Battery cell, battery pack, and vehicle

Abstract

The application provides a battery monomer, a battery pack and a vehicle, and relates to the technical field of electrochemical devices. The battery monomer comprises at least two pole groups, two conductive components and an expansion component. The pole group comprises at least two pole lugs with opposite polarities, the pole lugs with opposite polarities are electrically connected with different conductive components, the at least two pole groups are arranged at intervals along a first direction, for any two adjacent pole groups, a gap region is formed between the pole lugs of the two pole groups and the electrically connected conductive components, and when the expansion component is arranged in the gap region, the volume of the expansion component changes from small to large to fit the pole lugs. The application supports the pole lugs by the expansion component, avoids physical short circuit of the battery monomer caused by support failure of a support sheet, and improves the safety of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of electrochemical device technology, and more particularly to a battery cell, a battery pack, and a vehicle. Background Technology

[0002] Lithium-ion batteries achieve charging and discharging through the back-and-forth insertion and extraction of lithium ions between the positive and negative electrodes. Typically, a lithium-containing coating is applied to the current collector as the positive electrode, and a carbon-containing coating is applied to the current collector as the negative electrode.

[0003] During the battery cell assembly process, the tabs of each electrode are electrically connected to conductive components, and a support sheet, such as a polyethylene terephthalate (PET) sheet, is usually attached to the tab. After the electrodes are assembled, the support sheet is arc-shaped to provide support for the tab. However, the support sheet is weak, and the tab may bend and form a sharp corner due to support failure, which may then penetrate into the electrode assembly and eventually cause a physical short circuit at the lowest point of the bend. Utility Model Content

[0004] This application provides a battery cell, a battery pack, and a vehicle, which uses an expansion component to support the electrode tabs, thereby avoiding physical short circuits in the battery cell caused by the failure of the support plate and improving the safety of the battery cell.

[0005] A first aspect of this application provides a battery cell having a first orientation, comprising: at least two electrode groups, two conductive components, and an expansion component; The electrode assembly includes at least two tabs with opposite polarities, which are electrically connected to different conductive components. At least two pole groups are arranged at intervals along the first direction; For any two adjacent pole groups, a gap region is formed between the pole tabs of the two pole groups and the electrically connected conductive parts; When the expansion component is placed in the gap area, the volume of the expansion component increases from small to large until it fits against the electrode tab.

[0006] Optionally, the electrode group includes at least two electrode sheets arranged in staggered layers along the first direction. The electrode sheets are provided with electrode tabs. In the same electrode group, the polarities of two adjacent electrode sheets are opposite. In any two adjacent electrode groups, the two outermost electrode tabs at the end of the electrode group that are closer to the other electrode group along the first direction are adjacent electrode tabs. A gap region is formed between adjacent tabs of the same polarity and the electrically connected conductive parts.

[0007] Optionally, the adjacent tab has an electrical connection end, which is located at the end of the adjacent tab closest to the conductive component; The electrical connection end is bent in an arc shape relative to the conductive component.

[0008] Optionally, the adjacent tab has an integrally formed end, which is located at the end of the adjacent tab near the electrode sheet; The integrally molded end is curved relative to the electrode sheet.

[0009] Optionally, at least one end of the adjacent tab is bent away from the gap region.

[0010] Optionally, the conductive component has a second direction perpendicular to the first direction, and includes: a substrate and a reinforcing portion; One end of the reinforcing part along the second direction is fixedly connected to the substrate; The other end of the reinforcing part along the second direction is inserted into the expansion member that fits against the electrode tab.

[0011] Optionally, the reinforcing portion is inclined relative to the surface of the substrate.

[0012] Optionally, the expansion component includes thermally expandable microspheres or thermally expandable adhesive.

[0013] A second aspect of this application provides a battery pack comprising: a battery cell as described in any of the first aspects.

[0014] A third aspect of this application provides a vehicle including a battery pack as described in the second aspect.

[0015] This application provides a battery cell, a battery pack, and a vehicle. The battery cell includes: at least two electrode groups, two conductive components, and an expansion component. Each electrode group includes at least two tabs with opposite polarities, which are electrically connected to different conductive components. The at least two electrode groups are arranged at intervals along a first direction. For any two adjacent electrode groups, a gap region is formed between the tabs of the two electrode groups and the electrically connected conductive components. When the expansion component is arranged within the gap region, its volume increases until it fits snugly against the tabs. This achieves the following technical effects: by arranging the expansion component within the gap region, after expansion treatment, the expansion component fills and supports the tabs, forming a physical support structure, avoiding physical short circuits in the battery cell caused by support failure, and improving the safety of the battery cell; by causing the expansion component to expand in volume through expansion treatment, the expanded component supports the tabs, improving the operability of the battery cell filled with expansion material.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1A schematic diagram of the structure of a battery cell provided in the prior art; Figure 2 A schematic diagram of the structure of a single battery cell provided in the embodiments of this application. Figure 1 ; Figure 3 A schematic diagram of the structure of a single battery cell provided in the embodiments of this application. Figure 2 ; Figure 4 Provided for the embodiments of this application Figure 3 A magnified view of a portion of the image; Figure 5 A partial structural diagram of a battery cell provided in the embodiments of this application. Figure 1 ; Figure 6 A partial structural diagram of a battery cell provided in the embodiments of this application. Figure 2 .

[0018] Figure label: 100 - Electrode group; 110 - Electrode sheet; 111 - Tab; 111a - Adjacent tab; 1111 - Electrical connection terminal; 1112 - Integrated end; 120 - Diaphragm; 200 - Conductive component; 210 - Substrate; 220 - Reinforcing part; 300 - Expansion component; 400 - Void area; 500-Support plate; X - First direction; Y - Third direction; Z - Second direction. Detailed Implementation

[0019] The embodiments of this utility model will now be described in detail. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0020] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] To facilitate a clear description of the technical solution of this application, some of the terms and technologies involved in this application are briefly introduced below: Lithium-ion batteries are rechargeable batteries that achieve charging and discharging through the reciprocating insertion and extraction of lithium ions between the positive and negative electrodes. During charging, lithium ions are extracted from the positive electrode, pass through the electrolyte, and insert into the negative electrode, leaving the negative electrode in a lithium-intercalated state. During discharging, the movement of lithium ions is reversed compared to charging. Lithium-ion batteries typically use a lithium-containing coating applied to the current collector as the positive electrode and a carbon-containing coating applied to the current collector as the negative electrode.

[0024] Current collector: This refers to a conductive substrate material whose main function is to collect the current generated by the electrode coating during charging and discharging and conduct it to the external circuitry of the battery. Typically, aluminum foil is used for the positive electrode current collector, while copper foil is used for the negative electrode current collector.

[0025] Polyethylene terephthalate (PET) sheets: These are thermoplastic polyester plastics. In lithium-ion batteries, PET sheets are often used as insulating or protective materials due to their insulation properties, heat resistance, and chemical stability.

[0026] Conductive components: These are intermediate conductive structures that connect multiple electrode tabs to the external terminals of the battery. They are used to achieve electrical connection and current collection.

[0027] To clearly understand the technical solution of this application, the solutions of the prior art will be described in detail first.

[0028] During the cell assembly process, the tabs of each electrode are electrically connected to conductive components to form a battery cell. During this process, a PET sheet is typically bonded to the conductive components, with the shape of the PET sheet matching the shape of the bonding area.

[0029] For example, Figure 1 This is a schematic diagram of the structure of a battery cell provided in the prior art. For example... Figure 1 As shown, the tabs of the left electrode group 100 (not shown in the figure) are located in the area enclosed by the left electrode group 100, the conductive component 200 and the support sheet 500 (i.e., the PET sheet); the tabs of the right electrode group 100 are similar.

[0030] During the cell assembly process, a 0.2mm thick support piece 500, after being bent, is attached to the electrode tab. After the electrode assembly is completed, the support piece 500 is arc-shaped, providing some support for the shape of the electrode tab. However, the support of the support piece 500 is weak, and the electrode tab may bend and form a sharp corner due to support failure, which may pierce into the electrode assembly 100 and eventually cause a physical short circuit at the lowest point of the bend.

[0031] Specifically, the support piece 500 is made of a relatively soft material and may fail due to prolonged use or external impact. Simultaneously, the support piece 500 may exhibit adhesive failure after immersion in electrolyte, which will also lead to support failure. Once the support piece 500 fails, it will shift relative to the tab and conductive component 200, thus failing to support the tab. Without constraint, the tab may bend due to external forces such as vibration and compression, internal stress, or its own weight. When the bending is extremely severe, the tab may undergo plastic deformation, forming an acute angle (the sharp angle being the lowest point of bending) and piercing into the electrode assembly 100, causing a physical short circuit.

[0032] In one possible scenario, when the battery cell is installed upside down, the support plate 500 may fail to provide support for the tab. Specifically, the electrode assembly 100 may shift towards the tab under the influence of gravity, potentially causing the tab to be inserted upside down into the electrode assembly 100.

[0033] Therefore, in response to the problem of physical short circuits in battery cells caused by support sheet failure, the research found that, in order to solve this problem, conventional support sheets such as PET sheets can be replaced with components that expand in volume after expansion treatment. The expanded components fill the area between the tabs and conductive components, and support the tabs by the expanded components, thus avoiding physical short circuits in battery cells caused by support sheet failure and improving the safety of battery cells.

[0034] The technical solutions of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0035] Figure 2 A schematic diagram of the structure of a single battery cell provided in the embodiments of this application. Figure 1 In one scenario, the electrode sheet and electrode assembly are 100... Figure 2 Arranged as shown, Figure 2 In the process, the electrodes are arranged at intervals along the first direction X (the first direction X is perpendicular to the second direction Z and the third direction Y), and multiple electrode groups 100 are arranged along the third direction Y, with the arrangement direction of the electrode groups 100 perpendicular to the arrangement direction of the electrodes. Figure 3 A schematic diagram of the structure of a single battery cell provided in the embodiments of this application. Figure 2 In another scenario, the electrode and electrode assembly 100... Figure 3 Arranged as shown, Figure 3 In the process, the electrodes are arranged at intervals along the first direction X, and multiple electrode groups 100 are also arranged at intervals along the first direction X. The arrangement direction of the electrode groups 100 is parallel to the stacking direction of the electrodes.

[0036] It is important to note that Figure 2 and Figure 3 The fact that only two electrode groups and one conductive component are shown does not mean that a single battery cell consists only of these two electrode groups and the conductive component.

[0037] Example 1 like Figure 2 and Figure 3 As shown, an electrode unit with a first direction X includes: at least two electrode groups 100, two conductive parts 200 and an expansion part 300; The electrode assembly 100 includes at least two tabs 111 with opposite polarities, which are electrically connected to different conductive components 200.

[0038] Figure 4 for Figure 3 The middle circle shows a partially enlarged schematic diagram of part A. Figure 4 What is being shown is Figure 3 The pole group, that is, the pole group Figure 3 The circular selection area A in the image has been magnified. Figure 3 and Figure 4 Taking the arrangement shown as an example, the component filled with forward diagonal lines is one of the electrode sheets 110 that are both positive and negative, and the component filled with reverse diagonal lines is the other of the electrode sheets 110 that are both positive and negative (in this application, the component filled with forward diagonal lines is defined as the positive electrode sheet 110). It should be noted that... Figure 4The negative electrode 110 and the conductive component 200 electrically connected to the negative electrode 110 are not shown. The negative electrode 110 can be arranged in the same direction as the positive electrode 110, or opposite to the positive electrode 110, or in other positions.

[0039] Optionally, the electrode assembly 100 also includes a diaphragm 120, i.e. Figure 4 The component is filled with a grid line. The separator 120 is a thin layer with a microporous structure used to physically isolate the positive and negative electrodes to prevent short circuits; the separator 120 allows lithium ions to pass freely to achieve electrochemical reactions. In the electrode assembly 100, the positive electrode 110, the separator 120, and the negative electrode 110 are arranged in an alternating layered configuration. Each positive electrode 110 and each negative electrode 110 is provided with a tab 111, which is integrally formed with the electrode 110 or connected by welding. For example, if the number of positive electrode 110 and negative electrode 110 can both be one, then the positive electrode 110 and the negative electrode 110 are separated by a diaphragm 120, and the electrode group 100 includes two tabs 111 with opposite polarities; if the number of positive electrode 110 and negative electrode 110 can both be multiple, then the number of diaphragms 120 can be multiple, and each positive electrode 110 and each negative electrode 110 are separated by a diaphragm 120, and the electrode group 100 includes multiple tabs 111 with opposite polarities.

[0040] The tabs 111 of the electrodes 110 with opposite polarities are electrically connected to different conductive components 200. That is, the tabs 111 of all positive electrodes 110 are connected to one conductive component 200, and the tabs 111 of all negative electrodes 110 are connected to another conductive component 200. The electrical connection between the two can be welding, mechanical pressing or bonding.

[0041] Optionally, the tab 111 can be led out from the end face (one side in the thickness direction) of the electrode group 100 and connected to the conductive component 200 located at the end of the electrode group after being bent vertically or at an angle; the tab 111 can also be led out from the side (one side in the length or width direction) of the electrode group 100 and connected to the conductive component 200 arranged on the side in the horizontal direction; in the multilayer laminated structure, all tabs 111 of the same polarity are led out uniformly upward or downward and connected to the conductive component 200 located in the uppermost or lowermost layer.

[0042] Optionally, the conductive component 200 has multiple positive and negative busbars, with different busbars located at different positions and busbars of the same polarity electrically connected to each other, so that each busbar is electrically connected to several tabs 111.

[0043] At least two pole groups 100 are arranged at intervals along the first direction X; For any two adjacent pole groups 100, a gap region 400 is formed between the pole tabs 111 of the two pole groups 100 and the electrically connected conductive component 200. When the expansion component 300 is arranged in the gap region 400, the volume of the expansion component 300 increases from small to large until it fits against the tab 111.

[0044] Specifically, the shape of the electrode 110 determines the end face profile of the electrode assembly 100, which in turn affects the cross-sectional shape of the void region 400.

[0045] For example, when the shape of the electrode 110 is rectangular, the shape of the void region 400 can be rectangular, trapezoidal cross-section prism, or double-sided void, etc., and its spatial regularity is suitable for the arrangement and filling of expansion components.

[0046] When the electrode 110 is elliptical, the shape of the gap region 400 can be an elliptical cylinder or an hourglass, etc. Due to the curvature of the end face, the expansion component needs to match the curved surface, which makes the design slightly more complex.

[0047] When the shape of the electrode 110 is non-standard, such as L-shaped, U-shaped or T-shaped, the shape of the void region 400 depends entirely on the overall layout, and it may be divided into multiple small cavities.

[0048] An expansion component 300 is arranged in the void region 400. An expansion component 300 is a component that has undergone expansion treatment and has expanded in volume. After the expansion component 300 has undergone expansion treatment, the expanded expansion component 300 fills the void region 400 until it fits against the tab 111. The expanded expansion component 300 is used to support the tab 111.

[0049] Before undergoing the expansion process, the expansion component 300 has a small initial volume and can be arranged within the void region 400, located between the tab 111 and the conductive component 200 connection structure. Under specific conditions, such as heating, liquid absorption, or chemical reaction, the expansion component 300 expands in volume, completely or partially filling the void region 400 and coming into contact with the tab 111 and the conductive component 200.

[0050] For example, the expansion component 300 can be a foaming material, which is then heated (e.g., heated to above 80°C) after battery encapsulation to trigger foaming and expansion. Alternatively, the expansion component 300 can be a liquid-absorbing polymer material, which absorbs the electrolyte and expands after electrolyte injection, achieving adaptive filling of gaps in the electrolyte region. The expansion process is gentle, avoiding mechanical damage. Furthermore, the expansion component 300 can be a chemically reactive expansion material, containing various reactive components (e.g., acid + carbonate), which react with the electrolyte to generate carbon dioxide gas, propelling the material's expansion.

[0051] Figure 2 In the arrangement shown, the principle of supporting the tab 111 with the expansion material 300 is similar to... Figure 3 and Figure 4 In the arrangement shown, the principle of supporting the tab 111 with the expansion material 300 is similar, and this embodiment will not be described in detail here.

[0052] In another scenario, with Figures 2 to 4 Unlike the stacked electrode assembly 100 shown, the electrode assembly 100 can also be formed by winding. A positive electrode 110 and a negative electrode 110 are separated by a diaphragm 120. The electrode 110 and the diaphragm 120 are wound in a certain direction to form the electrode assembly 100.

[0053] Each electrode sheet 110 may have one tab 111, so after winding, the electrode assembly 100 will have one positive tab 111 and one negative tab. Alternatively, each electrode sheet 110 may have multiple tabs 111, so after winding, the electrode assembly 100 will have multiple positive tabs 111 and multiple negative tabs. The positive and negative tabs 111 can be located at both ends of the electrode assembly 100, or at different positions at one end of the electrode assembly 100. The principle of supporting the tabs 111 with the expanded material 300 in the wound electrode assembly 100 is similar to... Figure 3 and Figure 4 In the arrangement shown, the principle of supporting the tab 111 with the expansion material 300 is similar, and this embodiment will not be described in detail here.

[0054] This application provides a battery cell comprising: at least two electrode groups, two conductive components, and an expansion component; each electrode group includes at least two tabs with opposite polarities, the tabs being electrically connected to different conductive components; the at least two electrode groups are arranged at intervals along a first direction; for any two adjacent electrode groups, a gap region is formed between the tabs of the two electrode groups and the electrically connected conductive components; when the expansion component is arranged in the gap region, the volume of the expansion component increases from small to large until it fits against the tabs. The following technical effects are achieved: by arranging the expansion component in the gap region, after undergoing expansion treatment, the expansion component fills and supports the tabs, forming a physical support structure, avoiding physical short circuits in the battery cell caused by support failure, and improving the safety of the battery cell; by expanding the expansion component through expansion treatment, the expanded component supports the tabs, improving the operability of the battery cell filled with expansion material.

[0055] Example 2 When the arrangement direction of the electrode group 100 is perpendicular to the arrangement direction of the electrode sheet 110, the formation position and boundary of the gap region 400 are relatively intuitive; however, when the arrangement direction of the electrode group 100 is parallel to the arrangement direction of the electrode sheet 110, the formation position and boundary of the gap region 400 are difficult to define. Based on this, the following technical solution is proposed: Figure 5 This is a partial structural diagram of a battery cell provided in an embodiment of this application. Optionally, as shown... Figure 5 As shown, based on the aforementioned embodiment 1 of this application, the electrode group 100 in this embodiment includes at least two electrode pieces 110 arranged in an alternating manner along the first direction X. Each electrode piece 110 is provided with an electrode tab 111. In the same electrode group 100, the polarities of two adjacently stacked electrode pieces 110 are opposite. In any two adjacent electrode groups 100, the two outermost electrode tabs 111 at the end of the electrode group 100 that is closer to the other electrode group 100 along the first direction X are adjacent electrode tabs 111a. A gap region 400 is formed between the adjacent tabs 111a of the electrode 110 with the same polarity and the electrically connected conductive component 200.

[0056] For example, will Figure 5 The pole group 100 on the left is defined as pole group A, and the pole group 100 on the right is defined as pole group B. Both are arranged along the first direction X. Pole group A contains multiple tabs 111, among which the two tabs 111 closest to pole group B in pole group A are adjacent tabs 111a, namely the adjacent tab 111a that is positive and the adjacent tab 111a that is negative. Figure 5 Only the adjacent tab 111a that is the positive electrode is shown, that is, the rightmost tab of electrode group A, defined as tab a); similarly, the two tabs 111 in electrode group B that are closest to electrode group A are adjacent tabs 111a, namely the adjacent tab 111a of the positive electrode and the adjacent tab 111a of the negative electrode. Figure 5 Only the adjacent tab 111a that is positive is shown, that is, the leftmost tab of the electrode group B, which is defined as tab b). Two adjacent tabs 111a that are positive form a pair of adjacent tabs 111a, and two adjacent tabs 111a that are negative form a pair of adjacent tabs 111a.

[0057] The gap region 400 corresponding to the positive electrode 110 is enclosed by the following boundaries: the connection structure between the tab a and the conductive component 200, the connection structure between the tab b and the conductive component 200, and the end face plane of the conductive component 200 and the electrode group 100; the gap region 400 corresponding to the negative electrode 110 is similar, and will not be described in detail in this embodiment.

[0058] The technical effect of this application embodiment is that when multiple electrode groups are arranged linearly parallel to the stacking direction of the electrode sheets, the range of the gap region is determined by the adjacent tabs of two adjacent electrode groups.

[0059] Example 3 During the expansion process of the expansion component 300, if the expansion degree of the expansion component 300 exceeds the design threshold, the resulting expansion stress may exceed the structural bearing capacity of the adjacent tab 111a and the area connected to the conductive component 200. At this time, the tab 111 may be subjected to lateral or oblique compression, resulting in plastic deformation, bending, or even fracture. Based on this, the following technical solution is proposed: Optionally, based on the aforementioned embodiment 2 of this application, in this embodiment, the adjacent tab 111a has an electrical connection end 1111, which is located at the end of the adjacent tab 111a close to the conductive component 200; The electrical connection terminal 1111 is bent in an arc shape relative to the conductive component 200.

[0060] Specifically, the bending of the electrical connection end 1111 relative to the conductive component 200 refers to the non-linear and angled bending state of the electrical connection end 1111 relative to the surface or extension direction of the conductive component 200 during the electrical connection process. This bending shape can be a Z-shaped bend, that is, a vertical bend; it can also be an L-shaped bend, that is, a right-angle bend; or it can be an arc-shaped bend, such as a semi-circular bend, a multi-segment arc splicing bend, or a continuous gradual bend, etc., to achieve a flexible transition.

[0061] The electrical connection terminal 1111 is designed as an arc-shaped bent structure and electrically connected to the conductive component 200 to increase the effective contact area and connection stability between the two, thereby coping with the compressive force or separation stress that the expansion component 300 may exert when it is over-expanded.

[0062] For example, such as Figure 5 As shown, the electrical connection terminal 1111 and the conductive component 200 are connected and bent by multiple arc segments.

[0063] The technical effect of this application embodiment is that by bending the electrical connection end relative to the conductive component in an arc shape, the contact area and connection stability between the electrical connection end and the conductive component are increased, thereby resisting the compressive force or separation stress during the expansion process of the expansion component.

[0064] Example 4 The arc-shaped bend also has a certain elastic strain capacity, which can absorb some of the expansion pressure and avoid stress concentration at the weld point. Optionally, based on the aforementioned embodiment 3 of this application, the adjacent tab 111a in this embodiment of the application has an integrally formed end 1112, which is located at the end of the adjacent tab 111a near the electrode 110; The integrally formed end 1112 is bent in an arc relative to the electrode 110.

[0065] Specifically, the integrally molded end 1112 is curved relative to the electrode group 100 to accumulate more elastic strain capacity, further reducing the pressure or separation stress on the electrical connection part during the expansion of the expansion component 300.

[0066] Example 5 Optionally, based on the aforementioned embodiment 3 or embodiment 4 of this application, at least one end of the adjacent tab 111a in the embodiment of this application is bent away from the gap region 400.

[0067] Specifically, when the electrical connection end 1111 and / or the integrally molded end 1112 are bent toward the gap region 400, they encroach on the space originally used for arranging the expansion component 300, causing the volume of the gap region 400 to gradually decrease or even become blocked, affecting the support effect of the expansion component 300 on the tab 111. Therefore, by bending the electrical connection end 1111 and / or the integrally molded end 1112 away from the gap region 400, the expansion component 300 can be fully injected into and evenly fill the entire gap region 400, achieving the effect of uniformly applying support force.

[0068] Optionally, in order to maximize the volume of the void region 400, each tab 111 is bent away from the void region at both ends along the stacking direction of the electrode 110.

[0069] It should be noted that when at least three electrode groups 100 are arranged linearly parallel to the stacking direction of the electrode sheet 110, the electrode groups 100 located at both ends have two adjacent tabs 111a, and the remaining electrode groups 100 have four adjacent tabs 111a. The adjacent tabs 111a of the electrode groups 100 not located at both ends face the electrode groups 100 adjacent to their left and right sides, respectively: the adjacent tabs 111a facing the adjacent electrode group 100 on the left side have at least one end bent away from the left gap region 400; while the adjacent tabs 111a facing the adjacent electrode group 100 on the right side have at least one end bent away from the right gap region 400.

[0070] Optionally, in these pole groups 100, the other pole tabs 111 besides the adjacent pole tab 111a can be divided into two parts: the first part is the pole tab group located in the left region of the pole group 100, whose bending direction is the same as that of the adjacent pole tab 111a facing the left adjacent pole group 100; the second part is the pole tab group located in the right region of the pole group 100, whose bending direction is the same as that of the adjacent pole tab 111a facing the right adjacent pole group 100.

[0071] Example 6 Although the expansion member 300 is designed to support the tab 111, slight displacement may still occur between the tab 111 and the conductive member 200 under the influence of charge-discharge cycles, temperature changes, or mechanical vibrations, which may affect the stability of the electrical connection.

[0072] Figure 6 A partial structural diagram of a battery cell provided in the embodiments of this application. Figure 2 .like Figure 6 As shown, based on this, the following technical solution is proposed: Optionally, based on any one of the aforementioned embodiments 2 to 5 of this application, a second direction Z is provided, the second direction Z being perpendicular to the first direction X. In the embodiments of this application, the conductive component 200 includes: a substrate 210 and a reinforcing portion 220. One end of the reinforcing part 220 along the second direction Z is fixedly connected to the substrate 210; The other end of the reinforcing part 220 along the second direction Z is inserted into the expansion part 300 that fits against the tab 111.

[0073] Specifically, the tabs 111 of the electrode plates 110 with the same polarity are electrically connected to a substrate 210. The reinforcing portion 220 may be... Figure 6 The columnar structure (such as reinforcing bars) or plate structure (such as reinforcing ribs) shown can also be other non-standard structures, such as L-shaped or U-shaped bending structures. One end of the reinforcing part 220 along the second direction Z, that is, the end perpendicular to the stacking direction of the electrode 110, is fixedly connected to the substrate 210. The connection method between the two can be integral molding, welding, mechanical pressing, or bonding. After the expansion member 300 undergoes expansion treatment, the other end of the reinforcing part 220 along the second direction Z, that is, the other end perpendicular to the stacking direction of the electrode 110, is inserted into the expanded expansion member 300. The expansion member 300 wraps around this end of the reinforcing part 220, generating pull-out resistance, thereby improving the overall structural integration and stability, and reducing the relative displacement between the conductive member 200 and the expansion member 300.

[0074] The technical effect of this application embodiment is that the reinforcing part connects the substrate and the expanded component after expansion, which improves the integration and stability of the battery cell and reduces the relative displacement between the conductive component and the expanded component.

[0075] Furthermore, in one embodiment, based on the above embodiment 6, when the expansion member 300 tends to loosen due to aging, shrinkage, or vibration, the vertically inserted expansion member 300 mainly relies on the sidewall friction to resist pull-out. Under long-term dynamic loads, gradual slippage or dislodgement may occur. Based on this, the following technical solution is proposed: Optionally, in the embodiments of this application, the reinforcing part 220 is inclined relative to the surface of the substrate 210.

[0076] Specifically, the reinforcing part 220 is constructed as an inclined anchor structure in the expansion member 300. When the reinforcing part 220 tends to be pulled out, it needs to overcome greater material shear resistance and compressive resistance, thereby preventing the reinforcing part 220 from gradually slipping or coming off under long-term dynamic load.

[0077] The technical effect of this application embodiment is that the relative displacement between the conductive component and the expansion component is further reduced by the reinforcing portion that is inclined relative to the surface of the substrate.

[0078] Optionally, when the battery cell is installed upside down, the expansion member 300, supported by the conductive member 200, prevents the electrode group 100 from shifting towards the tab 111 under the action of gravity, thus preventing the tab 111 from being inserted upside down into the electrode group 100.

[0079] Example 7 Optionally, based on any one of the foregoing embodiments 1 to 6 of this application, the expansion component 300 in the embodiments of this application includes thermally expandable microspheres or thermally expandable adhesive.

[0080] Specifically, the expansion treatment is a thermal expansion treatment; the expansion component 300 is triggered to expand in volume by heating. The heating method can be the baking process during battery production, the Joule heat generated during the first charge and discharge of the battery, or achieved with the help of external heating equipment (such as fixture heating). When the temperature reaches the activation temperature of the expansion component 300, gas is generated or a phase change occurs inside the expansion component 300, resulting in a rapid increase in volume. For example, baking at a high temperature of 110-120℃ for 6-10 hours causes the expansion component 300 to expand due to heat, filling the void region 400.

[0081] Optionally, the expansion component 300 can be a thermally expandable microsphere. The thermally expandable microsphere consists of a thermoplastic shell encapsulating a low-boiling-point liquid foaming agent. Upon heating, the internal liquid vaporizes, the shell softens, and the microsphere expands accordingly. The advantage of thermally expandable microspheres is that the expansion process is controllable and the response is rapid.

[0082] Optionally, the expansion component 300 can also be a thermally expandable adhesive. Thermally expandable adhesives use epoxy resin, polyurethane, silicone, etc., as a matrix, incorporating thermally expandable microspheres or polymers with inherent thermal expansion properties. At room temperature, the thermally expandable adhesive is liquid or paste-like, facilitating dispensing or potting; upon heating, it expands and cures, forming an elastic or semi-rigid support. The advantage of thermally expandable adhesives lies in their combined bonding, sealing, and expansion functions.

[0083] The technical effect of this application embodiment is that the support for the electrode tab is achieved by static filling to dynamic active support through the thermally responsive expansion component.

[0084] Optionally, the thermally expandable microspheres and thermally expandable adhesive have good electrolyte resistance, and will not fail due to electrolyte immersion during long-term contact with the electrolyte inside the battery cell.

[0085] It should be noted that the battery cells involved in the above embodiments can be at least one of Embodiments 1 to 7. For example, Embodiment 1 can be implemented as an independent embodiment, Embodiments 1+2 can be implemented as independent embodiments, Embodiments 1+2+3 can be implemented as independent embodiments, Embodiments 1+2+3+4 can be implemented as independent embodiments, Embodiments 1+2+3+5 can be implemented as independent embodiments, Embodiments 1+2+3+4+5 can be implemented as independent embodiments, Embodiments 1+2+6 can be implemented as independent embodiments, Embodiments 1+2+3+4+6 can be implemented as independent embodiments, Embodiments 1+2+3+5+6 can be implemented as independent embodiments, Embodiments 1+2+3+4+5+6 can be implemented as independent embodiments, and Embodiment 1+7 can be implemented as an independent embodiment. Examples 1+2+7 can be implemented as independent embodiments, examples 1+2+3+7 can be implemented as independent embodiments, examples 1+2+3+4+7 can be implemented as independent embodiments, examples 1+2+3+5+7 can be implemented as independent embodiments, examples 1+2+3+4+5+7 can be implemented as independent embodiments, examples 1+2+6+7 can be implemented as independent embodiments, examples 1+2+3+6+7 can be implemented as independent embodiments, examples 1+2+3+4+6+7 can be implemented as independent embodiments, examples 1+2+3+5+6+7 can be implemented as independent embodiments, examples 1+2+3+4+5+6+7 can be implemented as independent embodiments, and so on, but are not limited to these, and will not be exemplified here.

[0086] Example 8 This application also provides a battery pack, including: the battery cells as described in the above embodiments.

[0087] Based on any one of the foregoing embodiments 1 to 7 of this application, in the embodiments of this application, the battery cells can be installed upright or inverted in the battery pack. Since the battery pack includes the aforementioned battery cells, it also possesses the beneficial effects of the aforementioned battery cells, which will not be elaborated here.

[0088] It should be noted that the battery pack involved in the above embodiments can be based on at least one of Embodiments 1 to 7. For example, Embodiments 1+8 can be implemented as independent embodiments, Embodiments 1+2+8 can be implemented as independent embodiments, Embodiments 1+2+3+8 can be implemented as independent embodiments, Embodiments 1+2+3+4+8 can be implemented as independent embodiments, Embodiments 1+2+3+5+8 can be implemented as independent embodiments, Embodiments 1+2+3+4+5+8 can be implemented as independent embodiments, Embodiments 1+2+6+8 can be implemented as independent embodiments, Embodiments 1+2+3+6+8 can be implemented as independent embodiments, Embodiments 1+2+3+4+6+8 can be implemented as independent embodiments, Embodiments 1+2+3+5+6+8 can be implemented as independent embodiments, Embodiments 1+2+3+4+5+6+8 can be implemented as independent embodiments, and Embodiment 1+7+8 can be implemented as independent embodiments. Implementation examples 1+2+7+8 can be implemented as independent embodiments, as can examples 1+2+3+7+8, 1+2+3+4+7+8, 1+2+3+5+7+8, 1+2+3+4+5+7+8, 1+2+6+7+8, 1+2+3+6+7+8, 1+2+3+4+6+7+8, 1+2+3+5+6+7+8, 1+2+3+4+5+6+7+8, etc., but are not limited to these examples, which will not be further illustrated here.

[0089] Example 9 This application also provides a vehicle, including a battery pack as described in the above embodiments.

[0090] Based on the aforementioned embodiment 8 of this application, in this embodiment of the application, since the vehicle includes the aforementioned battery pack, it also possesses the beneficial effects of the aforementioned battery cells, which will not be repeated here.

[0091] It should be noted that the vehicle involved in the above embodiments can be based on Embodiment 8. For example, Embodiments 1+8+9 can be implemented as independent embodiments, Embodiments 1+2+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+4+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+5+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+4+5+8+9 can be implemented as independent embodiments, Embodiments 1+2+6+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+6+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+5+6+8+9 can be implemented as independent embodiments, Embodiments 1+2+3+4+5+6+8+9 can be implemented as independent embodiments, Embodiments 1+7+8+9 can be implemented as independent embodiments. Examples can be used to implement this, such as Examples 1+2+7+8+9, Examples 1+2+3+7+8+9, Examples 1+2+3+4+7+8+9, Examples 1+2+3+5+7+8+9, Examples 1+2+3+4+5+7+8+9, Examples 1+2+6+7+8+9, Examples 1+2+3+6+7+8+9, Examples 1+2+3+4+6+7+8+9, Examples 1+2+3+5+6+7+8+9, Examples 1+2+3+4+5+6+7+8+9, etc., but are not limited to these examples, and will not be further exemplified here.

[0092] The battery cell, battery pack, and other components and operations of the vehicle according to the embodiments of this utility model are known to those skilled in the art and will not be described in detail here.

[0093] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell having a first orientation (X), characterized in that, include: At least two pole groups (100), two conductive parts (200) and an expansion part (300); The electrode group (100) includes at least two tabs (111) with opposite polarities, and the tabs (111) with opposite polarities are electrically connected to different conductive components (200). At least two of the pole groups (100) are arranged at intervals along the first direction (X); For any two adjacent pole groups (100), a gap region (400) is formed between the tabs (111) of the two pole groups (100) and the electrically connected conductive component (200). When the expansion component (300) is arranged in the gap region (400), the volume of the expansion component (300) increases from small to large until it fits against the tab (111).

2. The battery cell according to claim 1, characterized in that, The electrode group (100) includes at least two electrode pieces (110) arranged in an alternating manner along the first direction (X). Each electrode piece (110) is provided with an electrode tab (111). In the same electrode group (100), the polarities of two adjacent electrode pieces (110) are opposite. In any two adjacent electrode groups (100), the two outermost electrodes tabs (111) of the electrode group (100) that are closer to the other electrode group (100) along the first direction (X) are adjacent electrodes tabs (111a). The gap region (400) is formed between the adjacent tab (111a) of the electrode (110) of the same polarity and the electrically connected conductive member (200).

3. The battery cell according to claim 2, characterized in that, The adjacent tab (111a) has an electrical connection terminal (1111), which is located at one end of the adjacent tab (111a) near the conductive component (200); The electrical connection terminal (1111) is bent in an arc shape relative to the conductive component (200).

4. The battery cell according to claim 3, characterized in that, The adjacent tab (111a) has an integrally formed end (1112), which is located at one end of the adjacent tab (111a) near the electrode (110); The integrally formed end (1112) is curved relative to the electrode (110).

5. The battery cell according to claim 3 or 4, characterized in that, At least one end of the adjacent tab (111a) is bent away from the void region (400).

6. The battery cell according to any one of claims 2-5, characterized in that, Having a second direction (Z) perpendicular to the first direction (X), the conductive component (200) comprises: a substrate (210) and a reinforcing portion (220). The reinforcing part (220) is fixedly connected to the substrate (210) at one end along the second direction (Z); The reinforcing part (220) is inserted into the expansion member (300) which is attached to the tab (111) at the other end along the second direction (Z).

7. The battery cell according to claim 6, characterized in that, The reinforcing part (220) is inclined relative to the surface of the substrate (210).

8. The battery cell according to any one of claims 1-7, characterized in that, The expansion component (300) includes thermally expandable microspheres or thermally expandable adhesive.

9. A battery pack, characterized in that, include: The battery cell as described in any one of claims 1 to 8.

10. A vehicle, characterized in that, include: The battery pack as described in claim 9.

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