Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization equipment. The battery monomer comprises a shell, an electrode unit, a conductive piece and a separation piece. A first wall of the shell is provided with a first through hole. The electrode unit comprises a main body part and a first conductive part. The main body part is accommodated in the shell and located at one side of the first wall along a first direction. The first conductive part is led out from the main body part and arranged in the first through hole. A part of the first conductive part is located at the side of the first wall away from the main body part and welded to the first wall to form a first welding part. The conductive piece is arranged at the side of the first wall away from the main body part and covers the first through hole and the first welding part. The conductive piece is electrically connected to the first wall and used for welding with a busbar. At least part of the separation piece is arranged between the conductive piece and the first welding part along the first direction. The thermal conductivity coefficient of the separation piece is smaller than that of the conductive piece. The separation piece can reduce the heat transferred to the first welding part, reduce the risk of cracking or breaking of the first welding part and improve the reliability of the battery monomer.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to PCT application No. PCT / CN2025 / 145289, filed on December 24, 2025, entitled “Battery Cell, Battery Device and Electrical Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0004] Batteries 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, etc.

[0005] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Utility Model Content

[0006] This application provides a battery cell, a battery device, and an electrical appliance, which helps to improve the reliability of the battery cell.

[0007] According to a first aspect of this application, a battery cell is provided, comprising a casing, an electrode unit, a conductive element, and an insulating element. The casing includes a first wall with a first through hole; the electrode unit includes a main body and a first conductive part, the main body being housed within the casing and located on one side of the first wall along a first direction, the first conductive part extending from the main body and passing through the first through hole, a portion of the first conductive part being located on the side of the first wall away from the main body and welded to the first wall to form a first welded part; the conductive element is disposed on the side of the first wall away from the main body and covers the first through hole and the first welded part, the conductive element being electrically connected to the first wall, and the conductive element being used for welding to a busbar component; along the first direction, at least a portion of the insulating element is disposed between the conductive element and the first welded part, the thermal conductivity of the insulating element being less than the thermal conductivity of the conductive element.

[0008] The portion of the first conductive part extending to the outer side of the first wall is welded to the first wall to form a first welded part. This reduces the space occupied by the first conductive part within the casing and decreases the probability of welding particles falling into the casing, thus reducing the risk of short circuits. The separator has a low thermal conductivity, which helps reduce the heat transferred through it. This reduces the heat transferred to the first welded part during the welding of the conductive part and the busbar component, minimizing the adverse effects of the welding operation on the first welded part. It also reduces the risk of cracking or breaking of the first welded part leading to connection failure between the first conductive part and the first wall, thereby improving the reliability of the battery cell.

[0009] In some embodiments, the isolator completely covers the first weld portion along the direction from the first wall toward the main body. The isolator completely separates the first weld portion from the conductive element along the first direction. The isolator can prevent the heat generated during the welding of the conductive element and the busbar component from being transferred to the first weld portion, thereby reducing the adverse effects of the welding operation of the conductive element and the busbar component on the first weld portion.

[0010] In some embodiments, in the same plane perpendicular to the first direction, the orthographic projection of the isolator has a first outer contour, and the orthographic projection of the first weld portion has a second outer contour. The first outer contour surrounds the outer periphery of the second outer contour, and the first outer contour and the second outer contour are spaced apart. The outer peripheral edge of the isolator extends beyond the outer peripheral edge of the first weld portion. The isolator can prevent the heat generated during the welding of the conductive element and the busbar from being transferred to the first weld portion and the outer periphery of the first weld portion, thereby expanding the range of heat transfer obstruction by the isolator, reducing the heat diffused to the first weld portion during the welding of the conductive element and the busbar, and reducing the adverse effects on the first weld portion.

[0011] In some embodiments, the minimum distance between the first outer contour and the second outer contour is d, where 1mm ≤ d ≤ 10mm. d is greater than or equal to 1mm, which helps to expand the range of heat transfer obstruction by the insulating member, extend the diffusion path of heat from the conductive member to the first weld, and reduce the adverse effects on the first weld; d is less than or equal to 10mm, which helps to reduce interference between the insulating member and other components and reduce the risk of edge warping of the insulating member.

[0012] In some embodiments, the isolator completely covers the surface of the conductive element facing the electrode unit along the direction from the main body to the first wall. The isolator can prevent the conductive element from transferring heat to the side closer to the first wall, reduce the adverse effects on the first weld, the first conductive element, and the first wall during welding of the conductive element and the busbar component, reduce the risk of cracking or breaking of the first weld, and reduce the risk of bending deformation of the first conductive element or the first wall.

[0013] In some embodiments, the isolator is connected to at least one of the conductive element, the first conductive portion, and the first weld portion. This improves the installation stability of the isolator and reduces the risk of the isolator shifting or displacing and becoming completely misaligned with the first weld portion.

[0014] In some embodiments, the isolator is connected to the first conductive part and / or the first welded part, and the conductive part and the isolator are spaced apart along the first direction; or, the isolator is connected to the conductive part, and the isolator and the first welded part are spaced apart along the first direction. The spaced-apart arrangement of the conductive part and the isolator helps to reduce interference between them, reduces the adverse effects of the isolator on the connection between the conductive part and the first wall, and also reduces the risk of the first welded part cracking under pressure. Furthermore, the spaced-apart arrangement of the isolator and the first welded part helps to reduce interference between them, reducing the risk of the first welded part cracking under pressure. It also blocks heat conduction between the isolator and the first welded part, reducing the efficiency of heat transfer to the first welded part.

[0015] In some embodiments, the spacer is bonded to the first conductive portion, and the portion of the first conductive portion bonded to the spacer surrounds the first weld portion. Bonding the spacer and the first conductive portion around the first weld portion increases the bonding area and improves bonding strength; it also isolates the electrolyte around the outer periphery of the first weld portion, reducing the possibility of electrolyte seepage between the first conductive portion and the spacer, thereby reducing the risk of the spacer lifting.

[0016] In some embodiments, the separator includes a base layer and an adhesive layer stacked along a first direction, the adhesive layer being bonded to the conductive element or the first conductive portion; the base layer is made of polyimide or polyethylene terephthalate. Polyimide has good heat resistance and is not easily deformed or softened at high temperatures, which helps maintain good mechanical strength during welding of the conductive element and the busbar component, improving the effect of preventing heat transfer to the first welded portion. Polyethylene terephthalate has low cost and is easy to process, which helps reduce the cost of the battery cell while preventing heat transfer to the first welded portion.

[0017] In some embodiments, the thermal conductivity of the insulating element is less than or equal to 3.0 W / (m·K).

[0018] In some embodiments, the melting point of the insulating element is higher than that of the conductive element. A higher melting point of the insulating element helps reduce the risk of it melting during welding of the conductive element and the busbar, improves the structural stability of the insulating element, and thus enhances its thermal insulation performance.

[0019] In some embodiments, the melting point of the insulating element is greater than or equal to 250°C.

[0020] In some embodiments, the thickness of the separator is 20 μm-50 μm. A thickness greater than or equal to 20 μm is beneficial for improving the heat insulation effect of the separator, as well as enhancing its structural strength and reducing the risk of breakage. A thickness less than or equal to 50 μm is beneficial for reducing the space occupied by the separator in the first direction, thus minimizing the impact of the separator's placement on the energy density of the battery cell.

[0021] In some embodiments, a recess is provided on the side of the first wall away from the main body along the first direction. The first wall includes a first portion and a second portion, with the second portion corresponding to the recess along the first direction. A first through hole communicates with the recess, and a portion of the first conductive part is accommodated in the recess and welded to the second portion to form a first welded portion. The recess provides at least partial accommodating space for the portion of the first conductive part that protrudes from the first through hole. The first conductive part and the first wall share a portion of the space in the first direction, which can reduce the additional space occupied by the first conductive part on the outside of the casing, thereby improving the energy density of the battery cell.

[0022] In some embodiments, the first through hole extends through the second portion along a first direction. This reduces the height difference in the first direction between the position where the first conductive part emerges from the first through hole and the position where the first conductive part and the first wall are welded, reduces the phenomenon of the first conductive part arching in the recess, reduces the space occupied by the first conductive part in the first direction in the recess, and also reduces the degree of bending of the first conductive part, thereby reducing the risk of cracking of the first conductive part.

[0023] In some embodiments, at least a portion of the separator is received within a recess. The recess provides at least a partial receiving space for the separator, and the separator and the first wall share at least a portion of the space in a first direction, which can reduce the additional space occupied by the separator on the outside of the housing, thereby increasing the energy density of the battery cell.

[0024] In some embodiments, the separator is entirely housed in the recess, and at least a portion of the conductive element is housed in the recess. The recess provides accommodating space for at least a portion of the conductive element, the separator, the first weld portion, and a portion of the first conductive portion. The conductive element, the separator, the first weld portion, and the first conductive portion all share a portion of the space in the first direction with the first wall, which is beneficial for improving the structural compactness of the battery cell and increasing the energy density.

[0025] In some embodiments, the second part includes a first sub-part and a second sub-part. Along the first direction, the first surface of the first sub-part facing away from the main body is closer to the main body than the second surface of the second sub-part facing away from the main body. A first conductive part is welded to the first sub-part to form a first welded part. In the same plane perpendicular to the first direction, the orthographic projection of the portion of the first conductive part housed in the recess is spaced apart from the orthographic projection of the second sub-part. Compared to the portion of the recess corresponding to the second sub-part, the portion of the recess corresponding to the first sub-part is more recessed, providing more space for the first conductive part and the first welded part in the first direction. The first conductive part and the second sub-part do not overlap along the first direction, and the first conductive part and the second sub-part can share some space in the first direction, which is beneficial to improving space utilization. The portion of the first wall corresponding to the recess is stepped, which helps to reduce the molding difficulty of the recess and reduce the risk of breakage during the molding process of the first wall.

[0026] In some embodiments, the first through hole is formed by a first sub-part and a second sub-part. On one hand, this reduces the height difference in the first direction between the position where the first conductive part protrudes from the first through hole and the position where the first conductive part is welded to the first wall, thus reducing the arching of the first conductive part within the recess, reducing the space occupied by the first conductive part in the first direction within the recess, and also reducing the degree of bending of the first conductive part, thereby lowering the risk of cracking. On the other hand, it also helps to reduce the size of the first sub-part, reducing the impact of the first sub-part's arrangement on the structural strength of the first wall.

[0027] In some embodiments, the isolator is connected to the first conductive portion, and the orthographic projections of the isolator and the second sub-part are spaced apart in the same plane perpendicular to the first direction. The portion of the first conductive portion located on the first wall away from the main body may have a height difference with the second sub-part in the first direction. Since the orthographic projections of the isolator and the second sub-part do not overlap, and the isolator is not connected to the second sub-part, this improves the flatness of the isolator, reduces the risk of wrinkles or warping, and enhances the connection stability between the isolator and the first conductive portion.

[0028] In some embodiments, the second portion includes a third sub-portion connecting the first portion and the second sub-portion. Along a first direction, the third surface of the third sub-portion, facing away from the main body, is further away from the main body than the second surface. Along the direction from the main body towards the first wall, the spacer does not extend beyond the third surface, and the conductive element is connected to the third surface. A portion of the conductive element is accommodated in a recess and shares space in the first direction with the first wall, which helps improve space utilization. The spacer not extending beyond the third surface helps reduce interference between the spacer and the conductive element.

[0029] In some embodiments, along a first direction, the first portion includes a fourth surface facing the main body, and along the direction from the first wall toward the main body, the second portion at least partially protrudes from the fourth surface. This facilitates increasing the thickness of the second portion, reducing the impact of the recess on the structural strength of the first wall, and lowering the risk of deformation of the first wall.

[0030] In some embodiments, the battery cell includes a first insulating member, at least a portion of which is disposed between the main body and the first wall along a first direction. The first insulating member has a second through-hole extending along the first direction, a first conductive portion passing through the second through-hole, and a portion of the second part protruding from the fourth surface being at least partially accommodated in the second through-hole. This allows for full utilization of the space occupied by the first insulating member in the first direction to accommodate at least the portion of the second part protruding from the fourth surface, improving space utilization and reducing the additional space occupied by the second part inside the casing, thereby increasing the energy density of the battery cell.

[0031] In some embodiments, the battery cell includes two first conductive portions and two first through holes in the first wall, with the two first conductive portions respectively passing through the two first through holes. The separate arrangement of the two first conductive portions in the battery cell helps to reduce the thickness of a single first conductive portion and reduce the space occupied by the first conductive portion in the first direction inside the casing, thereby increasing the energy density of the battery cell.

[0032] In some embodiments, the outer casing includes two second walls disposed along a second direction perpendicular to the first direction; the first conductive portion includes a first tab connected to the main body, the first tab including multiple first tab layers, the first tab layers of the two first conductive portions respectively converging toward the two second walls. By employing a C-shaped bending method for the first tab, the overall length of the first tab can be extended, giving the first tab a certain degree of redundancy for stretching deformation. This helps to alleviate the pulling effect on the first tab when the first conductive portion passes through the first through hole, reducing the tensile stress on the first tab and lowering the risk of the first tab breaking.

[0033] In some embodiments, two first conductive parts are welded to a first wall to form two first welded parts; the battery cell includes two separators, which are respectively connected to the two first conductive parts, and at least a portion of each separator is located between the two first welded parts and the conductive parts along a first direction. By isolating the two first welded parts and the conductive parts with two separators respectively, the size of a single separator can be reduced, and the connection difficulty between the separator and the first conductive parts can be reduced.

[0034] In some embodiments, in the same plane perpendicular to the first direction, the portions of the two first conductive parts located on the side of the first wall away from the main body each have a first orthographic projection, and the isolation member has a second orthographic projection. The second orthographic projections of the two isolation members are respectively located within the two first orthographic projections. The edge of the isolation member does not extend beyond the portion of the first conductive part that protrudes from the first through hole, and the edge of the isolation member can be connected to the first conductive part, which helps to reduce the risk of edge lifting of the isolation member and improve the connection stability between the isolation member and the first conductive part.

[0035] In some embodiments, two first conductive parts are welded to a first wall to form two first welded parts; along a first direction, a portion of an isolation member is disposed between one of the welded parts and the conductive part, and another portion of the isolation member is disposed between the other welded part and the conductive part. Isolating the two first welded parts from the conductive part using an isolation member simplifies the structure and assembly process of the battery cell.

[0036] In some embodiments, the first conductive portion includes a first electrode tab, which is disposed in a first through hole, and a portion of the first electrode tab is located on the side of the first wall away from the main body and is welded to the first wall to form a first weld portion.

[0037] In some embodiments, the first conductive portion includes a first tab and a first adapter portion. The first tab is connected to the main body, and the first adapter portion is welded to the first tab. The first adapter portion passes through a first through hole, and a portion of the first adapter portion is located on the side of the first wall away from the main body and is welded to the first wall to form a first weld portion. The first tab is relatively soft, and the first tab typically includes multiple first tab layers. Therefore, it is difficult for the first tab to pass through the first through hole, and the first tab is more prone to cracking due to stress concentration. In this embodiment, the first adapter portion passes through the first through hole, which helps to reduce assembly difficulty, reduce interference between the first tab and the first wall, and reduce the risk of the first tab cracking due to stress concentration.

[0038] In some embodiments, the first adapter portion includes two adapter layers, with the end of the first electrode tab furthest from the main body disposed between the two adapter layers and welded to them. The two adapter layers provide constraint and protection for the first electrode tab, which helps reduce the risk of a short circuit caused by the end of the first electrode tab furthest from the main body being inserted backwards into the main body. Welding the first electrode tab between the two adapter layers improves welding strength and stability, and reduces damage to the first electrode tab caused by welding heat.

[0039] In some embodiments, the two transition layers are stacked and welded to the first wall on the side of the first wall away from the main body. The stacking and welding of the two transition layers to the first wall improves weld strength and stability.

[0040] In some embodiments, the housing includes a third wall, and along a first direction, the main body is disposed between the first wall and the third wall. The battery cell includes an electrode terminal disposed on the third wall. The electrode unit includes a second conductive portion extending from the main body and electrically connected to the electrode terminal.

[0041] In some embodiments, the second conductive portion includes a second tab connected to the main body portion; the battery cell includes two second conductive portions, with the second tabs of the two second conductive portions being separately disposed along a second direction, which is perpendicular to the first direction. The separate disposal of the two second conductive portions of the battery cell helps to reduce the thickness of a single second conductive portion and reduce the space occupied by the second conductive portion in the first direction inside the casing, thereby increasing the energy density of the battery cell.

[0042] In some embodiments, the housing includes a housing and an end cap, the housing having a housing opening on one side along a first direction, the end cap being connected to the housing and covering the housing opening; the third wall is the end cap, and the housing is integrally formed and includes the first wall.

[0043] In some embodiments, the housing includes a housing and two end caps, the housing having housing openings on both sides along a first direction, the two end caps being connected to the housing and respectively covering the two housing openings; a first wall is one of the end caps, and a third wall is the other end cap.

[0044] According to a second aspect of this application, this application also provides a battery device comprising a battery cell provided in any of the embodiments.

[0045] In some embodiments, the battery device includes a busbar component, which is welded to a conductive element to form a second welded portion. In the same plane perpendicular to the first direction, the orthographic projections of the first welded portion and the second welded portion are at least partially offset. This at least partial offset arrangement of the second welded portion and the first welded portion facilitates increasing the distance between them, reducing heat transferred to the first welded portion during welding of the busbar component and the conductive element, and minimizing adverse effects on the first welded portion.

[0046] In some embodiments, the battery device includes a current-combining component, which is welded to a conductive element to form a second welded portion. In the same plane perpendicular to the first direction, the orthographic projections of both the first and second welded portions lie within the orthographic projection of the separator. Along the direction from the main body to the first wall, the separator completely covers the second welded portion, reducing heat transfer from the second welded portion to the conductive element near the main body. The separator completely separates the first and second welded portions, which helps reduce heat transfer to the first welded portion and minimizes its adverse effects.

[0047] According to a third aspect of this application, this application also provides an electrical device that includes a battery device provided in any embodiment of the second aspect, the battery device being used to provide electrical energy. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application.

[0050] Figure 2 These are schematic diagrams of the vehicle structure provided in some embodiments of this application.

[0051] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application.

[0052] Figure 4 yes Figure 3 An exploded view of the battery cell shown.

[0053] Figure 5 yes Figure 3 The image shows a front view of a single battery cell.

[0054] Figure 6 It is along Figure 5 The sectional view taken from direction AA in the middle.

[0055] Figure 7 yes Figure 6 A magnified view of region B in the middle.

[0056] Figure 8 This is a partial cross-sectional view of a battery cell provided in other embodiments of this application.

[0057] Figure 9 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application.

[0058] Figure 10 This is a schematic diagram of the orthographic projection of the separator and the first weld portion of a battery cell provided in some embodiments of this application in the same plane perpendicular to the first direction.

[0059] Figure 11 This is a cross-sectional view of the separator of a battery cell provided in some embodiments of this application.

[0060] Figure 12 yes Figure 6 A magnified view of region C in the middle.

[0061] Figure 13 yes Figure 12 A magnified schematic diagram of region D in the middle.

[0062] Figure 14 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application.

[0063] Figure 15 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application.

[0064] Figure 16 This is a partial cross-sectional view of a battery device provided in some embodiments of this application.

[0065] The attached figures are labeled as follows:

[0066] 1. Vehicle, 2. Battery unit, 3. Controller, 4. Motor, 5. Housing, 5a. First housing section, 5b. Second housing section, 5c. Housing space, 6. Battery cell, 7. Busbar component;

[0067] 10. Electrode unit; 11. Main body; 12. First conductive part; 121. First tab; 122. First adapter; 1221. Adapter layer; 13. Second conductive part; 131. Second tab; 20. Outer shell; 21. Housing; 211. Housing opening; 22. End cap; 23. First wall; 231. First through hole; 232. Recess; 233. First part; 233a. Fourth surface; 234. Second part; 2341. First sub-part; 2341a. First surface. 2342, Second sub-part; 2342a, Second surface; 2343, Third sub-part; 2343a, Third surface; 24, Second wall; 25, Third wall; 26, Fourth wall; 30, Conductive component; 40, Isolating component; 41, Base layer; 42, Adhesive layer; 50, First insulating component; 51, Second through hole; 60, Electrode terminal; 70, Second insulating component; 80, Adapter component; S1, First outer contour; S2, Second outer contour; W1, First welding part; W2, Second welding part;

[0068] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0071] In this application, 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 application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "adhesion" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0073] In this application, 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, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0074] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0075] In this application, "multiple" means two or more (including two).

[0076] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0077] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0078] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0079] A typical battery cell includes an electrode assembly, a housing, and electrode terminals. The electrode assembly is housed within the housing, and the electrode terminals are located within the housing. The housing encapsulates the electrode assembly and electrolyte components. The electrode assembly includes tabs, which are electrically connected to the electrode terminals via adapters or directly to the electrode terminals. The electrode terminals are used to electrically connect the electrode assembly to external circuitry within the battery cell to enable charging or discharging of the battery cell.

[0080] The electrode assembly includes a positive electrode, a negative electrode, and an isolation structure. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The isolation structure, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0081] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0082] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0083] In some implementations, the isolation structure is positioned between the positive and negative electrodes.

[0084] In some embodiments, the isolation structure is an isolation membrane. This application does not impose any particular limitation on the type of isolation membrane; any known porous isolation membrane with good chemical and mechanical stability can be selected.

[0085] In some embodiments, the isolation structure is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0086] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0087] In some embodiments, the electrode assembly has a stacked structure.

[0088] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0089] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0090] A battery device typically includes a housing for encapsulating one or more individual battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0091] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by fixing the battery module within the housing. As an example, the housing can include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, creating a closed space inside the housing to house the battery cell assembly.

[0092] 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.

[0093] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0094] Tabs are typically welded to electrode terminals; alternatively, tabs are welded to adapters, and adapters are welded to electrode terminals. The welded portions between tabs and electrode terminals, tabs and adapters, and adapters and electrode terminals are usually located inside the casing, occupying internal space and affecting the energy density of the battery cells. Furthermore, welding particles generated during the welding process may fall into the casing, potentially damaging the insulating components and causing a short circuit between the positive and negative electrodes.

[0095] To address the aforementioned technical issues, related technologies involve extending a portion of the tab or adapter through the outer casing and directly welding it to the casing from the outside. This reduces the space occupied by the tab or adapter within the casing, eliminates the need for electrode terminals, and prevents welding particles from easily falling into the casing. However, since the solder mark is located on the outside of the casing, it is susceptible to the welding heat generated during the welding of battery cells and busbar components, potentially leading to reduced welding strength or even connection failure between the tab or adapter and the casing.

[0096] In view of this, the present application provides a technical solution that provides an isolation member between the welded part and the conductive part used for welding with the bus component. The isolation member can reduce the heat transferred to the welded part during the welding of the conductive part and the bus component, reduce the adverse effects of welding the conductive part and the bus component on the welded part, and reduce the risk of connection failure caused by cracking or breakage of the welded part.

[0097] The technical solutions provided in this application are applicable to battery cells, battery devices, and electrical equipment using battery devices.

[0098] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0099] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0100] Figure 1 This is a structural schematic diagram of a vehicle provided in some embodiments of this application. (Refer to...) Figure 1 Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0101] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0102] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application. (Refer to...) Figure 2The battery device 2 includes a housing 5 and a battery cell 6, with the battery cell 6 housed within the housing 5. The housing 5 provides a space for the battery cell 6 and can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, together defining a space 5c for accommodating the battery cell 6. The second housing portion 5b may be a hollow structure with one open end, while the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b so that the first housing portion 5a and the second housing portion 5b together define the space 5c. Alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one open side, with the open side of the first housing portion 5a overlapping the open side of the second housing portion 5b. Of course, the box 5 formed by the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0103] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0104] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0105] In the battery device 2, there can be multiple battery cells 6, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel configurations. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 6 is housed within the housing 5. Alternatively, the battery device 2 can also consist of multiple battery cells 6 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 5. The battery device 2 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 6.

[0106] For example, the battery cell 6 may be the smallest unit that makes up the battery device 2.

[0107] Figure 3 These are schematic diagrams of the structure of a single battery cell provided in some embodiments of this application. Figure 4 yes Figure 3 An exploded view of the battery cell shown. (Refer to...) Figure 3 and Figure 4 The battery cell 6 includes an electrode unit 10 and a housing 20, with a portion of the electrode unit 10 disposed within the housing 20.

[0108] The outer casing 20 is used to encapsulate the electrode unit 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0109] In some embodiments, the outer casing 20 is a hollow structure, with an internal space for accommodating the electrode unit 10 and the electrolyte. The shape of the outer casing 20 can be determined according to the specific shape of the electrode unit 10. For example, if the electrode unit 10 has a cuboid structure, a cuboid outer casing can be used.

[0110] The outer casing 20 can be made of various materials, such as metal or plastic. Optionally, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the outer casing 20 can be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as copper-aluminum composite casing), or aluminum-plastic film, etc.

[0111] As an example, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having a housing opening and the end cap 22 for closing the housing opening.

[0112] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate a part of the electrode unit 10, the electrolyte, and other components.

[0113] The housing 21 and the end cap 22 can be separate components. For example, a housing opening 211 can be provided on the housing 21, and the end cap 22 can be used to cover the housing opening 211 to form an internal cavity for the battery cell 6.

[0114] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21.

[0115] The end cap 22 can be connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0116] The housing 21 may be open at one end or open at both ends. For example, the housing 21 is open on one side, and the end cap 22 is configured as one housing opening 211 that covers the housing 21. As another example, the housing 21 may also be open on both sides, and two end caps 22 are configured, with the two end caps 22 respectively covering the two housing openings 211 of the housing 21.

[0117] Figure 5 yes Figure 3 The image shows a front view of a single battery cell. Figure 6 It is along Figure 5 The sectional view taken from direction AA in the middle. Figure 7 yes Figure 6 An enlarged schematic diagram of region B in the middle. Figure 8 This is a partial cross-sectional view of a battery cell provided in other embodiments of this application. Figure 9 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application. Figure 10 This is a schematic diagram of the orthographic projection of the separator and the first weld portion of a battery cell provided in some embodiments of this application in the same plane perpendicular to the first direction. Figure 11 This is a cross-sectional view of the separator of a battery cell provided in some embodiments of this application. Figure 12 yes Figure 6 An enlarged schematic diagram of region C in the middle. Figure 13 yes Figure 12 An enlarged schematic diagram of region D in the middle. Figure 14 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application. Figure 15 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application.

[0118] Reference Figures 3 to 15 The battery cell 6 includes an electrode unit 10, a housing 20, a conductive element 30, and a separator 40. The housing 20 includes a first wall 23 with a first through-hole 231. The electrode unit 10 includes a main body 11 and a first conductive part 12. The main body 11 is housed within the housing 20 and located on one side of the first wall 23 along a first direction X. The first conductive part 12 extends from the main body 11 and passes through the first through-hole 231. A portion of the first conductive part 12 is located on the side of the first wall 23 away from the main body 11 and is welded to the first wall 23 to form a first welded part W1. The conductive element 30 is located on the side of the first wall 23 away from the main body 11 and covers the first through-hole 231 and the first welded part W1. The conductive element 30 is electrically connected to the first wall 23 and is used for welding to a busbar component. In the first direction X, at least a portion of the insulating member 40 is disposed between the conductive member 30 and the first welded portion W1, and the thermal conductivity of the insulating member 40 is less than that of the conductive member 30.

[0119] The first wall 23 can be one of the walls of the housing 21, or it can be an end cap 22. Optionally, in Figure 4 In the embodiment shown, the first wall 23 is an end cap 22.

[0120] In one example, the first through hole 231 penetrates the first wall 23 along the first direction X. In other examples, the direction in which the first through hole 231 penetrates the first wall 23 may also intersect the first direction X.

[0121] The shape of the first through hole 231 can be various. For example, the first through hole 231 can be rectangular, oblong, or elliptical.

[0122] Optionally, the first through hole 231 is an elongated rectangular hole, the length direction of the first through hole 231 is parallel to the width direction of the first conductive part 12, and the width direction of the first conductive part 12 is perpendicular to the extension direction of the first conductive part 12 extending from the main body part 11.

[0123] A portion of the first conductive portion 12 is located between the main body portion 11 and the first wall 23. In one example, the first conductive portion 12 extends from the side of the main body portion 11 near the first wall 23 along the first direction X. In other examples, the first conductive portion 12 may also extend from other sides of the main body portion 11, with a portion of the first conductive portion 12 extending to the side of the main body portion 11 near the first wall 23.

[0124] The first conductive portion 12 is the power output structure of the electrode unit 10. The first conductive portion 12 includes at least a first tab 121, which is connected to the main body portion 11. Optionally, the first conductive portion 12 may also include a transition portion connected to the first tab 121.

[0125] The main body 11 includes a positive current collector, a positive active material layer disposed on the surface of the positive current collector, a negative current collector, a negative active material layer disposed on the surface of the negative current collector, and an isolation structure.

[0126] In one example, the first tab 121 is a positive tab, and the first tab 121 is connected to the positive current collector body. Optionally, the first tab 121 is integrally formed with the positive current collector body.

[0127] In another example, the first tab 121 is a negative tab, and the first tab 121 is connected to the negative current collector body. Optionally, the first tab 121 is integrally formed with the negative current collector body.

[0128] The portion of the first conductive part 12 extending from the first through hole 231 is bent toward the surface of the first wall 23 away from the main body part 11, so as to be welded to the first wall 23. Optionally, the first conductive part 12 and the first wall 23 are welded by laser or other means. During welding, a portion of the first conductive part 12 and a portion of the first wall 23 are heated and melted together to form a first welded portion W1.

[0129] In one example, the conductive element 30 is directly connected to the first wall 23, and the connection method between the conductive element 30 and the first wall 23 includes, but is not limited to, at least one of welding, snap-fitting or bonding.

[0130] In another example, the conductive element 30 establishes an electrical connection with the first wall 23 through an intermediate component.

[0131] The conductive element 30 covers the first through hole 231. The conductive element 30 can prevent the electrolyte inside the housing 20 from leaking, and can also prevent external particles, water and other impurities from entering the housing 20 through the first through hole 231, causing pollution or short circuit risk.

[0132] The conductive element 30 covers the first welded part W1. The conductive element 30 can prevent external particles, water and other impurities from adhering to the first welded part W1 and causing corrosion. It can also reduce the collision between the first welded part W1 and the external structure, and improve the welding strength and stability of the first conductive part 12 and the first wall 23.

[0133] The conductive component 30 comprises a conductive material. The material of the conductive component 30 can be the same as or different from that of the first wall 23. The conductive component 30 can replace the traditional electrode terminals and be welded to the busbar component, which helps to simplify the structure of the battery cell 6 and saves the space occupied by the electrode terminals inside the housing 20.

[0134] A portion of the first conductive part 12 passes through the first through hole 231 and extends to the outer side of the first wall 23 away from the main body 11. The portion of the first conductive part 12 extending to the outer side of the first wall 23 is welded to the first wall 23 to form a first welded part W1. This reduces the space occupied by the first conductive part 12 inside the housing 20, reduces the probability of welding particles generated during the welding operation falling into the housing 20, helps to reduce the risk of short circuits, and improves the reliability of the battery cell 6.

[0135] The isolator 40 can be a conductive component or an insulating component.

[0136] The separator 40 is at least partially disposed between the first welded portion W1 and the conductive component 30. The separator 40 reduces the heat transferred to the first welded portion W1 during welding of the conductive component 30 and the busbar component, minimizing the adverse effects of the welding operation on the first welded portion W1. It also reduces the risk of cracking or breakage of the first welded portion W1 leading to connection failure between the first conductive portion 12 and the first wall 23, thereby improving the reliability of the battery cell 6. The separator 40 has a low thermal conductivity, which helps reduce the heat transferred through it and improves its heat insulation effect.

[0137] In some embodiments, refer to Figures 7 to 9 Along the direction from the first wall 23 to the main body 11, the spacer 40 completely covers the first welded portion W1. In other words, in the same plane perpendicular to the first direction X, the orthographic projection of the first welded portion W1 lies within the orthographic projection of the spacer 40.

[0138] The orthographic projection of the first welded part W1 and the orthographic projection of the spacer 40 can completely overlap, and the orthographic projection of the spacer 40 can also exceed the orthographic projection range of the first welded part W1.

[0139] The isolator 40 completely separates the first welded part W1 from the conductive part 30 along the first direction X. The isolator 40 can prevent the heat generated during the welding of the conductive part 30 and the busbar component from being transferred to the first welded part W1, thereby reducing the adverse effects of the welding operation of the conductive part 30 and the busbar component on the first welded part W1.

[0140] In some embodiments, refer to Figure 10 In the same plane perpendicular to the first direction X, the orthographic projection of the separator 40 has a first outer contour S1, and the orthographic projection of the first welded part W1 has a second outer contour S2. The first outer contour S1 surrounds the outer periphery of the second outer contour S2, and the first outer contour S1 and the second outer contour S2 are spaced apart.

[0141] The shape of the first outer contour S1 can be various. For example, the first outer contour S1 can be a rectangle, a circle, a triangle or other shapes.

[0142] The shape of the second outer contour S2 can be various. For example, the second outer contour S2 can be a rectangle, a circle, a triangle or other shapes.

[0143] The shape of the first outer contour S1 and the shape of the second outer contour S2 can be the same or different.

[0144] The outer peripheral edge of the isolator 40 extends beyond the outer peripheral edge of the first welded portion W1. The isolator 40 can prevent the heat generated during the welding of the conductive component 30 and the busbar component from being transferred to the first welded portion W1 and its outer periphery, thereby expanding the range of heat transfer obstruction by the isolator 40, reducing the heat diffused to the first welded portion W1 during the welding of the conductive component 30 and the busbar component, and minimizing the adverse effects on the first welded portion W1.

[0145] In some embodiments, refer to Figure 10 The minimum distance between the first outer contour S1 and the second outer contour S2 is d, where 1mm≤d≤10mm.

[0146] The distance between the first outer contour S1 and the second outer contour S2 is the perpendicular distance between them. The distance between the first outer contour S1 and the second outer contour S2 can be the same or different in different regions.

[0147] Optionally, d is 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between two of these.

[0148] In this embodiment, setting d to be greater than or equal to 1 mm is beneficial to expanding the range of heat transfer obstruction by the insulating member 40, extending the diffusion path of heat from the conductive member 30 to the first welded part W1, and reducing the adverse effects on the first welded part W1; setting d to be less than or equal to 10 mm is beneficial to reducing interference between the insulating member 40 and other components, and reducing the risk of edge warping of the insulating member 40.

[0149] In some embodiments, refer to Figure 8 Along the direction from the main body 11 to the first wall 23, the insulating member 40 completely covers the surface of the conductive member 30 facing the electrode unit 10. In other words, in the same plane perpendicular to the first direction X, the orthographic projection of the conductive member 30 lies within the orthographic projection of the insulating member 40.

[0150] The isolator 40 can prevent the conductive component 30 from transferring heat to the side close to the first wall 23, reduce the adverse effects on the first welded part W1, the first conductive part 12 and the first wall 23 when the conductive component 30 and the busbar are welded, reduce the risk of cracking or breaking of the first welded part W1, and reduce the risk of bending deformation of the first conductive part 12 or the first wall 23.

[0151] In some embodiments, refer to Figure 7 and Figure 9 The isolator 40 is connected to at least one of the conductive member 30, the first conductive part 12, and the first welded part W1. This improves the installation stability of the isolator 40 and reduces the risk of the isolator 40 shifting or moving and becoming completely misaligned with the first welded part W1.

[0152] The isolator 40 may be connected to only one of the conductive member 30, the first conductive part 12 and the first welding part W1, or it may be connected to multiple of the conductive member 30, the first conductive part 12 and the first welding part W1.

[0153] In some embodiments, refer to Figure 7 and Figure 9 The isolator 40 is connected to the first conductive part 12 and / or the first welded part W1, and the conductive part 30 and the isolator 40 are spaced apart along the first direction X.

[0154] The insulating element 40 is connected to the first conductive part 12 and / or the first welded part W1 by bonding, coating or other means.

[0155] The spacing between the conductive element 30 and the isolating element 40 helps reduce interference between them, minimizes the adverse effects of the isolating element 40 on the connection between the conductive element 30 and the first wall 23, and reduces the risk of the first welded part W1 cracking under pressure. Furthermore, it also blocks heat conduction between the conductive element 30 and the isolating element 40, reducing the efficiency of heat transfer to the first welded part W1.

[0156] In some embodiments, refer to Figure 8 The isolator 40 is connected to the conductive member 30, and the isolator 40 and the first welded part W1 are spaced apart along the first direction X.

[0157] The insulating element 40 is attached to the conductive element 30 by adhesive, coating or other means.

[0158] The spacer 40 and the first welded part W1 are spaced apart, which helps to reduce interference between them and lowers the risk of the first welded part W1 cracking under pressure. Furthermore, it also blocks heat conduction between the spacer 40 and the first welded part W1, reducing the efficiency of heat transfer to the first welded part W1.

[0159] In some embodiments, the insulating member 40 is bonded to the first conductive portion 12, and the portion of the first conductive portion 12 bonded to the insulating member 40 surrounds the first weld portion W1.

[0160] The portion of the insulating member 40 that is bonded to the first conductive part 12 surrounds the outer periphery of the first welded part W1.

[0161] Compared to the first welded part W1, the surface of the first conductive part 12 is flatter. The isolation member 40 is bonded to the first conductive part 12, which helps to improve the bonding strength and reduce the risk of the isolation member 40 lifting.

[0162] The insulating member 40 and the first conductive part 12 are bonded around the first welding part W1, which helps to increase the bonding area and improve the bonding strength. It can also isolate the electrolyte on the outer periphery of the first welding part W1, reducing the possibility of electrolyte seeping between the first conductive part 12 and the insulating member 40, thereby reducing the risk of the insulating member 40 lifting.

[0163] In some embodiments, refer to Figure 11 The insulating member 40 includes a base layer 41 and an adhesive layer 42 stacked along a first direction X, the adhesive layer 42 being bonded to the conductive member 30 or the first conductive portion 12. The base layer 41 is made of polyimide or polyethylene terephthalate.

[0164] Polyimide has good heat resistance and is not easily deformed or softened at high temperatures. This helps maintain good mechanical strength when welding the conductive component 30 and the busbar component, and improves the effect of preventing heat transfer to the first welded part W1.

[0165] Polyethylene terephthalate is low in cost and easy to process, which helps to reduce the cost of the battery cell 6 while hindering heat transfer to the first welded part W1.

[0166] In some embodiments, the thermal conductivity of the insulating element 40 is less than or equal to 3.0 W / (m·K). A lower thermal conductivity of the insulating element 40 helps reduce the heat transferred through it and improves its insulation effect.

[0167] In some embodiments, the melting point of the insulating member 40 is higher than that of the conductive member 30.

[0168] Alternatively, the spacer 40 may be a metal component, for example, the spacer 40 may be made of steel.

[0169] Optionally, the separator 40 can be a non-metallic component, for example, the separator 40 includes polyimide adhesive or mica, etc.

[0170] The high melting point of the insulating element 40 helps reduce the risk of melting during welding of the conductive element 30 and the busbar component, improves the structural stability of the insulating element 40, and thus improves the heat insulation effect of the insulating element 40.

[0171] In some embodiments, the melting point of the separator 40 is greater than or equal to 250°C.

[0172] The high melting point of the insulating element 40 helps reduce the risk of melting after being heated, improves the structural stability of the insulating element 40, and thus improves the heat insulation effect of the insulating element 40.

[0173] In some embodiments, the thickness of the spacer 40 is 20 μm-50 μm.

[0174] Optionally, the thickness of the spacer 40 is 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm, 40 μm, 42 μm, 44 μm, 46 μm, 48 μm, 50 μm, or any value between two of these.

[0175] In this embodiment, the thickness of the separator 40 is set to be greater than or equal to 20 μm, which is beneficial to improving the heat insulation effect of the separator 40, enhancing its structural strength, and reducing the risk of breakage. In another embodiment, the thickness of the separator 40 is set to be less than or equal to 50 μm, which is beneficial to reducing the space occupied by the separator 40 in the first direction X, and minimizing the impact of the separator 40's placement on the energy density of the battery cell 6.

[0176] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13Along the first direction X, a recess 232 is provided on the side of the first wall 23 away from the main body 11. The first wall 23 includes a first part 233 and a second part 234, the second part 234 corresponding to the recess 232 along the first direction X. A first through hole 231 communicates with the recess 232, a portion of the first conductive part 12 is accommodated in the recess 232 and welded to the second part 234 to form a first welded part W1.

[0177] In one example, the first portion 233 is directly connected to the second portion 234. In another example, the first wall 23 includes a third portion that connects the first and second portions. The third portion is bent relative to the first portion 233 and also bent relative to the second portion 234. A first through-hole 231 extends through either the second portion 234 or the third portion.

[0178] Along the first direction X, the surface of the first part 233 facing away from the main body 11 is farther away from the main body 11 than the surface of the second part 234 facing away from the main body 11. The surface of the first part 233 facing the main body 11 can be flush with the surface of the second part 234 facing the main body 11, and the surface of the first part 233 facing the main body 11 can also be farther away from the main body 11 than the surface of the second part 234 facing the main body 11.

[0179] The portion of the first conductive part 12 that protrudes from the first through hole 231 can be entirely accommodated in the recess 232, or it can be partially accommodated in the recess 232.

[0180] The recess 232 provides at least a partial accommodating space for the portion of the first conductive part 12 that protrudes through the first through hole 231. The first conductive part 12 and the first wall 23 share a portion of the space in the first direction X, which can reduce the extra space occupied by the first conductive part 12 on the outside of the housing 20, thereby increasing the energy density of the battery cell 6.

[0181] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 The first through hole 231 penetrates the second part 234 along the first direction X. In this way, the height difference in the first direction X between the position where the first conductive part 12 protrudes from the first through hole 231 and the position where the first conductive part 12 and the first wall 23 are welded can be reduced, the phenomenon of the first conductive part 12 arching in the recess 232 can be reduced, the space occupied by the first conductive part 12 in the first direction X in the recess 232 can be reduced, and the degree of bending of the first conductive part 12 can be reduced, thus reducing the risk of cracking of the first conductive part 12.

[0182] In some alternative embodiments, the first wall 23 includes a third portion connecting the first and second portions, the third portion being bent relative to the first portion 233 and the second portion 234. The second portion 234 and the third portion form a first through-hole 231; or, the first through-hole 231 penetrates the region of the third portion near the second portion 234.

[0183] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 At least a portion of the first welded portion W1 is accommodated in the recess 232, which reduces the extra space occupied by the first welded portion W1 on the outside of the housing 20, thereby increasing the energy density of the battery cell 6.

[0184] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 At least a portion of the spacer 40 is accommodated in the recess 232.

[0185] The spacer 40 may be entirely contained in the recess 232, or only a portion of the spacer 40 may be contained in the recess 232. For example, another portion of the spacer 40 may extend beyond the recess 232 in the direction from the main body 11 toward the first wall 23.

[0186] The recess 232 provides at least a partial accommodating space for the separator 40. The separator 40 and the first wall 23 share at least a portion of the space in the first direction X, which can reduce the extra space occupied by the separator 40 on the outside of the housing 20, thereby increasing the energy density of the battery cell 6.

[0187] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 The isolator 40 is entirely accommodated in the recess 232, and at least a portion of the conductive element 30 is accommodated in the recess 232.

[0188] The conductive element 30 may be entirely housed in the recess 232, or only a portion of the conductive element 30 may be housed in the recess 232. For example, another portion of the conductive element 30 may extend beyond the recess 232 in the direction from the main body 11 toward the first wall 23.

[0189] The recess 232 provides a space for at least a portion of the conductive member 30, the separator 40, the first welded portion W1, and a portion of the first conductive portion 12. The conductive member 30, the separator 40, the first welded portion W1, and the first conductive portion 12 all share a portion of the space in the first direction X with the first wall 23, which is beneficial to improving the structural compactness of the battery cell 6 and increasing the energy density.

[0190] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 The second part 234 includes a first sub-part 2341 and a second sub-part 2342. Along the first direction X, the first surface 2341a of the first sub-part 2341 facing away from the main body 11 is closer to the main body 11 than the second surface 2342a of the second sub-part 2342 facing away from the main body 11. A first conductive part 12 is welded to the first sub-part 2341 to form a first welded part W1. In the same plane perpendicular to the first direction X, the orthographic projection of the portion of the first conductive part 12 housed in the recess 232 is spaced apart from the orthographic projection of the second sub-part 2342.

[0191] Optionally, along the first direction X, the surface of the first sub-part 2341 facing the main body 11 is closer to the main body 11 than the surface of the second sub-part 2342 facing the main body 11. This increases the thickness of the first sub-part 2341, reduces the impact of the recess 232 on the structural strength of the first sub-part 2341, and lowers the risk of deformation.

[0192] Alternatively, along the first direction X, the surface of the first sub-part 2341 facing the main body 11 may also be flush with the surface of the second sub-part 2342 facing the main body 11.

[0193] Along the first direction X, the thickness of the first sub-part 2341 and the thickness of the second sub-part 2342 can be the same or different.

[0194] In one example, the first sub-part 2341 is connected to the first part 233.

[0195] In another example, the first sub-part 2341 and the first part 233 are connected by other parts of the first wall 23.

[0196] Optionally, the first sub-part 2341 surrounds the outer periphery of the second sub-part 2342.

[0197] Compared to the portion of recess 232 corresponding to the second sub-part 2342, the portion of recess 232 corresponding to the first sub-part 2341 is more recessed, providing more space for the first conductive part 12 and the first welding part W1 in the first direction X. The first conductive part 12 and the second sub-part 2342 do not overlap along the first direction X, and can share some space in the first direction X, which improves space utilization.

[0198] The portion of the first wall 23 corresponding to the recess 232 is stepped. During the formation of the recess 232, a shallower second sub-part 2342 is formed first by stamping, cutting or other means, and then a deeper first sub-part 2341 is formed by stamping, cutting or other means. This helps to reduce the forming difficulty of the recess 232 and reduce the risk of breakage during the forming process of the first wall 23.

[0199] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 The first through hole 231 is formed by a first sub-part 2341 and a second sub-part 2342. The first conductive part 12 passes through the first through hole 231 and then bends towards the first sub-part 2341. On the one hand, this reduces the height difference in the first direction X between the position where the first conductive part 12 exits from the first through hole 231 and the position where the first conductive part 12 is welded to the first wall 23, thus reducing the arching of the first conductive part 12 within the recess 232, reducing the space occupied by the first conductive part 12 in the first direction X within the recess 232, and also reducing the degree of bending of the first conductive part 12, thereby reducing the risk of cracking. On the other hand, it also helps to reduce the size of the first sub-part 2341, reducing the impact of the arrangement of the first sub-part 2341 on the structural strength of the first wall 23.

[0200] In some alternative embodiments, the first through hole 231 may also extend through the first sub-part 2341.

[0201] In some embodiments, refer to Figures 7 to 9 , Figure 12 and Figure 13 The isolator 40 is connected to the first conductive part 12. In the same plane perpendicular to the first direction X, the orthographic projection of the isolator 40 and the orthographic projection of the second sub-part 2342 are spaced apart.

[0202] Optionally, the edge of the insulating member 40 is connected to the first conductive part 12 to reduce the risk of the insulating member 40 lifting.

[0203] The portion of the first conductive part 12 located on the first wall 23 away from the main body 11 may have a height difference with the second sub-part 2342 in the first direction X. The orthographic projection of the isolator 40 and the orthographic projection of the second sub-part 2342 do not overlap. The isolator 40 is not connected to the second sub-part 2342, which helps to improve the flatness of the isolator 40, reduce the risk of wrinkles or warping of the isolator 40, and improve the connection stability between the isolator 40 and the first conductive part 12.

[0204] In some embodiments, refer to Figure 12 and Figure 13 The second part 234 includes a third sub-part 2343, which connects the first part 233 and the second sub-part 2342. Along the first direction X, the third sub-part 2343 is further away from the main body 11 than the second surface 2342a. Along the direction from the main body 11 towards the first wall 23, the spacer 40 does not extend beyond the third surface 2343a, and the conductive element 30 is connected to the third surface 2343a.

[0205] Optionally, along the first direction X, the surface of the second sub-part 2342 facing the main body 11 is closer to the main body 11 than the surface of the third sub-part 2343 facing the main body 11. This increases the thickness of the second sub-part 2342, reduces the impact of the recess 232 on the structural strength of the second sub-part 2342, and lowers the risk of deformation.

[0206] Alternatively, along the first direction X, the surface of the second sub-part 2342 facing the main body 11 may also be flush with the surface of the third sub-part 2343 facing the main body 11.

[0207] Optionally, along the first direction X, the surface of the third sub-part 2343 facing the main body 11 is flush with the surface of the first part 233 facing the main body 11.

[0208] Along the first direction X, the surface of the conductive element 30 facing the main body 11 contacts the third surface 2343a, and the conductive element 30 can be supported by the third surface 2343a.

[0209] The connection methods between the conductive element 30 and the third surface 2343a include, but are not limited to, welding or bonding.

[0210] Optionally, the conductive element 30 is spaced apart from the first part 233 to facilitate the welding of the conductive element 30 to the second part 234. The gap between the conductive element 30 and the first part 233 can also accommodate the welded part between the conductive element 30 and the third surface 2343a.

[0211] The conductive element 30 is connected to the third surface 2343a, and a portion of the conductive element 30 is accommodated in the recess 232, sharing the space in the first direction X with the first wall 23, which helps to improve space utilization. The isolator 40 does not extend beyond the third surface 2343a, which helps to reduce interference between the isolator 40 and the conductive element 30.

[0212] In some embodiments, refer to Figure 12 and Figure 13 Along the first direction X, the first portion 233 includes a fourth surface 233a facing the main body portion 11, and along the direction of the first wall 23 pointing towards the main body portion 11, the second portion 234 at least partially protrudes from the fourth surface 233a.

[0213] In one example, along the direction from the first wall 23 toward the main body 11, only a portion of the first sub-part 2341 extends beyond the fourth surface 233a. Along the first direction X, the surface of the second sub-part 2342 near the main body 11 may be flush with the fourth surface 233a.

[0214] In another example, along the direction from the first wall 23 towards the main body 11, a portion of the first sub-part 2341 and a portion of the second sub-part 2342 both extend beyond the fourth surface 233a. The dimensions by which the first sub-part 2341 extends beyond the fourth surface 233a can be the same as or different from the dimensions by which the second sub-part 2342 extends beyond the fourth surface 233a. Optionally, the dimension by which the first sub-part 2341 extends beyond the fourth surface 233a is greater than the dimension by which the second sub-part 2342 extends beyond the fourth surface 233a.

[0215] Along the direction from the first wall 23 to the main body 11, a portion of the third sub-part 2343 may extend beyond the fourth surface 233a, or the third sub-part 2343 may not extend beyond the fourth surface 233a.

[0216] The second part 234 protrudes at least partially from the fourth surface 233a, which helps to increase the thickness of the second part 234, reduce the impact of the recess 232 on the structural strength of the first wall 23, and reduce the risk of deformation of the first wall 23.

[0217] In some embodiments, refer to Figure 12 and Figure 13 The battery cell 6 includes a first insulating member 50, at least a portion of which is disposed between the main body portion 11 and the first wall 23 along a first direction X. The first insulating member 50 has a second through hole 51 extending along the first direction X, and a first conductive portion 12 passes through the second through hole 51. A portion of the second part 234 protruding from the fourth surface 233a is at least partially accommodated in the second through hole 51.

[0218] The first insulating member 50 is used to insulate and isolate the main body 11 and the first wall 23. Optionally, the first insulating member 50 is a plastic part.

[0219] Optionally, the first insulating member 50 is connected to at least one of the first wall 23 and the main body 11 to improve the installation firmness of the first insulating member 50, thereby reducing the displacement or shaking of the first insulating member 50.

[0220] Optionally, in the same plane perpendicular to the first direction X, the orthographic projection of the first through hole 231 and the orthographic projection of the second through hole 51 at least partially overlap, so that the first conductive part 12 passes through the second through hole 51 and the first through hole 231 in sequence, reducing the bending of the first conductive part 12 and reducing the risk of cracking or breaking.

[0221] The embodiments of this application can make full use of the space occupied by the first insulating member 50 in the first direction X to accommodate at least a portion of the second part 234 protruding from the fourth surface 233a, which is beneficial to improve space utilization and reduce the extra space occupied by the second part 234 inside the casing 20, thereby increasing the energy density of the battery cell 6.

[0222] In some embodiments, refer to Figures 7 to 9 The battery cell 6 includes two first conductive parts 12, and the first wall 23 is provided with two first through holes 231, with the two first conductive parts 12 respectively passing through the two first through holes 231.

[0223] In one example, the battery cell 6 includes two electrode units 10, each electrode unit 10 including a first conductive portion 12. The first conductive portions 12 of the two electrode units 10 are respectively led out from the main body portions 11 of the two electrode units 10. The main body portions 11 of the two electrode units 10 are stacked, and the stacking direction of the main body portions 11 of the two electrode units 10 is perpendicular to the first direction X.

[0224] In another example, the battery cell 6 includes an electrode unit 10, which includes two first conductive portions 12. Both first conductive portions 12 extend from the body portion 11 of the electrode unit 10.

[0225] The arrangement direction of the two first conductive parts 12 is the same as the arrangement direction of the two first through holes 231, so that they can pass through the two first through holes 231 respectively. Optionally, the two first through holes 231 are arranged along the second direction Y, which is perpendicular to the first direction X.

[0226] The two first through holes 231 are spaced apart, which helps to reduce interference between the two first conductive parts 12. Along the first direction X, the two first conductive parts 12 do not overlap.

[0227] In one example, two first through holes 231 are located on opposite sides of the first sub-part 2341, and both first through holes 231 are enclosed by the first sub-part 2341 and the second sub-part 2342.

[0228] In another example, both first through holes 231 can penetrate the first sub-part 2341.

[0229] The two first conductive parts 12 of the battery cell 6 are arranged separately, which helps to reduce the thickness of the individual first conductive part 12 and reduce the space occupied by the first conductive part 12 in the first direction X inside the housing 20, thereby improving the energy density of the battery cell 6.

[0230] In some embodiments, refer to Figures 7 to 9 The outer casing 20 includes two second walls 24 disposed along a second direction Y, which is perpendicular to the first direction X. The first conductive part 12 includes a first tab 121 connected to the main body part 11. The first tab 121 includes a plurality of first tab layers (not shown in the figure), and the first tab layers of the two first conductive parts 12 are respectively converged toward the two second walls 24.

[0231] The second direction Y is parallel to the thickness direction of electrode unit 10.

[0232] Multiple first tab layers of the same first conductive part 12 are stacked together in a direction close to the same second wall 24, and then extend in a direction gradually away from the second wall 24. The portion of the first tab 121 located inside the outer casing 20 is generally C-shaped.

[0233] In this embodiment, the first electrode tab 121 is bent in a C-shape, which can extend the overall length of the first electrode tab 121 and give the first electrode tab 121 a certain redundancy for being stretched and deformed. This helps to alleviate the pulling effect on the first electrode tab 121 when the first conductive part 12 passes through the first through hole 231, reduce the tensile stress on the first electrode tab 121, and reduce the risk of the first electrode tab 121 being pulled off.

[0234] In some embodiments, refer to Figure 14 Two first conductive portions 12 are respectively welded to the first wall 23 to form two first welded portions W1. The battery cell 6 includes two separators 40, which are respectively connected to the two first conductive portions 12. Along the first direction X, at least a portion of the two separators 40 is located between the two first welded portions W1 and the conductive portions 30.

[0235] Optionally, along the direction from the first wall 23 to the main body 11, the two spacers 40 respectively cover the two first welded parts W1.

[0236] Optionally, the two spacers 40 do not overlap along the first direction X. The two spacers 40 are arranged separately along the arrangement direction of the two first conductive portions 12.

[0237] In this embodiment, two first welding parts W1 and conductive parts 30 are isolated by two isolation members 40 respectively, which can reduce the size of a single isolation member 40 and reduce the difficulty of connecting the isolation member 40 and the first conductive part 12.

[0238] In some embodiments, refer to Figure 14 In the same plane perpendicular to the first direction X, the portions of the two first conductive parts 12 located on the side of the first wall 23 away from the main body 11 each have a first orthographic projection, and the isolation member 40 has a second orthographic projection. The second orthographic projections of the two isolation members 40 are respectively located within the two first orthographic projections.

[0239] The edge of the isolator 40 does not extend beyond the portion of the first conductive part 12 that protrudes from the first through hole 231. The edge of the isolator 40 can be connected to the first conductive part 12, which helps to reduce the risk of the edge of the isolator 40 lifting and improves the connection stability between the isolator 40 and the first conductive part 12.

[0240] In some embodiments, refer to Figure 7Two first conductive parts 12 are respectively welded to the first wall 23 to form two first welded parts W1. Along the first direction X, a part of the isolation member 40 is disposed between one of the first welded parts W1 and the conductive member 30, and another part of the isolation member 40 is disposed between the other first welded part W1 and the conductive member 30.

[0241] Optionally, along the direction from the first wall 23 to the main body 11, the spacer 40 completely covers the two first welded parts W1.

[0242] The isolator 40 is connected to the two first conductive parts 12, or the isolator 40 is connected to the conductive part 30.

[0243] In this embodiment, a separator 40 is used to isolate the two first welded parts W1 from the conductive part 30, which helps to simplify the structure and assembly process of the battery cell 6.

[0244] In some embodiments, the first conductive portion 12 includes a first tab 121 and a first adapter portion 122. The first tab 121 is connected to the main body portion 11, and the first adapter portion 122 is welded to the first tab 121. The first adapter portion 122 passes through the first through hole 231, and a portion of the first adapter portion 122 is located on the side of the first wall 23 away from the main body portion 11 and is welded to the first wall 23 to form a first weld portion W1.

[0245] Optionally, the first electrode tab 121 is entirely located on the side of the first wall 23 near the main body 11. Alternatively, a portion of the first electrode tab 121 is located on the side of the first wall 23 near the main body 11, and another portion of the first electrode tab 121 can be accommodated in the first through hole 231.

[0246] A portion of the first adapter 122 is located on the side of the first wall 23 near the main body 11 and is welded to the first tab 121. A portion of the first adapter 122 extends through the first through hole 231 and is welded to the first wall 23.

[0247] The first tab 121 is relatively soft, and it typically comprises multiple tab layers. Therefore, it is difficult for the first tab 121 to pass through the first through hole 231, and the first tab 121 is more prone to cracking due to concentrated stress. In this embodiment, the first adapter 122 is inserted into the first through hole 231, which helps to reduce assembly difficulty, reduce interference between the first tab 121 and the first wall 23, and reduce the risk of the first tab 121 cracking due to concentrated stress.

[0248] In some embodiments, refer to Figures 12 to 14 The first adapter 122 includes two adapter layers 1221. The end of the first tab 121 away from the main body 11 is located between the two adapter layers 1221 and is welded to the two adapter layers 1221.

[0249] The welding methods for the transition layer 1221 and the first tab 121 include, but are not limited to, ultrasonic welding or laser welding.

[0250] The thicknesses of the two transition layers 1221 can be the same or different.

[0251] The two transition layers 1221 restrict and protect the first electrode tab 121, which helps reduce the risk of short circuit caused by the end of the first electrode tab 121 away from the main body 11 being inserted into the main body 11. The first electrode tab 121 is welded between the two transition layers 1221, which helps to improve the welding strength and stability and reduce the damage to the first electrode tab 121 caused by welding heat.

[0252] In some embodiments, the two transition layers 1221 are partially stacked and welded to the first wall 23 on the side of the first wall 23 away from the main body 11.

[0253] The welding methods for the transition layer 1221 and the first wall 23 include, but are not limited to, ultrasonic welding or laser welding.

[0254] The two transition layers 1221 are stacked and welded to the first wall 23, which is beneficial to the welding strength and stability.

[0255] In other embodiments, reference is made to Figure 15 The first conductive part 12 includes a first tab 121, which is disposed in the first through hole 231. A portion of the first tab 121 is located on the side of the first wall 23 away from the main body 11 and is welded to the first wall 23 to form a first welded part W1.

[0256] In some embodiments, refer to Figure 6 The outer casing 20 includes a third wall 25, and the main body 11 is disposed between the first wall 23 and the third wall 25 along the first direction X. The battery cell 6 includes an electrode terminal 60 disposed on the third wall 25. The electrode unit 10 includes a second conductive part 13, which extends from the main body 11 and is electrically connected to the electrode terminal 60.

[0257] At least a portion of the second conductive portion 13 is located between the main body portion 11 and the third wall 25. In one example, the second conductive portion 13 extends from the side of the main body portion 11 near the third wall 25 along a first direction X. In other examples, the second conductive portion 13 may also extend from other sides of the main body portion 11, with a portion of the second conductive portion 13 extending to the side of the main body portion 11 near the third wall 25.

[0258] The second conductive part 13 is the power extraction structure of the electrode unit 10. The first conductive part 12 and the second conductive part 13 have opposite polarities.

[0259] The second conductive part 13 includes at least a second tab 131, which is connected to the main body part 11. Optionally, the second conductive part 13 may also include a transition part connected to the second tab 131.

[0260] The first electrode 121 and the second electrode 131 have opposite polarities. One of the first electrode 121 and the second electrode 131 is a positive electrode and is connected to the positive current collector, while the other of the first electrode 121 and the second electrode 131 is a negative electrode and is connected to the negative current collector.

[0261] At least a portion of the first conductive part 12 and at least a portion of the second conductive part 13 are located on both sides of the main body 11 along the first direction X, respectively occupying space in the first direction X and affecting the energy density of the battery cell 6. In this embodiment, a portion of the first conductive part 12 extends to the outside of the first wall 23 and is welded to the first wall 23. This helps to eliminate one electrode terminal, reduce the space occupied by the first conductive part 12 in the housing 20, reduce welding difficulty, and reduce the impact of the space occupied by the first conductive part 12 and the second conductive part 13 in the first direction X on the energy density of the battery cell 6.

[0262] In some embodiments, refer to Figure 6 The second conductive part 13 includes a second tab 131, which is connected to the main body part 11. The battery cell 6 includes two second conductive parts 13, and the second tabs 131 of the two second conductive parts 13 are disposed separately along a second direction Y, which is perpendicular to the first direction X.

[0263] In one example, the second conductive part 13 further includes a second adapter part, which is soldered to the second tab 131 and the electrode terminal 60.

[0264] In another example, the battery cell 6 includes an adapter 80, which is welded to the electrode terminal 60 and to the second tab 131 of all electrode cells 10.

[0265] In one example, refer to Figure 4 and Figure 6 The battery cell 6 includes two electrode units 10, each electrode unit 10 including a second conductive portion 13. The second conductive portions 13 of the two electrode units 10 are respectively led out from the main body portions 11 of the two electrode units 10. The main body portions 11 of the two electrode units 10 are stacked, and the stacking direction of the main body portions 11 of the two electrode units 10 is perpendicular to the first direction X.

[0266] In another example, the battery cell 6 includes an electrode unit 10, which includes two second conductive portions 13. Both second conductive portions 13 extend from the main body portion 11 of the electrode unit 10.

[0267] The two second conductive parts 13 of the battery cell 6 are arranged separately, which helps to reduce the thickness of the individual second conductive part 13 and reduce the space occupied by the second conductive part 13 in the first direction X inside the housing 20, thereby improving the energy density of the battery cell 6.

[0268] In some embodiments, refer to Figure 4 and Figure 6 The battery cell 6 includes a second insulating member 70, at least a portion of which is disposed between the main body 11 and the third wall 25. The second insulating member 70 serves to insulate and isolate the main body 11 and the third wall 25.

[0269] In some embodiments, refer to Figure 4 The outer casing 20 includes a casing 21 and two end caps 22. The casing 21 has casing openings 211 on both sides along the first direction X. The two end caps 22 are connected to the casing 21 and cover the two casing openings 211 respectively. The first wall 23 is one of the end caps 22, and the third wall 25 is the other end cap 22.

[0270] During assembly, firstly, the second conductive part 13 is welded to the electrode terminal 60, or firstly, the adapter 80 is welded to the second conductive part 13 and the electrode terminal 60. Then, the electrode unit 10 is installed into the housing 21, and the third wall 25 and the housing 21 are welded together. After the electrode unit 10 is installed in the housing, a portion of the first conductive part 12 is passed through the first through hole 231 of the first wall 23, the first wall 23 is welded to the housing 21, and the first conductive part 12 is welded to the first wall 23 (the welding order of the first wall 23 and the housing 21, and the welding order of the first conductive part 12 and the first wall 23 can be interchanged). Finally, the conductive element 30 can be connected to the first wall 23 to cover the first through hole 231. Passing the first conductive part 12 through the first through hole 231 before welding the first wall 23 and the housing 21 helps to reduce assembly difficulty and improve assembly efficiency.

[0271] In other embodiments, the housing 20 includes a housing 21 and an end cap 22. The housing 21 has a housing opening 211 on one side along the first direction X, and the end cap 22 is connected to the housing 21 and covers the housing opening 211. The third wall 25 is the end cap 22, and the housing 21 is integrally formed and includes a first wall 23.

[0272] During assembly, the second conductive part 13 is first welded to the electrode terminal 60, or the adapter 80 is first welded to the second conductive part 13 and the electrode terminal 60; then, the electrode unit 10 is installed into the housing 21, and the third wall 25 and the housing 21 are welded together; during the process of inserting the electrode unit 10 into the housing, a portion of the first conductive part 12 is passed through the first through hole 231 of the first wall 23, and the first conductive part 12 is welded to the first wall 23; finally, the conductive part 30 can be connected to the first wall 23 to cover the first through hole 231.

[0273] In some embodiments, refer to Figure 4 The outer casing 20 includes two fourth walls 26 arranged along a third direction Z, with the first direction X, the second direction Y, and the third direction Z being perpendicular to each other. The fourth walls 26 connect to the two second walls 24, and the fourth walls 26 connect to the first wall 23 and the third wall 25. Optionally, the two second walls 24 and the two fourth walls 26 are integrally formed to form the casing 21. The first wall 23, serving as one end cap 22, is welded to the casing 21, and the third wall 25, serving as the other end cap 22, is welded to the casing 21.

[0274] According to a second aspect of this application, embodiments of this application also provide a battery device 2, referring to... Figure 2 The battery device 2 includes a battery cell 6 provided according to any embodiment of the first aspect of this application.

[0275] In some embodiments, refer to Figure 16 The battery device 2 includes a current-collecting component 7, which is welded to the conductive component 30 to form a second welded portion W2. In the same plane perpendicular to the first direction X, the orthographic projection of the second welded portion W2 and the orthographic projection of the first welded portion W1 are at least partially offset.

[0276] Optionally, in the same plane perpendicular to the first direction X, the orthographic projection of the second welded part W2 and the orthographic projection of the first welded part W1 do not overlap.

[0277] Optionally, a portion of the spacer 40 is located between the second welded portion W2 and the first wall 23.

[0278] The second welding part W2 and the first welding part W1 are at least partially staggered, which helps to increase the distance between the second welding part W2 and the first welding part W1, reduce the heat transferred to the first welding part W1 during the welding of the busbar component 7 and the conductive component 30, and reduce the adverse effects on the first welding part W1.

[0279] In some embodiments, refer to Figure 16 The battery device 2 includes a current-collecting component 7, which is welded to the conductive component 30 to form a second welded portion W2. In the same plane perpendicular to the first direction X, the orthographic projection of the first welded portion W1 and the orthographic projection of the second welded portion W2 are both located within the orthographic projection of the separator 40.

[0280] In the same plane perpendicular to the first direction X, the orthographic projection of the second welded part W2 and the orthographic projection of the first welded part W1 may at least partially overlap, or they may not overlap.

[0281] Along the direction from the main body 11 to the first wall 23, the isolation member 40 completely covers the second welded part W2, which can reduce the heat transferred from the second welded part W2 to the side of the conductive member 30 closer to the main body 11; the isolation member 40 completely separates the first welded part W1 and the second welded part W2, which helps to reduce the heat transferred to the first welded part W1 and reduce the adverse effects on the first welded part W1.

[0282] According to a third aspect of this application, embodiments of this application also provide an electrical device, which includes a battery device 2 provided according to any embodiment of the second aspect of this application, the battery device 2 being used to provide electrical energy.

[0283] This application provides a battery cell 6, which includes an electrode unit 10, a housing 20, a conductive element 30, a separator 40, and electrode terminals 60. The housing 20 includes a first wall 23 and a third wall 25 disposed opposite each other along a first direction X. The first wall 23 has a first through hole 231, and the electrode terminals 60 are disposed on the third wall 25. The electrode unit 10 includes a main body 11, two first conductive parts 12, and two second conductive parts 13. The main body 11 is housed within the housing 20 and located between the first wall 23 and the third wall 25. The first conductive parts 12 and the second conductive parts 13 extend from both sides of the main body 11 along the first direction X. The first conductive parts 12 pass through the first through hole 231, and a portion of the first conductive parts 12 is located on the side of the first wall 23 away from the main body 11 and is welded to the first wall 23 to form a first welded portion W1. The second conductive parts 13 are connected to the electrode terminals 60. Two first conductive portions 12 are separated along a second direction Y, and two second conductive portions 13 are separated along a second direction Y, which is perpendicular to the first direction X. A conductive member 30 is disposed on the side of the first wall 23 away from the main body 11 and covers the first through hole 231 and the first welded portion W1. The conductive member 30 is electrically connected to the first wall 23 and is used for welding to the busbar component. An isolator 40 is bonded to the first conductive portion 12, and at least a portion of the isolator 40 is disposed between the conductive member 30 and the first welded portion W1 along the first direction X. Along the direction from the first wall 23 to the main body 11, the isolator 40 completely covers the first welded portion W1.

[0284] The insulating member 40 includes a base layer 41 and an adhesive layer 42 stacked along a first direction X, the adhesive layer 42 being bonded to the first conductive portion 12. The base layer 41 is made of polyimide or polyethylene terephthalate.

[0285] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer casing includes a first wall, the first wall having a first through hole; An electrode unit includes a main body and a first conductive part. The main body is housed within the housing and is located on one side of the first wall along a first direction. The first conductive part extends from the main body and passes through the first through hole. A portion of the first conductive part is located on the side of the first wall away from the main body and is welded to the first wall to form a first welded part. A conductive element is disposed on the side of the first wall away from the main body and covers the first through hole and the first welded portion. The conductive element is electrically connected to the first wall and is used for welding to a busbar component. An isolation element, along the first direction, at least a portion of which is disposed between the conductive element and the first welded portion, wherein the thermal conductivity of the isolation element is less than that of the conductive element.

2. The battery cell according to claim 1, characterized in that, Along the direction from the first wall toward the main body, the spacer completely covers the first welded portion.

3. The battery cell according to claim 1 or 2, characterized in that, In the same plane perpendicular to the first direction, the orthographic projection of the separator has a first outer contour, and the orthographic projection of the first weld has a second outer contour. The first outer contour surrounds the outer periphery of the second outer contour, and the first outer contour and the second outer contour are spaced apart.

4. The battery cell according to claim 3, characterized in that, The minimum distance between the first outer contour and the second outer contour is d, where 1mm ≤ d ≤ 10mm.

5. The battery cell according to claim 1, characterized in that, Along the direction from the main body to the first wall, the insulating member completely covers the surface of the conductive member facing the electrode unit.

6. The battery cell according to claim 1, characterized in that, The insulating element is connected to at least one of the conductive element, the first conductive portion, and the first welded portion.

7. The battery cell according to claim 1, characterized in that, The insulating member is connected to the first conductive part and / or the first welded part, and the conductive member and the insulating member are spaced apart along the first direction; or The insulating member is connected to the conductive member, and the insulating member and the first welded part are spaced apart along the first direction.

8. The battery cell according to claim 1, characterized in that, The insulating element is bonded to the first conductive portion, and the portion of the first conductive portion bonded to the insulating element surrounds the first weld portion.

9. The battery cell according to claim 1, characterized in that, The insulating member includes a base layer and an adhesive layer stacked along the first direction, the adhesive layer being bonded to the conductive member or the first conductive portion; The base layer material includes polyimide or polyethylene terephthalate.

10. The battery cell according to claim 1, characterized in that, The thermal conductivity of the insulating element is less than or equal to 3.0 W / (m·K).

11. The battery cell according to claim 1, characterized in that, The melting point of the insulating element is higher than that of the conductive element.

12. The battery cell according to claim 1, characterized in that, The melting point of the insulating element is greater than or equal to 250°C.

13. The battery cell according to claim 1, characterized in that, The thickness of the insulating element is 20μm-50μm.

14. The battery cell according to claim 1, characterized in that, Along the first direction, a recess is provided on the side of the first wall away from the main body. The first wall includes a first part and a second part, and the second part corresponds to the recess along the first direction. The first through hole communicates with the recess, a portion of the first conductive portion is accommodated in the recess, and is welded to the second portion to form the first welded portion.

15. The battery cell according to claim 14, characterized in that, The first through hole penetrates the second portion along the first direction.

16. The battery cell according to claim 14 or 15, characterized in that, At least a portion of the spacer is accommodated in the recess.

17. The battery cell according to claim 14, characterized in that, The insulating member is entirely housed in the recess, and at least a portion of the conductive member is housed in the recess.

18. The battery cell according to claim 14, characterized in that, The second part includes a first sub-part and a second sub-part, wherein along the first direction, the first sub-part is closer to the main body than the second sub-part is closer to the main body than the second sub-part is closer to the main body than the second sub-part is. The first conductive part is welded to the first sub-part to form the first welded part. In the same plane perpendicular to the first direction, the orthographic projection of the portion of the first conductive part housed in the recess is spaced apart from the orthographic projection of the second sub-part.

19. The battery cell according to claim 18, characterized in that, The first through hole is formed by the first sub-part and the second sub-part.

20. The battery cell according to claim 18, characterized in that, The isolator is connected to the first conductive part, and in the same plane perpendicular to the first direction, the orthographic projection of the isolator and the orthographic projection of the second sub-part are spaced apart.

21. The battery cell according to claim 18, characterized in that, The second part includes a third sub-part that connects the first part and the second sub-part. Along the first direction, the third surface of the third sub-part is further away from the main body than the second surface. Along the direction from the main body to the first wall, the insulating member does not extend beyond the third surface, and the conductive member is connected to the third surface.

22. The battery cell according to claim 14, characterized in that, Along the first direction, the first portion includes a fourth surface facing the main body portion, and along the direction from the first wall toward the main body portion, the second portion at least partially protrudes from the fourth surface.

23. The battery cell according to claim 22, characterized in that, The battery cell includes a first insulating member, and at least a portion of the first insulating member is disposed between the main body and the first wall along the first direction; The first insulating member has a second through hole extending along the first direction, the first conductive part passes through the second through hole, and the portion of the second part protruding from the fourth surface is at least partially accommodated in the second through hole.

24. The battery cell according to claim 1, characterized in that, The battery cell includes two first conductive parts, and the first wall is provided with two first through holes, with the two first conductive parts respectively passing through the two first through holes.

25. The battery cell according to claim 24, characterized in that, The outer casing includes two second walls disposed along a second direction, the second direction being perpendicular to the first direction; The first conductive part includes a first tab connected to the main body. The first tab includes a plurality of first tab layers, and the first tab layers of the two first conductive parts respectively converge toward the two second walls.

26. The battery cell according to claim 24 or 25, characterized in that, The two first conductive parts are respectively welded to the first wall to form two first welded parts; The battery cell includes two separators, which are respectively connected to two first conductive portions. Along the first direction, at least a portion of each separator is located between the two first welded portions and the conductive portions.

27. The battery cell according to claim 26, characterized in that, In the same plane perpendicular to the first direction, the portions of the two first conductive parts located on the side of the first wall away from the main body each have a first orthographic projection, and the isolation member has a second orthographic projection. The second orthographic projections of the two isolation members are respectively located within the two first orthographic projections.

28. The battery cell according to claim 24 or 25, characterized in that, The two first conductive parts are respectively welded to the first wall to form two first welded parts; Along the first direction, a portion of the insulating member is disposed between one of the welded portions and the conductive member, and another portion of the insulating member is disposed between the other welded portion and the conductive member.

29. The battery cell according to claim 1, characterized in that, The first conductive part includes a first electrode tab, which is disposed in the first through hole. A portion of the first electrode tab is located on the side of the first wall away from the main body and is welded to the first wall to form the first welded part.

30. The battery cell according to claim 1, characterized in that, The first conductive part includes a first electrode tab and a first adapter portion. The first electrode tab is connected to the main body portion, and the first adapter portion is welded to the first electrode tab. The first adapter portion passes through the first through hole, and a portion of the first adapter portion is located on the side of the first wall away from the main body portion and is welded to the first wall to form the first weld portion.

31. The battery cell according to claim 30, characterized in that, The first adapter includes two adapter layers, and the end of the first electrode away from the main body is disposed between the two adapter layers and welded to the two adapter layers.

32. The battery cell according to claim 31, characterized in that, The two transition layers are stacked and welded to the first wall on the side of the first wall away from the main body.

33. The battery cell according to claim 1, characterized in that, The outer casing includes a third wall, and along the first direction, the main body is disposed between the first wall and the third wall, and the battery cell includes an electrode terminal disposed on the third wall; The electrode unit includes a second conductive part, which extends from the main body and is electrically connected to the electrode terminal.

34. The battery cell according to claim 33, characterized in that, The second conductive part includes a second electrode tab, which is connected to the main body part; The battery cell includes two second conductive portions, and the second tabs of the two second conductive portions are separated along a second direction, which is perpendicular to the first direction.

35. The battery cell according to claim 33 or 34, characterized in that, The outer casing includes a housing and an end cap. The housing has a housing opening on one side along the first direction, and the end cap is connected to the housing and covers the housing opening. The third wall is the end cap, and the housing is integrally formed and includes the first wall.

36. The battery cell according to claim 33 or 34, characterized in that, The outer casing includes a housing and two end caps. The housing has openings on both sides along the first direction. The two end caps are connected to the housing and cover the two housing openings respectively. The first wall is one of the end caps, and the third wall is the other end cap.

37. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1-36.

38. The battery device according to claim 37, characterized in that, The battery device includes a current-collecting component, which is welded to the conductive element to form a second welded portion. In the same plane perpendicular to the first direction, the orthographic projections of the first welded portion and the orthographic projections of the second welded portion are at least partially offset.

39. The battery device according to claim 37, characterized in that, The battery device includes a current-collecting component, which is welded to the conductive component to form a second welded portion. In the same plane perpendicular to the first direction, the orthographic projections of the first welded portion and the second welded portion are both located within the orthographic projection of the insulating component.

40. An electrical appliance, characterized in that, Includes the battery device according to any one of claims 37-39, the battery device being used to provide electrical energy.

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