Battery cell, secondary battery and electric device

Abstract

The battery cell comprises a shell, a pole core and a separator, a containing cavity is formed in the shell, the pole core is arranged in the containing cavity, at least one side, facing the shell, of the pole core is provided with a pole lug, and the pole lug comprises a first connecting section connected to the shell, a second connecting section connected to the pole core and a bent section connected between the first connecting section and the second connecting section; at least part of the isolation piece is located between the first connecting section and the second connecting section, and a gap is formed between the isolation piece and the bent section. The separator is arranged in the tab, when the battery is extruded, the separator is used for separating the first connecting section and the second connecting section of the tab, and meanwhile, as the gap is formed between the separator and the bent section of the tab, when the tab is extruded by external force, the gap can provide a buffer space for deformation of the bent section, so that the deformation of the bent section is reduced, and the reliability of the battery is improved. And the risk that the tab is extruded and damaged due to overlarge stress when the tab is bent is reduced, so that the reliability of the battery is improved.

Description

Technical Field

[0001] This application belongs to the field of battery packaging technology, specifically relating to a battery cell, a secondary battery, and an electrical device. Background Technology

[0002] With the advent of the mobile era, smart mobile products are constantly being updated and iterated. For example, tablets and laptops have seen rapid development in recent years. Batteries are one of the key components of smart electronic products; therefore, battery safety and reliability are of paramount importance.

[0003] Normally, the tabs are the connection points between the internal electrodes of the battery cell and the external circuit. Under some abnormal conditions, the tabs may be damaged, affecting the battery's performance and reliability. Utility Model Content

[0004] This application aims to provide a battery cell, a secondary battery, and an electrical device that reduces the risk of short circuits in the tabs and improves the reliability of the battery cell.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application provide a battery cell, comprising: a housing having a receiving cavity; an electrode core disposed within the receiving cavity, the electrode core having an electrode tab on at least one side facing the housing; the electrode tab including a first connecting segment connected to the housing, a second connecting segment connected to the electrode core, and a bent segment connecting the first connecting segment and the second connecting segment; and a spacer, at least a portion of the spacer being located between the first connecting segment and the second connecting segment, and having a gap with the bent segment.

[0007] Optionally, the separator includes a first end face facing the first connecting segment, a second end face facing the second connecting segment, and an inclined or vertical surface facing one side of the bent segment, wherein the inclined or vertical surface has the gap with the bent segment.

[0008] Optionally, one end of the inclined surface is connected to the first end face, and the other end is connected to the second end face, and the included angle formed by the connection between the inclined surface and the first end face is an acute angle;

[0009] And / or, the area of ​​the first end face is greater than the area of ​​the second end face;

[0010] And / or, the housing includes a cover and an electrode post, the electrode post being disposed in the cover, the electrode core having an electrode tab at one end facing the electrode post, the first connecting section being electrically connected to the electrode post, and the first end face covering the end of the electrode post facing the electrode core.

[0011] Optionally, an arc transition surface is provided at the connection between the first end face and the inclined surface;

[0012] And / or, an arc transition surface is provided at the connection between the second end face and the inclined surface.

[0013] Optionally, the battery cell must satisfy at least one of the following conditions:

[0014] a. The thickness of the spacer ranges from 2.5 mm to 3.40 mm;

[0015] b. The separator has a porous structure for absorbing electrolyte;

[0016] c. The insulating element is an elastic insulating element;

[0017] d. The yield strength of the isolation element is in the range of 5 MPa to 20 MPa.

[0018] Optionally, the battery cell may include a cell without a negative electrode or a cell with a negative electrode; the cell with a negative electrode may include a silicon negative electrode cell or a graphite negative electrode cell.

[0019] Optionally, the electrode core is provided with a plurality of electrode tabs on the side facing the housing, and each electrode tab is provided with an isolation member between the first connecting section and the second connecting section, and the isolation member in at least two electrode tabs is an integral structure;

[0020] Alternatively, the cavity may contain a plurality of electrode cores, each electrode core having an electrode tab on the side facing the housing, and an isolation member between the first connecting section and the second connecting section of each electrode tab, wherein the isolation member in the electrode tabs of at least two electrode cores is an integral structure.

[0021] Optionally, the battery cell has a height direction, and the insulating member has inclined surfaces on both sides perpendicular to the height direction, each of the inclined surfaces corresponding to the bent section of one of the tabs; the insulating member has a center line extending along the height direction, and the two inclined surfaces of the insulating member are axially symmetrical about the center line.

[0022] Secondly, embodiments of this application propose a secondary battery comprising the cell described in any of the above claims.

[0023] Thirdly, embodiments of this application provide an electrical device including any of the secondary batteries described above.

[0024] In this embodiment, by providing a separator between the first connecting segment and the second connecting segment of the electrode tab, the first connecting segment and the second connecting segment of the electrode tab are separated when the battery is impacted or squeezed. At the same time, since there is a gap between the separator and the bent segment of the electrode tab, the gap can provide a buffer space for the deformation of the bent segment when the electrode tab is squeezed by external force, reducing the risk of excessive stress and damage to the electrode tab when it is bent, thereby improving the reliability of the battery.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0027] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0028] Figure 2 This is one of the structural schematic diagrams of the isolation component according to an embodiment of this application;

[0029] Figure 3 This is a second schematic diagram of the structure of the isolation component according to an embodiment of this application;

[0030] Figure 4 This is the third schematic diagram of the structure of the isolation component according to an embodiment of this application.

[0031] Figure label:

[0032] 100: Pole core; 200: Housing; 201: Receiving cavity; 202: Cover; 203: Pole post; 300: Pole tab; 301: First connecting section; 302: Second connecting section; 303: Bending section; 400: Isolator; 401: First end face; 402: Second end face; 403: Inclined surface; 404: Arc transition surface; 405: Vertical surface; 406: Hole; 500: Gap. Detailed Implementation

[0033] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated 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 application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] 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 application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0035] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "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 based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not 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 application.

[0036] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] The following description, in conjunction with the accompanying drawings, details a battery cell, a secondary battery, and an electrical device provided in this application through specific embodiments and application scenarios.

[0038] In general, the connection method between the core, tabs, and terminals in battery packaging is crucial, directly affecting the battery's performance and stability. The core is composed of a positive electrode, a negative electrode, and a separator positioned between them, wound or stacked. The positive and negative electrodes store chemical energy at different potentials, undergoing redox reactions during charging and discharging to release and absorb electrons, thus generating current. The separator not only reduces direct contact between the positive and negative electrodes but also allows for efficient ion transfer between them, ensuring normal battery operation. The tabs are metal conductors led out from either the positive or negative electrode. One end of the tab is connected to the positive or negative electrode via welding, and the other end is connected to the terminals mounted on the casing via welding. These tabs conduct current from the core to the terminals, which are then used to connect to external circuitry.

[0039] However, in related technologies, the tabs in the battery are easily damaged when the battery is subjected to impact or external pressure after it is packaged, which will affect the reliability of the battery.

[0040] like Figure 1 As shown in the embodiment of this application, a battery cell is proposed, including a housing 200, an electrode core 100, and an insulating member 400. A receiving cavity 201 is formed in the housing 200. The electrode core 100 is disposed in the receiving cavity 201, and an electrode tab 300 is provided on at least one side of the electrode core 100 facing the housing 200. The electrode tab 300 includes a first connecting section 301 connected to the housing 200, a second connecting section 302 connected to the electrode core 100, and a bent section 303 connected between the first connecting section 301 and the second connecting section 302. At least a portion of the insulating member 400 is located between the first connecting section 301 and the second connecting section 302, and has a gap 500 between it and the bent section 303.

[0041] In this embodiment, by providing a separator 400 between the first connecting segment 301 and the second connecting segment 302 of the tab 300, the first connecting segment 301 and the second connecting segment 302 of the tab 300 are separated when the battery is impacted or squeezed. At the same time, since there is a gap 500 between the separator 400 and the bent segment 303 of the tab 300, the gap 500 can provide a buffer space for the deformation of the bent segment 303 when the tab 300 is squeezed by external force, reducing the risk of excessive stress and damage to the tab 300 when it is bent, thereby improving the reliability of the battery.

[0042] like Figures 1 to 3 As shown, optionally, the separator 400 includes a first end face 401 facing the first connecting segment 301, a second end face 402 facing the second connecting segment 302, and an inclined surface 403 or a vertical surface 405 facing the side of the bent segment 303, with a gap 500 between the inclined surface 403 or the vertical surface 405 and the bent segment 303.

[0043] In some embodiments, the side of the isolator 400 facing the bent section 303 can be configured as an inclined surface 403, that is, the cross-section of the isolator 400 is trapezoidal. Within the limited space between the first connecting section 301 and the second connecting section 302, the inclined surface 403 allows for more space between the isolator 400 and the second connecting section 302. When the electrode core 100 expands and deforms or when an external force compresses the electrode tab 300, the bent section 303 and part of the second connecting section 302 have more deformation space. This allows the second connecting section 302 to contact the inclined surface 403 more, thereby reducing the risk of short circuit due to contact between the second connecting section 302 and the first connecting section 301.

[0044] In other embodiments, the side of the spacer 400 facing the bent section 303 is made into a vertical surface 405, that is, the cross-section of the spacer 400 is rectangular. The spacer 400 with the vertical surface 405 allows for a larger gap 500 between the bent section 303 and the spacer 400, providing more deformation space for the bent section 303, reducing the risk of short circuit caused by the bent section 303 inserting into the electrode core 100 when the tab 300 is subjected to external pressure; furthermore, making the side of the spacer 400 facing the bent section 303 into a vertical surface 405 also facilitates processing and reduces processing costs.

[0045] like Figure 1 As shown, in some embodiments, one end of the inclined surface 403 is connected to the first end surface 401, and the other end is connected to the second end surface 402. The angle formed by the connection between the inclined surface 403 and the first end surface 401 is an acute angle.

[0046] In this embodiment, by setting the included angle formed by the connection between the inclined surface 403 and the first end face 401 to an acute angle, that is, the separator has an inverted trapezoidal structure, the inclined surface 403 is inclined toward the second connecting section 302 of the tab 300. When the tab 300 is squeezed, the deformed second connecting section 302 can contact the inclined surface 403 more, thereby reducing the risk of battery short circuit or voltage fluctuation caused by the contact between the second connecting section 302 and the first connecting section 301.

[0047] like Figure 1 and Figure 3 As shown, in some embodiments, the area of ​​the first end face 401 is larger than the area of ​​the second end face 402.

[0048] In this embodiment, the area of ​​the first end face 401 of the separator 400 is made larger than the area of ​​the second end face 402 to increase the area of ​​the separator 400 on the side facing away from the electrode core 100. When the battery is subjected to vibration, the electrode core will exert a pulling force on the tab, which will lead to a decrease in the connection stability between the tab 300 and the housing 200. However, when the area of ​​the first end face 401 of the separator 400 is larger than the area of ​​the second end face 402, the first end face 401 can provide support at the connection between the tab 300 and the housing 200, thereby improving the stability of the connection between the first connecting segment 301 and the housing 200.

[0049] like Figure 1 As shown, in some embodiments, the housing 200 includes a cover 202 and an electrode post 203. The electrode post 203 is disposed in the cover 202. The end of the electrode core 100 facing the electrode post 203 is provided with an electrode tab 300. The first connecting section 301 is electrically connected to the electrode post 203. The first end face 401 covers the end of the electrode post 203 facing the electrode core 100.

[0050] In this embodiment of the application, by having the first end face 401 of the isolator 400 cover the end of the pole post 203 facing the pole core 100, the first end face 401 can provide support for the entire end face of the pole post 203, thereby improving the connection stability between the first connecting section 301 and the pole post 203.

[0051] It should be noted that the first connecting segment 301 of the tab 300 can be directly electrically connected to the terminal 203. When the size difference between the tab 300 and the terminal 203 is significant, or when the material of the tab 300 is relatively soft or thin, the first connecting segment 301 of the tab 300 can also be electrically connected to the terminal 203 via an adapter plate. The adapter plate typically uses a material with high hardness and good conductivity, such as copper or aluminum, which not only allows the current on the tab 300 to be effectively transferred to the terminal 203, but also enhances the reliability and stability of the connection between the tab 300 and the terminal 203. Of course, the electrical connection method between the first connecting segment 301 of the tab 300 and the terminal 203 can be flexibly selected according to actual process requirements, and this embodiment does not impose any limitations on it.

[0052] like Figure 3 As shown, optionally, an arc transition surface 404 is provided at the connection between the first end face 401 and the inclined surface 403.

[0053] In this embodiment of the application, by setting the connection between the first end face 401 and the inclined surface 403 as an arc transition surface 404, the sharpness of the connection can be reduced, and the risk of stress concentration and easy breakage at the point where the connection contacts the tab 300 can be reduced, thereby extending the service life of the cell and improving the reliability of the battery.

[0054] like Figure 3 As shown, optionally, an arc transition surface 404 is provided at the connection between the second end face 402 and the inclined surface 403.

[0055] In this embodiment, by setting the connection between the second end face 402 and the inclined surface 403 as an arc transition surface 404, when the electrode core 100 expands and causes extrusion deformation to the second connecting section 302, the arc transition surface 404 can reduce the risk of stress concentration and breakage of the second connecting section 302 at that point, thereby extending the service life of the cell and improving the reliability of the battery.

[0056] In some embodiments, the thickness of the spacer 400 ranges from 2.5 mm to 3.40 mm.

[0057] In this embodiment, by setting the thickness of the insulating member 400 to be greater than or equal to 2.5 mm, it is beneficial to have a certain distance between the first connecting segment 301 and the second connecting segment 302 of the tab 300. Under the pressure of the battery cell, the first connecting segment 301 and the second connecting segment 302 of the tab 300 are less likely to come into contact, thereby reducing the risk of short circuit in the battery cell. At the same time, by setting the thickness of the insulating member 400 to be less than or equal to 3.4 mm, the space occupied by the insulating member 400 inside the battery cell can be reduced, thereby reducing the space occupancy rate of the battery cell.

[0058] It is understandable that when the electrode core 100 expands and deforms, it will exert a squeezing effect on the tab 300. Under the squeezing force, the bent section 303 will undergo significant deformation. Since the space for the tab 300 to deform within the housing 200 is small, the bent section 303 can easily be inserted backwards into the electrode core 100, causing the tab 300 to short-circuit with the electrode sheet of the opposite shape. To address this, this application provides a spacer 400 between the first connecting section 301 and the second connecting section 302, with the thickness of the spacer 400 ranging from 2.5 mm to 3.40 mm. In this way, when the tab 300 is deformed by external force, on the one hand, the spacer 400 with a certain thickness can reduce deformation due to its isolation and support effect between the first connecting section 301 and the second connecting section 302. On the other hand, the gap 500 formed between the spacer 400 and the bent section 303 provides deformation space for the bent section 303, reducing the risk of the bent section 303 being inserted backwards into the electrode core 100 and causing a short circuit.

[0059] It should be noted that the separator 400 is deformable. When the separator 400 is installed into the battery cell, it will undergo a small amount of deformation due to the squeezing action of the housing 200 or the electrode core 100. The thickness of the separator 400 mentioned in this embodiment refers to the thickness of the separator 400 in its natural state.

[0060] For example, the thickness of the spacer 400 can be set to any value such as 2.5mm, 3.0mm, or 3.4mm.

[0061] A numerical value or a range of values ​​between any two numerical values.

[0062] In some embodiments, the spacer 400 is configured as an elastic insulator. Through the elastic action of the elastic insulator, when the tab 300 is subjected to external force, the elastic insulator can undergo a certain elastic deformation to absorb and disperse these external forces, thereby reducing the direct impact of external forces on the tab 300 and reducing the risk of damage such as breakage of the tab 300; and when the external force is removed, it can return to its initial state, serving as a support between the first connecting section 301 and the second connecting section 302.

[0063] In some embodiments, such as Figure 4As shown, the separator 400 has a porous structure. When the electrode core 100 expands and deforms, the space for the electrolyte inside the cell becomes smaller. The pores 406 in the porous structure can provide space for the electrolyte inside the cell, thereby reducing the risk of electrolyte leakage.

[0064] In other embodiments, the yield strength of the spacer 400 ranges from 5 MPa to 20 MPa.

[0065] In this embodiment, by setting the yield strength of the isolator 400 to be greater than or equal to 5 MPa, when the external force on the battery cell is large, the isolator 400 can have sufficient yield strength to effectively isolate the first connecting section 301 and the second connecting section 302 of the tab 300, thereby reducing the risk of short circuit between the first connecting section 301 and the second connecting section 302 of the tab 300. Simultaneously, by setting the yield strength of the isolator 400 to be less than or equal to 20 MPa, when the squeezing force on the battery cell is small, the isolator 400 can also undergo corresponding deformation to buffer the impact force, thereby reducing the risk of breakage or other damage to the tab 300.

[0066] It should be noted that the yield strength of the spacer 400 can be obtained by testing with a universal testing machine, and the test method can be performed in accordance with the ASTM D412 standard.

[0067] For example, the yield strength of the spacer 400 can be set to any value such as 5 MPa, 10 MPa, 15 MPa, 20 MPa, or a range between any two values.

[0068] In some embodiments, the battery cell is a cell without a negative electrode.

[0069] It is understood that a negative electrode-free battery cell refers to a battery cell without a negative electrode active material, instead using a negative electrode current collector (such as copper foil) as the negative electrode. During the charging process, metal ions (such as lithium ions) are deposited on the surface of the negative electrode current collector. During the discharging process, the metal deposited on the surface of the negative electrode current collector dissolves and returns to the positive electrode. Due to the deposition and dissolution of metal ions in a negative electrode-free battery cell, the battery cell undergoes repeated expansion and contraction changes during charging and discharging. As the battery cell volume changes, the tab 300 is prone to deformation. Therefore, in this embodiment, an isolation member 400 is provided in the negative electrode-free battery cell. The isolation member can play a certain limiting role, reducing the expansion and contraction deformation during the charging and discharging process, thereby effectively protecting the tab.

[0070] For example, a negative-electrode cell can be a negative-electrode lithium metal cell, which uses lithium-containing material as the positive electrode and copper foil as the negative electrode current collector. Of course, negative-electrode cells can also be of other types, which are not limited here.

[0071] In some embodiments, the battery cell is a battery cell with a negative electrode. That is, a negative electrode active material is provided on the negative electrode current collector of the battery cell. Specifically, the battery cell with a negative electrode includes a silicon negative electrode battery cell or a graphite negative electrode battery cell. Among them, a silicon negative electrode battery cell refers to a battery cell with silicon-based material as the negative electrode active material, and a graphite negative electrode battery cell refers to a battery cell with graphite material as the negative electrode active material.

[0072] It is understandable that for silicon anode cells, since the silicon-based material will also undergo volume changes during the charging and discharging process of the cell, the embodiments of this application provide an isolation member 400 in the silicon anode cell. Since the isolation member 400 has a certain degree of deformability, it can not only adapt to the volume changes of the silicon-based material and play a protective role for the tab 300, but also play a certain limiting role by providing an isolation member 400 in the cell.

[0073] Of course, the specific type of battery cell can be flexibly selected according to actual process requirements, and no restrictions are imposed here.

[0074] Optionally, the electrode core 100 is provided with a plurality of electrode tabs 300 on the side facing the housing 200, and each electrode tab 300 is provided with an isolation member 400 between the first connecting section 301 and the second connecting section 302, and the isolation member 400 in at least two electrode tabs 300 is an integral structure.

[0075] In this embodiment, the electrode core 100 is provided with a plurality of electrode tabs 300 on the side facing the cover 202 in the housing 200. Furthermore, by providing a spacer 400 between the first connecting section 301 and the second connecting section 302 of each electrode tab 300, and making the spacers 400 in at least two electrode tabs 300 an integral structure, that is, by using one spacer 400 to isolate at least two electrode tabs 300 at the same time, such an integral structure can not only improve the stability of the fit between the plurality of electrode tabs 300 and the spacer 400, but also facilitate the assembly of the spacer 400.

[0076] In one embodiment, the electrode core 100 is provided with a plurality of electrode tabs 300 on the side facing the housing 200. At least two adjacent electrode tabs 300 have bent sections 303 that bend and protrude in opposite directions. Each of the two adjacent electrode tabs 300 is provided with a spacer 400, and the spacer 400 in the two electrode tabs 300 is an integral structure, that is, one spacer 400 extends into both electrode tabs 300 at the same time. Both sides of the spacer 400 are provided with inclined surfaces 403, and each inclined surface 403 corresponds to a bent section 303 of an electrode tab 300.

[0077] In other embodiments, the electrode core 100 is provided with a plurality of electrode tabs 300 on the side facing the housing 200. At least two adjacent electrode tabs 300 have bent sections 303 that bend and protrude in the same direction. Each of the two adjacent electrode tabs 300 is provided with a spacer 400, and the spacer 400 in the two electrode tabs 300 is an integral structure, that is, one spacer 400 extends into the two electrode tabs 300 at the same time. One side of the spacer 400 is provided with an inclined surface 403, which corresponds to the bent section 303 of the two electrode tabs 300.

[0078] It is understandable that an integrated structure means that the isolating element 400 in multiple tabs 300 is the same, or it can mean that the isolating elements 400 in multiple tabs 300 are connected to each other to form an integrated structure.

[0079] Optionally, the receiving cavity 201 is provided with a plurality of pole cores 100, each pole core 100 having a tab 300 on the side facing the housing 200, and a spacer 400 being provided between the first connecting section 301 and the second connecting section 302 of each tab 300, wherein the spacer 400 in the tabs 300 of at least two pole cores 100 is an integral structure.

[0080] In this embodiment of the application, by providing an integrally structured separator 400 in multiple electrode cores 100, the electrode tabs 300 led out from the multiple electrode cores 100 can be subjected to more uniform force, thereby making the current led out from the electrode tabs 300 more stable, and thus improving the stability of the battery.

[0081] In one embodiment, a plurality of pole cores 100 are provided in the receiving cavity 201. Each pole core 100 has a tab 300 on the side facing the housing 200. At least two adjacent pole cores 100 have bent sections 303 of their tabs 300 that bend and protrude in opposite directions. Each of the two adjacent pole cores 100 has a spacer 400 in its tab 300. The spacers 400 in the two adjacent pole cores 100 are integral structures, that is, one spacer 400 extends into the tabs 300 of the two adjacent pole cores 100 at the same time. Both sides of the spacer 400 have inclined surfaces 403, and each inclined surface 403 corresponds to a bent section 303 of the tab 300 of one pole core 100.

[0082] In other embodiments, a plurality of pole cores 100 are provided in the receiving cavity 201. Each pole core 100 has a tab 300 on the side facing the housing 200. At least two adjacent pole cores 100 have bent sections 303 of their tabs 300 that bend and protrude in the same direction. Each of the tabs 300 of these two adjacent pole cores 100 has a spacer 400. The spacers 400 in the tabs 300 of these two adjacent pole cores 100 are integral structures, that is, one spacer 400 extends into the tabs 300 of these two adjacent pole cores 100 at the same time. One side of the spacer 400 has an inclined surface 403, which corresponds to the bent section 303 of the tabs 300 of these two adjacent pole cores 100.

[0083] It is understood that the electrode structure of the battery cell in this application can adopt a single-out electrode, a double-out electrode, or a multi-out electrode. Among them, when the battery cell adopts a double-out electrode structure, that is, the electrode core 100 has two electrodes 300 on the side facing the housing 200. Each electrode 300 is formed by bending multiple loosely attached sub-electrodes. With this electrode structure, the span of the electrode 300 is relatively large. When the electrode 300 is subjected to external pressure, the first connecting section 301 and the second connecting section 302 of the electrode 300 are prone to short-circuiting, and the bent section 303 of the electrode 300 is prone to deforming and inserting into the electrode core 100. In this application, an integrally structured isolator 400 is provided between the first connecting section 301 and the second connecting section 302 of the two tabs 300, and a gap 500 is provided between the isolator 400 and the bending section 303 of each tab. In this way, an isolation limit can be formed between the first connecting section 301 and the second connecting section 302 of the tabs 300 to reduce the up-and-down shaking of the tabs 300 during the movement of the battery cell, and a limit can also be formed on the bending section 303 of the tabs 300 on both sides to prevent the battery core 100 from being inserted into the bending section 303 and causing a short circuit.

[0084] Furthermore, since the tab 300 is formed by the loose bonding of multiple sub-tabs, the loose sub-tabs near the core 100 have less deformation space during compression, making them prone to indentation. Repeated expansion of the battery cell can cause the tabs at this location to break. This application addresses this by providing an insulating member 400 to limit the deformation of the tab 300. Simultaneously, a certain amount of space is reserved between the insulating member 400 and the bent section 303 of the tab 300, thereby reducing the risk of localized breakage of the tab 300.

[0085] In addition, the separator 400 set in the two electrode cores 100 is an integral structure, which can make the supporting force on the tabs 300 led out from the two electrode cores 100 more uniform, thereby making the current led out from the two tabs 300 more stable and improving the stability of the battery.

[0086] like Figure 3As shown, optionally, the battery cell has a height direction. It is understood that in some embodiments, the height direction refers to the direction from the bottom of the battery cell to the top cover. The separator 400 has inclined surfaces 403 on both sides perpendicular to the height direction, each inclined surface 403 corresponding to a bent section 303 of a tab 300. The separator 400 has a center line X extending along the height direction, and the two inclined surfaces 403 of the separator 400 are axially symmetric about the center line X. That is, the cross-section of the separator 400 is an isosceles trapezoidal structure.

[0087] In this embodiment, an inclined surface 403 is provided on one side of the bend 303 of the spacer 400 facing each tab 300, and the two inclined surfaces 403 of the spacer 400 are symmetrical.

[0088] This makes the supporting effect of the separator 400 on the two tabs 300 more uniform and balanced, ensuring that the shape of the two tabs 300 isolated by the separator 400 is consistent, thereby improving the performance consistency of the two tabs 300 and thus improving the stability of the battery.

[0089] Furthermore, by symmetrically arranging the separator 400, when the cell expands and compresses the separator 400, the forces on both sides of the separator 400 are more balanced. This results in more uniform forces on different parts of the cell, thereby reducing polarization caused by uneven forces within the cell. For example, in a cell without a negative electrode, uneven forces on different parts of the cell during expansion may lead to uneven deposition of active metal at different locations in the negative electrode current collector, which in turn affects the battery's cycle performance.

[0090] Optionally, embodiments of this application also propose a secondary battery, including the battery cell in any of the above embodiments.

[0091] In this embodiment, by providing an isolator 400 between the first connecting segment 301 and the second connecting segment 302 of the tab 300, when the battery is impacted or squeezed, the isolator 400 separates the first connecting segment 301 and the second connecting segment 302 of the tab 300, reducing the risk of battery voltage fluctuations or short circuits caused by contact between the first connecting segment 301 and the second connecting segment 302 of the tab 300; at the same time, since there is a gap 500 between the isolator 400 and the bent segment 303 of the tab 300, when the tab 300 is squeezed by external force, the gap 500 can provide buffer space for the deformation of the bent segment 303, reducing the risk of short circuit caused by the bent segment 303 being inserted into the core 100, thereby improving the reliability of the battery.

[0092] Optionally, embodiments of this application also propose an electrical device, including the secondary battery in any of the above embodiments, wherein the secondary battery is used to provide electrical energy.

[0093] In this embodiment, by providing a separator 400 between the first connecting segment 301 and the second connecting segment 302 of the tab 300, the first connecting segment 301 and the second connecting segment 302 of the tab 300 are separated when the battery is impacted or squeezed. At the same time, since there is a gap 500 between the separator 400 and the bent segment 303 of the tab 300, the gap 500 can provide a buffer space for the deformation of the bent segment 303 when the tab 300 is squeezed by external force, reducing the risk of excessive stress and damage to the tab when it is bent, thereby improving the reliability of the battery.

[0094] 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 this application. 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.

[0095] Although embodiments of this application 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 this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An electric cell, characterized by, The application relates to a battery cell, which comprises: a shell (200) formed with a containing cavity (201); a pole core (100) arranged in the containing cavity (201), the pole core (100) being provided with a pole lug (300) towards at least one side of the shell (200); the pole lug (300) comprises a first connecting section (301) connected to the shell (200), a second connecting section (302) connected to the pole core, and a bending section (303) connected between the first connecting section (301) and the second connecting section (302); a separator (400) arranged at least partially between the first connecting section (301) and the second connecting section (302) and having a gap (500) with the bending section (303).

2. The electric cell of claim 1, wherein, The separator (400) comprises a first end face (401) towards the first connecting section (301), a second end face (402) towards the second connecting section (302), and an inclined face (403) or a vertical face towards one side of the bending section (303), the inclined face (403) or the vertical face having the gap (500) with the bending section (303).

3. The electric cell of claim 2, wherein, One end of the inclined face (403) is connected to the first end face (401), and the other end is connected to the second end face (402), and the included angle between the inclined face (403) and the first end face (401) is an acute angle; and / or, the area of the first end face (401) is greater than the area of the second end face (402); and / or, the shell (200) comprises a cover body (202) and a pole column (203), the pole column (203) is arranged in the cover body (202), the pole lug (300) is arranged at one end of the pole core (100) towards the pole column (203), the first connecting section (301) is electrically connected to the pole column (203), and the first end face (401) covers one end of the pole column (203) towards the pole core (100).

4. The electric cell of claim 2, wherein, A circular arc transition face (404) is arranged at the connection between the first end face (401) and the inclined face (403); and / or, a circular arc transition face (404) is arranged at the connection between the second end face (402) and the inclined face (403).

5. The electric cell of claim 1, wherein, The battery cell at least meets one of the following conditions: a. the thickness of the separator (400) ranges from 2.5 mm to 3.40 mm; b. the separator (400) has a porous structure for absorbing electrolyte; c. the separator (400) is an elastic insulating piece; d. the yield strength of the separator (400) ranges from 5 Mpa to 20 Mpa.

6. The electric cell of claim 1, wherein, The battery cell comprises a battery cell without negative electrode or a battery cell with negative electrode; The battery cell with negative electrode comprises a silicon negative electrode battery cell or a graphite negative electrode battery cell.

7. The cell of any of claims 1-6, wherein, The pole core (100) is provided with a plurality of the pole lug (300) on one side thereof facing the shell (200), the first connecting section (301) and the second connecting section (302) of each of the pole lug (300) are provided with the isolation piece (400), and the isolation pieces (400) in the at least two pole lugs (300) are of an integral structure. Alternatively, the accommodating cavity (201) is provided with a plurality of the pole core (100), each of the pole core (100) is provided with the pole lug (300) on one side thereof facing the shell (200), the first connecting section (301) and the second connecting section (302) of each of the pole lug (300) are provided with the isolation piece (400), and the isolation pieces (400) in the pole lug (300) of the at least two pole cores (100) are of an integral structure.

8. The electric cell of claim 7, wherein, The electric core has a height direction, the isolation piece (400) is provided with an inclined surface (403) on two sides perpendicular to the height direction, each of the inclined surfaces (403) corresponds to the bent section (303) of one of the pole lugs (300), the isolation piece (400) has a center line (X) extending along the height direction, and the two inclined surfaces (403) of the isolation piece (400) are in an axial symmetric structure with the center line (X) as the axis of symmetry.

9. A secondary battery characterized by comprising: The electric core comprises any one of the electric cores according to claims 1-8.

10. An electrical device, characterized by The secondary battery comprises the secondary battery according to claim 9.

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