Battery cell, battery pack, and electric device

Abstract

Embodiments of the present disclosure provide a battery monomer, a battery pack and an electric device. The present disclosure relates to the technical field of batteries. The battery monomer comprises a shell and an electrode assembly. The shell comprises a shell body, a cover plate and an explosion-proof valve, the shell body and the cover plate enclose a containing cavity, and the explosion-proof valve is arranged on the cover plate; the electrode assembly is contained in the containing cavity, wherein the shell body comprises a first side wall arranged on one side of a second direction and connected with the cover plate, the first side wall is connected with the cover plate, the first side wall comprises a wall body and a buffer part arranged on the wall body, the buffer part is a part of the wall body protruding outward from the containing cavity relative to the remaining part, and in the orthographic projection of the first direction, the projection of the buffer part is arranged opposite to the projection of the explosion-proof valve in the second direction. Therefore, the battery monomer of the embodiments of the present disclosure has the advantages of improving the structural stability and safety of the battery monomer.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, specifically to a battery cell, a battery pack having the battery cell, and an electrical device. Background Technology

[0002] The casing of a battery cell prevents the electrode assembly from shifting or deforming when subjected to external impacts. However, during use, stress concentration and other factors can cause damage to the electrode assembly. In particular, when the electrode assembly undergoes thermal expansion, an improperly designed casing structure can prevent the effective release of the expansion stress generated by the electrode assembly, leading to cracking at the connection between the casing and the cover plate. Utility Model Content

[0003] In view of this, the present disclosure aims to provide a battery cell, a battery pack, and an electrical device to solve the problem in the prior art where cracks occur at the connection between the casing and the cover plate because the expansion force of the electrode assembly cannot be released.

[0004] This disclosure provides a battery cell. The battery cell includes a housing and an electrode assembly. The housing includes a casing, a cover plate, and an explosion-proof valve. The casing has an opening at one end in a first direction, and the cover plate is fitted onto the opening of the casing. The casing and the cover plate together form a receiving cavity, and the explosion-proof valve is disposed on the cover plate. The electrode assembly is received within the receiving cavity. The casing includes a first sidewall disposed on one side in a second direction and connected to the cover plate. The first sidewall includes a wall body and a buffer portion disposed on the wall body. The buffer portion is a portion of the wall body that protrudes outward from the receiving cavity relative to the remaining portion. In the first direction, the projection of the buffer portion and the projection of the explosion-proof valve are opposite to each other in the second direction. The first direction is the height direction of the battery, and the second direction is the width direction of the battery. The first direction and the second direction are perpendicular to each other.

[0005] This disclosure also provides a battery pack. The battery pack includes the battery cells as described above.

[0006] This disclosure also provides an electrical appliance. The electrical appliance includes a battery pack as described above.

[0007] The battery cell described above utilizes a buffer section on one side wall of the casing. When the electrode assembly expands, the buffer section deforms to absorb some of the expansion force. When the force generated by the electrode assembly's expansion acts on the casing, the buffer section dissipates and disperses this force through its own deformation, thereby reducing the stress at the connection between the casing and the cover plate. This reduces the direct impact of the expansion force on the connection, effectively preventing cracking due to stress concentration at the connection and improving the structural stability and safety of the battery cell. Furthermore, it reduces casing deformation corresponding to the explosion-proof valve. Since the electrode assembly typically expands at a higher rate perpendicular to its height, by aligning the projection of the buffer section with the projection of the explosion-proof valve in a second direction, the expansion force can be preferentially concentrated in the area of ​​the buffer section, allowing it to fully utilize its deformation buffering function. This enables the buffer section to more effectively absorb the expansion force generated by the electrode assembly, thereby reducing the degree of casing deformation in the area where the explosion-proof valve is located. Meanwhile, if the battery is subjected to external impact or compression during transportation, stacking, or use, the buffer section, facing the explosion-proof valve area, can preferentially absorb the impact energy, preventing external forces from directly acting on the explosion-proof valve or its surrounding weak areas. This prevents the explosion-proof valve from prematurely rupturing or failing to seal due to mechanical deformation, and prevents accidental triggering or blockage of the explosion-proof valve, thus extending the service life of the battery cell. Therefore, the battery cell of the present disclosure embodiment has the advantage of improving the structural stability and safety of the battery cell. Attached Figure Description

[0008] It should be understood that the following figures only illustrate certain embodiments of this disclosure and should not be construed as limiting the scope.

[0009] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0010] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0011] Figure 1 This is a perspective view of a battery cell according to an embodiment of the present disclosure.

[0012] Figure 2 This is a front view of a battery cell according to an embodiment of this disclosure.

[0013] Figure 3 This is a top view of a battery cell according to an embodiment of this disclosure.

[0014] Figure 4 This is an exploded view of a single battery cell according to an embodiment of this disclosure.

[0015] Figure 5 This is an exploded view of the outer casing according to an embodiment of this disclosure.

[0016] Figure 6 This is a perspective view of the housing according to an embodiment of the present disclosure.

[0017] Explanation of reference numerals in the attached figures: Outer shell 1; 11; shell; 111; cavity; 112; first sidewall; 113; wall body; 1131; buffer section; 1132; groove; 1133; second sidewall; bottom wall surface; 115; 12. Cover plate; 13. Explosion-proof valve; Electrode assembly 2. Detailed Implementation

[0018] The technical solutions of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments.

[0019] During battery charging and discharging, the expansion and contraction of the electrode assembly 2 exerts periodic stress on the casing 11. In related technologies, the sidewalls of the casing 11 are often planar, and the electrode assembly 2 assembled inside the casing 11 cannot effectively disperse and alleviate this stress, causing stress to act at the connection between the casing 11 and the cover plate 12. Over time, this stress concentration can lead to material fatigue at the connection, resulting in cracking. This not only affects the sealing performance of the battery cells but may also pose a safety hazard.

[0020] To address this issue, the battery cell assembly of this disclosure effectively solves the aforementioned technical problem by providing a buffer portion 1132 on the first sidewall 113 of the housing 11. Specifically, the buffer portion 1132 is formed by a portion of the wall body 1131 protruding outward relative to the rest towards the receiving cavity 112, allowing the buffer portion 1132 to deform to a certain extent when subjected to stress generated by the expansion of the electrode assembly 2, thereby absorbing and dispersing the stress. Simultaneously, in the orthographic projection in the first direction, the projection of the buffer portion 1132 is positioned opposite to the projection of the explosion-proof valve 13 in the second direction, further optimizing the stress dispersion path near the housing 11 in the area where the explosion-proof valve 13 is located, ensuring the stability and reliability of the housing 11 structure.

[0021] The disclosed battery pack includes a battery pack composed of multiple battery cells connected in series and / or in parallel to form a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (outer shell 1, brackets, etc.), and protective components, etc., and the above components are placed in a box and sealed by a cover plate 12 to form a complete functional unit that can directly output electrical energy.

[0022] In this embodiment of the disclosure, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0023] The battery apparatus mentioned in the embodiments of this disclosure may include one or more battery cells for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar. Battery cells may be, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc. A battery cell generally includes an electrode assembly 2. The electrode assembly 2 includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, disposed between the positive and negative electrodes, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0024] The aforementioned battery cell refers to a battery that can store chemical energy and controllably convert it into electrical energy. In recyclable batteries, the active materials can be reactivated by charging after discharge, allowing for continued use. A battery cell typically includes a casing 1 and an electrode assembly 2 disposed within the casing 1.

[0025] The following is for reference. Figures 1-6 The present disclosure provides examples of battery cells, battery packs, and electrical devices according to embodiments thereof.

[0026] The battery cell of this disclosure includes a housing 1 and an electrode assembly 2. The housing 1 includes a shell 11, a cover plate 12, and an explosion-proof valve 13. The shell 11 is positioned in a first direction (e.g., Figure 1 One end of the housing 11 (shown in the vertical direction) has an opening 111, and a cover plate 12 is fitted onto the opening 111 of the housing 11. The housing 11 and the cover plate 12 enclose a receiving cavity 112, and an explosion-proof valve 13 is disposed on the cover plate 12. The electrode assembly 2 is accommodated in the receiving cavity 112, wherein the housing 11 includes components disposed in the second direction (e.g., Figure 1The first sidewall 113 (shown in the left-right direction) is connected to the cover plate 12. The first sidewall 113 includes a wall body 1131 and a buffer portion 1132 disposed on the wall body 1131. The buffer portion 1132 is formed by a portion of the wall body 1131 protruding outward relative to the rest of the receiving cavity 112. In the orthographic projection in the first direction, the projection of the buffer portion 1132 is opposite to the projection of the explosion-proof valve 13 in the second direction, wherein the first direction is the height direction of the battery, the second direction is the width direction of the battery, and the first and second directions are perpendicular to each other. It can be understood that the buffer portion 1132 is integrally formed on the first sidewall 113 of the housing 11.

[0027] In this embodiment of the battery cell, a buffer portion 1132 is provided on one side wall of the housing 11. When the electrode assembly 2 expands, the buffer portion 1132 can deform to absorb part of the expansion force. When the force generated by the expansion of the electrode assembly 2 acts on the housing 11, the buffer portion 1132 can consume and disperse this force through its own deformation, thereby reducing the stress borne at the connection between the housing 11 and the cover plate 12. This reduces the direct effect of the expansion force on the connection between the housing 11 and the cover plate 12, effectively preventing the problem of cracking at the connection between the housing 11 and the cover plate 12 due to stress concentration, and improving the structural stability and safety of the battery cell.

[0028] Furthermore, since the electrode assembly 2 typically has a higher expansion rate perpendicular to its height when expanding, by aligning the projection of the buffer section 1132 with the projection of the explosion-proof valve 13 in the second direction, the expansion force can be preferentially concentrated in the area where the buffer section 1132 is located. This allows the buffer section 1132 to fully utilize its deformation buffering function, enabling it to more effectively absorb the expansion force generated by the electrode assembly 2. Consequently, the deformation of the housing 11 in the area where the explosion-proof valve 13 is located is reduced, preventing the explosion-proof valve 13 from being falsely triggered or failing due to excessive deformation of the housing 11. Simultaneously, when subjected to external impact, the external force is prevented from directly acting on the explosion-proof valve 13 or its surrounding weak areas, further reducing the deformation of the housing 11 in the area where the explosion-proof valve 13 is located and preventing premature rupture or sealing failure of the explosion-proof valve 13 due to mechanical deformation. This, in turn, extends the service life of the battery cell.

[0029] In addition, the buffer portion 1132 is formed by a part of the wall body 1131 protruding outward relative to the rest of the receiving cavity 112. This structure has the advantage of good structural integrity while ensuring the overall strength of the shell 11.

[0030] Therefore, the battery cells of the present disclosure have the advantage of improving the structural stability and safety of the battery cells.

[0031] like Figure 1 , Figure 2 and Figure 6 As shown, the buffer portion 1132 extends along the first direction, and a groove 1133 is formed on the surface of the first sidewall 113 facing away from the buffer portion 1132.

[0032] In this embodiment of the battery cell, a groove 1133 is formed on the surface of the first sidewall 113 facing away from the buffer portion 1132. This not only enhances the overall strength of the housing 11 structure, but the groove 1133 can also accommodate gas generated during the electrode assembly 2's cycling due to side reactions of the electrochemical reaction. This mitigates the risk that deformation of the middle region of the electrode assembly 2 may block the exhaust channel, preventing gas from escaping from the inside of the housing 1. Therefore, it improves the risk of damage to the battery cell's performance due to excessive gas accumulation inside the housing 1.

[0033] In the second direction, the ratio of the height of the outward protrusion of the buffer portion 1132 to the thickness of the housing 11 is 0.002-0.03.

[0034] In this embodiment of the battery cell, by controlling the ratio range of the outward protrusion height of the buffer portion 1132 to the thickness of the casing 11, on the one hand, given a fixed casing 1, it prevents the buffer portion 1132 from protruding too much, which would reduce the overall strength of the buffer portion 1132; on the other hand, it prevents the buffer portion 1132 from protruding too little, which would result in poor buffering effect and inability to effectively absorb the force generated by the expansion of the electrode assembly 2. Thus, by reasonably optimizing the ratio range of the outward protrusion height of the buffer portion 1132 to the thickness of the casing 11, it combines the advantages of good buffering capacity and high structural strength.

[0035] Optionally, in the second direction, the ratio of the height of the outward protrusion of the buffer portion 1132 to the thickness of the housing 11 is 0.002, 0.004 mm, 0.008 mm, 0.01 mm, 0.015 mm, 0.02 mm, 0.025 mm, and 0.03 mm, as well as a range between any two point values.

[0036] Furthermore, in the second direction, the height of the outward protrusion of the buffer portion 1132 is 0.2mm-1mm, and the thickness of the housing 11 is 28mm-72mm.

[0037] In this embodiment of the battery cell, by controlling the range of the outward protrusion height of the buffer portion 1132, it is possible to avoid the outward protrusion height being too large, which would cause the buffer portion 1132 to undergo excessive deformation when subjected to external force or the expansion force of the electrode assembly 2, thus affecting the overall structural stability of the battery cell; on the other hand, it is also possible to prevent the outward protrusion height from being too small, which would not provide sufficient buffering and would cause the connection between the shell 11 and the cover plate 12 to still bear large stress, thereby leading to safety problems such as cracking.

[0038] Similarly, the thickness of the casing 11 should not be too large, as this would increase the overall weight of the battery cell, which would be detrimental to the lightweight design of the battery cell and the improvement of energy density. On the other hand, if the thickness of the casing 11 is too small, the overall strength of the casing 11 will be insufficient, making it difficult to effectively protect the internal electrode assembly 2, which is prone to damage when subjected to external impact or when the electrode assembly 2 expands.

[0039] Optionally, in the second direction, the height of the outward protrusion of the buffer portion 1132 is 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm and 1.0 mm, and the range between any two point values.

[0040] Optionally, the thickness of the housing 11 can be 28mm, 30mm, 35mm, 38mm, 40mm, 42mm, 45mm, 48mm, 50mm, 55mm, 58mm, 60mm, 62mm, 65mm, 70mm and 72mm, as well as a range between any two point values.

[0041] In the third direction, the width of the buffer section 1132 is 5mm-15mm, wherein the first direction, the second direction and the third direction are arranged perpendicular to each other.

[0042] In this embodiment of the battery cell, the width range of the buffer portion 1132 in the third direction is limited. This is because, on the one hand, an excessively large width may occupy too much internal space of the battery cell, affecting the arrangement of the electrode assembly 2 and the energy density and structural compactness of the battery cell; on the other hand, an excessively small width may prevent the buffer portion 1132 from adequately dispersing and absorbing stress from the third direction, leading to localized stress concentration. Thus, limiting the width range of the buffer portion 1132 combines the advantages of good buffering capacity and high structural compactness.

[0043] Optionally, in a third direction, the width of the buffer portion 1132 is 5mm, 8mm, 10mm, 12mm, 14mm, and 15mm, and the range between any two point values.

[0044] In the third direction, the distance between the centerline of the buffer section 1132 and the centerline of the explosion-proof valve 13 is less than 1 mm, wherein the first direction, the second direction and the third direction are arranged perpendicular to each other.

[0045] By rationally designing the distance between the center line of the buffer section 1132 and the center line of the explosion-proof valve 13, the battery cell of this disclosure can ensure that the stress can be effectively dispersed when the battery cell is subjected to internal pressure or external impact, and avoid stress concentration at the connection between the explosion-proof valve 13 or the housing 11 and the cover plate 12, thereby further improving the impact resistance and safety of the battery cell.

[0046] Optionally, in a third direction, the distance between the centerline of the buffer section 1132 and the centerline of the explosion-proof valve 13 is 0, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm and 0.99 mm, and the range between any two point values.

[0047] In the first direction, the ratio of the height h of the buffer section 1132 to the height H of the housing 11 is 0.5-0.9.

[0048] In this embodiment of the battery cell, by controlling the ratio range of the height of the buffer portion 1132 to the height of the casing 11, the following is achieved: Firstly, the ratio is prevented from being too large, resulting in the buffer portion 1132 being too close to the weld formed by the cover plate 12 and the casing 11. This would cause deformation of the buffer portion 1132, leading to expansion stress at the weld and potential cracking in that area. Secondly, the ratio is prevented from being too small, as the height of the buffer portion 1132 would be insufficient to effectively absorb the expansion force of the electrode assembly 2 near the cover plate 12, thereby reducing the buffering effect. Therefore, limiting the h / H value combines the advantages of high sealing reliability, high structural stability, and good buffering capacity.

[0049] Optionally, in the first direction, the ratio of the height h of the buffer portion 1132 to the height H of the housing 11 is 0.5, 0.6, 0.7, 0.8 and 0.9, and a range between any two points.

[0050] Furthermore, the connection between the cover plate 12 and the housing 11 has a weld, and in the first direction, the minimum distance between the buffer portion 1132 and the weld is 5mm-15mm.

[0051] The battery cell of this embodiment effectively avoids cracks or failures in the weld area due to stress concentration by using the minimum distance range between the buffer portion 1132 and the weld, further improving the structural strength and sealing reliability of the battery cell. Simultaneously, this distance design ensures that the buffer portion 1132 has sufficient deformation space when subjected to compression or impact, fully utilizing its buffering and energy absorption function to reduce the impact of external impacts on the internal electrode assembly 2. Furthermore, it avoids the minimum distance being too large, which would prevent the buffer portion 1132 from effectively covering the stress concentration area near the weld, weakening the overall protective effect; and also prevents the distance from being too small, which would cause the buffer portion 1132 and the weld to interfere with each other, affecting the welding quality or causing excessive local rigidity, reducing buffering performance. Therefore, by optimizing this distance, the reliability of the battery cell under complex operating conditions such as vibration and impact can be improved while ensuring structural safety.

[0052] Optionally, in the first direction, the minimum distance between the buffer portion 1132 and the weld is 5 mm, 8 mm, 10 mm, 12 mm, 14 mm and 15 mm and the range between any two point values.

[0053] like Figure 1 and Figure 2 As shown, in the first direction, the end of the housing 11 away from the opening 111 in the first direction has a bottom wall surface 115, and the buffer portion 1132 extends to the bottom wall surface 115.

[0054] Because the bottom wall 115 and side wall of the casing 11 are generally integrally formed, there are no welds in this area. In this embodiment of the battery cell, the buffer portion 1132 extends to the bottom wall 115, fully utilizing the structural strength at the connection between the bottom wall 115 and the side wall. This allows the buffer portion 1132 to transfer some stress to the bottom wall 115 when absorbing the expansion force of the electrode assembly 2. Since the bottom wall 115 and side wall are integrally formed, there are no weak points such as welds, effectively avoiding problems such as weld cracking due to stress concentration, further improving the overall structural stability of the battery cell. Simultaneously, it enhances the buffer portion 1132's ability to absorb internal expansion forces and external impact forces in the bottom region. The continuous transition structure between the buffer portion 1132 and the bottom wall 115 effectively reduces stress abrupt changes at the interface, preventing crack propagation caused by geometrical abrupt changes, and further enhancing the fatigue resistance of the casing 11.

[0055] The area of ​​the first sidewall 113 is greater than the area of ​​the other walls adjacent to the first sidewall 113.

[0056] In this embodiment of the battery cell, by designing the area of ​​the first wall surface of the casing to be larger than the area of ​​the adjacent remaining surfaces, it can be understood that the buffer portion 1132 is disposed on the large surface of the casing. Since the large surface of the battery casing is more prone to expansion, the provision of the buffer portion 1132 can better disperse the stress generated by the expansion of the electrode assembly 2, avoid local stress concentration, reduce the risk of damage to the battery cell, and further improve the reliability and service life of the battery cell. Moreover, it can make full use of the large surface space of the casing, providing sufficient placement area for the buffer portion 1132 while ensuring the overall compactness of the battery cell structure.

[0057] The housing 11 also includes a second sidewall 114 disposed opposite to it, and at least one second sidewall 114 is provided with a buffer portion 1132. It is understood that the buffer portion 1132 may be disposed on the first sidewall 113 and the second sidewall 114.

[0058] The battery cell in this embodiment further enhances its resistance to expansion and impact in multiple directions by also providing a buffer portion 1132 on the second sidewall 114. This design can more comprehensively disperse the stress generated by the electrode assembly 2 during charging and discharging, avoiding excessive stress concentration in local areas, thereby reducing the risk of deformation or damage to the battery cell. In addition, this multi-faceted buffer design also enhances the battery cell's resistance to external impacts from different directions, improving its safety and reliability in complex operating environments.

[0059] For example, the outer casing 1 is a rectangular shell, and the buffer portion 1132 can be provided on all four side walls of the outer casing 1. When the outer casing 1 is designed as a rectangular shell and the buffer portion 1132 is provided on all four side walls, it can absorb and disperse the stress generated by the electrode assembly 2 during charging and discharging in all directions. Specifically, the buffer portions 1132 on the four side walls can work together to resist external impacts from different directions, ensuring that the battery cell can maintain its structural integrity and performance stability when subjected to external forces such as vibration and collision.

[0060] In some embodiments, the buffer portion 1132 is a rectangular protrusion. The rectangular protrusion facilitates arrangement and space utilization.

[0061] The battery cell of this disclosure is not limited to this. In other embodiments, the buffer portion 1132 may also be a wavy protrusion, an arc-shaped protrusion, or an irregularly shaped protrusion. The battery cell of this disclosure can enhance elastic deformation capability by using wavy or arc-shaped protrusions, while irregularly shaped protrusions are suitable for specific stress distribution scenarios, further optimizing the buffering effect.

[0062] Furthermore, buffer sections 1132 of different shapes can be integrally stamped in a mold forming process to ensure structural strength and consistency.

[0063] The minimum distance between the periphery of the explosion-proof valve 13 and the periphery of the cover plate 12 is 5mm.

[0064] In this embodiment of the battery cell, by controlling the minimum distance between the explosion-proof valve 13 and the periphery of the cover plate 12, it is found that if the distance between the periphery of the explosion-proof valve 13 and the periphery of the cover plate 12 is too small, the structural strength of the area surrounding the explosion-proof valve 13 will be insufficient. When the internal pressure of the battery rises abnormally, the explosion-proof valve 13 may open prematurely because the surrounding structure cannot effectively bear the pressure, affecting the normal safety protection function of the battery and even potentially causing local structural damage. Therefore, optimizing the minimum distance between the periphery of the explosion-proof valve 13 and the periphery of the cover plate 12 further extends the service life of the battery cell.

[0065] Optionally, the minimum distance between the periphery of the explosion-proof valve 13 and the periphery of the cover plate 12 is 5 mm, 8 mm, 10 mm, 12 mm, 14 mm and 15 mm and the range between any two points.

[0066] This disclosure provides a battery pack comprising any of the battery cells described above.

[0067] Therefore, the embodiments of this disclosure have the advantage of improving the structural stability and safety of battery cells.

[0068] This disclosure also provides an electrical device including the battery pack described above. This disclosure provides an electrical device that uses the electrical device as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric motorcycles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0069] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

[0070] In the description of this disclosure, 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0072] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0073] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0074] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0075] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A battery cell, characterized in that, include: The housing includes a shell, a cover plate, and an explosion-proof valve. The shell has an opening at one end in a first direction. The cover plate is fitted onto the opening of the shell. The shell and the cover plate enclose a receiving cavity. The explosion-proof valve is disposed on the cover plate. An electrode assembly is housed within the receiving cavity. The housing includes a first sidewall disposed on one side in a second direction and connected to the cover plate. The first sidewall is connected to the cover plate and includes a wall body and a buffer portion disposed on the wall body. The buffer portion is formed by a portion of the wall body protruding outward from the receiving cavity relative to the rest of the wall body. In the orthographic projection in the first direction, the projection of the buffer portion and the projection of the explosion-proof valve are disposed opposite to each other in the second direction. The first direction is the height direction of the battery, and the second direction is the width direction of the battery. The first direction and the second direction are perpendicular to each other.

2. The battery cell according to claim 1, characterized in that, The buffer portion extends along the first direction, and a groove is formed on the surface of the first sidewall facing away from the buffer portion.

3. The battery cell according to claim 2, characterized in that, In the second direction, the ratio of the height of the outward protrusion of the buffer portion to the thickness of the housing is 0.002-0.

03.

4. The battery cell according to claim 3, characterized in that, In the second direction, the height at which the buffer portion protrudes outward relative to the wall body is 0.2mm-1mm; The thickness of the shell is 28mm-72mm.

5. The battery cell according to claim 2, characterized in that, In the third direction, the width of the buffer portion is 5mm-15mm, wherein the first direction, the second direction and the third direction are arranged perpendicular to each other.

6. The battery cell according to claim 1, characterized in that, In the third direction, the distance between the centerline of the buffer section and the centerline of the explosion-proof valve is less than 1 mm, wherein the first direction, the second direction and the third direction are arranged perpendicular to each other.

7. The battery cell according to claim 1, characterized in that, In the first direction, the ratio of the height h of the buffer portion to the height H of the housing is 0.5-0.

9.

8. The battery cell according to claim 1, characterized in that, The connection between the cover plate and the housing has a weld, and in the first direction, the minimum distance between the buffer part and the weld is 5mm-15mm.

9. The battery cell according to claim 1, characterized in that, In the first direction, the housing has a bottom wall surface at the end away from the opening in the first direction, and the buffer extends to the bottom wall surface.

10. The battery cell according to claim 1, characterized in that, The area of ​​the first sidewall is greater than the area of ​​the remaining walls adjacent to the first sidewall.

11. The battery cell according to claim 1, characterized in that, The housing also includes a second sidewall disposed opposite to it, and at least one of the second sidewalls is provided with the buffer portion.

12. The battery cell according to claim 1, characterized in that, The buffer portion is a rectangular protrusion, a wavy protrusion, an arc-shaped protrusion, or an irregularly shaped protrusion.

13. The battery cell according to claim 1, characterized in that, The minimum distance between the periphery of the explosion-proof valve and the periphery of the cover plate is 5mm.

14. A battery pack, characterized in that, Includes the battery cell as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-13 or a battery pack according to claim 14.

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