Battery cell, battery device, and electric device

Abstract

A battery cell, a battery device, and an electric device, the battery cell including an electrode assembly including a positive electrode tab, a negative electrode tab, and a separator between the positive electrode tab and the negative electrode tab, the positive electrode tab including a positive electrode current collector base material and a positive electrode active material layer disposed on the positive electrode current collector base material, the negative electrode tab including a negative electrode current collector base material and a negative electrode active material layer disposed on the negative electrode current collector base material, the positive electrode tab, the negative electrode tab, and the separator being disposed in at least one of the following ways: the negative electrode active material layer protruding at least on one side in at least one of a tab width direction and a tab length direction relative to the positive electrode active material layer; and the separator protruding at least on one side in at least one of the tab width direction and the tab length direction relative to at least one of the positive electrode current collector base material and the negative electrode current collector base material.

Description

Technical Field

[0001] This disclosure relates to the field of batteries, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0002] With increasing environmental pollution, the new energy industry is attracting more and more attention. Within the new energy industry, battery technology is a crucial factor in its development.

[0003] Rechargeable battery cells, also known as secondary battery cells, are battery cells that can be recharged after discharge to reactivate the active materials and continue to be used. Rechargeable battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Further improving the performance of battery cells is currently a key research focus. Utility Model Content

[0004] In one aspect of this disclosure, a battery cell is provided, comprising: an electrode assembly including a positive electrode, a negative electrode, and a separator, the separator being located between the positive electrode and the negative electrode; the positive electrode including a positive current collector substrate and a positive active material layer disposed on the positive current collector substrate, the negative electrode including a negative current collector substrate and a negative active material layer disposed on the negative current collector substrate; the positive electrode, the negative electrode, and the separator are disposed in at least one of the following ways: the negative active material layer extends beyond at least one side of at least one of the positive active material layer in the electrode width direction and the electrode length direction; and the separator extends beyond at least one side of at least one of the positive current collector substrate and the negative current collector substrate in the electrode width direction and the electrode length direction.

[0005] In this embodiment, by extending the negative electrode active material layer beyond at least one side of the positive electrode active material layer in at least one of the electrode width direction and the electrode length direction, the space for the negative electrode to receive lithium ions can be increased in at least one of the electrode width direction and the electrode length direction. This allows the electrical performance of the positive electrode active material layer to be fully utilized, reduces the risk of edge lithium plating in at least one of the negative electrode in the electrode width direction and the electrode length direction, and improves the reliability of the electrode assembly. By extending the separator beyond at least one side of the positive electrode current collector substrate and the negative electrode current collector substrate in at least one of the electrode width direction and the electrode length direction, it is less likely that the positive electrode current collector substrate and the negative electrode current collector substrate will experience short circuits on at least one side of at least one of the electrode width direction and the electrode length direction, thus improving the reliability of the electrode assembly.

[0006] In some embodiments, the negative electrode active material layer extends beyond the positive electrode active material layer on both sides of at least one of the electrode width direction and the electrode length direction.

[0007] In this embodiment, the negative electrode active material layer extends beyond the positive electrode active material layer on both sides in the electrode width direction and / or electrode length direction perpendicular to the thickness direction of the main body. This can further reduce the risk of lithium plating at the edges of the negative electrode sheet in all directions perpendicular to the main body, improve the reliability of the electrode assembly, and help reduce the precision requirements of the manufacturing process.

[0008] In some embodiments, the negative electrode active material layer extends beyond the positive electrode active material layer on one side of at least one of the electrode width direction and the electrode length direction, and is flush with the other side of at least one of the electrode width direction and the electrode length direction.

[0009] In this embodiment, the negative electrode active material layer extends beyond the positive electrode active material layer on one side in the electrode width direction and / or electrode length direction. This reduces the risk of edge lithium plating on the negative electrode, improves the reliability of the electrode assembly, and helps reduce the precision requirements of the manufacturing process. The negative electrode active material layer is flush with the positive electrode active material layer on the other side in the electrode width direction and / or electrode length direction. This improves the effective reaction area between the positive and negative electrodes, increases the utilization rate of the active materials in both electrodes, and helps improve the volumetric energy density of the electrode assembly. This, in turn, helps improve the cell structure design, increases the capacity of the battery cell, and reduces costs. Thus, the battery cell can meet the requirements of both reliability and volumetric energy density.

[0010] In some embodiments, the positive electrode further includes at least one of a first insulating layer and a second insulating layer. The first insulating layer is located at a first end of the electrode assembly along at least one of the electrode width direction and the electrode length direction, and is located on at least one of the positive current collector substrate and the positive active material layer, and extends beyond the positive active material layer. The second insulating layer is located at a second end of the electrode assembly along at least one of the electrode width direction and the electrode length direction, and is located on at least one of the positive current collector substrate and the positive active material layer, and extends beyond the positive active material layer. The first end and the second end are disposed opposite to each other.

[0011] In this embodiment, for the edge of the current collector substrate of the negative electrode sheet obtained by cutting, at least one first insulating layer located at the first end of the electrode assembly and / or a second insulating layer located at the second end of the electrode assembly along the electrode sheet width direction and the electrode sheet length direction can reduce the risk of burrs at the cut edge piercing the separator and causing a short circuit with the positive electrode current collector substrate, thereby improving the reliability of the battery cell.

[0012] In some embodiments, the first insulating layer is flush with or extends beyond the negative electrode current collector substrate in at least one of the electrode width direction and the electrode length direction; the second insulating layer is flush with or extends beyond the negative electrode current collector substrate in at least one of the electrode width direction and the electrode length direction.

[0013] In this embodiment, the first edge of at least one of the first insulating layers in the width and length directions of the electrode sheet is flush with the negative current collector substrate. This reduces the likelihood of short circuits between the positive and negative electrode sheets when the tab is folded and bent, and correspondingly reduces the length requirement of the separator at the first end, thus saving on the amount of separator used. Similarly, the second edge of at least one of the second insulating layers in the width and length directions of the electrode sheet is flush with the negative current collector substrate. This also reduces the likelihood of short circuits between the positive and negative electrode sheets when the tab is folded and bent, and correspondingly reduces the length requirement of the separator at the second end, thus saving on the amount of separator used.

[0014] The first insulating layer has a first end edge extending beyond the negative current collector substrate in at least one of the electrode width and length directions. The edge of the negative current collector substrate is laterally positioned within the first insulating layer corresponding to the position of the positive electrode. Consequently, even if burrs on the edge of the negative current collector substrate pierce the separator, the risk of a short circuit with the positive electrode is minimized due to the insulation provided by the first insulating layer. Similarly, the second insulating layer has a second end edge extending beyond the negative current collector substrate in at least one of the electrode width and length directions. The edge of the negative current collector substrate is laterally positioned within the second insulating layer corresponding to the position of the positive electrode. Consequently, even if burrs on the edge of the negative current collector substrate pierce the separator, the risk of a short circuit with the positive electrode is minimized due to the insulation provided by the second insulating layer.

[0015] In some embodiments, the battery cell further includes: a housing, in which the electrode assembly is housed; wherein the negative current collector substrate is flush with the positive current collector substrate on the side adjacent to the bottom of the housing in both the electrode width and electrode length directions.

[0016] In this embodiment, the housing can contain electrolyte. By aligning the edge of the negative current collector substrate, located near the bottom of the housing, with the edge of the positive current collector substrate, a relatively flat end surface can be formed on the lower side of the electrode assembly. This facilitates stable coverage of the separator, making it less prone to breakage, and reduces the required length of the separator, thus lowering costs. The flush lower ends of the positive and negative electrodes also contribute to the stable placement of the electrode assembly within the housing, allowing the electrolyte at the bottom of the housing to travel a shorter distance to the positive and negative electrodes, thereby improving the wetting effect of the electrolyte on the electrode assembly.

[0017] In some embodiments, the separator extends beyond or is flush with both sides of at least one of the positive current collector substrate and the negative current collector substrate in the electrode width direction and the electrode length direction.

[0018] In this embodiment, the extended separator, relative to at least one of the positive and negative current collector substrates, effectively prevents the edges of the positive and negative electrodes from crossing the separator and causing short circuits, thereby improving reliability and enhancing the cell withstand voltage test value. The separator can also cover the positive and negative electrodes to prevent them from directly contacting the inside of the casing, reducing the risk of casing corrosion or electrode breakage. Furthermore, by ensuring that the edges of at least one end of the separator in the electrode width and length directions are flush with both the positive and negative current collector substrates, the utilization rate of the separator can be effectively improved, and the cost of the separator can be reduced.

[0019] In some embodiments, the separator extends beyond one side of at least one of the positive electrode current collector substrate and the negative electrode current collector substrate in the electrode width direction and the electrode length direction, and is flush with the other side of at least one of the electrode width direction and the electrode length direction.

[0020] In this embodiment, the separator extending beyond one side, relative to at least one of the positive and negative current collector substrates, effectively isolates the edges of the positive and negative current collector substrates on that side, reducing the risk of short circuits due to overlap and improving the reliability of the battery cell. Meanwhile, the structure on the other side, flush with one of the positive and negative current collector substrates, improves the utilization rate of the separator and reduces its cost. This allows the battery cell to meet both reliability and cost requirements.

[0021] In some embodiments, the electrode assembly is a stacked electrode assembly, the separator is arranged in a folded manner, and the positive electrode and the negative electrode are arranged in a stacked manner; the separator extends beyond both sides of the positive current collector substrate and the negative current collector substrate in the length direction of the electrode.

[0022] In this embodiment, the separator that extends beyond the positive and negative current collector substrates in the length direction of the electrode sheet can effectively prevent the edges of the positive and negative electrode sheets from crossing the separator and causing a short circuit, thereby improving reliability and improving the cell withstand voltage test value.

[0023] In some embodiments, the electrode assembly is a stacked electrode assembly, wherein the separator and the negative electrode are arranged in a folded manner, the positive electrode is arranged in a stacked manner and inserted into the folded space formed by the separator and the negative electrode, the negative electrode extends beyond the positive electrode on at least one side of the electrode length direction, and the separator extends beyond or is flush with the negative electrode on at least one side of the electrode length direction.

[0024] In this embodiment, the negative electrode extends beyond the positive electrode on at least one side of the electrode length direction, which reduces the risk of edge lithium plating on the negative electrode, thereby improving the reliability of the electrode assembly. The separator extends beyond the negative electrode on one or both sides of the electrode length direction, making it less likely for the edges of the positive and negative electrodes to cross the separator and cause short circuits, thus improving reliability and the cell withstand voltage test value. Conversely, if the separator is flush with the negative electrode on one or both sides of the electrode length direction, it can effectively improve the utilization rate of the separator and reduce its cost.

[0025] In some embodiments, the electrode assembly is a wound electrode assembly formed by stacking and winding the positive electrode, the negative electrode, and the two separators according to the first separator, the negative electrode, and the second separator, wherein the negative electrode extends beyond the positive electrode in both the start and end sides of the winding direction of the electrode assembly.

[0026] In this embodiment, the winding direction of the electrode assembly is consistent with the length direction of at least one of the positive and negative electrode sheets. Along the winding direction of the electrode assembly, the starting edge of the negative electrode sheet extends beyond the starting edge of the positive electrode sheet, and the ending edge of the negative electrode sheet extends beyond the ending edge of the positive electrode sheet. This reduces the risk of lithium plating at the edge of the negative electrode sheet on both the inner and outer sides of the winding structure, thereby improving the reliability of the electrode assembly.

[0027] In some embodiments, at least one of the two isolators extends beyond the positive and negative electrode sheets on the starting side of the winding direction of the electrode assembly, and the isolator located on the outermost ring of the wound electrode assembly extends beyond the negative electrode sheet on the ending side of the winding direction of the electrode assembly.

[0028] In this embodiment, this structure can effectively separate the positive electrode and the negative electrode, reduce the risk of short circuit between the negative electrode and the positive electrode, thereby improving the reliability of the electrode assembly and being compatible with fluctuations in actual production.

[0029] In some embodiments, the electrode assembly further includes:

[0030] The finishing tape is bonded to the tail of the isolator located on the outermost ring of the wound electrode assembly and covers the tail of the isolator located on the outermost ring of the wound electrode assembly.

[0031] In this embodiment, the finishing tape can finish the winding structure. The outermost separator and the portion of another separator that extends beyond the end edge of the negative electrode sheet can be bonded together to the surface of the outermost separator by the finishing tape, thereby stably and reliably constraining the winding structure.

[0032] In some embodiments, the negative electrode extends beyond the outermost of the two insulating members located on the end side of the winding direction of the electrode assembly, or is flush with the outermost of the two insulating members located on the end side of the winding direction of the electrode assembly, and the other of the two insulating members extends beyond the positive electrode.

[0033] In this embodiment, the negative electrode sheet has a termination edge in the winding direction, which is flush with the isolator located on the outermost ring of the wound electrode assembly. The termination edge of the negative electrode sheet in the winding direction can also extend beyond the isolator on the outermost ring of the wound electrode assembly, thus improving the utilization rate of the isolator and reducing its usage and cost. Another isolator extends beyond the positive electrode sheet on the termination edge in the winding direction, effectively separating the termination edge of the positive electrode sheet from the negative electrode sheet to reduce the risk of short circuits due to contact.

[0034] In some embodiments, the electrode assembly further includes:

[0035] The finishing tape is bonded to the tail of the insulating member located on the outermost ring of the wound electrode assembly, and covers the tail of the negative electrode sheet and the tail of the insulating member and the tail of the negative electrode sheet located on the outermost ring of the wound electrode assembly.

[0036] In this embodiment, since the finishing tape has stronger adhesion and a certain puncture resistance than the separator, and its strength is also significantly greater, using the finishing tape for finishing allows the thickness of the finishing tape to be less than the thickness of two turns of the separator film during conventional winding finishing, which helps to save costs. The thickness of the finishing tape is usually greater than the thickness of the separator film, which can reduce the risk of electrode burrs puncturing the separator film due to cutting, and can also fix the tail of the negative electrode film to prevent slippage.

[0037] In some embodiments, the negative electrode active material layer is flush with both sides of the positive electrode active material layer relative to at least one of the electrode width direction and the electrode length direction.

[0038] Wherein, the separator extends beyond at least one of the positive electrode current collector substrate and the negative electrode current collector substrate on both sides of at least one of the electrode width direction and the electrode length direction; or, the separator extends beyond at least one of the positive electrode current collector substrate and the negative electrode current collector substrate on one side of at least one of the electrode width direction and the electrode length direction, and is flush with the other side of at least one of the electrode width direction and the electrode length direction.

[0039] In this embodiment, the negative electrode active material layer and the positive electrode active material layer are flush on both sides of at least one of the electrode width direction and the electrode length direction. This can improve the effective reaction area between the positive electrode and the negative electrode, increase the utilization rate of the active materials of the positive electrode and the negative electrode, and help improve the volumetric energy density of the electrode assembly. This, in turn, helps improve the cell structure design, increase the capacity of the battery cell, and reduce costs.

[0040] The separator extends beyond the positive and / or negative current collector substrates on at least two sides in both the electrode width and length directions, effectively separating the edges of the positive and negative electrodes. This prevents them from easily crossing the separator and causing a short circuit, thus improving reliability and increasing the cell's withstand voltage test values. The separator extending to one side effectively isolates the edges of the positive and negative current collector substrates on that side, reducing the risk of a short circuit and improving the reliability of the battery cell. A structure where the other side is flush with one of the positive and negative current collector substrates on that side increases the utilization rate of the separator and reduces its cost. This allows the battery cell to meet both reliability and cost requirements.

[0041] In one aspect of this disclosure, a battery device is provided, comprising: the aforementioned battery cell.

[0042] The battery device using the above-described battery cells can improve performance.

[0043] In one aspect of this disclosure, an electrical device is provided, comprising: the aforementioned battery device.

[0044] The electrical equipment using the above-described battery device can improve performance. Attached Figure Description

[0045] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0046] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0047] Figure 1 These are schematic diagrams of the structure of some embodiments of the electrical equipment according to this disclosure;

[0048] Figure 2 This is an exploded schematic diagram of some embodiments of the battery device according to the present disclosure;

[0049] Figure 3 and Figure 4 These are schematic diagrams of the mounting structure and exploded structure of some embodiments of the battery cell according to this disclosure;

[0050] Figure 5 This is a schematic diagram of the structure of a wound electrode assembly according to some embodiments of the battery cell of this disclosure;

[0051] Figure 6 This is a schematic diagram of the structure of a stacked electrode assembly according to some embodiments of the battery cell of this disclosure;

[0052] Figure 7 (a)-(c) are respectively Figure 5 Schematic diagrams of partial layers in sections aa, bb, and cc, or Figure 6 Schematic diagram of some layers in sections AA, BB, and CC;

[0053] Figures 8-10 They are Figure 5 AA section or Figure 6 A schematic diagram of partial layers of multiple deformed examples at section aa;

[0054] Figure 11 and Figure 12A They are Figure 5 Schematic diagrams of two deformation examples of the dd section;

[0055] Figure 12B yes Figure 12A An enlarged schematic diagram of the area enclosed by the middle circle G;

[0056] Figure 13 and Figure 14 They are Figure 6 Schematic diagrams of partial layers of several deformation examples of the DD section;

[0057] Figure 15 (a)-(b) are respectively Figure 5 AA section or Figure 6 A schematic diagram of partial layers of multiple deformed examples at section aa;

[0058] Figure 15 (c) is Figure 6 A schematic diagram of a partial layer of a deformed example of the DD section;

[0059] Figure 16 and Figure 17 These are schematic diagrams of the mounting structure and exploded structure of other embodiments of the battery cell according to the present disclosure;

[0060] Figure 18 This is a schematic diagram of the structure of a stacked electrode assembly or a wound electrode assembly according to some other embodiments of the battery cell of this disclosure;

[0061] Figure 19 (a) and (b) are respectively Figure 18 Schematic diagram of partial layers in the EE and FF sections.

[0062] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components.

[0063] Explanation of reference numerals in the attached figures:

[0064] 10-Battery cell; 11-Casing; 111-Outer shell; 112, 113-Top cover; 12-Electrode assembly; 121t-Positive electrode tab; 122t-Negative electrode tab; 121-Positive electrode sheet; 1211-Positive current collector substrate; 1212-Positive active material layer; 1213-First insulating layer; 1214-Second insulating layer; 122-Negative electrode sheet; 1221-Negative current collector substrate; 1222-Negative active material layer; 123-Separator; 124-Finishing tape; 131, 132-Current collectors; 141-Positive terminal; 142-Negative terminal;

[0065] 20 - Battery assembly; 21 - Housing; 22 - Housing cover;

[0066] 30-Vehicle; 31-Controller; 32-Motor; 33-Axle; 34-Wheel.

[0067] dr1 - electrode width direction; dr2 - electrode length direction; r - winding direction; x - width direction; y - thickness direction; z - height direction. Detailed Implementation

[0068] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.

[0069] Unless otherwise defined, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains; the terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings of this disclosure are intended to cover non-exclusive inclusion.

[0070] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0071] In this disclosure, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this disclosure can be combined with other embodiments.

[0072] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, if the character " / " appears in this disclosure, it generally indicates that the preceding and following related objects have an "or" relationship.

[0073] In the description of the embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0074] In the description of embodiments of this disclosure, the term "at least one" refers to one or more (including two), similarly, "at least one group" refers to one or more (including two) groups, and "at least one piece" refers to one or more (including two) pieces. In the description of embodiments of this disclosure, the term "at least part" refers to part or all of them.

[0075] Unless otherwise specified, in the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0076] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0077] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0078] In some related technologies, the design of the relative positions and dimensions of the positive electrode, negative electrode, and separator in the electrode assembly needs to take into account the reliability of the battery cell, as well as factors such as volumetric energy density, cost, and manufacturing difficulty.

[0079] In view of this, the present disclosure provides a battery cell, a battery device, and an electrical appliance that can improve the performance of the battery cell.

[0080] In one aspect of this disclosure, a battery cell is provided, comprising: an electrode assembly including a positive electrode, a negative electrode, and a separator, the separator being located between the positive electrode and the negative electrode; the positive electrode including a positive current collector substrate and a positive active material layer disposed on the positive current collector substrate, the negative electrode including a negative current collector substrate and a negative active material layer disposed on the negative current collector substrate; the positive electrode, the negative electrode, and the separator are arranged in at least one of the following ways: the negative active material layer extends beyond at least one side of at least one of the positive active material layer in the electrode width direction and the electrode length direction; and the separator extends beyond at least one side of at least one of the positive current collector substrate and the negative current collector substrate in the electrode width direction and the electrode length direction.

[0081] In this embodiment, by extending the negative electrode active material layer beyond at least one side of the positive electrode active material layer in at least one of the electrode width direction and the electrode length direction, the space for the negative electrode to receive lithium ions can be increased in at least one of the electrode width direction and the electrode length direction. This allows the electrical performance of the positive electrode active material layer to be fully utilized, reduces the risk of edge lithium plating in at least one of the negative electrode in the electrode width direction and the electrode length direction, and improves the reliability of the electrode assembly. By extending the separator beyond at least one side of the positive electrode current collector substrate and the negative electrode current collector substrate in at least one of the electrode width direction and the electrode length direction, it is less likely that the positive electrode current collector substrate and the negative electrode current collector substrate will experience short circuits on at least one side of at least one of the electrode width direction and the electrode length direction, thus improving the reliability of the electrode assembly.

[0082] In this embodiment of the disclosure, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0083] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this disclosure does not limit the type. The battery cell can be cylindrical, flat, cuboid, or other shapes, and this application also does not limit the shape. Battery cells are generally classified according to their packaging method into cylindrical battery cells, square battery cells, and pouch battery cells, and this application also does not limit the shape.

[0084] The battery cells of this disclosure are applicable to various battery devices. The battery device referred to herein is a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0085] In some embodiments, the battery device may include a housing and battery modules. The housing provides a space for the battery modules, which are mounted within the housing. The housing may be made of metal. The battery modules may include multiple battery cells connected in series, parallel, or a combination thereof. A battery cell is the smallest unit constituting the battery device. A battery cell includes electrode components capable of undergoing electrochemical reactions.

[0086] In some embodiments, the battery device may include a housing and individual battery cells, with the individual battery cells housed within the housing.

[0087] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0088] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0089] The battery device of this disclosure is applicable to various electrical devices that use battery devices. These electrical devices can be mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; and power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. This disclosure does not impose any particular limitation on the above-mentioned electrical devices.

[0090] Figure 1 This is a structural schematic diagram of some embodiments of the electrical equipment disclosed herein. For convenience, a vehicle is used as an example for explanation. The vehicle 30 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle or a hybrid vehicle, etc. A battery device 20 can be installed at the bottom, front, or rear of the vehicle 30.

[0091] The battery device 20 can be used to power the vehicle 30. For example, the battery device 20 can serve as the operating power source for the vehicle 30's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 30. The battery device 20 can not only serve as the operating power source for the vehicle 30, but also as the driving power source, replacing or partially replacing fuel or natural gas to provide propulsion for the vehicle 30.

[0092] The interior of vehicle 30 may also include an axle 33, wheels 34, a motor 32, and a controller 31. The controller 31 controls the battery device 20 to supply power to the motor 32. For example, when vehicle 30 uses the battery device 20 as its driving power source, the controller 31 can provide the motor 32 with the power required for constant speed and acceleration. The motor 32 drives the axle 33 to rotate, thereby driving the wheels 34 to rotate.

[0093] Figure 2 This is an exploded view of some embodiments of the battery device according to the present disclosure. (See reference) Figure 2 In some embodiments, the battery device 20 includes a housing 21, a cover 22, and one or more battery cells 10 disposed in the housing 21. The housing 21, while accommodating the battery cells 10, also provides functions such as cooling, sealing, and impact protection for the battery cells 10, and can prevent liquids or other foreign objects from adversely affecting the charging, discharging, or reliability of the battery cells 10. The cover 22 can be closed onto the end of the housing 21 to seal the housing 21.

[0094] exist Figure 2 In this system, the individual battery cells 10 can be electrically connected in various ways, such as series, parallel, or mixed connection, to achieve the required electrical performance parameters of the battery device 20. Multiple battery cells 10 can be arranged in rows, and one or more rows of battery cells 10 can be arranged in the housing as needed.

[0095] In some embodiments, the individual battery cells 10 of the battery device 20 can be arranged along at least one of the length and width directions of the housing 21. At least one row or column of battery cells 10 can be provided as needed. Alternatively, one or more layers of battery cells 10 can be provided along the height direction of the battery device 20 as required.

[0096] In some embodiments, multiple battery cells 10 may first be connected in series, parallel, or in a mixed manner to form a battery module, and then the multiple battery modules may be connected in series, parallel, or in a mixed manner to form a whole, which is housed within the housing 21. In other embodiments, all battery cells 10 are directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 10 is housed within the housing 21. The electrode terminals of the battery cells 10 may be electrically connected to adjacent battery cells 10 via a busbar.

[0097] Figure 3 and Figure 4 These are schematic diagrams of the mounting structure and exploded structure of some embodiments of the battery cell according to this disclosure. Figure 5 This is a schematic diagram of the structure of a wound electrode assembly according to some embodiments of the battery cell of this disclosure. Figure 6 This is a schematic diagram of the structure of a stacked electrode assembly according to some embodiments of the battery cell of this disclosure. Figure 7(a)-(c) are respectively Figure 5 Schematic diagrams of partial layers in sections aa, bb, and cc, or Figure 6 Schematic diagram of some layers in sections AA, BB and CC.

[0098] refer to Figures 3-7 This disclosure provides a battery cell 10, including: an electrode assembly 12, the electrode assembly 12 including a positive electrode 121, a negative electrode 122, and a separator 123, the separator 123 being located between the positive electrode 121 and the negative electrode 122; the positive electrode 121 including a positive current collector substrate 1211 and a positive active material layer 1212 disposed on the positive current collector substrate 1211, and the negative electrode 122 including a negative current collector substrate 1221 and a negative active material layer 1222 disposed on the negative current collector substrate 1221.

[0099] The positive electrode 121, the negative electrode 122, and the separator 123 are arranged in at least one of the following ways: the negative electrode active material layer 1222 extends beyond at least one side of at least one of the positive electrode active material layer 1212 in the electrode width direction dr1 and the electrode length direction dr2; and the separator 123 extends beyond at least one side of at least one of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 in the electrode width direction dr1 and the electrode length direction dr2.

[0100] The electrode assembly 12 includes a positive electrode 121, a negative electrode 122, and a separator 123. The separator 123 is located between the positive electrode 121 and the negative electrode 122. The operation of the battery cell 10 is achieved by the movement of internal metal ions between the positive electrode 121 and the negative electrode 122. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) repeatedly insert and extract between the positive electrode 121 and the negative electrode 122. The separator 123, located between the positive electrode 121 and the negative electrode 122, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0101] like Figure 7 As shown, the positive electrode 121 includes a positive active material layer 1212. The positive electrode 121 may also include a positive current collector substrate 1211, and the positive active material layer 1212 is disposed on the surface of the positive current collector substrate 1211. For example, the positive active material layer 1212 may be disposed on one surface or both opposite surfaces in the thickness direction of the positive current collector substrate 1211.

[0102] As an example, the positive electrode current collector substrate 1211 can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by placing a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0103] As an example, the positive electrode active material layer 1212 may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this disclosure is not limited to these materials, and other conventional materials that can be used as the positive electrode active material layer 1212 may also be used. These positive electrode active material layers 1212 may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05At least one of O2 and its modified compounds.

[0104] like Figure 7 As shown, the negative electrode 122 includes a negative electrode active material layer 1222. The negative electrode 122 may also include a negative electrode current collector substrate 1221, and the negative electrode active material layer 1222 is disposed on the surface of the negative electrode current collector substrate 1221. For example, the negative electrode active material layer 1222 may be disposed on one side surface or both opposite sides of the negative electrode current collector substrate 1221 in the thickness direction.

[0105] As an example, the negative electrode current collector substrate 1221 can be made of metal foil, foamed metal, or composite current collector. For example, as a metal foil, it can be made of silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collector can include a polymer material base layer and a metal layer. Composite current collector can be formed by applying a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) onto a polymer material base layer (such as a base layer of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0106] As an example, the negative electrode active material layer 1222 may employ a negative electrode active material layer known in the art for use in battery cells. As an example, the negative electrode active material layer 1222 may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this disclosure is not limited to these materials, and other conventional materials that can be used as the negative electrode active material layer 1222 may also be used. These negative electrode active material layers 1222 may be used alone or in combination of two or more.

[0107] In some embodiments, the separator 123 is a diaphragm. This disclosure does not impose any particular limitation on the type of diaphragm; the separator 123 can be any known porous structure separator with good chemical and mechanical stability.

[0108] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrode plates, or it can be located between the positive and negative electrode plates while being attached to the surface of the positive electrode plate and / or the surface of the negative electrode plate.

[0109] In some embodiments, the separator 123 is a solid electrolyte. The solid electrolyte is disposed between the positive electrode 121 and the negative electrode 122, and serves to both transport ions and isolate the positive and negative electrodes.

[0110] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This disclosure does not impose specific limitations on the type of electrolyte, which can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0111] As an example, liquid electrolytes include electrolyte salts and solvents.

[0112] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0113] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0114] As an example, gel electrolytes include a polymer-based backbone network combined with an ionic liquid—a lithium salt.

[0115] As an example, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0116] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0117] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0118] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0119] exist Figures 4-6 In the electrode, the width direction dr1 can be the width direction of at least one of the positive electrode 121 and the negative electrode 122, and the length direction dr2 can be the length direction of at least one of the positive electrode 121 and the negative electrode 122. Figure 4 In this embodiment, the electrode assembly 12 may further include a positive electrode tab 121t connected to the positive electrode 121 and a negative electrode tab 122t connected to the negative electrode 122. The positive electrode tab 121t and the negative electrode tab 122t may be located at the same end of the electrode assembly 12 along the electrode width direction dr1 to facilitate the production of short cells with a shorter width (e.g., ≤300mm). In other embodiments, the tabs 121t and 122t may also be located at both ends of the electrode assembly 12 along the electrode width direction dr1 or the electrode length direction dr2, thereby facilitating the production of long cells with a larger width (e.g., >300mm).

[0120] For the positive electrode 121 or negative electrode 122, which is basically rectangular in shape, the direction of extension corresponding to the longer side is the length direction, and the direction of extension corresponding to the shorter side is the width direction. Figure 4 The width direction dr1 of the intermediate electrode is parallel to the height direction z of the battery cell. (Reference) Figure 5 In the wound electrode assembly, the winding direction *r* of the positive electrode 121 or negative electrode 122 is the same as the length direction of the positive electrode 121 or negative electrode 122. Therefore, the length direction dr2 of the electrode is actually parallel to the winding direction *r*. (Reference) Figure 6 The length direction of the electrode in the stacked electrode assembly is dr2 and Figure 4 The width direction z of the battery cell is parallel.

[0121] exist Figure 5 In the diagram, sections aa, bb, and cc are all parallel to the electrode width direction dr1. Section aa is located outside the electrode tab, therefore... Figure 7 The tabs are not shown in (a), while sections bb and cc are located at the positions of tabs 122t and 121t, respectively. Figure 7 (b) and (c) respectively show the tab 122t connected to the negative electrode 122 and the tab 121t connected to the positive electrode 121.

[0122] like Figure 7 As shown in (a)-(c), the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on one side of the electrode width direction dr1. In another embodiment, the negative electrode active material layer 1222 may extend beyond the positive electrode active material layer 1212 on the other side of the electrode width direction dr1, or it may extend beyond both sides. In other embodiments, the direction in which the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 may also be the electrode length direction dr2.

[0123] In this embodiment, by extending the negative electrode active material layer 1222 beyond at least one side of the positive electrode active material layer 1212 in at least one of the electrode width direction dr1 and the electrode length direction dr2, the space for the negative electrode to receive lithium ions can be increased in at least one of the electrode width direction dr1 and the electrode length direction dr2. This allows the electrical performance of the positive electrode active material layer 1212 to be fully utilized, reduces the risk of edge lithium plating of the negative electrode 122 in at least one of the electrode width direction dr1 and the electrode length direction dr2, and improves the reliability of the electrode assembly. By extending the separator 123 beyond at least one side of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 in at least one of the electrode width direction dr1 and the electrode length direction dr2, the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 are less likely to experience short circuits on at least one side of at least one of the electrode width direction dr1 and the electrode length direction dr2, and improves the reliability of the electrode assembly 12.

[0124] Here, "object A exceeding object B on a certain side in a specific direction" means that the edge of object A on that side in that specific direction is entirely located at the edge of object B on the same side in that specific direction. Later, "object A being flush with object B on a certain side in a specific direction" means that the edge of object A on that side in that specific direction is flush with the edge of object B on the same side in that specified direction, within the allowable tolerance range of the manufacturing process. This flushing does not mean absolute overlap between the edges, but rather a relatively close flush within the allowable manufacturing process range.

[0125] The excess length of the negative electrode active material layer 1222 relative to the positive electrode active material layer 1212 on at least one side of the electrode width direction dr1 and the electrode length direction dr2 can be set according to factors such as fluctuations in electrode production and electrode assembly assembly, and the balance of electrode utilization. For example, the excess length can be within 3 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, etc. Similarly, the excess length of the separator 123 relative to at least one of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 on at least one side of the electrode width direction dr1 and the electrode length direction dr2 can also be set according to factors such as fluctuations in separator production and electrode assembly assembly, and the balance of separator utilization. For example, the excess length can be within 3 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, etc.

[0126] For wound electrode assemblies, the excess length of the negative electrode active material layer 1222 relative to the positive electrode active material layer 1212 on the starting side of the electrode length direction dr2 (parallel to the winding direction r) can be between 3mm and 10mm, such as 3mm, 5mm, 6.5mm, 8mm, 9mm, or 10mm. Depending on this spacing value, space utilization and the amount of negative electrode material used can be improved, which is beneficial for increasing the effective capacity of the battery, reducing costs, and also reducing the risk of lithium plating, thus improving the reliability of the electrode assembly.

[0127] Figures 8-10 They are Figure 5 AA section or Figure 6 A schematic diagram of partial layers of multiple deformed examples at section aa. (Reference) Figures 7-10 The electrode width direction dr1 is drawn as a vertical black solid line segment with an arrow pointing upwards. The first end of the electrode assembly can be the end pointed to by the arrow in the electrode width direction dr1, and the second end of the electrode assembly can be the end away from the arrow in the electrode width direction dr1. In other embodiments, the second end of the electrode assembly can also be the end pointed to by the arrow in the electrode width direction dr1, and the first end of the electrode assembly can be the side away from the arrow in the electrode width direction dr1.

[0128] refer to Figure 7 (a)-(c) Figure 8 (a)-(b) Figure 9 (a), (c), (e), (f) and Figure 10In some embodiments (a)-(d), the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on one side of at least one of the electrode width direction dr1 and the electrode length direction dr2, and is flush with the other side of at least one of the electrode width direction dr1 and the electrode length direction dr2.

[0129] like Figure 7 of (a), Figure 8 of (a), Figure 9 (a), (c) and Figure 10 As shown in (a)-(d), the first edge of the negative electrode active material layer 1222 along the electrode width direction dr1 extends beyond the first edge of the positive electrode active material layer 1212 along the electrode width direction dr1, while the second edge of the negative electrode active material layer 1222 along the electrode width direction dr1 is flush with the second edge of the positive electrode active material layer 1212 along the electrode width direction dr1, with the first and second edges facing each other. In this embodiment, the first edge and the second edge of the negative electrode active material layer 1222 are respectively the front edge and the rear edge of the negative electrode active material layer 1222 along the electrode width direction dr1, and the first edge and the second edge of the positive electrode active material layer 1212 are respectively the front edge and the rear edge of the positive electrode active material layer 1212 along the electrode width direction dr1.

[0130] The length direction dr2 of the electrode can be perpendicular to the width direction dr1. For example... Figure 8 (b) and Figure 9 As shown in (e) and (f), the first and second end edges of the negative electrode active material layer 1222 are the rear and front edges of the negative electrode active material layer 1222 along the electrode width direction dr1, respectively. Similarly, the first and second end edges of the positive electrode active material layer 1212 are the rear and front edges of the positive electrode active material layer 1212 along the electrode width direction dr1, respectively. The structure where the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on one side and is flush with the other side can also be applied to the electrode length direction dr2.

[0131] In this embodiment, the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on one side in the electrode width direction dr1 and / or electrode length direction dr2. This reduces the risk of edge lithium plating on the negative electrode 122, improves the reliability of the electrode assembly, and helps reduce the precision requirements of the manufacturing process. The negative electrode active material layer 1222 is flush with the positive electrode active material layer 1212 on the other side in the electrode width direction dr1 and / or electrode length direction dr2. This improves the effective reaction area between the positive electrode 121 and the negative electrode 122, increases the utilization rate of the active materials in both electrodes, and helps improve the volumetric energy density of the electrode assembly 12. This, in turn, helps improve the cell structure design, increases the capacity of the battery cell, and reduces costs. Thus, the battery cell can meet the requirements of both reliability and volumetric energy density.

[0132] refer to Figure 8 (c) Figure 9 (b), (d), (g)-(i) and Figure 10 In some embodiments (e)-(h), the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on both sides of at least one of the electrode width direction dr1 and the electrode length direction dr2.

[0133] like Figure 8 (c) Figure 9 (b), (d), (g)-(i) and Figure 10 As shown in (e)-(h), the first edge of the negative electrode active material layer 1222 extends beyond the first edge of the positive electrode active material layer 1212 along the width direction dr1, and the second edge of the negative electrode active material layer 1222 also extends beyond the second edge of the positive electrode active material layer 1212 along the width direction dr1. This structure, in which the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on both sides, can also be applied to the length direction dr2 of the electrode.

[0134] In this embodiment, the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on both sides in the electrode width direction dr1 and / or electrode length direction dr2, which can further reduce the risk of lithium plating at the edges of the negative electrode 122 in the electrode width direction dr1 and / or electrode length direction dr2, improve the reliability of the electrode assembly, and help reduce the precision requirements of the manufacturing process.

[0135] refer to Figure 9 (a)-(i) and Figure 10In some embodiments (e)-(h), the positive electrode 121 further includes at least one of a first insulating layer 1213 and a second insulating layer 1214. The first insulating layer 1213 is located at a first end of the electrode assembly 12 along at least one of the electrode width direction dr1 and the electrode length direction dr2, and is located on at least one of the positive current collector substrate 1211 and the positive active material layer 1212, and extends beyond the positive active material layer 1212. The second insulating layer 1214 is located at a second end of the electrode assembly 12 along at least one of the electrode width direction dr1 and the electrode length direction dr2, and is located on at least one of the positive current collector substrate 1211 and the positive active material layer 1212, and extends beyond the positive active material layer 1212. The first end and the second end are disposed opposite to each other.

[0136] The first insulating layer 1213 can be integrally disposed on the surface of the positive electrode current collector substrate 1211, or integrally disposed on the surface of the positive electrode active material layer 1212, or partially disposed on the positive electrode active material layer 1212 and partially disposed on the surface of the positive electrode current collector substrate 1211. The first insulating layer 1213 can be formed on the positive electrode sheet 121 by coating, bonding, or other means. The composition of the first insulating layer 1213 may include at least one of alumina, boehmite, silicon oxide, zirconium oxide, magnesium oxide, hafnium dioxide, and titanium oxide. The first insulating layer 1213 may possess certain corrosion resistance, wear resistance, and good toughness.

[0137] like Figure 9 As shown in (a)-(c), the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 at its leading edge in the electrode width direction dr1, and the first insulating layer 1213 in the positive electrode 121 extends beyond the positive electrode active material layer 1212. The first insulating layer 1213 may also be provided on one side in the electrode length direction dr2. For the current collector substrate edge of the cut negative electrode 122, the first insulating layer 1213 located at at least one of the electrode width direction dr1 and the electrode length direction dr2 at the first end of the electrode assembly 12 can reduce the risk of burrs at the cut edge piercing the separator 123 and short-circuiting with the positive electrode current collector substrate 1211, thereby improving the reliability of the battery cell.

[0138] The second insulating layer 1214 can be integrally disposed on the surface of the positive electrode current collector substrate 1211, or integrally disposed on the surface of the positive electrode active material layer 1212, or partially disposed on the positive electrode active material layer 1212 and partially disposed on the surface of the positive electrode current collector substrate 1211. The second insulating layer 1214 can be formed on the positive electrode sheet 121 by coating, bonding, or other means. The composition of the second insulating layer 1214 may include at least one of alumina, boehmite, silicon oxide, zirconium oxide, magnesium oxide, hafnium dioxide, and titanium oxide. The second insulating layer 1214 may possess certain corrosion resistance, wear resistance, and good toughness.

[0139] like Figure 9 As shown in (d)-(f), the negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 at its rear edge in the electrode width direction dr1, and the second insulating layer 1214 in the positive electrode 121 extends beyond the positive electrode active material layer 1212. The second insulating layer 1214 can also be provided on one side in the electrode length direction dr2. For the current collector substrate edge of the cut negative electrode 122, the second insulating layer 1214 located at at least one of the electrode width direction dr1 and the electrode length direction dr2 at the second end of the electrode assembly 12 can reduce the risk of burrs at the cut edge piercing the separator 123 and short-circuiting with the positive electrode current collector substrate 1211, thereby improving the reliability of the battery cell.

[0140] The positive electrode 121 may include only the first insulating layer 1213 or the second insulating layer 1214. In other embodiments, the positive electrode 121 may include both the first insulating layer 1213 and the second insulating layer 1214. Figure 9 As shown in (g)-(i), the first insulating layer 1213 and the second insulating layer 1214 are located on both sides of the positive electrode active material layer 1212 along the electrode width direction dr1, and are connected to the two ends of the positive electrode active material layer 1212 along the electrode width direction dr1. In other embodiments, the first insulating layer 1213 and the second insulating layer 1214 may also be located on both sides of the positive electrode active material layer 1212 along the electrode length direction dr2, and are connected to the two ends of the positive electrode active material layer 1212 along the electrode length direction dr1.

[0141] refer to Figure 4 and Figure 5 The second insulating layer 1214 is located near the bottom of the housing 11. The second insulating layer 1214 can prevent the positive electrode active material layer 1212 from being directly exposed to the lower edge of the positive electrode plate 121, reducing the possibility of damage caused by contact and collision between the positive electrode active material layer 1212 and the bottom of the housing. Moreover, the second insulating layer 1214 is not easy to react with the electrolyte at the bottom of the housing 11, which helps to reduce reliability problems caused by the scouring of the separator during electrolyte injection.

[0142] refer to Figure 9 In some embodiments, the first insulating layer 1213 is flush with or extends beyond the negative electrode current collector substrate 1221 on at least one of the electrode width direction dr1 and the electrode length direction dr2; the second insulating layer 1214 is flush with or extends beyond the negative electrode current collector substrate 1221 on at least one of the electrode width direction dr1 and the electrode length direction dr2.

[0143] refer to Figure 9 In (a), (b), (g), and (i), the first end edge of the first insulating layer 1213 extends beyond the negative current collector substrate 1221 at least one of the electrode width direction dr1 and the electrode length direction dr2. It can be seen that the edge of the negative current collector substrate 1221, laterally corresponding to the position of the positive electrode 121, is located within the first insulating layer 1213. Correspondingly, even if the burrs on the edge of the negative current collector substrate 1221 pierce the separator 123, the risk of a short circuit with the positive electrode can be minimized under the insulating isolation of the first insulating layer 1213. Similarly, refer to... Figure 9 In (d), (e), and (g), the second end edge of the second insulating layer 1214 extends beyond the negative current collector substrate 1221 at at least one of the electrode width direction dr1 and the electrode length direction dr2. It can be seen that the edge of the negative current collector substrate 1221 is laterally located in the second insulating layer 1214 corresponding to the position of the positive electrode 121. Accordingly, even if the burrs on the edge of the negative current collector substrate 1221 pierce the separator 123, the risk of short circuit with the positive electrode can be minimized under the insulation isolation of the second insulating layer 1214.

[0144] refer to Figure 9 In (c) and (h), the first end edge of at least one of the electrode width direction dr1 and the electrode length direction dr2 is flush with the negative current collector substrate 1221. This prevents short circuits between the positive electrode 121 and the negative electrode 122 when the electrode tab is folded and bent, and correspondingly reduces the length requirement of the separator 123 at that end, thereby saving the amount of separator 123 used. (See reference) Figure 9 In (f), (h) and (i), the second end edge of at least one of the electrode width direction dr1 and the electrode length direction dr2 is flush with the negative current collector substrate 1221. This makes it less likely for a short circuit to occur between the positive electrode 121 and the negative electrode 122 when the electrode tab is folded and bent. Correspondingly, the length requirement of the isolator 123 at this end can also be reduced, thereby saving the amount of isolator 123 used.

[0145] refer to Figure 7 (a)-(c) Figure 8 of (a), Figure 9 (a), (c), (f), (h), (i) and Figure 10 In some embodiments, (a)-(d), (f), and (i), the battery cell 10 further includes: a housing 11, in which the electrode assembly 12 is housed; the negative electrode current collector substrate 1221 is flush with the positive electrode current collector substrate 1211 on the side adjacent to the bottom surface of the housing 11 in the electrode width direction dr1 and the electrode length direction dr2.

[0146] like Figure 3 and Figure 4 As shown, the housing 11 may include an outer shell 111 for forming a receiving cavity for accommodating the electrode assembly 12 and a top cover 112 having an end opening at at least one end of the outer shell 111. The outer shell 111 may be formed by one or more side plates. The shape of the outer shell 111 may be determined according to the shape of one or more electrode assemblies 12, and the outer shell 111 may be a hollow cuboid, a hollow cube, a hollow cylinder, or the like. The outer shell 111 may be made of a conductive metal material or plastic; optionally, the outer shell 111 may be made of aluminum or an aluminum alloy.

[0147] The top cover 112 forms a sealed cavity with the outer casing 111 to accommodate the electrode assembly 12. Functional components, such as electrode terminals, a liquid injection mechanism, and a pressure relief mechanism, may be mounted on the top cover 112. Figure 4 As shown, a positive terminal 141 and a negative terminal 142 are provided on the top cover 112, which has an end opening at one end of the outer casing 111. The positive terminal 141 is electrically connected to the positive electrode plate 121 of the electrode assembly 12, and the negative terminal 142 is electrically connected to the negative electrode plate 122 of the electrode assembly 12.

[0148] The top cover 112 can be made of a metal (such as aluminum, aluminum alloy, etc.) or a non-metallic material (plastic) with a certain hardness and strength. The top cover 112 and the outer shell 111 can be fixedly connected by welding, bonding or by means of connectors.

[0149] Combination Figure 4The housing 11 can contain electrolyte. By aligning the edge of the negative current collector substrate 1221 located near the bottom surface of the housing 11 with the edge of the positive current collector substrate 1211, a relatively flat end surface can be formed on the lower side of the electrode assembly 12. This facilitates stable coverage of the separator 123, making it less prone to breakage, and reduces the required length of the separator 123, thus lowering costs. The flush lower ends of the positive and negative electrodes also facilitate the stable placement of the electrode assembly 12 within the housing 11, allowing the electrolyte at the bottom of the housing 11 to travel a shorter distance to the positive electrode 121 and the negative electrode 122, thereby improving the wetting effect of the electrolyte on the electrode assembly 12.

[0150] refer to Figures 7-10 In some embodiments, the separator 123 extends beyond or is flush with at least one of the positive current collector substrate 1211 and the negative current collector substrate 1221 on both sides of at least one of the electrode width direction dr1 and the electrode length direction dr2.

[0151] like Figure 7-9 and Figure 10 As shown in (a), the separator 123 extends beyond both sides of the positive current collector substrate 1211 and the negative current collector substrate 1221 in the electrode width direction dr1. In other embodiments, the separator 123 may also extend beyond both sides of the positive current collector substrate 1211 and the negative current collector substrate 1221 in the electrode length direction dr2. The extended separator 123 effectively prevents the edges of the positive electrode 121 and the negative electrode 122 from crossing the separator 123 and causing a short circuit, thereby improving reliability and increasing the cell withstand voltage test value. The separator 123 can also reduce the risk of casing corrosion or electrode breakage by covering the positive electrode 121 and the negative electrode 122 so that they do not directly contact the interior of the casing.

[0152] like Figure 10 As shown in (d), the two edges of the separator 123 in the electrode width direction dr1 are flush with the negative electrode current collector substrate 1221. Figure 10 As shown in (g), the two edges of the separator 123 in the electrode width direction dr1 are flush with the positive electrode current collector substrate 1211. Figure 10As shown in (h), the two side edges of the separator 123 in the electrode width direction dr1 are flush with the positive current collector substrate 1211 and the negative current collector substrate 1221. In other embodiments, the two side edges of the separator 123 in the electrode length direction dr2 may also be flush with the positive current collector substrate 1211 and / or the negative current collector substrate 1221. By making the two side edges of at least one of the separator 123 in the electrode width direction dr1 and the electrode length direction dr2 flush with the positive current collector substrate 1211 and the negative current collector substrate 1221, the utilization rate of the separator 123 can be effectively improved and the cost of the separator 123 can be reduced.

[0153] refer to Figure 10 In some embodiments, (b), (c), (e), and (f), the separator 123 extends beyond one side of at least one of the positive current collector substrate 1211 and the negative current collector substrate 1221 in the electrode width direction dr1 and the electrode length direction dr2, and is flush with the other side of at least one of the electrode width direction dr1 and the electrode length direction dr2.

[0154] Compared to at least one of the positive current collector substrate 1211 and the negative current collector substrate 1221, the separator 123 extending beyond one side can effectively isolate the edges of the positive current collector substrate 1211 and the negative current collector substrate 1221 on that side, reducing the risk of short circuits due to overlap and improving the reliability of the battery cell. Meanwhile, a structure with the other side flush with one of the positive current collector substrate 1211 and the negative current collector substrate 1221 on that side can improve the utilization rate of the separator 123 and reduce its cost. This allows the battery cell to meet the requirements of both reliability and cost.

[0155] Figure 11 and Figure 12A They are Figure 5 Schematic diagrams of two deformation examples of the dd section. Figure 12B yes Figure 12A An enlarged view of the area enclosed by the middle circle G. (Reference) Figure 5 , Figure 11 , Figure 12A and Figure 12B In some embodiments, the electrode assembly 12 is a wound electrode assembly formed by stacking and winding the positive electrode 121, the negative electrode 122, and the two separators 123 according to the first separator 123, the negative electrode 122, and the second separator 123. The negative electrode 122 extends beyond the positive electrode 121 at both the start and end sides of the winding direction r of the electrode assembly 12.

[0156] exist Figure 11, Figure 12A and Figure 12B In the winding assembly 12, the negative electrode 122 has a starting edge 122s and an ending edge 122e in the winding direction r, and the positive electrode 121 has a starting edge 121s and an ending edge 121e in the winding direction r. The winding direction r of the electrode assembly 12 is consistent with the length direction of at least one of the positive electrode 121 and the negative electrode 122. Along the winding direction r of the electrode assembly 12, the starting edge 122s of the negative electrode 122 extends beyond the starting edge 121s of the positive electrode 121, and the ending edge 122e of the negative electrode 122 extends beyond the ending edge 121e of the positive electrode 121. This reduces the risk of lithium plating at the edges of the negative electrode on both the inner and outer sides of the winding structure, improving the reliability of the electrode assembly.

[0157] refer to Figure 11 In some embodiments, at least one of the two separators 123 extends beyond the positive electrode 121 and the negative electrode 122 on the starting side of the winding direction r of the electrode assembly 12, and the separator 123 located on the outermost ring of the wound electrode assembly extends beyond the negative electrode 122 on the ending side of the winding direction r of the electrode assembly 12.

[0158] like Figure 11 As shown, both of the separators 123 extend beyond the positive electrode 121 and the negative electrode 122 at both the start and end sides of the winding direction r. The ends of the two separators 123 at the start side can be connected together. In some embodiments, only one separator 123 may extend beyond the positive electrode 121 and the negative electrode 122 at both the start and end sides of the winding direction r. This structure can effectively separate the positive electrode 121 and the negative electrode 122, reducing the risk of short circuit between the negative and positive electrodes, thereby improving the reliability of the electrode assembly and being compatible with fluctuations in actual production.

[0159] refer to Figure 11 In some embodiments, the electrode assembly 12 further includes a finishing tape 124, which is bonded to the tail of the spacer 123 located on the outermost ring of the wound electrode assembly and covers the tail of the spacer 123 located on the outermost ring of the wound electrode assembly.

[0160] Finishing tape 124 can finish the wound structure, in Figure 11 In the middle, the outermost insulating element 123 and the portion of another insulating element 123 that extends beyond the end edge 122e of the negative electrode sheet 122 can be jointly bonded to the surface of the outermost insulating element 123 by the finishing tape 124, thereby stably and reliably constraining the winding structure.

[0161] refer to Figure 12A and Figure 12B In some embodiments, the negative electrode 122 extends beyond the outermost of the two separators 123 located in the winding direction r of the electrode assembly on the end side of the winding direction r, or is flush with the outermost of the two separators 123 located in the winding direction r of the electrode assembly, and the other separator 123 extends beyond the positive electrode 121 on the end side of the winding direction r.

[0162] exist Figure 12A and Figure 12B In this configuration, the negative electrode 122 has a termination edge 122e in the winding direction r, which is flush with the separator 123 located on the outermost ring of the wound electrode assembly. The negative electrode 122 may also extend beyond the separator 123 on the termination side in the winding direction r, thus improving the utilization rate of the separator 123 and reducing its usage and cost. Another separator 123 extends beyond the positive electrode 121 on the termination side in the winding direction r, effectively separating the termination edge 121e of the positive electrode 121 from the negative electrode 122, thereby reducing the risk of short circuits due to contact between the two.

[0163] refer to Figure 12A and Figure 12B In some embodiments, the electrode assembly 12 further includes a finishing tape 124, which is bonded to the tail of the insulating member 123 located on the outermost ring of the wound electrode assembly, and covers the tail of the negative electrode sheet 122 and the tail of the insulating member 123 and the tail of the negative electrode sheet 122 located on the outermost ring of the wound electrode assembly.

[0164] Because the finishing tape 124 has stronger adhesion and a certain puncture resistance than the separator 123, and its strength is also significantly greater than that of the separator, using the finishing tape 124 for finishing allows the thickness of the finishing tape to be less than the thickness of two turns of the separator during conventional winding finishing, which helps to save costs. For example, for a finishing tape 124 with a thickness of 0.05mm, its thickness is greater than the thickness of the separator by 0.02mm, which can reduce the risk of electrode burrs puncturing the separator due to cutting, and can also fix the tail of the negative electrode sheet to prevent slippage.

[0165] Figure 13 and Figure 14 They are Figure 6 Schematic diagrams of partial layers of several deformed examples of the DD section. (Reference) Figure 6 and Figure 13In some embodiments (a)-(c), the electrode assembly 12 is a stacked electrode assembly, the separator 123 is arranged in a folded form, and the positive electrode 121 and the negative electrode 122 are arranged in a stacked form; the separator 123 extends beyond both sides of the positive current collector substrate 1211 and the negative current collector substrate 1221 in the length direction dr2 of the electrode.

[0166] exist Figure 13 In (a), the stacked electrode assembly includes a plurality of positive electrode plates 121 and a plurality of negative electrode plates 122, which are alternately arranged along the stacking direction. The spacer 123 can be folded in a zigzag pattern to separate the positive electrode plates 121 and negative electrode plates 122 by passing between each set of adjacent positive electrode plates 121 and negative electrode plates 122.

[0167] The edges of the separator 123 extend beyond the positive current collector substrate 1211 and the negative current collector substrate 1221 on both sides of the electrode length direction dr2. Figure 13 In (a), the negative electrode 122 extends beyond the positive electrode 121 on both sides of the electrode length direction dr2. Figure 13 In (b), the negative electrode 122 is flush with the positive electrode 121 on one side of the electrode length direction dr2 (i.e., the left side in the figure), and extends beyond it on the other side (i.e., the right side in the figure). Figure 13 In (c), the negative electrode 122 extends beyond the positive electrode 121 on one side of the electrode length direction dr2 (i.e., the left side in the figure) and is flush with it on the other side (i.e., the right side in the figure).

[0168] In this embodiment, the separator 123 extending beyond the positive current collector substrate 1211 and the negative current collector substrate 1221 in the electrode length direction dr2 can effectively prevent the edges of the positive electrode 121 and the negative electrode 122 from crossing the separator 123 and causing a short circuit, thereby improving reliability and improving the cell withstand voltage test value.

[0169] refer to Figure 14 In some embodiments, the electrode assembly 12 is a stacked electrode assembly, the separator 123 and the negative electrode 122 are arranged in a folded manner, the positive electrode 121 is arranged in a stacked manner and inserted into the folded space formed by the separator 123 and the negative electrode 122, the negative electrode 122 extends beyond at least one side of the electrode length direction dr2 relative to the positive electrode 121, and the separator 123 extends beyond or is flush with at least one side of the electrode length direction dr2 relative to the negative electrode 122.

[0170] exist Figure 14In the stacked electrode assembly, multiple positive electrode plates 121 and one negative electrode plate 122 are arranged alternately along the stacking direction. Two spacers 123 sandwich the negative electrode plate 122 and are folded together in a Z-shaped manner to separate the positive and negative electrode plates 121 by passing between adjacent groups of positive electrode plates 121. It can be seen that... Figure 14 The negative electrode 122 is wrapped around the left or right side of each positive electrode 121, so that it extends beyond the positive electrode 121 on at least one side of the electrode length direction dr2.

[0171] In this embodiment, the negative electrode 122 extends beyond the positive electrode 121 on at least one side of the electrode length direction dr2, which reduces the risk of edge lithium plating on the negative electrode 122, thereby improving the reliability of the electrode assembly. The separator 123 extends beyond the negative electrode 122 on one or both sides of the electrode length direction dr2, making it less likely for the edges of the positive and negative electrodes to cross the separator 123 and cause short circuits, thus improving reliability and the cell withstand voltage test value. Furthermore, the separator 123 being flush with the negative electrode 122 on one or both sides of the electrode length direction dr2 effectively improves the utilization rate of the separator 123 and reduces its cost.

[0172] In other embodiments, the stacked electrode assembly may include a plurality of positive electrode plates 121, a plurality of negative electrode plates 122, and a plurality of spacers 123, and the plurality of positive electrode plates 121, a plurality of negative electrode plates 122, and a plurality of spacers 123 are arranged in a stacked manner. The edge positional relationship of the positive electrode plates 121, negative electrode plates 122, and spacers 123 in the electrode width direction or the electrode length direction can be referred to the previous embodiments, and will not be repeated here.

[0173] Figure 15 (a)-(b) are respectively Figure 5 AA section or Figure 6 A schematic diagram of partial layers of multiple deformed examples of section aa. Figure 15 (c) is Figure 6 A schematic diagram of a partial layer of a deformed example of the DD section. (Reference) Figure 15In some embodiments, the negative electrode active material layer 1222 is flush with both sides of at least one of the electrode width direction dr1 and the electrode length direction dr2 relative to the positive electrode active material layer 1212; wherein, the separator 123 extends beyond both sides of at least one of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 relative to at least one of the electrode width direction dr1 and the electrode length direction dr2; or, the separator 123 extends beyond one side of at least one of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 relative to at least one of the electrode width direction dr1 and the electrode length direction dr2, and is flush with the other side of at least one of the electrode width direction dr1 and the electrode length direction dr2.

[0174] like Figure 15 As shown in (a) and (b), the negative electrode active material layer 1222 and the positive electrode active material layer 1212 are flush on both sides of the electrode width direction dr1, which can improve the effective reaction area between the positive electrode 121 and the negative electrode 122, increase the utilization rate of the active materials of the positive electrode 121 and the negative electrode 122, and help improve the volumetric energy density of the electrode assembly 12, thereby helping to improve the cell structure design, increase the capacity of the battery cell, and reduce the cost.

[0175] and Figure 15 Compared to (a), Figure 15 The positive electrode 121 in (b) further includes a first insulating layer 1213 and a second insulating layer 1214, which causes the positive current collector substrate 1211 of the positive electrode 121 to extend beyond the negative current collector substrate 1221 on both sides of the electrode width direction dr1. However, in Figure 15 In (a) and (b), the separator 123 extends beyond the positive current collector substrate 1211 and the negative current collector substrate 1221 on both sides of the electrode width direction dr1, thereby effectively separating the edges of the positive electrode 121 and the negative electrode 122, making it less likely for them to cross the separator 123 and cause a short circuit, thereby improving reliability and improving the cell withstand voltage test value.

[0176] The separator 123 may extend beyond one side of at least one of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 in the electrode width direction dr1 and the electrode length direction dr2, and be flush with the other side of at least one of the electrode width direction dr1 and the electrode length direction dr2. The separator 123 extending beyond one side effectively isolates the edges of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 on that side, reducing the risk of short circuits due to overlap and improving the reliability of the battery cell. The structure where the separator 123 is flush with one of the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 on that side improves the utilization rate of the separator 123 and reduces its cost. This allows the battery cell to meet the requirements of both reliability and cost.

[0177] like Figure 15 As shown in (c), the negative electrode active material layer 1222 and the positive electrode active material layer 1212 are flush on both sides of the electrode length direction dr2. The separator 123 not only wraps between each positive electrode 121 and negative electrode 122, but also extends beyond the positive electrode current collector substrate 1211 and negative electrode current collector substrate 1221 on both sides of the electrode length direction dr2, thereby effectively separating the edges of the positive electrode 121 and negative electrode 122, making it less likely for them to cross the separator 123 and cause a short circuit, thus improving reliability and improving the cell withstand voltage test value.

[0178] Figure 16 and Figure 17 These are schematic diagrams of the mounting structure and exploded structure of other embodiments of the battery cell according to this disclosure. Figure 18 This is a schematic diagram of the structure of a stacked electrode assembly or a wound electrode assembly according to some other embodiments of the battery cell of this disclosure. Figure 19 (a) and (b) are respectively Figure 18 Schematic diagram of partial layers in the EE and FF sections.

[0179] refer to Figures 16-18 In some embodiments, the housing 11 may include an outer shell 111 with openings at both ends, and correspondingly, a top cover 112 and a top cover 113 are respectively provided at the two end openings. Positive electrode tabs 121t and negative electrode tabs 122t extend from both ends of the electrode assembly 12. The positive electrode tabs 121t and negative electrode tabs 122t can be electrically connected to electrode terminals respectively provided on the top cover 112 and the top cover 113.

[0180] Figure 18 The electrode assembly shown can be a wound electrode assembly or a stacked electrode assembly. Figure 19 (a) and (b) respectively show Figure 17Schematic diagram of partial layers in the EE and FF sections. Both the EE and FF sections are parallel to the electrode length direction dr2 and perpendicular to the electrode width direction dr1. A variation example of the EE section can be found here. Figures 8-10 Various variations of the text will not be elaborated here. Figure 18 The cross-sections of the middle electrode assembly 12 can be referenced. Figures 11-14 The examples in the text will not be repeated here.

[0181] Based on the various embodiments of the battery cell 10 described above, this disclosure provides a battery device 20, including the aforementioned battery cell 10. The battery device 20 employing the embodiments of the battery cell 10 described above can improve performance.

[0182] Based on the various embodiments of the battery device 20 described above, this disclosure provides an electrical device including the aforementioned battery device 20. The electrical device employing the embodiments of the battery device 20 can improve performance.

[0183] In some specific embodiments, such as Figures 3-5 , Figure 7 and Figure 12A As shown, the battery cell 10 includes a housing 11 and an electrode assembly 12 housed within the housing 11. The electrode assembly 12 includes a positive electrode 121, a negative electrode 122, and two separators 123. The separators 123 are located between the positive electrode 121 and the negative electrode 122. The positive electrode 121, the negative electrode 122, and the two separators 123 are stacked and wound along the winding direction r to form a wound electrode assembly.

[0184] The positive electrode 121 includes a positive current collector substrate 1211 and a positive active material layer 1212 disposed on the positive current collector substrate 1211, and the negative electrode 122 includes a negative current collector substrate 1221 and a negative active material layer 1222 disposed on the negative current collector substrate 1221.

[0185] The negative electrode active material layer 1222 extends beyond the positive electrode active material layer 1212 on the side of the electrode width direction dr1 away from the bottom of the housing 11, and is flush with the side adjacent to the bottom of the housing 11. The separator 123 extends beyond both the positive electrode current collector substrate 1211 and the negative electrode current collector substrate 1221 on both sides of the electrode width direction dr1, and the separator 123 located on the side adjacent to the bottom of the housing 11 covers the ends of the negative electrode active material layer 1222 and the positive electrode active material layer 1212 on that side.

[0186] The negative electrode 122 extends beyond the positive electrode 121 at both the start and end sides of the winding direction r. The negative electrode 122 extends beyond the outermost of the two insulating members 123 located in the winding electrode assembly or is flush with the outermost of the two insulating members 123 located in the winding electrode assembly at the end side of the winding direction r. The other insulating member 123 extends beyond the positive electrode 121 at the end side of the winding direction r.

[0187] The finishing tape 124 is bonded to the tail of the separator 123 located on the outermost ring of the wound electrode assembly, and covers the tail of the negative electrode 122 and part of the separator 123 located on the outermost ring of the wound electrode assembly.

[0188] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0189] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A battery cell (10), characterized in that, The device includes an electrode assembly (12), which includes a positive electrode (121), a negative electrode (122), and an insulating member (123), wherein the insulating member (123) is located between the positive electrode (121) and the negative electrode (122). The positive electrode (121) includes a positive current collector substrate (1211) and a positive active material layer (1212) disposed on the positive current collector substrate (1211), and the negative electrode (122) includes a negative current collector substrate (1221) and a negative active material layer (1222) disposed on the negative current collector substrate (1221). The positive electrode (121), the negative electrode (122), and the separator (123) are arranged in at least one of the following ways: The negative electrode active material layer (1222) extends beyond at least one side of the positive electrode active material layer (1212) in at least one of the electrode width direction (dr1) and the electrode length direction (dr2); and The separator (123) extends beyond at least one side of at least one of the positive current collector substrate (1211) and the negative current collector substrate (1221) in the electrode width direction (dr1) and the electrode length direction (dr2).

2. The battery cell (10) according to claim 1, characterized in that, The negative electrode active material layer (1222) extends beyond the positive electrode active material layer (1212) on both sides of at least one of the electrode width direction (dr1) and electrode length direction (dr2).

3. The battery cell (10) according to claim 1, characterized in that, The negative electrode active material layer (1222) extends beyond the positive electrode active material layer (1212) on one side of at least one of the electrode width direction (dr1) and electrode length direction (dr2), and is flush with the other side of at least one of the electrode width direction (dr1) and electrode length direction (dr2).

4. The battery cell (10) according to claim 2 or 3, characterized in that, The positive electrode (121) further includes at least one of a first insulating layer (1213) and a second insulating layer (1214). The first insulating layer (1213) is located at a first end of the electrode assembly (12) along at least one of the electrode width direction (dr1) and the electrode length direction (dr2), and is located on at least one of the positive current collector substrate (1211) and the positive active material layer (1212), and extends beyond the positive active material layer (1212). The second insulating layer (1214) is located at a second end of the electrode assembly (12) along at least one of the electrode width direction (dr1) and the electrode length direction (dr2), and is located on at least one of the positive current collector substrate (1211) and the positive active material layer (1212), and extends beyond the positive active material layer (1212). The first end and the second end are disposed opposite to each other.

5. The battery cell (10) according to claim 4, characterized in that, The first insulating layer (1213) is flush with or extends beyond the negative electrode current collector substrate (1221) on at least one of the electrode width direction (dr1) and the electrode length direction (dr2); the second insulating layer (1214) is flush with or extends beyond the negative electrode current collector substrate (1221) on at least one of the electrode width direction (dr1) and the electrode length direction (dr2).

6. The battery cell (10) according to any one of claims 2-5, characterized in that, Also includes: The housing (11) contains the electrode assembly (12). The negative current collector substrate (1221) is flush with the positive current collector substrate (1211) on the side adjacent to the bottom of the housing (11) in the electrode width direction (dr1) and electrode length direction (dr2).

7. The battery cell (10) according to any one of claims 2-6, characterized in that, The separator (123) extends beyond or is flush with at least one of the positive current collector substrate (1211) and the negative current collector substrate (1221) on both sides of at least one of the electrode width direction (dr1) and the electrode length direction (dr2).

8. The battery cell (10) according to any one of claims 2-6, characterized in that, The separator (123) extends beyond one side of at least one of the positive current collector substrate (1211) and the negative current collector substrate (1221) in the width direction (dr1) and the length direction (dr2) of the electrode sheet, and is flush with the other side of at least one of the width direction (dr1) and the length direction (dr2) of the electrode sheet.

9. The battery cell (10) according to any one of claims 2-8, characterized in that, The electrode assembly (12) is a stacked electrode assembly, the separator (123) is arranged in a folded form, and the positive electrode (121) and the negative electrode (122) are arranged in a stacked form; the separator (123) extends beyond both sides of the electrode in the length direction (dr2) of the electrode relative to the positive current collector substrate (1211) and the negative current collector substrate (1221).

10. The battery cell (10) according to any one of claims 2-8, characterized in that, The electrode assembly (12) is a stacked electrode assembly. The separator (123) and the negative electrode (122) are arranged in a folded form. The positive electrode (121) is arranged in a stacked form and inserted into the folded space formed by the separator (123) and the negative electrode (122). The negative electrode (122) extends beyond the positive electrode (121) on at least one side of the electrode length direction (dr2). The separator (123) extends beyond or is flush with the negative electrode (122) on at least one side of the electrode length direction (dr2).

11. The battery cell (10) according to any one of claims 2-8, characterized in that, The electrode assembly (12) is a wound electrode assembly formed by stacking and winding the positive electrode (121), the negative electrode (122) and the two separators (123) in the order of the positive electrode (121), the first separator (123), the negative electrode (122) and the second separator (123). The negative electrode (122) extends beyond the positive electrode (121) at both the start and end sides of the winding direction (r) of the electrode assembly (12).

12. The battery cell (10) according to claim 11, characterized in that, At least one of the two separators (123) extends beyond the positive electrode (121) and the negative electrode (122) on the starting side of the winding direction (r) of the electrode assembly (12), and the separator (123) located on the outermost ring of the wound electrode assembly extends beyond the negative electrode (122) on the ending side of the winding direction (r) of the electrode assembly (12).

13. The battery cell (10) according to claim 12, characterized in that, The electrode assembly (12) also includes: A finishing tape (124) is bonded to the tail of the spacer (123) located on the outermost ring of the wound electrode assembly and covers the tail of the spacer (123) located on the outermost ring of the wound electrode assembly.

14. The battery cell (10) according to claim 11, characterized in that, The negative electrode (122) extends beyond the outermost of the two separators (123) located in the winding direction (r) of the electrode assembly (12) on the end side, or is flush with the outermost of the two separators (123) located in the winding direction (r) of the electrode assembly (12), and the other separator (123) extends beyond the positive electrode (121) on the end side of the winding direction (r) of the electrode assembly (12).

15. The battery cell (10) according to claim 14, characterized in that, The electrode assembly (12) also includes: The finishing tape (124) is bonded to the tail of the insulating member (123) located on the outermost ring of the wound electrode assembly, and covers the tail of the negative electrode sheet (122) and the tail of the insulating member (123) and the tail of the negative electrode sheet (122) located on the outermost ring of the wound electrode assembly.

16. The battery cell (10) according to claim 1, characterized in that, The negative electrode active material layer (1222) is flush with the positive electrode active material layer (1212) on both sides of at least one of the electrode width direction (dr1) and the electrode length direction (dr2); Wherein, the separator (123) extends beyond at least one of the positive current collector substrate (1211) and the negative current collector substrate (1221) on both sides of at least one of the electrode width direction (dr1) and the electrode length direction (dr2); or, the separator (123) extends beyond at least one of the positive current collector substrate (1211) and the negative current collector substrate (1221) on one side of at least one of the electrode width direction (dr1) and the electrode length direction (dr2), and is flush with the other side of at least one of the electrode width direction (dr1) and the electrode length direction (dr2).

17. A battery device (20), characterized in that, include: The battery cell (10) according to any one of claims 1-16.

18. An electrical appliance, characterized in that, include: The battery device (20) according to claim 17.

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