assembly, the electrode assembly includes an initial region, an intermediate region, and a closing region connected in sequence. The number of winding turns in the initial region is in the range of 1 to 3 turns, and the number of winding turns in the closing region is in the range of 1 to 2 turns. The extension direction of the winding axis of the electrode assembly is parallel to the first direction. In the direction from the initial region to the closing region, the minimum dimension of the insulating layer extending beyond the first edge in the initial region gradually decreases, the minimum dimension of the insulating layer extending beyond the first edge in the intermediate region remains unchanged, and the minimum dimension of the insulating layer extending beyond the first edge in the closing region gradually increases.

4. The battery cell according to claim 1, characterized in that, The battery cell also includes: The housing contains the electrode assembly disposed within it, and the housing includes a first wall whose thickness direction is parallel to the first direction. The positive terminal is disposed on the first wall; The negative terminal is disposed on the first wall; The positive current collector includes a second main body region and a positive electrode tab. The positive active material layer is disposed in the second main body region. The positive electrode tab extends from the second edge and is electrically connected to the positive terminal. The negative electrode tab is electrically connected to the negative terminal.

5. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall gradually decreases in the first direction, and the distance between the second edge and the first wall gradually decreases in the first direction.

6. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall gradually increases in the first direction, and the distance between the second edge and the first wall gradually increases in the first direction.

7. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall gradually decreases in the first direction, while the distance between the second edge and the first wall gradually increases in the first direction.

8. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall gradually increases in the first direction, and the distance between the second edge and the first wall gradually decreases in the first direction.

9. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall in the first direction remains constant, while the distance between the second edge and the first wall in the first direction gradually decreases.

10. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall in the first direction remains constant, while the distance between the second edge and the first wall in the first direction gradually increases.

11. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall in the first direction gradually decreases, while the distance between the second edge and the first wall in the first direction remains unchanged.

12. The battery cell according to claim 4, characterized in that, The electrode assembly has a wound structure and includes an initial region and a closing region. In the direction from the initial region to the closing region, the distance between the first edge and the first wall in the first direction gradually increases, while the distance between the second edge and the first wall in the first direction remains unchanged.

13. The battery cell according to claim 4, characterized in that, The first wall is configured to support the electrode assembly.

14. The battery cell according to claim 4, characterized in that, The electrode assembly includes a main body, a positive electrode tab, and a negative electrode tab, wherein the first main body region, the negative electrode active material layer, the second main body region, and the positive electrode active material layer constitute the main body; The battery cell also includes: An insulating element is disposed on the side of the first wall facing the electrode assembly; A support member is disposed between the insulating member and the main body portion, and supports the main body portion.

15. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-14.

16. The battery device according to claim 15, characterized in that, The battery device includes a housing, and the individual battery cells are disposed within the housing; The battery cell includes a casing, a positive terminal, and a negative terminal. The electrode assembly is disposed inside the casing. The casing includes a first wall. The positive terminal and the negative terminal are both disposed on the first wall. The positive electrode tab of the electrode assembly is connected to the positive terminal, and the negative electrode tab of the electrode assembly is connected to the negative terminal. The first wall supports the electrode assembly.

17. An electrical device, characterized in that, Includes a battery cell as described in any one of claims 1-14 or a battery device as described in any one of claims 15-16, wherein the battery cell or the battery device is used to provide electrical energy to the electrical device.

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