Battery cell, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. Each battery monomer comprises a shell, an electrode assembly and an end cover, and the shell is provided with an opening; the electrode assembly is arranged in the shell; the end cover covers the opening of the shell and comprises a cover body and a protruding part, the protruding part is arranged on the side, facing the electrode assembly, of the cover body and comprises a supporting wall and a connecting wall, the supporting wall is arranged on the side, facing the electrode assembly, of the supporting wall, the connecting wall is connected with the cover body and the supporting wall, and the side, away from the electrode assembly, of the supporting wall is provided with a concave part. The reliability of the battery monomer can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] In recent years, with the rapid development of new energy technologies, new energy vehicles have been increasingly widely used and are gradually replacing traditional fuel vehicles, becoming one of the mainstream modes of transportation. As the power source of new energy vehicles, the power battery is one of their core components; therefore, the safety performance of the power battery has become a key focus of attention.

[0003] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device that can improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and an end cap. The housing has an opening; the electrode assembly is disposed inside the housing; the end cap is disposed over the opening of the housing, and the end cap includes a cover body and a protrusion. The protrusion is disposed on the side of the cover body facing the electrode assembly, and the protrusion includes a support wall and a connecting wall. The support wall is disposed on the side facing the electrode assembly, and the connecting wall connects the cover body and the support wall. The support wall has a recess on the side away from the electrode assembly.

[0006] In the above scheme, the support wall and the connecting wall together form a protrusion that protrudes to one side of the electrode assembly, which supports the electrode assembly. At the same time, by setting a recessed part on the side of the support wall away from the electrode assembly, the elongated part of the electrode sheet can be avoided, reducing the risk of the protrusion damaging the electrode sheet and preventing electrode sheet deformation to a certain extent, thereby improving the reliability of the battery cell.

[0007] In some embodiments, protrusions are provided at both ends of the cover along the length of the battery cell.

[0008] In the above solution, by providing protrusions at both ends along the length of the battery cell, the support effect on the end of the electrode assembly can be improved, thereby improving the stability of the electrode assembly during transportation or operation.

[0009] In some embodiments, the connecting wall includes a first connecting sub-wall and a second connecting sub-wall disposed along the length direction, the second connecting sub-wall being located on the outer side of the battery cell relative to the first connecting sub-wall, and a recess being disposed on the side of the supporting wall close to the first connecting sub-wall.

[0010] In the above solution, by setting the recessed portion on the side close to the first connector wall facing the inner side of the battery cell, the widened portion of the negative electrode sheet of the inner ring of the wound electrode assembly can be avoided, thereby both supporting and fixing the electrode assembly and reducing the risk of the protrusion damaging the negative electrode sheet.

[0011] In some embodiments, the edge of the recess and the edge of the protrusion have a predetermined gap along the width direction of the battery cell.

[0012] In the above solution, by setting a preset gap between the edge of the recessed portion along the width direction and the edge of the protruding portion along the width direction, the area of ​​the protruding portion can be increased, thereby increasing the support of the end cap on the electrode assembly while reducing the risk of damaging the electrode sheet.

[0013] In some embodiments, the recess includes a first sub-edge and a second sub-edge near the second connecting sub-wall. The first sub-edge and the second sub-edge are respectively connected to the edges of both ends of the support wall along the width direction of the battery cell, and the first sub-edge and the second sub-edge are respectively inclined toward the direction of the second connecting sub-wall.

[0014] In the above scheme, by connecting the inclined first sub-edge and the second sub-edge to the edge of the support wall respectively, the area of ​​the recessed part is increased, which to a certain extent avoids more of the electrode being damaged by pressure.

[0015] In some embodiments, the recess further includes a third sub-edge, one end of the first sub-edge is connected to the edge of the support wall, and the other end of the first sub-edge is connected to the third sub-edge; one end of the second sub-edge is connected to the edge of the support wall, and the other end of the second sub-edge is connected to the third sub-edge.

[0016] In the above scheme, the setting of the third sub-edge can provide a certain degree of fixation for the end of the electrode assembly.

[0017] In some embodiments, the first sub-edge and the second sub-edge are interconnected.

[0018] In the above solution, by connecting the first sub-edge and the second sub-edge to each other, the area of ​​the recessed portion can be further increased, thereby further reducing the risk of the end cap damaging the electrode sheet.

[0019] In some embodiments, the thickness of the recess gradually decreases in the direction along the length of the battery cell and pointing towards the interior of the battery cell.

[0020] In the above solution, by setting the recessed part to be inclined, the corner of the electrode can be prevented from getting stuck on the right-angle side, thus avoiding damage to the electrode.

[0021] In some embodiments, each support wall is provided with a plurality of spaced recesses.

[0022] In the above solution, by setting multiple recesses at different positions on each support wall, the risk of the electrode plates at different positions of the electrode assembly corresponding to each protrusion being damaged by pressure can be reduced.

[0023] In some embodiments, the connecting wall is provided with an exhaust port for the flow of gas inside the battery cell.

[0024] In the above scheme, by setting vent holes on the connecting wall, when a battery cell experiences thermal runaway, the gas at the bottom of the battery cell can flow through the vent holes to the pressure relief mechanism for discharge, thereby reducing the risk of the battery cell exploding.

[0025] Secondly, embodiments of this application also provide a battery device, including a battery cell of any of the above embodiments.

[0026] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to provide electrical energy.

[0027] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0030] Figure 2 Exploded views of battery devices according to some embodiments of this application;

[0031] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application;

[0032] Figure 4 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0033] Figure 5 These are schematic diagrams of the end cap structure of some embodiments of this application;

[0034] Figure 6 This is a top view of the end cap of some embodiments of this application;

[0035] Figure 7 This is a top view of the end cap of some other embodiments of this application;

[0036] Figure 8 This is a top view of the end cap of some embodiments of this application;

[0037] Figure 9 This is a schematic diagram of the end cap structure of some other embodiments of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor; 10, Top cover; 30, Housing; 400, Battery module; 20, Battery cell; 22, Housing; 21, End cap; 23, Electrode assembly; 26, Electrode terminal; 40, Cover; 50, Protrusion; 51, Support wall; 52, Connecting wall; 521, First connecting sub-wall; 522, Second connecting sub-wall; 523, Vent; 53, Recess; 531, First sub-edge; 532, Second sub-edge; 533, Third sub-edge; 60, Pressure relief mechanism; X, Length direction; Y, Width direction. Detailed Implementation

[0040] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, 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 on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0042] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0043] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application 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 direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid / square battery cells, and pouch battery cells, and the embodiments of this application are not limited thereto.

[0045] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0046] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0047] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0048] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0049] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0050] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0051] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0052] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0053] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0054] Please refer to Figure 2 , Figure 2 This is an exploded view of the apparatus provided in some embodiments of this application. The battery device 100 includes a battery housing and battery cells 20. In some embodiments, the battery housing may include a top cover 10 and a housing 30, with the top cover 10 and housing 30 covering each other, and the top cover 10 and housing 30 together defining a receiving cavity for receiving the battery cells 20. The housing 30 may be a hollow structure with one end open, and the top cover 10 may be a plate-like structure, with the top cover 10 covering the open side of the housing 30 so that the top cover 10 and housing 30 together define the receiving cavity; the top cover 10 and housing 30 may also be hollow structures with one side open, with the open side of the top cover 10 covering the open side of the housing 30. Of course, the battery housing formed by the top cover 10 and housing 30 can be of various shapes, such as a cylinder, a cuboid, etc.

[0055] Figure 3This is a schematic diagram of the structure of a battery module according to some embodiments of this application. In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 20 is housed in a housing. Of course, the battery device 100 can also be in the form of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module 400, and then multiple battery modules 400 are connected in series, parallel, or in a mixed manner to form a whole and housed in a housing. The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component for realizing the electrical connection between multiple battery cells 20.

[0056] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0057] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 26 can be provided on end cap 21. Electrode terminals 26 can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0058] To prevent the electrode assembly from shifting upwards during transportation or operation, a protrusion is usually provided on the side of the end cap facing the electrode assembly. However, the protrusion can easily damage the electrode plates of the electrode assembly. For example, the negative electrode plate is wider than the positive electrode plate, making the width of the negative electrode plate relatively larger along the height direction of the battery cell. The protrusion can easily damage the negative electrode plate, causing it to deform, or even causing the negative electrode plate to short-circuit with the positive electrode plate, reducing the reliability of the battery cell.

[0059] To address the aforementioned technical problems, this application provides a battery cell comprising a housing, an electrode assembly, and an end cap. The housing has an opening; the electrode assembly is disposed inside the housing; the end cap covers the opening of the housing and includes a cover body and a protrusion. The protrusion is disposed on the side of the cover body facing the electrode assembly. The protrusion includes a support wall and a connecting wall. The support wall is disposed on the side facing the electrode assembly, and the connecting wall connects the cover body and the support wall. The support wall has a recess on the side away from the electrode assembly.

[0060] In the above scheme, the support wall and the connecting wall together form a protrusion that protrudes to one side of the electrode assembly, which supports the electrode assembly. At the same time, by setting a recessed part on the side of the support wall away from the electrode assembly, the elongated part of the electrode sheet can be avoided, reducing the risk of the protrusion damaging the electrode sheet and preventing electrode sheet deformation to a certain extent, thereby improving the reliability of the battery cell.

[0061] Figure 5 This is a schematic diagram of the end cap structure of some embodiments of this application.

[0062] like Figure 5 As shown, in a first aspect, embodiments of this application provide a battery cell 20, which includes a housing 22, an electrode assembly 23, and an end cap 21. The housing 22 has an opening; the electrode assembly 23 is disposed inside the housing 22; the end cap 21 covers the opening of the housing 22, and the end cap 21 includes a cover body 40 and a protrusion 50. The protrusion 50 is disposed on the side of the cover body 40 facing the electrode assembly 23, and the protrusion 50 includes a support wall 51 and a connecting wall 52. The support wall 51 is disposed on the side facing the electrode assembly 23, and the connecting wall 52 connects the cover body 40 and the support wall 51. The support wall 51 has a recess 53 on the side away from the electrode assembly 23.

[0063] The protrusion 50 can be fixed to the cover 40, or it can be a separate, independent component. The cover 40 can be made of the same material as the housing 22, such as aluminum or steel. The protrusion 50 can be made of insulating material, or its surface can be coated with insulating material to isolate the electrode assembly 23 inside the housing 22 from the cover 40, thereby reducing the risk of short circuits. The protrusion 50 can also effectively support the end face of the electrode assembly 23. After the electrode assembly 23 is installed in the housing and the end cap 21 is welded, the electrode assembly 23 is under slight pressure and insufficient restraint, which can easily affect the life of the winding core or cause a short circuit. Therefore, the protrusion 50 needs to effectively support the end face of the electrode assembly 23 to reduce the possibility of the electrode assembly 23 moving up and down.

[0064] A pressure relief mechanism 60 can be provided on the end cap 21. This mechanism 60 can be a pressure valve type, containing an elastic component (such as a spring) and a sealing structure. Under normal circumstances, the spring force keeps the sealing structure closed, preventing gas leakage from the battery. When the pressure exceeds the spring's resistance, the sealing structure is opened, and the gas is released through a designated channel. Alternatively, the pressure relief mechanism 60 can utilize material properties. For example, it can employ a fracture-resistant weak point; when the pressure reaches the limit that the weak point can withstand, it ruptures, releasing the gas.

[0065] Along the height of the battery cell 20, the length of the negative electrode is generally greater than that of the positive electrode, so that the edge of the negative electrode extends beyond the edge of the positive electrode to prevent lithium plating to some extent. Especially for the wound electrode assembly 23, the inner and outer rings are more prone to misalignment, so the width of the inner and outer rings along the height of the battery cell 20 is increased to improve the stability of the wound electrode assembly 23. However, the widened electrode portion is also more easily damaged and deformed by the protrusion 50 of the end cap 21.

[0066] Because the protrusion 50 has a recess 53, the average thickness of the recess 53 is reduced, which can avoid the widened electrode portion. This embodiment is particularly suitable for inverted battery cells 20, where the end cap 21 is located below the electrode assembly 23 and supports the electrode assembly 23. When the protrusion 50 supports the electrode assembly 23, it is more likely to damage the electrode; therefore, this embodiment is particularly effective for inverted battery cells 20. Of course, this embodiment is also applicable to battery cells 20 where the end cap 21 is located above the electrode assembly 23.

[0067] In the above scheme, the support wall 51 and the connecting wall 52 together form a protrusion 50 protruding to one side of the electrode assembly 23, which supports the electrode assembly 23. At the same time, by providing a recess 53 on the side of the support wall 51 away from the electrode assembly 23, the extended part of the electrode sheet of the electrode assembly 23 can be avoided, reducing the risk of the protrusion 50 damaging the electrode sheet and preventing the electrode sheet from deforming to a certain extent, thereby improving the reliability of the battery cell 20.

[0068] In some embodiments, protrusions 50 are provided at both ends of the cover 40 along the length direction X of the battery cell 20.

[0069] For example, protrusions 50 are provided at both the left and right ends of the cover 40, and each protrusion 50 is provided with a recess 53 with a smaller average thickness, which can avoid the widened part of the electrode sheet at the corner of the wound electrode assembly 23.

[0070] In the above solution, by providing protrusions 50 at both ends along the length direction X of the battery cell 20, the support effect on the end of the electrode assembly 23 can be improved, thereby improving the stability of the electrode assembly 23 during transportation or operation.

[0071] In some embodiments, the connecting wall 52 includes a first connecting sub-wall 521 and a second connecting sub-wall 522 disposed along the length direction X. The second connecting sub-wall 522 is located on the outer side of the battery cell 20 relative to the first connecting sub-wall 521, and a recess 53 is disposed on the side of the support wall 51 near the first connecting sub-wall 521.

[0072] The non-recessed portion of the support wall 51 is used to support the electrode assembly 23. The recessed portion 53 can be in contact with the electrode end of the electrode assembly 23, or have a certain gap.

[0073] For example, the pressure relief mechanism 60 is disposed between two protrusions 50, with the first connecting sub-wall 521 being closer to the pressure relief mechanism 60 than the second connecting sub-wall 522. The recess 53 is relatively closer to the first connecting sub-wall 521.

[0074] The support wall 51 can be a flat plane, and then it is recessed inward to form a recessed part 53. After the recessed part 53 is connected to a transitional plane, it is recessed inward to the side away from the electrode assembly 23 until the plane of the cover 40, forming a step.

[0075] In the above solution, by setting the recessed portion 53 on the side close to the first connecting sub-wall 521 facing the inner side of the battery cell 20, the widened portion of the negative electrode sheet of the inner ring of the wound electrode assembly 23 can be avoided, thereby both supporting and fixing the electrode assembly 23 and reducing the risk of the protrusion 50 damaging the negative electrode sheet.

[0076] Figure 6 This is a top view of the end cap of some embodiments of this application.

[0077] like Figure 6 As shown, in some embodiments, the edge of the recess 53 and the edge of the protrusion 50 have a predetermined gap along the width direction Y of the battery cell 20.

[0078] That is, the protrusion 50 does not recede downwards on both sides along the width direction Y of the battery cell 20, but only in the middle part. The preset gap can be set as needed, and the preset gap can support the electrode assembly 23.

[0079] In the above solution, by setting a preset gap between the edge of the recessed portion 53 along the width direction Y and the edge of the protrusion 50 along the width direction Y, the area of ​​the protrusion 50 can be increased, thereby increasing the support of the end cap 21 on the electrode assembly 23 while reducing the risk of damaging the electrode sheet.

[0080] Please refer to the following: Figure 7 and Figure 8 In some embodiments, the recess 53 includes a first sub-edge 531 and a second sub-edge 532 near the second connecting sub-wall 522. The first sub-edge 531 and the second sub-edge 532 are respectively connected to the edges of the support wall 51 at both ends along the width direction Y of the battery cell 20, and the first sub-edge 531 and the second sub-edge 532 are respectively inclined toward the direction of the second connecting sub-wall 522.

[0081] The first sub-edge 531 and the second sub-edge 532 can be straight edges or curved edges. The protrusion 50 is recessed downward on both sides along the width direction Y of the battery cell 20, and the first sub-edge 531 and the second sub-edge 532 gradually move closer together.

[0082] In the above scheme, by connecting the inclined first sub-edge 531 and the second sub-edge 532 to the edge of the support wall 51 respectively, the area of ​​the recessed part 53 is increased, which to a certain extent avoids more of the electrode being damaged by pressure.

[0083] Figure 7 This is a top view of the end cap of some other embodiments of this application.

[0084] like Figure 7 As shown, in some embodiments, the recess 53 further includes a third sub-edge 533, one end of the first sub-edge 531 is connected to the edge of the support wall 51, and the other end of the first sub-edge 531 is connected to the third sub-edge 533; one end of the second sub-edge 532 is connected to the edge of the support wall 51, and the other end of the second sub-edge 532 is connected to the third sub-edge 533.

[0085] The third sub-edge 533 can be parallel to or intersect with the width direction Y of the battery cell 20.

[0086] In the above scheme, the setting of the third sub-edge 533 can fix the end of the electrode assembly 23 to a certain extent.

[0087] Figure 8 This is a top view of the end cap of some embodiments of this application.

[0088] like Figure 8 As shown, in some embodiments, the first sub-edge 531 and the second sub-edge 532 are interconnected.

[0089] The first sub-edge 531 and the second sub-edge 532 are connected to form a triangle, which can create a large recessed area 53.

[0090] In the above solution, by connecting the first sub-edge 531 and the second sub-edge 532 to each other, the area of ​​the recessed portion 53 can be further increased, and the risk of the end cap 21 damaging the electrode sheet can be further reduced.

[0091] In some embodiments, the thickness of the recess 53 gradually decreases in the direction along the length X of the battery cell 20 and in the direction pointing into the battery cell 20.

[0092] In other words, the recess 53 is not directly recessed vertically downward at a 90-degree angle, but rather gradually recesses downward at a slope, with the thickness gradually decreasing. If the recess 53 were recessed vertically downward at a 90-degree angle, the corner of the wound electrode assembly 23 would easily get stuck on the right-angled side of the recess 53, or the end of the stacked electrode assembly 23 would easily get stuck on the right-angled side of the recess 53.

[0093] For example, the protrusion 50 is provided at the end of the battery cell 20 along the length direction X. The recess 53 of the protrusion 50 on the left side gradually recesses from left to right in the direction away from the electrode assembly 23, and the thickness gradually decreases from left to right. The recess 53 of the protrusion 50 on the right side gradually recesses from right to left in the direction away from the electrode assembly 23, and the thickness gradually decreases from right to left.

[0094] In the above solution, by setting the recessed part 53 to be inclined, the corner of the electrode can be prevented from getting stuck on the right-angle side to a certain extent, thus avoiding damage to the electrode.

[0095] In some embodiments, each support wall 51 is provided with a plurality of spaced recesses 53.

[0096] Multiple spaced recesses 53 can be provided on each support wall 51 along the length direction X of the battery cell 20, or along the width direction Y of the battery cell 20. Alternatively, multiple spaced recesses 53 can be provided in different directions.

[0097] In the above solution, by providing multiple recesses 53 at different positions of each support wall 51, the risk of the electrode sheets at different positions of the electrode assembly 23 corresponding to each protrusion 50 being damaged by pressure can be reduced.

[0098] Figure 9 This is a schematic diagram of the end cap structure of some other embodiments of this application.

[0099] like Figure 9 As shown, in some embodiments, the connecting wall 52 is provided with an exhaust port 523 for the flow of gas inside the battery cell 20.

[0100] Under certain abnormal conditions, a single battery cell (20) may experience thermal runaway. Thermal runaway is usually caused by a series of complex and uncontrolled chemical reactions inside the battery, such as severe heating caused by abnormal operating conditions like internal short circuits, overcharging, and over-discharging. During thermal runaway, substances such as the electrolyte inside the battery undergo decomposition and vaporization, resulting in the generation of a large amount of gas.

[0101] If these gases cannot be released in time, they will accumulate rapidly inside the battery cell 20, causing a sharp increase in internal pressure. Since the battery cell 20 is generally a relatively sealed structure, excessive internal pressure with nowhere to be released will exert enormous compressive force on the battery casing 22 and internal components. When the pressure exceeds the battery's tolerance limit, it is highly likely to cause serious safety accidents such as explosions.

[0102] The vent 523 can be rectangular, circular, or trapezoidal in shape. The vent 523 acts as a "bridge" between the battery cell 20 and the pressure relief mechanism 60, allowing accumulated gas to pass through and be discharged in an orderly manner, thereby effectively alleviating the ever-increasing pressure inside the battery cell 20 and keeping the pressure within a relatively safe range.

[0103] In the above scheme, by setting an exhaust hole 523 on the connecting wall 52, when the battery cell 20 experiences thermal runaway, the gas at the bottom of the battery cell 20 can flow through the exhaust hole 523 to the pressure relief mechanism 60 for discharge, thereby reducing the risk of the battery cell 20 exploding.

[0104] Secondly, embodiments of this application also provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0105] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device 100, which is used to provide electrical energy.

[0106] According to some embodiments of this application, a battery cell 20 is provided. The battery cell 20 includes a housing 22, an electrode assembly 23, and an end cap 21. The housing 22 has an opening. The electrode assembly 23 is disposed inside the housing 22. The end cap 21 covers the opening of the housing 22. The end cap 21 includes a cover body 40 and a protrusion 50. The protrusion 50 is disposed on the side of the cover body 40 facing the electrode assembly 23. The protrusion 50 includes a support wall 51 and a connecting wall 52. The support wall 51 is disposed on the side facing the electrode assembly 23. The connecting wall 52 connects the cover body 40 and the support wall 51. The support wall 51 has a recess 53 on the side away from the electrode assembly 23. The thickness of the recess 53 gradually decreases in the direction X along the length direction of the battery cell 20 and pointing towards the interior of the battery cell 20.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The casing has an opening; The electrode assembly is disposed inside the housing; An end cap is provided over the opening of the housing. The end cap includes a cover body and a protrusion. The protrusion is located on the side of the cover body facing the electrode assembly. The protrusion includes a support wall and a connecting wall. The support wall is located on the side facing the electrode assembly. The connecting wall connects the cover body and the support wall. The support wall has a recess on the side away from the electrode assembly.

2. The battery cell according to claim 1, characterized in that, The protrusions are provided at both ends of the cover along the length of the battery cell.

3. The battery cell according to claim 2, characterized in that, The connecting wall includes a first connecting sub-wall and a second connecting sub-wall arranged along the length direction. The second connecting sub-wall is located on the outer side of the battery cell relative to the first connecting sub-wall, and the recess is located on the side of the supporting wall near the first connecting sub-wall.

4. The battery cell according to claim 3, characterized in that, Along the width direction of the battery cell, the edge of the recess and the edge of the protrusion have a predetermined gap.

5. The battery cell according to claim 3, characterized in that, The recessed portion includes a first sub-edge and a second sub-edge near the second connecting sub-wall. The first sub-edge and the second sub-edge are respectively connected to the edges of both ends of the support wall along the width direction of the battery cell, and the first sub-edge and the second sub-edge are respectively inclined towards the direction of the second connecting sub-wall.

6. The battery cell according to claim 5, characterized in that, The recessed portion further includes a third sub-edge, one end of the first sub-edge is connected to the edge of the support wall, and the other end of the first sub-edge is connected to the third sub-edge; one end of the second sub-edge is connected to the edge of the support wall, and the other end of the second sub-edge is connected to the third sub-edge.

7. The battery cell according to claim 5, characterized in that, The first sub-edge and the second sub-edge are connected to each other.

8. The battery cell according to any one of claims 1-7, characterized in that, The thickness of the recess gradually decreases along the length of the battery cell and in the direction pointing inwards from the battery cell.

9. The battery cell according to any one of claims 1-7, characterized in that, Each of the support walls is provided with a plurality of spaced recesses.

10. The battery cell according to any one of claims 1-7, characterized in that, The connecting wall is provided with an exhaust port for the internal gas of the battery cell to circulate.

11. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-10.

12. An electrical appliance, characterized in that, Includes the battery device according to claim 11, the battery device being used to provide electrical energy.

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