Battery cell, battery device, and electric device

Abstract

A battery monomer, a battery device and an electric equipment, the battery monomer includes an electrode assembly, the electrode assembly includes a positive pole sheet, a negative pole sheet and a separator, the positive pole sheet includes a positive pole active material layer, and the negative pole sheet includes a negative pole active material layer, along the width direction of the sheet, the two ends of the positive pole active material layer are respectively provided with a first active layer edge and a second active layer edge, the two ends of the negative pole active material layer are respectively provided with a third active layer edge and a fourth active layer edge, the first and third active layer edges are located at the first end of the electrode assembly along the width direction of the sheet, the second and fourth active layer edges are located at the second end of the electrode assembly along the width direction of the sheet, the first end is oppositely arranged with the second end, the first and third active layer edges are flush in the width direction of the sheet, and the fourth active layer edge exceeds the second active layer edge in the width direction of the sheet.

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. Summary of the Invention

[0004] In one aspect of this disclosure, a battery cell is provided, including an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, the separator being located between the positive and negative electrode. The positive electrode includes a positive active material layer, and the negative electrode includes a negative active material layer. Along the width direction of the electrode, the two ends of the positive active material layer have a first active layer edge and a second active layer edge, respectively, and the two ends of the negative active material layer have a third active layer edge and a fourth active layer edge, respectively. The first and third active layer edges are located at a first end of the electrode assembly along the width direction of the electrode, and the second and fourth active layer edges are located at a second end of the electrode assembly along the width direction of the electrode, with the first end and the second end facing each other. The first and third active layer edges are flush with each other in the width direction of the electrode, and the fourth active layer edge extends beyond the second active layer edge in the width direction of the electrode.

[0005] In this embodiment, the edge of the first active layer of the positive electrode and the edge of the third active layer of the negative electrode are flush in the electrode width direction, which can improve the effective reaction area between the positive and negative electrodes, increase the utilization rate of the positive and negative electrodes, and help improve the volumetric energy density of the electrode assembly. The edge of the fourth active layer of the negative electrode extends beyond the edge of the second active layer of the positive electrode in the electrode width direction, which can reduce the risk of lithium plating at the negative electrode edge and improve the safety performance of the electrode assembly, so that the battery cell can meet the requirements of reliability and volumetric energy density.

[0006] In some embodiments, the positive electrode further includes a positive current collector substrate, and the positive active material layer is disposed on the surface of the positive current collector substrate; the negative electrode further includes a negative current collector substrate, and the negative active material layer is disposed on the surface of the negative current collector substrate; in the electrode width direction, the two ends of the positive current collector substrate have a first substrate edge and a second substrate edge, and the two ends of the negative current collector substrate have a third substrate edge and a fourth substrate edge, the first substrate edge and the third substrate edge are located at the first end of the electrode assembly along the electrode width direction, and are both flush with the edge of the first active layer in the electrode width direction.

[0007] In this embodiment, since the edges of the first active layer and the third active layer are flush with each other in the width direction of the electrode sheet, when the edges of the first substrate and the third substrate are both flush with the edge of the first active layer in the width direction of the electrode sheet, the edge of the first substrate is the edge of the entire positive electrode sheet on this side, and the edge of the third substrate is the edge of the entire negative electrode sheet on this side. Moreover, since these two substrate edges are flush, this side can form an end with the positive and negative electrodes flush. This not only improves the utilization rate of the active material layers of the positive and negative electrodes, but also makes the end structure more stable, which is convenient for stable coating of the separator and is not easy to break. It also helps to reduce the length of the separator required and reduce costs.

[0008] In some embodiments, the battery cell further includes: a housing, in which the electrode assembly is housed; wherein the electrode assembly further includes a positive electrode tab and a negative electrode tab, the positive electrode tab being connected to the positive current collector substrate, the negative electrode tab being connected to the negative current collector substrate, the positive electrode tab and the negative electrode tab being located at a second end of the electrode assembly along the width direction of the electrode sheet, and the bottom of the housing being disposed adjacent to a first end of the electrode assembly.

[0009] In this embodiment, the positive electrode tab and the negative electrode tab are located at the second end of the electrode assembly along the width direction of the electrode sheet. Since the edges of the first substrate and the third substrate are flush at the first end of the electrode assembly, the positive and negative electrodes can be formed at the same end. This structure not only has the effects of improving the utilization rate of the active material layer and reducing the cost of the electrode assembly, but also shortens the distance that the electrolyte at the bottom of the housing crawls to the positive and negative electrode sheets, which is beneficial to improving the wetting effect of the electrolyte on the electrode assembly.

[0010] In some embodiments, in the electrode width direction, the two ends of the separator have a first separator edge and a second separator edge, respectively, and the first separator edge and the second separator edge are located at the first end and the second end of the electrode assembly along the electrode width direction; the first separator edge extends beyond the first active layer edge in the electrode width direction, and the second substrate edge extends beyond the fourth active layer edge in the electrode width direction.

[0011] In this embodiment, on the side where the ends of the positive and negative electrodes are flush, the edge of the first insulating member extends beyond the edge of the first active layer in the electrode width direction, that is, beyond the ends of the positive and negative electrodes. This makes it less likely for the positive and negative electrodes to overlap and short-circuit on this side, thereby improving reliability. In embodiments where the first end of the electrode assembly is adjacent to the bottom of the housing, the insulating member can be used to protect the positive and negative electrodes so that they do not directly contact the interior of the housing, reducing the risk of housing corrosion or electrode breakage.

[0012] In some embodiments, the edges of the first substrate, the first active layer, the third substrate, and the third active layer are covered and fixed at a portion of the first end of the electrode assembly by the spacer.

[0013] In this embodiment, the separator covers and fixes the ends of the positive and negative electrodes at the first end of the electrode assembly. For example, each layer of separator is bent to the same side and bonded to the ends of the positive and negative electrodes, so that the ends of both the positive and negative electrodes are covered by the separator and not exposed. The bottom of the electrode assembly is buffered by the separator, reducing the risk of breakage and detachment caused by contact between the electrodes and the housing, and lowering the risk of short circuits due to overlap between the positive and negative electrodes. Furthermore, when the separator covers the electrode ends, the positive and negative electrodes are flush on that side, making the separator more stable and saving on the required length, thus reducing the amount of separator used and lowering costs.

[0014] In some embodiments, in the electrode width direction, the two ends of the insulating member have a first insulating member edge and a second insulating member edge, respectively, and the first insulating member edge and the second insulating member edge are located at the first end and the second end of the electrode assembly along the electrode width direction; the first insulating member edge is flush with the edge of the first active layer in the electrode width direction.

[0015] In this embodiment, the edges of the first substrate, the third substrate, the first active layer, and the third active layer can all be flush with the edge of the first separator in the electrode width direction. This creates a relatively flat end surface at the first end of the electrode assembly, facilitating the installation of the insulating protective element and promoting stable placement within the housing. This allows the electrolyte at the bottom of the housing to climb to the positive and negative electrode plates in a shorter distance, thereby improving the wetting effect of the electrolyte on the electrode assembly.

[0016] In some embodiments, the positive electrode further includes a first insulating layer located at a second end of the electrode assembly along the width direction of the electrode. The first insulating layer is disposed on at least one of the positive current collector substrate and the positive active material layer, and has a first insulating edge that extends beyond the edge of the second active layer in the width direction of the electrode.

[0017] In this embodiment, a first insulating layer is provided on the positive electrode at the position corresponding to the second end of the electrode assembly, and the first insulating edge of the first insulating layer extends beyond the edge of the second active layer. In this way, the first insulating layer hides the positive active material layer inside and does not directly expose it to the edge of the positive electrode, thereby making it less likely for the edge of the negative electrode to overlap and short-circuit with the positive electrode, thereby improving the reliability of the electrode assembly.

[0018] In some embodiments, in the electrode width direction, the two ends of the insulating member have a first insulating member edge and a second insulating member edge, respectively. The second substrate edge and the second insulating member edge are located at the second end of the electrode assembly along the electrode width direction. The second substrate edge and the first insulating edge are flush with each other in the electrode width direction. The second insulating member edge is flush with or extends beyond the first insulating edge in the electrode width direction.

[0019] In this embodiment, at the second end of the electrode assembly, the isolator can extend beyond the first insulating edge on the positive electrode sheet. This allows for better isolation between the first insulating edge and the adjacent negative electrode sheet, improving reliability and allowing for some process fluctuations and precision errors. Furthermore, the multiple positive and negative electrodes in the tab portion are respectively folded and bent for welding to the electrode terminals or current collector. This causes the positive and negative electrodes on the tab side to tend to move closer together. By providing a first insulating layer and an isolator with a second insulating edge extending beyond the first insulating edge, the risk of short circuits due to tab folding and bending can be effectively reduced.

[0020] At the second end of the electrode assembly, the insulating element can also be flush with the first insulating edge on the positive electrode plate. This improves the utilization rate of the insulating element, reduces the amount of material used, and helps to reduce the space occupied and material cost of the insulating element.

[0021] In some embodiments, the first insulating edge is flush with or extends beyond the edge of the fourth active layer in the electrode width direction.

[0022] In this embodiment, at the second end of the electrode assembly, the first insulating edge can extend beyond the edge of the fourth active layer. This ensures that the edge of the negative electrode and the position directly opposite the positive electrode are located within the first insulating layer. Even if the negative electrode has burrs at its edge that could pierce the insulating material, the first insulating layer reduces the risk of a short circuit with the positive electrode, thereby improving the reliability of the electrode assembly and making it compatible with fluctuations in actual production. Alternatively, at the second end of the electrode assembly, the first insulating edge can be flush with the edge of the fourth active layer. This reduces the likelihood of a short circuit between the positive and negative electrodes when the tabs are folded and bent, thus saving on the use of insulating materials and improving their utilization rate.

[0023] In some embodiments, the positive electrode further includes a second insulating layer located at a first end of the electrode assembly along the width direction of the electrode. The second insulating layer is disposed on at least one of the positive current collector substrate and the positive active material layer, and has a second insulating edge. The second insulating edge is flush with the edge of the first substrate in the width direction of the electrode. The edge of the first separator extends beyond the edge of the third active layer in the width direction of the electrode, and is flush with or extends beyond the second insulating edge in the width direction of the electrode.

[0024] In this embodiment, in the electrode width direction, the second insulating edge is flush with the edge of the first substrate, and the edge of the positive electrode at the first end is both the second insulating edge and the edge of the first substrate. For the separator, the edge of the first separator extends beyond the edge of the third active layer in the electrode width direction and is flush with the second insulating edge. This reduces the likelihood of short circuits between the positive and negative electrodes and saves on the use of separators, improving their utilization rate. Alternatively, the edge of the first separator can also extend beyond the second insulating edge in the electrode width direction. The separator can effectively separate the positive and negative electrodes, reducing the risk of short circuits between them, thereby improving the reliability of the electrode assembly and making it compatible with fluctuations in actual production.

[0025] In some embodiments, in the width direction of the electrode sheet, two ends of the separator are respectively provided with a first separator edge and a second separator edge; the first substrate edge, the third substrate edge and the first separator edge are located at the first end of the electrode assembly along the width direction of the electrode sheet, and the second substrate edge, the fourth substrate edge and the second separator edge are located at the second end of the electrode assembly along the width direction of the electrode sheet; the distance between the second separator edge and the fourth active layer edge in the width direction of the electrode sheet is L1, the distance between the first insulating edge and the fourth active layer edge in the width direction of the electrode sheet is L2, the distance between the fourth active layer edge and the second active layer edge in the width direction of the electrode sheet is L3, the distance between the first separator edge and the first substrate edge in the width direction of the electrode sheet is L4, the thickness of the positive electrode sheet is T1, and the thickness of the negative electrode sheet is T2; where 0≤L1≤3mm, L2≥0mm, 0<L3≤3mm, L4≥T1, L4≥T2.

[0026] In this embodiment, by setting the value of L2 to satisfy L2≥0mm, the risk of lap short circuit between the positive electrode sheet and the negative electrode sheet can be reduced through the first insulating member, and the reliability of the electrode assembly is improved; by setting the value of L3 to satisfy 0<L3≤3mm, the risk of lithium precipitation at the edge of the negative electrode sheet can be reduced, the safety performance of the electrode assembly is improved, the precision requirement for the manufacturing process is favorably lowered, and by controlling L3 within 3mm, the utilization rate of the electrode sheets can be improved, which is beneficial to increasing the volumetric energy density of the electrode assembly; by making the distance L4 no less than T1 and T2, the separator 123 can cover the end of the positive electrode sheet 121 and the end of the negative electrode sheet 122 at the second end S2 of the electrode assembly 12m, so that both ends of the positive electrode sheet 121 and the negative electrode sheet 122 are covered by the separator 123 without being exposed. With the separator 123 serving as a buffer at the bottom of such an electrode assembly, the damage and shedding caused by the contact between the electrode sheets in the electrode assembly and the housing can be reduced, and the risk of lap short circuit between the positive electrode sheet and the negative electrode sheet can be lowered.

[0027] In some embodiments, the electrode assembly is a wound structure, and in the winding direction of the wound structure, two ends of the positive electrode sheet are respectively provided with a first head edge and a first tail edge, two ends of the negative electrode sheet are respectively provided with a second head edge and a second tail edge, and two ends of the separator are respectively provided with a third head edge and a third tail edge; the second tail edge extends beyond the first tail edge in the winding direction of the wound structure, and the second head edge extends beyond the first head edge in the winding direction of the wound structure.

[0028] In this embodiment, by making the second tail edge extend beyond the first tail edge in the winding direction of the winding structure, and by making the second head edge extend beyond the first head edge in the winding direction of the winding structure, the risk of lithium plating on the edge of the negative electrode can be reduced on both the inner and outer sides of the winding structure, thereby improving the safety performance of the electrode assembly and reducing the precision requirements of the manufacturing process.

[0029] In some embodiments, the distance between the second head edge and the first head edge in the winding direction of the winding structure is L6, wherein 3mm≤L6≤10mm.

[0030] In this embodiment, depending on the value of the spacing, the distance between the second head edge of the negative electrode sheet and the first head edge of the positive electrode sheet is between 3mm and 10mm. This can improve space utilization and the amount of negative electrode sheet material used, which is beneficial to increasing the effective capacity of the battery, reducing costs, and reducing the risk of lithium plating, which is beneficial to improving the reliability of the electrode assembly.

[0031] In some embodiments, the electrode assembly further includes a finishing tape bonded to the tail of the outermost insulating member of the electrode assembly and covering the tail of the negative electrode sheet and the tail of the insulating member; the second tail edge is flush with or extends beyond the third tail edge of the outermost insulating member of the electrode assembly in the winding direction of the winding structure.

[0032] In this embodiment, the second tail edge of the negative electrode sheet can extend beyond the third tail edge of the outermost separator or be flush with the third tail edge of the outermost separator in the winding direction. In this way, the finishing tape can reduce the risk of short circuit caused by the exposed tail end of the negative electrode sheet by covering the tail end of the negative electrode sheet and the tail end of the separator. It can also effectively save the amount of material used in the separator and improve the volumetric energy density of the winding structure.

[0033] In one aspect of this disclosure, a battery device is provided, comprising: the aforementioned battery cell.

[0034] The battery device using the above-described battery cells can meet the requirements of both reliability and volumetric energy density.

[0035] In one aspect of this disclosure, an electrical device is provided, comprising: the aforementioned battery device.

[0036] The electrical equipment using the above-described battery device can balance the requirements of reliability and space occupancy. Attached Figure Description

[0037] 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.

[0038] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0039] Figure 1 These are schematic diagrams of the structure of some embodiments of the electrical equipment according to this disclosure;

[0040] Figure 2 This is an exploded schematic diagram of some embodiments of the battery device according to the present disclosure;

[0041] 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;

[0042] Figure 5 This is a schematic diagram of the electrode assembly structure according to some embodiments of the battery cell of this disclosure;

[0043] Figure 6 yes Figure 5 A schematic diagram of a portion of the layers in section AA;

[0044] Figure 7 yes Figure 5 A schematic diagram of a portion of the layers in the BB section;

[0045] Figure 8 yes Figure 5 A schematic diagram of a portion of the layers in the CC section;

[0046] Figures 9A-9E These are schematic diagrams of partial layers of AA cross sections in other embodiments of the battery cell disclosed herein;

[0047] Figure 10 This is a schematic diagram of the electrode assembly dimensions in section AA according to some embodiments of the battery cell of this disclosure;

[0048] Figure 11A yes Figure 5 Schematic diagram of the DD section;

[0049] Figure 11B yes Figure 11A An enlarged diagram of the position corresponding to circle F in the middle;

[0050] Figure 12 and Figure 13 These are schematic diagrams of the mounting structure and exploded structure of other embodiments of the battery cell according to the present disclosure;

[0051] Figure 14These are schematic diagrams of the electrode assembly in other embodiments of the battery cell according to this disclosure;

[0052] Figure 15 yes Figure 14 A schematic diagram of a portion of the EE section.

[0053] 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.

[0054] Explanation of reference numerals in the attached figures:

[0055] 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;

[0056] 20 - Battery assembly; 21 - Housing; 22 - Housing cover;

[0057] 30-Vehicle; 31-Controller; 32-Motor; 33-Axle; 34-Wheel.

[0058] S1 - First end; S2 - Second end; dr1 - Electrode width direction; r - Winding direction; x - Width direction; y - Thickness direction; z - Height direction;

[0059] e11 - Edge of the first substrate; e12 - Edge of the second substrate; e13 - Edge of the first active layer; e14 - Edge of the second active layer; e15 - Edge of the first head; e16 - Edge of the first tail;

[0060] e21 - Edge of the third substrate; e22 - Edge of the fourth substrate; e23 - Edge of the third active layer; e24 - Edge of the fourth active layer; e25 - Edge of the second head; e26 - Edge of the second tail;

[0061] e31 - First insulating edge; e32 - Second insulating edge; e33 - Third head edge; e34 - Third tail edge; e41 - First insulating edge; e42 - Second insulating edge. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] In view of this, the present disclosure provides a battery cell, a battery device, and an electrical device that can balance the requirements of battery cell reliability and volumetric energy density.

[0074] In one aspect of this disclosure, a battery cell is provided, including an electrode assembly comprising a positive electrode, a negative electrode, and a separator, the separator being located between the positive and negative electrode. The positive electrode includes a positive active material layer, and the negative electrode includes a negative active material layer. Along the width direction of the electrode, the two ends of the positive active material layer have a first active layer edge and a second active layer edge, respectively, and the two ends of the negative active material layer have a third active layer edge and a fourth active layer edge, respectively. The first and third active layer edges are located at a first end of the electrode assembly along the width direction of the electrode, and the second and fourth active layer edges are located at a second end of the electrode assembly along the width direction of the electrode, with the first end and the second end facing each other. The first and third active layer edges are flush with each other in the width direction of the electrode, and the fourth active layer edge extends beyond the second active layer edge in the width direction of the electrode.

[0075] In this embodiment, the edge of the first active layer of the positive electrode and the edge of the third active layer of the negative electrode are flush in the electrode width direction, which can improve the effective reaction area between the positive and negative electrodes, increase the utilization rate of the positive and negative electrodes, and help improve the volumetric energy density of the electrode assembly. The edge of the fourth active layer of the negative electrode extends beyond the edge of the second active layer of the positive electrode in the electrode width direction, which can reduce the risk of lithium plating at the negative electrode edge and improve the safety performance of the electrode assembly, so that the battery cell can meet the requirements of reliability and volumetric energy density.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] In some embodiments, the battery device may include a housing and individual battery cells, with the individual battery cells housed within the housing.

[0081] 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.

[0082] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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 adverse effects of liquids or other foreign matter on the charging, discharging, or safety of the battery cells 10. The cover 22 can be closed onto the end of the housing 21 to seal the housing 21.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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 the electrode assembly according to some embodiments of the battery cell of this disclosure. Figure 6 yes Figure 5 A schematic diagram of a portion of the layers in section AA.

[0092] refer to Figures 3-6 This disclosure provides a battery cell 10, including an electrode assembly 12. The electrode assembly 12 includes a positive electrode 121, a negative electrode 122, and a separator 123, with the separator 123 located between the positive electrode 121 and the negative electrode 122. The positive electrode 121 includes a positive active material layer 1212, and the negative electrode 122 includes a negative active material layer 1222. Along the width direction dr1 of the electrode, the two ends of the positive active material layer 1212 have a first active layer edge e13 and a second active layer edge e14, respectively, and the two ends of the negative active material layer 1222 have a third active layer edge e23, respectively. The first active layer edge e13 and the third active layer edge e23 are located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1, and the second active layer edge e14 and the fourth active layer edge e24 are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1. The first end S1 and the second end S2 are arranged opposite to each other. The first active layer edge e13 and the third active layer edge e23 are flush with each other in the electrode width direction dr1, and the fourth active layer edge e24 extends beyond the second active layer edge e14 in the electrode width direction dr1.

[0093] 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.

[0094] 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.

[0095] 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.).

[0096] 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.

[0097] 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.

[0098] 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.).

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] As an example, liquid electrolytes include electrolyte salts and solvents.

[0105] 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.

[0106] 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.

[0107] As an example, gel electrolytes include a polymer-based backbone network combined with an ionic liquid—a lithium salt.

[0108] As an example, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0109] 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.

[0110] 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.

[0111] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0112] by Figures 3-5 Taking the square battery cell shown as an example, the height direction z of the electrode assembly 12 disposed inside the housing 11 is the same as the height direction of the battery cell in its upright state, and is parallel to the thickness direction of the top cover 112. The thickness direction y of the electrode assembly 12 is parallel to the perpendicular direction of the opposite maximum side surface of the battery cell, and the width direction x of the electrode assembly 12 is parallel to the perpendicular direction of the opposite minimum side surface of the battery cell. The width direction x, the thickness direction y, and the height direction z are all mutually perpendicular.

[0113] Figure 6 The electrode width direction dr1 shown can be the width direction of at least one of the positive electrode 121 and the negative electrode 122, which can be parallel to the height direction z of the electrode assembly 12 and perpendicular to both the thickness direction y and the width direction x of the electrode assembly 12. For a cylindrical battery cell, the electrode width direction is parallel to the axial direction of the cylinder.

[0114] by Figure 5 Taking the AA cross-section shown as an example, the width direction dr1 of the electrode is parallel to the height direction z of the electrode assembly 12. Figure 6 In the diagram, the electrode width direction dr1 is drawn as a vertical, upward-pointing black solid line segment with an arrow. The first end S1 of the electrode assembly is the end pointed to by the arrow in the electrode width direction dr1, and the second end S2 of the electrode assembly is the end away from the arrow in the electrode width direction dr1. In other embodiments, the second end S2 of the electrode assembly may also be the end pointed to by the arrow in the electrode width direction dr1, and the first end S1 of the electrode assembly may be the end away from the arrow in the electrode width direction dr1.

[0115] like Figure 6As shown, along the electrode width direction dr1, the positive electrode active material layer 1212 has a first active layer edge e13 and a second active layer edge e14 at both ends, and the negative electrode active material layer 1222 has a third active layer edge e23 and a fourth active layer edge e24 at both ends. The first active layer edge e13 and the third active layer edge e23 are located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1, and the second active layer edge e14 and the fourth active layer edge e24 are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1.

[0116] The first active layer edge e13 and the third active layer edge e23 are flush with each other in the electrode width direction dr1, and the fourth active layer edge e24 extends beyond the second active layer edge e14 in the electrode width direction dr1.

[0117] In this article, edge alignment refers to two or more edges being aligned in a specified direction within the allowable process tolerance. This alignment does not mean absolute overlap between edges, but rather a relatively close alignment within the allowable process tolerance. Edge overshoot refers to one edge extending beyond another edge in a specified direction, and being located outside the other edge.

[0118] In this embodiment, the first active layer edge e13 of the positive electrode 121 and the third active layer edge e23 of the negative electrode 122 are aligned in the electrode width direction dr1, which is parallel to the width direction of at least one of the positive and negative electrode 121. This improves the effective reaction area between the positive and negative electrode 121, increases their utilization rate, 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. The fourth active layer edge e24 of the negative electrode 122 extends beyond the second active layer edge e14 of the positive electrode 121 in the electrode width direction. This reduces the risk of lithium plating at the negative electrode edge, improves the safety performance of the electrode assembly, and helps reduce the precision requirements of the manufacturing process. Thus, the battery cell can meet the requirements of both reliability and volumetric energy density.

[0119] refer to Figure 6In some embodiments, the positive electrode 121 further includes 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; the negative electrode 122 further includes a negative current collector substrate 1221, and the negative active material layer 1222 is disposed on the surface of the negative current collector substrate 1221; in the electrode width direction dr1, the two ends of the positive current collector substrate 1211 respectively have a first substrate edge e11 and a second substrate edge e12, and the two ends of the negative current collector substrate 1221 respectively have a third substrate edge e21 and a fourth substrate edge e22, the first substrate edge e11 and the third substrate edge e21 are located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1, and are both flush with the first active layer edge e13 in the electrode width direction dr1.

[0120] A positive electrode active material layer 1212 is attached to the surface of the positive electrode current collector substrate 1211, and other functional layers can also be attached as needed. A negative electrode active material layer 1222 is attached to the surface of the negative electrode current collector substrate 1221, and other functional layers can also be attached as needed. As mentioned earlier, the edges e13 of the first active layer and e23 of the third active layer are flush with each other in the electrode width direction dr1. When both the edges e11 and e21 of the first substrate are flush with the edge e13 of the first active layer in the electrode width direction dr1, the edge of the first substrate edge e11 is the edge of the entire positive electrode 121 on this side, and the edge of the third substrate edge e13 is the edge of the entire negative electrode 122 on this side. Moreover, since these two substrate edges e11 are flush, this side can form an end with the positive and negative electrodes flush. This not only improves the utilization rate of the active material layers of the positive and negative electrodes respectively, but also makes the end structure more stable, facilitating stable coating of the separator, reducing the risk of breakage, and reducing the required length of the separator, thus lowering costs.

[0121] Figure 7 yes Figure 5 A schematic diagram of a portion of the layers in the BB section. Figure 8 yes Figure 5 A schematic diagram of a portion of the layers in the CC section. (Reference) Figure 4 , Figure 5 , Figure 7 and Figure 8In some embodiments, the battery cell 10 further includes a housing 11, within which the electrode assembly 12 is housed. The electrode assembly 12 further includes a positive electrode tab 121t and a negative electrode tab 122t. The positive electrode tab 121t is connected to the positive current collector substrate 1211, and the negative electrode tab 122t is connected to the negative current collector substrate 1221. The positive electrode tab 121t and the negative electrode tab 122t are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1. The bottom of the housing 11 is disposed adjacent to the first end S1 of the electrode assembly 12.

[0122] like 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 or a hollow cube, etc. 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.

[0123] 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 through a positive electrode tab 121t, and the negative terminal 142 is electrically connected to the negative electrode plate 122 of the electrode assembly 12 through a negative electrode tab 122t.

[0124] 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.

[0125] The positive electrode tab 121t and the negative electrode tab 122t can be located at the same end of the electrode assembly 12 along the electrode width direction dr1, which facilitates the production of short cells with shorter widths (e.g., ≤300mm). In other embodiments, the tabs 121t and 122t can also be located at both ends of the electrode assembly 12 along the electrode width direction dr1 (see reference). Figure 13 and Figure 14 This facilitates the production of long battery cells with a larger width (e.g., >300mm).

[0126] exist Figure 4In the middle, the positive electrode tab 121t can be electrically connected to the positive terminal 141 through the current collector 131, and the negative electrode tab 122t can be electrically connected to the negative terminal 142 through the current collector 132.

[0127] Based on the positions of the positive electrode tab 121t and the negative electrode tab 122t relative to the electrode assembly 12, the first end S1 and the second end S2 of the electrode assembly 12 can be determined, for example... Figure 5 and Figure 6 The positive electrode tab 121t and the negative electrode tab 122t are both located at the first end S1 of the electrode assembly 12, and are not located at the second end S2.

[0128] In this embodiment, the positive electrode tab 121t and the negative electrode tab 122t are located at the second end S2 of the electrode assembly 12 along the width direction dr1 of the electrode sheet. Since the first substrate edge e11 and the third substrate edge e21 are flush at the first end S1 of the electrode assembly 12, the positive and negative electrodes can be formed at the same end. This structure not only has the effects of improving the utilization rate of the active material layer and reducing the cost of the electrode assembly, but also shortens the distance of the electrolyte crawling from the bottom of the housing 11 to the positive and negative electrode sheets, which is beneficial to improving the wetting effect of the electrolyte on the electrode assembly.

[0129] refer to Figures 5-8 In some embodiments, along the electrode width direction dr1, the two ends of the insulating member 123 have a first insulating member edge e31 and a second insulating member edge e32, respectively, and the first insulating member edge e31 and the second insulating member edge e32 are located at the first end S1 and the second end S2 of the electrode assembly 12 along the electrode width direction dr1; the first insulating member edge e31 extends beyond the first active layer edge e13 in the electrode width direction dr1.

[0130] In this embodiment, on the side where the ends of the positive and negative electrodes are flush, the first insulating edge e31 of the insulating member 123 extends beyond the edge e13 of the first active layer in the electrode width direction dr1, that is, beyond the ends of the positive and negative electrodes. This makes it less likely for the positive and negative electrodes to cross the insulating member 123 and short-circuit on this side, thereby improving reliability and improving the cell withstand voltage test value. For embodiments where the first end S1 of the electrode assembly is adjacent to the bottom of the housing 11, the insulating member 123 can be used to protect the positive and negative electrodes so that they do not directly contact the inside of the housing, reducing the risk of housing corrosion or electrode breakage.

[0131] In some embodiments, the first substrate edge e11, the first active layer edge e13, the third substrate edge e21, and the third active layer edge e23 are covered and fixed at the first end S1 of the electrode assembly 12 by the separator 123.

[0132] exist Figures 6-8 In the partial cross-section of the electrode assembly shown, to facilitate comparison of the edge alignment or overlap between the positive electrode 121, the negative electrode 122, and the separator 123, the tabs 121t of the positive electrode, 122t of the negative electrode, and the separator 123 are all unfolded parallel to the width direction of the electrode. During actual assembly, the separator 123 can cover and fix the ends of the positive electrode 121 and the negative electrode 122 at the first end S1 of the electrode assembly 12. For example, each layer of separator 123 can be bent to the same side and bonded to the ends of the positive electrode 121 and the negative electrode 122, so that the ends of both the positive and negative electrode 121 are covered by the separator 123 and not exposed. With the separator 123 acting as a buffer at the bottom of the electrode assembly 12, damage and detachment caused by contact between the electrode and the housing in the main body can be reduced, and the risk of short circuits due to overlap between the positive and negative electrode is also reduced.

[0133] In addition, when the separator 123 covers the end of the electrode, the positive electrode and the negative electrode are flush at that end, which makes the fixing of the separator 123 more stable. This helps to save the length required for the separator 123, thereby reducing the amount of separator 123 used and reducing costs.

[0134] Figures 9A-9E These are schematic diagrams of partial layers of AA cross-sections in other embodiments of the battery cell of this disclosure. (Reference) Figures 9A-9E In some embodiments, the positive electrode 121 further includes a first insulating layer 1213, which is located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1. The first insulating layer 1213 is disposed on at least one of the positive current collector substrate 1211 and the positive active material layer 1212, and has a first insulating edge e41 that extends beyond the edge e14 of the second active layer in the electrode width direction dr1.

[0135] 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.

[0136] The first insulating layer 1213 may be formed on the positive electrode 121 by coating, bonding, or other means. The composition of the first insulating layer 1213 may include at least one of alumina, boehmite, silicon dioxide, zirconium oxide, magnesium oxide, hafnium dioxide, and titanium oxide. The first insulating layer 1213 may have certain corrosion resistance, wear resistance, and good toughness.

[0137] In this embodiment, the positive electrode 121 is provided with a first insulating layer 1213 at the position corresponding to the second end S2 of the electrode assembly 12, and the first insulating edge e41 of the first insulating layer 1213 extends beyond the edge e14 of the second active layer. In this way, the first insulating layer 1213 hides the positive active material layer 1212 inside and does not directly expose it to the edge of the positive electrode 121, so that the edge of the negative electrode 122 is less likely to overlap and short-circuit with the positive electrode 121, thereby improving the reliability of the electrode assembly.

[0138] refer to Figures 9A-9D In some embodiments, along the electrode width direction dr1, the two ends of the insulating member 123 respectively have a first insulating member edge e31 and a second insulating member edge e32. The second substrate edge e12 and the second insulating member edge e32 are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1. The second substrate edge e12 and the first insulating edge e41 are flush with each other along the electrode width direction dr1, and the second insulating member edge e32 is flush with or extends beyond the first insulating edge e41 along the electrode width direction dr1.

[0139] like Figure 9A , Figure 9B As shown, at the second end S2 of the electrode assembly 12, the isolator 123 can extend beyond the first insulating edge e41 on the positive electrode 121. This allows for better isolation between the first insulating edge e41 and the adjacent negative electrode 122 via the isolator 123, which not only improves reliability but also allows for certain process fluctuations and precision errors. Furthermore, refer to... Figure 7 and Figure 8 Corresponding to the BB and CC sections respectively, the multiple positive electrodes in the tab portion 121t and the multiple negative electrodes in the tab portion 122t are respectively gathered and bent to be welded to the electrode terminals or current collector. This causes the positive and negative electrodes at the tab end to tend to move closer to each other. By setting the first insulating layer 1213 and the second insulating edge e32 extending beyond the first insulating edge e41, the risk of short circuit due to the gathering and bending of the tabs can be effectively reduced.

[0140] like Figure 9C , Figure 9D As shown, at the second end S2 of the electrode assembly 12, the insulating member 123 can also be flush with the first insulating edge e41 on the positive electrode plate 121. This improves the utilization rate of the insulating member 123, reduces the amount of material used in the insulating member 123, and helps to reduce the space occupied by the insulating member 123 and the material cost.

[0141] refer to Figures 9A-9D In some embodiments, the first insulating edge e41 is flush with or extends beyond the edge e24 of the fourth active layer in the electrode width direction dr1.

[0142] like Figure 9A and Figure 9C At the second end S2 of the electrode assembly 12, the first insulating edge e41 can extend beyond the edge e24 of the fourth active layer. In this way, the edge of the negative electrode and the position directly opposite the positive electrode are located in the first insulating layer 1213. Even if there are burrs on the edge of the negative electrode that can pierce the insulating member, the risk of short circuit with the positive electrode will be reduced due to the first insulating layer 1213, thereby improving the reliability of the electrode assembly and being compatible with the fluctuations in actual production.

[0143] like Figure 9B As shown, at the second end S2 of the electrode assembly 12, the first insulating edge e41 can also be flush with the edge e24 of the fourth active layer. This makes it less likely for a short circuit to occur between the positive electrode 121 and the negative electrode 122 when the tab is folded and bent, thereby saving the use of the insulating member 123 and improving the utilization rate of the insulating member 123.

[0144] refer to Figure 9D In some embodiments, along the electrode width direction dr1, the two ends of the insulating member 123 have a first insulating member edge e31 and a second insulating member edge e32, respectively, and the first insulating member edge e31 and the second insulating member edge e32 are located at the first end S1 and the second end S2 of the electrode assembly 12 along the electrode width direction dr1; the first insulating member edge e31 is flush with the first active layer edge e13 in the electrode width direction dr1.

[0145] The edges e11 of the first substrate, e21 of the third substrate, e13 of the first active layer, and e23 of the third active layer can all be flush with the edge e31 of the first separator along the width direction dr1 of the electrode assembly. This creates a relatively flat end surface at the first end S1 of the electrode assembly 12, facilitating the installation of insulating protective components and ensuring stable placement within the housing 11. This allows the electrolyte at the bottom of the housing 11 to travel a shorter distance to the positive and negative electrode plates, thereby improving the wetting effect of the electrolyte on the electrode assembly.

[0146] refer to Figure 9EIn some embodiments, the positive electrode 121 further includes a second insulating layer 1214, which is located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1. The second insulating layer 1214 is disposed on at least one of the positive current collector substrate 1211 and the positive active material layer 1212, and has a second insulating edge e42. The second insulating edge e42 is flush with the first substrate edge e11 in the electrode width direction dr1, and the first insulating member edge e32 extends beyond the third active layer edge e23 in the electrode width direction dr1, and is flush with or extends beyond the second insulating edge e42 in the electrode width direction dr1.

[0147] 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.

[0148] The second insulating layer 1214 can be formed on the positive electrode 121 by coating, bonding, or other means. The composition of the second insulating layer 1214 may include at least one of alumina, boehmite, silicon dioxide, zirconium oxide, magnesium oxide, hafnium dioxide, and titanium oxide. The second insulating layer 1214 can possess certain corrosion resistance and wear resistance, and has good toughness, thus making it less likely to react with the electrolyte. This helps reduce reliability issues caused by the electrolyte eroding the separator during electrolyte injection.

[0149] In the electrode width direction dr1, the second insulating edge e42 is flush with the first substrate edge e11, and the edge of the positive electrode at the first end S1 is both the second insulating edge e42 and the first substrate edge e11. For the separator 123, the first separator edge e32 extends beyond the third active layer edge e23 in the electrode width direction dr1 and is flush with the second insulating edge e42 in the same direction. This design reduces the likelihood of short circuits between the positive electrode 121 and the negative electrode 122, and also saves on the use of the separator 123, improving its utilization rate.

[0150] In the electrode width direction dr1, the edge e32 of the first insulating member can also extend beyond the second insulating edge e42. The insulating member 123 can effectively separate the positive electrode 121 and the negative electrode 123, reducing 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.

[0151] Figure 10This is a schematic diagram of the electrode assembly dimensions in section AA according to some embodiments of the battery cell of this disclosure. Reference Figure 10 In some embodiments, along the electrode width direction dr1, the two ends of the separator 123 respectively have a first separator edge e31 and a second separator edge e32; the first substrate edge e11, the third substrate edge e21, and the first separator edge e31 are located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1, and the second substrate edge e12, the fourth substrate edge e22, and the second separator edge e32 are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1; the second separator edge e32 and the fourth active layer The distance between edge e24 in the electrode width direction dr1 is L1; the distance between the first insulating edge e41 and the fourth active layer edge e24 in the electrode width direction dr1 is L2; ​​the distance between the fourth active layer edge e24 and the second active layer edge e14 in the electrode width direction dr1 is L3; the distance between the first insulating element edge e31 and the first substrate edge e11 in the electrode width direction dr1 is L4; the thickness of the positive electrode 121 is T1; and the thickness of the negative electrode 122 is T2; wherein, 0 ≤ L1 ≤ 3 mm, L2 ≥ 0 mm, 0 <L3≤3mm,L4≥T1,L4≥T2。

[0152] L1 is the distance between the edge e32 of the second insulating element and the edge e24 of the fourth active layer in the electrode width direction dr1, and can be 0mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc. Depending on this distance, the edge e32 of the second insulating element extends beyond or is flush with the edge e24 of the fourth active layer in the electrode width direction dr1. By ensuring that L1 satisfies 0≤L1≤3mm, the utilization rate of the insulating element 123 can be improved, the reliability of the electrode assembly can be enhanced, and a certain degree of fluctuation during actual production can be tolerated.

[0153] L2 is the distance between the first insulating edge e41 and the fourth active layer edge e24 in the electrode width direction dr1, and can be 0mm, 0.5mm, 1mm, 1.5mm, 2mm, or a larger value. Depending on this distance, the first insulating edge e41 extends beyond or is flush with the fourth active layer edge e24 in the electrode width direction dr1. By ensuring that L2 ≥ 0mm, the risk of short circuits between the positive and negative electrodes can be reduced through the first insulating element, thus improving the reliability of the electrode assembly.

[0154] L3 is the distance between the fourth active layer edge e24 and the second active layer edge e14 in the electrode sheet width direction dr1, which can take values of 0.2mm, 0.6mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc. According to the value of this distance, the fourth active layer edge e24 extends beyond the second active layer edge e14 in the electrode sheet width direction dr1. By making the value of L3 satisfy 0<L3≤3mm, the risk of lithium precipitation at the edge of the negative electrode sheet can be reduced, the safety performance of the electrode assembly can be improved, the precision requirement for the manufacturing process can be lowered, and by controlling L3 within 3mm, the utilization rate of the electrode sheet can be improved, which is beneficial to increasing the volumetric energy density of the electrode assembly.

[0155] L4 is the distance between the first separator edge e31 and the first substrate edge e11 in the electrode sheet width direction dr1, and T1 and T2 are the thickness of the positive electrode sheet 121 and the thickness of the negative electrode sheet 122, respectively. By making this distance L4 not less than T1 and T2, the separator 123 can cover the end of the positive electrode sheet 121 and the end of the negative electrode sheet 122 at the second end S2 of the electrode assembly 12, so that the ends of the positive electrode sheet 121 and the negative electrode sheet 122 are both covered by the separator 123 without being exposed. In this way, the bottom of the main body part uses the separator 123 as a buffer, which can reduce the damage and falling off caused by the contact between the electrode sheets in the main body part and the housing, and reduce the risk of lap short circuit between the positive electrode sheet and the negative electrode sheet.

[0156] Figure 11A is Figure 5 a schematic diagram of the DD cross section therein. Figure 11B is Figure 11A an enlarged schematic view of the position corresponding to circle F therein. Reference Figure 5 , Figure 11A and Figure 11B , in some embodiments, the electrode assembly 12 has a wound structure. In the winding direction r of the wound structure, the two ends of the positive electrode sheet 121 have a first head edge e15 and a first tail edge e16 respectively, the two ends of the negative electrode sheet 122 have a second head edge e25 and a second tail edge e26 respectively, and the two ends of the separator 123 have a third head edge e33 and a third tail edge e34 respectively; the second tail edge e26 extends beyond the first tail edge e16 in the winding direction r of the wound structure, and the second head edge e25 extends beyond the first head edge e15 in the winding direction r of the wound structure.

[0157] In this embodiment, by making the second tail edge e26 extend beyond the first tail edge e16 in the winding direction r of the winding structure, and by making the second head edge e25 extend beyond the first head edge e15 in the winding direction r of the winding structure, the risk of lithium plating at the edge of the negative electrode sheet can be reduced on both the inner and outer sides of the winding structure of the positive electrode sheet 121 and the negative electrode sheet 122, thereby improving the safety performance of the electrode assembly and reducing the precision requirements of the manufacturing process.

[0158] refer to Figure 11A and Figure 11B In some embodiments, the distance between the second head edge e25 and the first head edge e15 in the winding direction r of the winding structure is L5, wherein 3mm≤L5≤10mm.

[0159] L5 represents the distance between the second head edge e25 and the first head edge e15 in the winding direction r of the winding structure, and can be 3mm, 5mm, 6.5mm, 8mm, 9mm, or 10mm, etc. Based on this distance, the distance between the second head edge e25 of the negative electrode and the first head edge e15 of the positive electrode is between 3mm and 10mm. This improves space utilization and the amount of negative electrode material used, 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.

[0160] In other embodiments, for the winding structure, the second tail edge e26 may also be flush with the first tail edge e16 in the winding direction r of the winding structure, and the second head edge e25 may also be flush with the first head edge e15 in the winding direction r of the winding structure.

[0161] refer to Figure 11A and Figure 11B In some embodiments, the electrode assembly 12 further includes a finishing tape 124, which is bonded to the tail of the outermost insulating member 123 of the electrode assembly 12 and covers the tail of the negative electrode sheet 122 and the tail of the insulating member 123; the second tail edge e26 is flush with or extends beyond the third tail edge e34 of the outermost insulating member 123 of the electrode assembly 12 in the winding direction r of the winding structure.

[0162] The finishing tape 124 finishes the winding structure. Since the finishing tape 124 has stronger adhesion and a certain puncture resistance than the separator 123, and its strength significantly exceeds 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 save costs. For example, for a 0.05mm thick finishing tape 124, its thickness is 0.02mm greater than the separator thickness, which reduces the risk of electrode burrs puncturing the separator due to cutting, and simultaneously fixes the tail of the negative electrode to prevent slippage.

[0163] like Figure 11A and Figure 11B As shown, for the electrode assembly formed by the positive electrode 121, the first separator 123, the negative electrode 122, and the second separator 123, the second tail edge e26 of the negative electrode 122 can extend beyond the third tail edge e34 of the outermost separator 123 in the winding direction r, or it can be flush with the third tail edge e34 of the outermost separator 123. In this way, the finishing tape 124 can achieve finishing by covering the tail of the negative electrode 122 and the tail of the separator 123. This reduces the risk of short circuits caused by the exposed tail of the negative electrode 122, effectively saves material usage of the separator 123, and increases the volumetric energy density of the winding structure.

[0164] Figure 12 and Figure 13 These are schematic diagrams of the mounting structure and exploded structure of other embodiments of the battery cell according to this disclosure. Figure 14 This is a schematic diagram of the electrode assembly in some other embodiments of the battery cell according to the present disclosure. Figure 15 yes Figure 14 A schematic diagram of a portion of the EE section.

[0165] refer to Figures 12-15 In some embodiments, the housing 11 may include an outer shell 111 with end 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, respectively, to be electrically connected to electrode terminals respectively provided on the top cover 112 and the top cover 113.

[0166] Different from Figure 11A The corresponding wound electrode assembly is replaced by a stacked electrode assembly in this embodiment. For example... Figure 14 As shown, for the electrode assembly 12, which has positive electrode tabs 121t and negative electrode tabs 122t respectively arranged on opposite sides of the electrode width direction dr1, Figure 15As shown in the EE cross section, the edges of the first active layer e13 and the third active layer e23 are flush with each other in the electrode width direction dr1, and the edge of the fourth active layer e24 extends beyond the edge of the second active layer in the electrode width direction dr1.

[0167] Accordingly, the aforementioned Figures 6-10 The embodiments shown are also applicable to stacked electrode assemblies. For details, please refer to the preceding content, which will not be repeated here.

[0168] 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 can balance the requirements of reliability and volumetric energy density.

[0169] 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 balance the requirements of reliability and space utilization.

[0170] In some specific embodiments, such as Figures 3-8 and Figure 11A 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 an electrode assembly 12, a positive electrode tab 121t, and a negative electrode tab 122t. The electrode assembly 12 includes a positive electrode sheet 121, a negative electrode sheet 122, and a separator 123, with the separator 123 located between the positive electrode sheet 121 and the negative electrode sheet 122. The positive electrode sheet 121, the negative electrode sheet 122, and the separator 123 are wound along the winding direction r to form a wound structure.

[0171] 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. 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 tab 121t is connected to the positive current collector substrate 1211, and the negative electrode tab 122t is connected to the negative current collector substrate 1221. The positive electrode tab 121t and the negative electrode tab 122t are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1. The bottom of the housing 11 is disposed adjacent to the first end S1 of the electrode assembly 12.

[0172] Along the electrode width direction dr1, the positive electrode active material layer 1212 has a first active layer edge e13 and a second active layer edge e14 at both ends, and the negative electrode active material layer 1222 has a third active layer edge e23 and a fourth active layer edge e24 at both ends. The first active layer edge e13 and the third active layer edge e23 are located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1, and the second active layer edge e14 and the fourth active layer edge e24 are located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1. The first end S1 and the second end S2 are arranged opposite to each other.

[0173] The edges e13 and e23 of the first active layer are flush with each other in the electrode width direction dr1, and the edge e24 of the fourth active layer extends beyond the edge e14 of the second active layer in the electrode width direction dr1. The tab is located at the second end S2 of the electrode assembly 12 along the electrode width direction dr1.

[0174] Along the electrode width direction dr1, the positive electrode current collector substrate 1211 has a first substrate edge e11 and a second substrate edge e12 at both ends, and the negative electrode active material layer 1222 has a third substrate edge e21 and a fourth substrate edge e22 at both ends. The first substrate edge e11 and the third substrate edge e21 are located at the first end S1 of the electrode assembly 12 along the electrode width direction dr1, and are both flush with the first active layer edge e13 along the electrode width direction dr1.

[0175] Along the electrode width direction dr1, the two ends of the separator 123 have a first separator edge e31 and a second separator edge e32, respectively, and the first separator edge e31 and the second separator edge e32 are located at the first end S1 and the second end S2 of the electrode assembly 12 along the electrode width direction dr1; the first separator edge e31 extends beyond the first active layer edge e13 in the electrode width direction dr1.

[0176] The first substrate edge e11, the first active layer edge e13, the third substrate edge e21, and the third active layer edge e23 are covered and fixed at the first end S1 of the electrode assembly 12 by the separator 123.

[0177] In the winding direction r of the winding structure, the two ends of the positive electrode 121 have a first head edge e15 and a first tail edge e16, the two ends of the negative electrode 122 have a second head edge e25 and a second tail edge e26, and the two ends of the separator 123 have a third head edge e33 and a third tail edge e34, respectively; the second tail edge e26 extends beyond the first tail edge e16 in the winding direction r of the winding structure, and the second head edge e25 extends beyond the first head edge e15 in the winding direction r of the winding structure.

[0178] The second tail edge e26 is flush with or extends beyond the third tail edge e34 of the outermost insulating member 123 of the electrode assembly 12 in the winding direction r of the winding structure; wherein, the electrode assembly 12 further includes a finishing tape 124, which is bonded to the tail of the outermost insulating member 123 of the electrode assembly 12 and covers the tail of the positive electrode 121, the tail of the negative electrode 122 and the tail of the insulating member 123.

[0179] 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.

[0180] 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 active material layer (1212), and the negative electrode (122) includes a negative active material layer (1222). Along the electrode width direction (dr1), the positive electrode active material layer (1212) has a first active layer edge (e13) and a second active layer edge (e14) at both ends, and the negative electrode active material layer (1222) has a third active layer edge (e23) and a fourth active layer edge (e24) at both ends, respectively. The first active layer edge (e13) and the third active layer edge (e23) are located at the first end (S1) of the electrode assembly (12) along the electrode width direction (dr1), and the second active layer edge (e14) is located at the second end (S1) of the electrode assembly (12). The edge of the active layer (e14) and the edge of the fourth active layer (e24) are located at the second end (S2) of the electrode assembly (12) along the electrode width direction (dr1), and the first end (S1) and the second end (S2) are arranged opposite to each other; the edge of the first active layer (e13) and the edge of the third active layer (e23) are flush with each other in the electrode width direction (dr1), and the edge of the fourth active layer (e24) extends beyond the edge of the second active layer (e14) in the electrode width direction (dr1).

2. The battery cell (10) according to claim 1, wherein, The positive electrode (121) further includes 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); the negative electrode (122) further includes a negative current collector substrate (1221), and the negative active material layer (1222) is disposed on the surface of the negative current collector substrate (1221); Along the electrode width direction (dr1), the positive electrode current collector substrate (1211) has a first substrate edge (e11) and a second substrate edge (e12) at both ends, and the negative electrode current collector substrate (1221) has a third substrate edge (e21) and a fourth substrate edge (e22) at both ends. The first substrate edge (e11) and the third substrate edge (e21) are located at the first end (S1) of the electrode assembly (12) along the electrode width direction (dr1), and are both flush with the first active layer edge (e13) along the electrode width direction (dr1).

3. The battery cell (10) according to claim 2 further includes: The housing (11) contains the electrode assembly (12). The electrode assembly (12) further includes a positive electrode tab (121t) and a negative electrode tab (122t). The positive electrode tab (121t) is connected to the positive current collector substrate (1211), and the negative electrode tab (122t) is connected to the negative current collector substrate (1221). The positive electrode tab (121t) and the negative electrode tab (122t) are located at the second end (S2) of the electrode assembly (12) along the width direction (dr1) of the electrode sheet. The bottom of the housing (11) is disposed adjacent to the first end (S1) of the electrode assembly (12).

4. The battery cell (10) according to claim 2 or 3, wherein, Along the electrode width direction (dr1), the two ends of the separator (123) have a first separator edge (e31) and a second separator edge (e32), and the first separator edge (e31) and the second separator edge (e32) are located at the first end (S1) and the second end (S2) of the electrode assembly (12) along the electrode width direction (dr1); the first separator edge (e31) extends beyond the edge of the first active layer (e13) in the electrode width direction (dr1).

5. The battery cell (10) according to claim 4, wherein, The first substrate edge (e11), the first active layer edge (e13), the third substrate edge (e21), and the third active layer edge (e23) are covered and fixed at the first end (S1) of the electrode assembly (12) by the separator (123).

6. The battery cell (10) according to claim 2 or 3, wherein, Along the electrode width direction (dr1), the two ends of the separator (123) have a first separator edge (e31) and a second separator edge (e32), and the first separator edge (e31) and the second separator edge (e32) are located at the first end (S1) and the second end (S2) of the electrode assembly (12) along the electrode width direction (dr1); the first separator edge (e31) is flush with the edge of the first active layer (e13) in the electrode width direction (dr1).

7. The battery cell (10) according to any one of claims 2-6, wherein, The positive electrode (121) further includes a first insulating layer (1213), which is located at the second end (S2) of the electrode assembly (12) along the width direction (dr1) of the electrode. The first insulating layer (1213) is disposed on at least one of the positive current collector substrate (1211) and the positive active material layer (1212), and has a first insulating edge (e41) that extends beyond the edge (e14) of the second active layer in the width direction (dr1) of the electrode.

8. The battery cell (10) according to claim 7, wherein, Along the electrode width direction (dr1), the two ends of the separator (123) have a first separator edge (e31) and a second separator edge (e32), respectively. The second substrate edge (e12) and the second separator edge (e32) are located at the second end (S2) of the electrode assembly (12) along the electrode width direction (dr1). The second substrate edge (e12) and the first insulating edge (e41) are flush with each other along the electrode width direction (dr1). The second separator edge (e32) is flush with or extends beyond the first insulating edge (e41) along the electrode width direction (dr1).

9. The battery cell (10) according to claim 7 or 8, wherein, The first insulating edge (e41) is flush with or extends beyond the edge of the fourth active layer (e24) in the electrode width direction (dr1).

10. The battery cell (10) according to claim 8, wherein, The positive electrode (121) further includes a second insulating layer (1214), which is located at the first end (S1) of the electrode assembly (12) along the electrode width direction (dr1). The second insulating layer (1214) is disposed on at least one of the positive current collector substrate (1211) and the positive active material layer (1212), and has a second insulating edge (e42). The second insulating edge (e42) is flush with the edge of the first substrate (e11) in the electrode width direction (dr1). The edge of the first separator (e31) extends beyond the edge of the third active layer (e23) in the electrode width direction (dr1), and is flush with or extends beyond the second insulating edge (e42) in the electrode width direction (dr1).

11. The battery cell (10) according to any one of claims 7-10, wherein, In the electrode width direction (dr1), the two ends of the separator (123) have a first separator edge (e31) and a second separator edge (e32), respectively; The first substrate edge (e11), the third substrate edge (e21), and the first separator edge (e31) are located at the first end (S1) of the electrode assembly (12) along the electrode width direction (dr1), and the second substrate edge (e12), the fourth substrate edge (e22), and the second separator edge (e32) are located at the second end (S2) of the electrode assembly (12) along the electrode width direction (dr1). The distance between the edge of the second insulating member (e32) and the edge of the fourth active layer (e24) in the electrode width direction (dr1) is L1, the distance between the edge of the first insulating member (e41) and the edge of the fourth active layer (e24) in the electrode width direction (dr1) is L2, the distance between the edge of the fourth active layer (e24) and the edge of the second active layer (e14) in the electrode width direction (dr1) is L3, the distance between the edge of the first insulating member (e31) and the edge of the first substrate (e11) in the electrode width direction (dr1) is L4, the thickness of the positive electrode (121) is T1, and the thickness of the negative electrode (122) is T2. Where 0≤L1≤3mm, L2≥0mm, 0 <L3≤3mm,L4≥T1,L4≥T2。 12. The battery cell (10) according to any one of claims 1-11, wherein, The electrode assembly (12) is a wound structure. In the winding direction (r) of the wound structure, the two ends of the positive electrode (121) have a first head edge (e15) and a first tail edge (e16), the two ends of the negative electrode (122) have a second head edge (e25) and a second tail edge (e26), and the two ends of the separator (123) have a third head edge (e33) and a third tail edge (e34). The second tail edge (e26) extends beyond the first tail edge (e16) in the winding direction (r) of the wound structure, and the second head edge (e25) extends beyond the first head edge (e15) in the winding direction (r) of the wound structure.

13. The battery cell (10) according to claim 12, wherein, The distance between the second head edge (e25) and the first head edge (e15) in the winding direction (r) of the winding structure is L5, wherein 3mm≤L5≤10mm.

14. The battery cell (10) according to claim 12 or 13, wherein, The electrode assembly (12) further includes a finishing tape (124) that is bonded to the tail of the outermost insulating member (123) of the electrode assembly (12) and covers the tail of the negative electrode sheet (122) and the tail of the insulating member (123); the second tail edge (e26) is flush with or extends beyond the third tail edge (e34) of the outermost insulating member (123) of the electrode assembly (12) in the winding direction (r) of the winding structure.

15. A battery device (20), comprising: The battery cell (10) according to any one of claims 1-14.

16. An electrical appliance, comprising: The battery device (20) according to claim 15.

Images