Battery monomer, battery device and electric equipment

Abstract

The utility model relates to the technical field of battery equipment, and discloses a battery monomer, a battery device and electric equipment. The single battery comprises a shell, the shell comprises a bottom wall, two large side walls and two small side walls, the two large side walls and the two small side walls are connected to the bottom wall, a containing space is defined by the bottom wall, the two large side walls and the two small side walls, and corner positions are arranged between the large side walls and the adjacent small side walls; the electrode assembly is accommodated in the accommodating space; the binding structure comprises a body part and side edge parts connected to the two ends of the body part, the body part is arranged between the large side wall and the electrode assembly, the corner positions are filled with the side edge parts, and the side edge parts extend to the small side wall. By applying the technical scheme, the problem that the use safety performance of the battery monomer is affected due to the fact that the electrode piece of the electrode assembly including but not limited to the battery monomer is extruded and wrinkled at the corner position is solved.

Description

Technical Field

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

[0002] Currently, battery devices are generally formed by assembling at least one battery cell into a casing and connecting it with other components. The battery cell performs charging and energy storage or discharging and energy supply, i.e., charge and discharge operation. During the charge and discharge process of a square battery cell, the electrode assembly of the cell undergoes an expansion process. Because the casing of a square battery cell has corners, and the electrode assembly is generally wound, there is a large gap between the electrode assembly and the corners when the electrode assembly is assembled into the casing. This causes the electrode plates of the electrode assembly to easily move towards the corners during the expansion process. Furthermore, the portion of the electrode plate that has moved to the corner due to the expansion process cannot return to its original position; that is, the electrode plate cannot recover after deforming towards the corner. Over time, the deformation of the electrode plate accumulates at the corner, causing the electrode plate to wrinkle and deform. The wrinkled areas of the electrode plate are prone to dendrite formation that punctures the separator of the electrode assembly, leading to an internal short circuit in the battery cell. This, in turn, makes the battery cell susceptible to thermal runaway, affecting the safety performance of the battery cell. Utility Model Content

[0003] The purpose of this application is to provide a battery cell, battery device, and electrical equipment to solve the problem that the electrode plates of the electrode assembly of the battery cell are squeezed and wrinkled at the corners, which affects the safety performance of the battery cell.

[0004] To achieve the above objectives, according to a first aspect of an embodiment of this application, a battery cell is provided, comprising:

[0005] The shell includes a bottom wall and two large side walls and two small side walls connected to the bottom wall. The bottom wall, the two large side walls and the two small side walls enclose an accommodating space. There is a corner between the large side walls and the adjacent small side walls.

[0006] Electrode assembly, housed within the housing space;

[0007] The restraint structure includes a main body and side portions connected to both ends of the main body. The main body is disposed between the large sidewall and the electrode assembly, the side portions fill the corner positions, and the side portions extend to the small sidewall.

[0008] The battery cell of this application uses a binding structure to constrain and restrict the electrode assembly within the housing's accommodating space. Specifically, the two sides of the binding structure's main body contact the large sidewall and the electrode assembly, respectively. The side portions at both ends of the binding structure fill the corners of the housing and extend to the small sidewall, abutting against the small sidewall and the electrode assembly. Thus, the electrode assembly is constrained by the binding structure. During charging and discharging operations and the accompanying expansion process, the electrode plates opposite the corners are constrained by the side portions of the binding structure, and the portion opposite the large sidewall is abutted and constrained by the main body of the binding structure. This reduces the degree to which the electrode plates opposite the corners move towards the corners, effectively slowing down or preventing the accumulation of movement and subsequent squeezing and wrinkling of the electrode plates. This effectively reduces the probability of dendrite formation on the electrode plates, thus effectively reducing the probability of internal short circuits and thermal runaway in the battery cell, effectively improving the safety performance of the battery cell.

[0009] In some embodiments of this application, the battery cell includes two binding structures, which are respectively disposed on both sides of the electrode assembly along its thickness direction, and each corner is filled with a side portion.

[0010] In some embodiments of this application, the two binding structures are integrally formed to form a rectangular frame structure; or, the two binding structures are separately arranged, with the two binding structures extending to the two side portions of the same small sidewall that are connected to each other or spaced apart.

[0011] In some embodiments of this application, the two side portions of the two binding structures extend to the same small sidewall and are connected. The expansion of the electrode assembly along the thickness direction X of the battery cell is constrained by the body portions of the two binding structures, the expansion of the electrode assembly along the length direction Y of the battery cell is constrained by the side portions of the binding structures, and the side portions of the binding structures fill the large gap formed between the electrode assembly and the corner position, thereby the electrode sheet at the part of the electrode assembly opposite to the corner position is constrained by the side portions of the binding structures.

[0012] In some embodiments of this application, the electrode assembly includes a straight portion and a corner portion. The straight portion is disposed opposite to the main body portion, and the corner portion is disposed opposite to the corner position. The side portion facing the electrode assembly has an arc-shaped surface, which is adapted to fit and conform to the corner portion (the corner portion is the position of the electrode assembly opposite to the corner position). The side portion of the binding structure can abut and restrict the position of the electrode assembly opposite to the corner position, thereby constraining and restricting the electrode sheet at the part of the electrode assembly opposite to the corner position by the side portion of the binding structure.

[0013] In some embodiments of this application, the portion of the side extending to the small sidewall is further provided with an abutting surface on the side facing away from the small sidewall. The abutting surface is adjacent to the arcuate surface and is parallel to the inner surface of the small sidewall. Furthermore, the battery cell includes multiple electrode assemblies, which are stacked in the receiving space, with the ends of the multiple electrode assemblies facing the small sidewall abutting against the corresponding abutting surfaces.

[0014] In some embodiments of this application, the battery cell includes at least two electrode assemblies, which are stacked together. Two separate binding structures are also provided, extending to two opposite sides of the same small sidewall. Each side has at least one abutting arc surface located at the end of the abutting surface away from the arc-shaped surface. The abutting arc surface is adapted to fit and adhere to the arc-shaped surfaces of the electrode assemblies that are offset at corners. The arc-shaped surfaces of each electrode assembly are all wrapped and restrained by the abutting arc surface, further improving the ability of the side sides of the binding structure to constrain the expansion of the electrode assembly along the length direction Y.

[0015] In some embodiments of this application, the two binding structures are separately arranged, and the two binding structures extend to two side portions of the same small sidewall that are spaced apart; the battery cell includes only one electrode assembly, the end of which faces the small sidewall abuts against the small sidewall; or, the battery cell includes multiple electrode assemblies, which are stacked in the receiving space, and the ends of the multiple electrode assemblies facing the small sidewall all abut against the small sidewall.

[0016] In some embodiments of this application, the height of the binding structure is less than or equal to the height of the electrode assembly along the height direction of the battery cell. The two binding structures are fully assembled into the receiving space of the housing, so that when the end cap assembly is closed onto the housing, the binding structures will not interfere with the end cap assembly, allowing the end cap assembly to be smoothly closed onto the housing.

[0017] In some embodiments of this application, the restraining structure is supported by an elastic material capable of elastic deformation. When the restraining structure is assembled into the receiving space, it undergoes elastic deformation due to the clamping and compression of the housing and the electrode assembly, thereby achieving a high degree of fit between the corners of the housing, the sides of the restraining structure, and the electrode assembly.

[0018] In some embodiments of this application, the elastic material used in the restraint structure is one of polytetrafluoroethylene, silicone, polyurethane rubber, thermoplastic elastomer, and EPDM rubber.

[0019] In some embodiments of this application, the binding structure is a component made of porous material. Based on the constraint and restriction provided by the binding structure on the electrode assembly, the porous space formed by the binding structure made of porous material can store electrolyte.

[0020] In some embodiments of this application, the battery cell further includes an insulating film having a covering space in which the binding structure and electrode assembly are disposed. Furthermore, the circumferential edge of the end cap assembly is sealed to the insulating film. The insulating film prevents electrolyte leakage from contacting the casing and causing an internal short circuit leading to thermal runaway, thus improving the safety performance of the battery cell.

[0021] In some embodiments of this application, the two ends of the restraining structure along the height direction of the battery cell abut against the end cap assembly and the bottom wall, respectively. This prevents the restraining structure and the electrode assembly from wobbling relative to the housing within the accommodating space.

[0022] In some embodiments of this application, the restraint structure further includes a bottom, which is connected to the body portion and the side portion. The bottoms of the two restraint structures are connected to each other and abut against the bottom wall. The two connected bottoms of the two restraint structures can replace the aforementioned bottom support plate. Furthermore, the bottoms of the two restraint structures and the insulating film separate the bottom end of the electrode assembly from the bottom wall of the housing, ensuring the insulation between the bottom end of the electrode assembly and the bottom wall of the housing.

[0023] In some embodiments of this application, the two restraint structures are assembled into a single component.

[0024] According to a second aspect of an embodiment of this application, a battery device is provided. The battery device includes a battery cell as described above, the battery cell being used to store or provide electrical energy.

[0025] According to a third aspect of an embodiment of this application, an electrical appliance is provided. The electrical appliance includes an electrical load; and,

[0026] The electrical equipment also includes multiple battery cells as described above, and the electrical load is electrically connected to the multiple battery cells;

[0027] Alternatively, the electrical equipment may also include a battery device as described above, with the electrical load electrically connected to the battery device;

[0028] Among them, individual battery cells or battery devices are used to store or provide electrical energy. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art 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.

[0030] Figure 1 This is a perspective view of a battery cell according to an embodiment of this application;

[0031] Figure 2 This is an exploded view of a first type of battery cell according to an embodiment of this application;

[0032] Figure 3 This is a top view of a second type of battery cell according to an embodiment of this application, wherein the end cap assembly and the insulating film are not shown;

[0033] Figure 4 for Figure 3 The diagram shows a structural schematic of one of the binding structures of a battery cell being assembled into the receiving space.

[0034] Figure 5 This is a top view of a third type of battery cell according to an embodiment of this application, wherein the end cap assembly and the insulating film are not shown;

[0035] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0036] Figure 7 This is a top view of a fourth type of battery cell according to an embodiment of this application, wherein the end cap assembly and the insulating film are not shown;

[0037] Figure 8 for Figure 7 Enlarged view of point B in the middle;

[0038] Figure 9 This is a top view of a fifth type of battery cell according to an embodiment of this application, wherein the end cap assembly and the insulating film are not shown;

[0039] Figure 10 for Figure 9 Enlarged view of point C in the middle;

[0040] Figure 11 This is an exploded view of the sixth type of battery cell according to an embodiment of this application;

[0041] Figure 12 This is an exploded view of a battery device according to an embodiment of this application;

[0042] Figure 13 This is a schematic diagram of the structure of an electrical device according to an embodiment of this application.

[0043] The figures in the diagram are labeled as follows:

[0044] 100. Battery cell;

[0045] 10. Shell; 12. Large sidewall; 13. Small sidewall; 14. Corner; 15. Accommodation space;

[0046] 20. Electrode assembly; 21. Straight section; 22. Corner section;

[0047] 30. Restraint structure; 31. Main body; 32. Side part; 33. Bottom; 34. Abutting surface; 35. Curved surface; 36. Abutting curved surface;

[0048] 40. Insulating film; 41. Encapsulation space;

[0049] 50. End cap assembly; 51. End cap body; 52. Pole post structure; 53. Injection port; 54. Pressure relief mechanism;

[0050] 61. Plane of symmetry; 62. Base plate;

[0051] 200. Battery assembly; 201. Box body; 202. Box cover; 203. Assembly space;

[0052] 400. Electrical equipment; 410. Electrical load; 420. Control device; 430. Chassis; 440. Wheel;

[0053] X, thickness direction; Y, length direction; Z, height direction. Detailed Implementation

[0054] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0055] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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.

[0056] Furthermore, the terms "first," "second," etc., 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. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "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 or an electrical connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants (batteries used in these applications are generally referred to as energy storage batteries), but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace (batteries used in these applications are generally referred to as power batteries). With the continuous expansion of battery device applications, the requirements for product quality in various fields are also constantly increasing. The quality requirements for battery devices include not only safety performance but also service life, demanding continuous improvement in both safety and lifespan.

[0059] In related technologies, the electrode assembly of a battery cell is initially formed by stacking and combining positive electrode sheets, negative electrode sheets, and a separator, followed by winding. The wound electrode assembly then undergoes hot or cold pressing to compress and shape the positive electrode sheets, negative electrode sheets, and separator into a dense state, resulting in a square structure, commonly known as a square electrode assembly. Because the electrode assembly is formed through winding and compression molding processes, the final assembly has large surfaces on both sides and smaller curved surfaces at both ends. When the electrode assembly is assembled into the housing, the curved surfaces and corresponding corners are empty and unconstrained.

[0060] During long-term use of a battery cell, the active materials of the electrode assembly repeatedly undergo reversible electrochemical reactions with the electrolyte, causing the electrode assembly to expand. Because there are gaps and no constraints between the curved surface and the corresponding corners, the electrode sheets of the electrode assembly tend to move towards the corners during expansion. Furthermore, the portion of the electrode sheet that has moved to the corner due to expansion cannot return to its original position; that is, the electrode sheet cannot recover after deforming towards the corner. Over time, the deformation of the electrode sheet accumulates at the corners, causing compression wrinkling. The wrinkled areas of the electrode sheet are prone to dendrite formation that punctures the separator of the electrode assembly, leading to internal short circuits in the battery cell. This, in turn, makes the battery cell susceptible to thermal runaway, affecting the safety performance of the battery cell.

[0061] Based on the above considerations, embodiments of this application provide a battery cell, which is then used to assemble and manufacture battery devices and electrical equipment. In this battery cell, the two sides of the main body of the binding structure contact the large sidewall and the electrode assembly, respectively. The side portions at both ends of the binding structure fill the corners of the casing and extend to the small sidewall, abutting against the small sidewall and the electrode assembly. Thus, the electrode assembly is constrained by the binding structure. During charging and discharging of the electrode assembly and the accompanying expansion process, the electrode plates at the corner positions are constrained by the side portions of the binding structure, and the portion of the electrode assembly opposite the large sidewall is abutted and constrained by the main body of the binding structure. This reduces the degree to which the electrode plates at the corner positions move towards the corner, effectively slowing down or preventing the accumulation of movement and subsequent squeezing and wrinkling of the electrode plates.

[0062] To illustrate the technical solutions provided by the embodiments of this application, the following detailed description is provided in conjunction with specific drawings and embodiments.

[0063] Among them, such as Figure 1 The coordinates shown are X, Y, and Z. Direction X represents the thickness direction, direction Y represents the length direction, and direction Z represents the height direction.

[0064] According to a first aspect of the embodiments of this application, embodiments of this application provide a battery cell 100. For example... Figure 1 and Figure 2 As shown, the battery cell 100 includes a housing 10, an electrode assembly 20, and a restraining structure 30, both of which are assembled within the housing 10. Specifically, the housing 10 includes a bottom wall and two large sidewalls 12 and two small sidewalls 13 connected to the bottom wall. The bottom wall, the two large sidewalls 12, and the two small sidewalls 13 form a receiving space 15. Furthermore, there are corner positions 14 between the large sidewalls 12 and adjacent small sidewalls 13. A total of four circumferentially spaced corner positions 14 are located on the inner wall of the receiving space 15 of the housing 10. The electrode assembly 20 is accommodated within the receiving space 15. The restraint structure 30 includes a main body 31 and side portions 32 connected to both ends of the main body 31 along its length direction Y. The main body 31 is disposed between the large sidewall 12 and the electrode assembly 20, that is, the two sides of the main body 31 are in contact with the large sidewall 12 and the electrode assembly 20 respectively. The side portions 32 fill the corner position 14 and extend to the small sidewall 13. The side portions 32 abut against the small sidewall 13 and the electrode assembly 20.

[0065] The battery cell 100 of this application uses a binding structure 30 to constrain and restrict the electrode assembly 20 assembled in the receiving space 15 of the housing 10. Specifically, the two sides of the body part 31 of the binding structure 30 are in contact with the large side wall 12 and the electrode assembly 20, respectively. The side parts 32 at both ends of the binding structure 30 fill the corner 14 of the housing 10 and extend to the small side wall 13, and the side parts 32 abut against the small side wall 13 and the electrode assembly 20. Thus, the electrode assembly 20 is constrained by the binding structure 30. During the charging and discharging process of the electrode assembly 20 and the accompanying expansion process, the electrode sheet at the location opposite the corner position 14 is constrained by the side portion 32 of the binding structure 30, and the portion of the electrode assembly 20 opposite the large sidewall 12 is abutted and constrained by the body portion 31 of the binding structure 30. This reduces the degree of movement of the electrode sheet at the location opposite the corner position 14 towards the corner position 14, effectively slowing down or preventing the accumulation of movement of the electrode sheet of the electrode assembly 20 and the resulting squeezing and wrinkling. This effectively reduces the probability of dendrite formation on the electrode sheet of the electrode assembly 20, that is, effectively reduces the probability of internal short circuit and thermal runaway in the battery cell 100, effectively improving the safety performance of the battery cell 100.

[0066] It should be noted that, in the embodiments of this application, the "large" of the large sidewall 12 and the "small" of the small sidewall 13 are a pair of relative structures. That is, the large sidewall 12 is "large" relative to the small sidewall 13, and similarly, the "small" of the small sidewall 13 is "small" relative to the large sidewall 12. For the two large sidewalls and the two small sidewalls, they can be directly distinguished by the size of their surface areas.

[0067] In the embodiments of this application, the battery cell 100 provided in the embodiments of this application is a square battery cell, also referred to as a square cell, that is, the housing 10 is a square housing, and a right-angled corner 14 is formed between the large sidewall 12 and the adjacent small sidewall 13. Since the electrode assembly 20 is formed by a winding process and an extrusion forming process, the finally formed electrode assembly 20 has a large surface area on both sides and an arc-shaped surface area at both ends. That is, the electrode assembly 20 includes a straight part 21 and a corner part 22, such as Figures 2 to 4 , Figure 6 , Figure 8 , Figure 10 and Figure 11As shown, the two side surfaces of the straight portion 21 along its thickness direction X are the larger surfaces of the electrode assembly 20, while the surface of the corner portion 22 is part of the smaller arcuate surface of the electrode assembly 20. When the electrode assembly 20 is assembled into the receiving space 15 of the housing 10, the two large surfaces of the electrode assembly 20 face the large sidewall 12 (i.e., the straight portion 21 and the main body portion 31 are opposite each other), and the arcuate surfaces at both ends of the electrode assembly 20 face the small sidewall 13, with the corner portion 22 and the corner position 14 facing each other. Before the binding structure 30 is assembled, the part where the large surface of the electrode assembly 20 meets the arcuate surface (i.e., the corner portion 22) faces the corner position 14, thus forming a large gap between the corner portion 22 and the corner position 14 of the electrode assembly 20. When the restraining structure 30 is assembled into the receiving space 15, the side portion 32 of the restraining structure 30 fills the corner position 14. That is, the side portion 32 fills the gap between the corner portion 22 of the electrode assembly 20 and the corner position 14, creating a large gap. Thus, the electrode sheet at the location opposite the corner portion 22 and corner position 14 of the electrode assembly 20 is constrained by the side portion 32 of the restraining structure 30. This reduces the degree to which the electrode sheet at the corner portion 22 of the electrode assembly 20 moves towards the corner position 14, effectively slowing down or preventing the accumulation of movement and subsequent compression and wrinkling of the electrode sheet. This effectively reduces the probability of dendrite formation on the electrode sheet of the electrode assembly 20, thus effectively reducing the probability of internal short circuits in the battery cell 100 leading to thermal runaway, and effectively improving the safety performance of the battery cell 100.

[0068] In some embodiments of this application, such as Figure 3 and Figure 4As shown, the battery cell 100 includes only one electrode assembly 20. At this time, the outer contour of the battery cell 100 is square sheet-like, commonly known as a square sheet battery. In this battery cell 100, the end of the electrode assembly 20 facing the small sidewall 13 abuts against the small sidewall 13. That is to say, the side portions 32 of the two binding structures 30 assembled into the receiving space 15 are not connected. That is, the two binding structures 30 are separately arranged and the two side portions 32 of the two binding structures 30 extending to the same small sidewall 13 are spaced apart. The arc-shaped surfaces at both ends of the electrode assembly 20 are in contact with the inner wall of the small sidewall 13. In this embodiment, the expansion of the electrode assembly 20 along the thickness direction X of the battery cell 100 is constrained by the body portions 31 of the two binding structures 30, and the expansion of the electrode assembly 20 along the length direction Y of the battery cell 100 is constrained by the two small sidewalls 13 of the housing 10. Furthermore, the side portions 32 of the binding structures 30 fill the gap between the electrode assembly 20 and the corner position 14, thus constraining the electrode sheet at the location opposite to the corner position 14. This reduces the degree of movement of the electrode sheet at the corner portion 22 of the electrode assembly 20 towards the corner position 14, thereby effectively slowing down or preventing the accumulation of movement of the electrode sheet of the electrode assembly 20, which could lead to compression and wrinkling.

[0069] In other embodiments of this application, such as Figure 5 , Figure 7 and Figure 9As shown, the battery cell 100 includes multiple electrode assemblies 20. The battery cell 100 has a square-shaped outline, commonly referred to as a cube battery. In this battery cell 100, the multiple electrode assemblies 20 are stacked in the receiving space 15. The ends of the multiple electrode assemblies 20 facing the small sidewall 13 all abut against the small sidewall 13. That is, the side portions 32 of the two binding structures 30 assembled into the receiving space 15 are not joined together; that is, the two binding structures 30 are separately arranged, and the two side portions 32 of the two binding structures 30 extending to the same small sidewall 13 are spaced apart. Furthermore, the arc-shaped surfaces at both ends of each electrode assembly 20 are in contact with the inner wall of the small sidewall 13. In this embodiment, the expansion of multiple electrode assemblies 20 along the thickness direction X of the battery cell 100 is constrained by the body portions 31 of the two binding structures 30, and the expansion of multiple electrode assemblies 20 along the length direction Y of the battery cell 100 is constrained by the two small sidewalls 13 of the housing 10. Furthermore, the side portions 32 of the binding structures 30 fill the gap between the two outermost electrode assemblies 20 and the corner position 14 along the thickness direction X, thus constraining the electrode sheet at the corner portion 22 opposite to the corner position 14. This reduces the degree of movement of the electrode sheet at the portion opposite to the corner position 14 towards the corner position 14, thereby effectively slowing down or preventing the accumulation of movement of the electrode sheet of the electrode assembly 20, which could lead to compression and wrinkling.

[0070] In the embodiments of this application, such as Figure 2 , Figure 3 , Figure 5 , Figure 7 , Figure 9 and Figure 11 As shown, the battery cell 100 includes two binding structures 30, which are respectively disposed on both sides of the electrode assembly 20 along its thickness direction X. Each corner 14 is filled with a side portion 32. The two binding structures 30 constrain and restrict the electrode assembly 20 assembled into the receiving space 15 of the housing 10. Each corner 14 is filled with a side portion 32, so that the electrode sheet of the part of the electrode assembly 20 opposite to the corner 14 is constrained by the side portion 32 of the binding structure 30, and the part of the electrode assembly 20 opposite to the large sidewall 12 is abutted and constrained by the body portion 31 of the binding structure 30. This reduces the degree of movement of the electrode sheet of the corner portion 22 of the electrode assembly 20 opposite to the corner 14 towards the corner 14, thereby effectively slowing down or avoiding the accumulation of movement of the electrode sheet of the electrode assembly 20 and causing squeezing and wrinkling.

[0071] In some other embodiments of this application, such as Figure 7 , Figures 9 to 11As shown, the two side portions 32 of the two binding structures 30 extending to the same small sidewall 13 are connected to each other. That is, the two binding structures 30 surround and cover the electrode assembly 20 circumferentially, and the two binding structures 30 form a circumferential covering restriction on the electrode assembly 20 assembled into the receiving space 15. The surface of the body portion 31 contacts the corresponding large surface of the corresponding electrode assembly 20, and the arcuate surfaces at both ends of the electrode assembly 20 contact the side portions 32 of the binding structures 30. In this embodiment, the expansion of the electrode assembly 20 along the thickness direction X of the battery cell 100 is constrained by the body portions 31 of the two binding structures 30, the expansion of the electrode assembly 20 along the length direction Y of the battery cell 100 is constrained by the side portions 32 of the binding structures 30, and the side portions 32 of the binding structures 30 fill the large gap formed between the electrode assembly 20 and the corner position 14, so that the electrode of the corner portion 22 opposite to the corner position 14 is constrained by the side portions 32 of the binding structures 30. This reduces the degree to which the electrode sheet at the location opposite the corner 14 of the electrode assembly 20 moves towards the corner 14, thereby effectively slowing down or preventing the accumulation of movement of the electrode sheet of the electrode assembly 20 and causing compression and wrinkling. Furthermore, the binding structure 30 is a component made of insulating material. Thus, the two binding structures 30 circumferentially separate the electrode assembly 20 from the housing 10, improving the insulation between the electrode assembly 20 and the housing 10.

[0072] like Figure 2 , Figure 4 , Figure 6 , Figure 8 , Figure 10 and Figure 11 As shown, in the battery cell 100 of this embodiment, the side portion 32 of the binding structure 30 has an arc-shaped surface 35 facing the electrode assembly 20. The arc-shaped surface 35 is adapted to fit against the corner portion 22 (i.e., the position of the electrode assembly 20 opposite to the corner position 14; "the position of the electrode assembly 20 opposite to the corner position 14" refers to the arc-shaped surface at the end of the electrode assembly 20 opposite to the corner position 14). In this way, the side portion 32 of the binding structure 30 can abut and restrict the position of the electrode assembly 20 opposite to the corner position 14, thereby constraining the electrode sheet of the electrode assembly 20 at the position opposite to the corner position 14 by the side portion 32 of the binding structure 30. This reduces the degree of movement of the electrode sheet of the electrode assembly 20 at the position opposite to the corner position 14 towards the corner position 14, thereby effectively slowing down or avoiding the accumulation of movement of the electrode sheet of the electrode assembly 20 and causing compression and wrinkling. This effectively reduces the probability of dendrite formation on the electrode assembly 20, which in turn reduces the probability of thermal runaway caused by internal short circuit in the battery cell 100, thus effectively improving the safety performance of the battery cell 100.

[0073] And, as Figure 8 , Figure 10 and Figure 11 As shown, on the two adjacent side portions 32, the portion of the side portion 32 extending to the small sidewall 13 has an abutment surface 34 on the side facing away from the small sidewall 13. The abutment surface 34 is adjacent to the arcuate surface 35 and is parallel to the inner surface of the small sidewall 13. That is, the abutment surface 34 is a plane parallel to the inner surface of the small sidewall 13. In the battery cell 100 of this embodiment, the battery cell 100 includes a plurality of electrode assemblies 20, which are stacked in the receiving space 15. The ends of the plurality of electrode assemblies 20 facing the small sidewall 13 abut against the corresponding abutment surfaces 34. This allows the side portions 32 of the restraining structure 30 to constrain and limit the expansion of the electrode assemblies 20 along the length direction Y.

[0074] In other embodiments of this application, such as Figure 2 , Figure 3 , Figure 5 , Figure 7 , Figure 9 and Figure 11 As shown, the two restraint structures 30 are separately arranged, and the two restraint structures 30 extend to the two side portions 32 of the same small sidewall 13 and meet each other. Figure 10As shown, on the two adjacent side portions 32, each side portion 32 is further provided with at least one abutting arc surface 36. The abutting arc surface 36 is located on the side of the abutting surface 34 away from the arc-shaped surface 35. The abutting arc surface 36 is adapted to the arc-shaped surface of the electrode assembly 20 that is offset from the corner position 14, and the abutting arc surface 36 is attached to the arc-shaped surface. In this embodiment, the battery cell 100 includes at least two electrode assemblies 20, which are stacked. Furthermore, the two binding structures 30 are symmetrically arranged with respect to the symmetry plane 61 of the battery cell 100, which is parallel to the large sidewall 12. The symmetry plane 61 is a plane that bisects the battery cell 100. When the side portion 32 has only one abutting arc surface 36, the abutting arc surface 36, the abutting surface 34 and the arc surface 35 are connected in sequence, and the battery cell 100 has only two stacked electrode assemblies 20. In this way, the abutting arc surfaces 36 of the two binding structures 30 are connected, and the two abutting arc surfaces 36 are respectively adapted to fit and adhere to the two adjacent arc surfaces of the two electrode assemblies 20. When the side portion 32 is provided with multiple abutting arc surfaces 36, the abutting arc surface 36, the abutting surface 34, and the arc surface 35 near the corner position 14 are connected in sequence, and the remaining abutting arc surfaces 36 are distributed in sequence along the direction away from the abutting surface 34. The abutting surface 34 is provided between two adjacent abutting arc surfaces 36, and the arc surfaces of any two adjacent abutting arc surfaces 36 are opposite to each other. In this way, the two abutting arc surfaces 36 of the two binding structures 30 away from the arc surface 35 are connected, and the battery cell 100 includes three or more stacked electrode components 20. The arc surface of each electrode component 20 that is offset from the corner position 14 is adapted and attached to the corresponding abutting arc surface 36 of the two binding structures 30. In this way, the arcuate surfaces of each electrode assembly 20 that are offset from the corner position 14 are all wrapped and restrained by the abutting arc surface 36, and the arcuate surfaces of the electrode assembly 20 opposite to the corner position 14 are attached and restrained by the arcuate surface 35. Furthermore, the ends of the electrode assemblies 20 also abut against the abutting surface 34, thereby further enhancing the ability of the side portion 32 of the restraining structure 30 to constrain the expansion of the electrode assembly 20 along the length direction Y. This reduces the degree to which the electrode sheet at the portion of the electrode assembly 20 opposite to the corner position 14 moves towards the corner position 14, effectively slowing down or preventing the accumulation of movement of the electrode sheet and subsequent compression and wrinkling.

[0075] In some embodiments of this application, such as Figure 2 and Figure 11As shown, along the height direction Z of the battery cell 100, the height H1 of the binding structure 30 is less than or equal to the height H2 of the electrode assembly 20. That is, the two binding structures 30 are completely assembled into the receiving space 15 of the housing 10. Furthermore, when the height H1 of the binding structure 30 is less than the height H2 of the electrode assembly 20, the height difference between the two is small, generally within 10mm, for example, 3mm, 5mm, or 10mm.

[0076] like Figure 1 , Figure 2 and Figure 11 As shown, the battery cell 100 also includes an end cap assembly 50, which is fitted onto the housing 10. Since the two restraining structures 30 are fully assembled into the receiving space 15 of the housing 10, the restraining structures 30 will not interfere with the end cap assembly 50 when it is fitted onto the housing 10, allowing the end cap assembly 50 to be fitted onto the housing 10 smoothly.

[0077] Furthermore, the binding structure 30 abuts against the end cap assembly 50 and the bottom wall of the housing 10 at both ends along the height direction Z of the battery cell 100, respectively. This fixes the binding structure 30 within the receiving space 15, and because the binding structure 30 restricts the electrode assembly 20, the binding structure 30 and the electrode assembly 20 will not wobble relative to the housing 10 within the receiving space 15.

[0078] In some embodiments of this application, the restraint structure 30 is made of an elastic material that is capable of elastic deformation, meaning the restraint structure 30 can elastically deform. In reality, due to unavoidable manufacturing and assembly process errors among the housing 10, electrode assembly 20, and restraint structure 30, the corner 14 of the housing 10, the side 32 of the restraint structure 30, and the electrode assembly 20 cannot actually be perfectly matched. Therefore, when the restraint structure 30 is assembled into the receiving space 15, it undergoes elastic deformation due to the clamping and compression of the housing 10 and the electrode assembly 20, thereby achieving a high degree of fit between the corner 14 of the housing 10, the side 32 of the restraint structure 30, and the electrode assembly 20. That is, the two sides of the side portion 32 of the binding structure 30 are closely attached to the corner position 14 and the electrode assembly 20 respectively, so that the electrode sheet of the part opposite to the corner position 14 of the electrode assembly 20 is constrained and restricted by the side portion 32 of the binding structure 30, thereby forming resistance. This reduces the degree of movement of the electrode sheet of the part opposite to the corner position 14 towards the corner position 14, thereby effectively slowing down or avoiding the accumulation of movement of the electrode sheet of the electrode assembly 20 and causing squeezing and wrinkling.

[0079] Furthermore, the elastic material used in the restraint structure 30 includes, but is not limited to, polytetrafluoroethylene (PTFE), silicone, rubber, polystyrene (PS), polyimide (PI), polyurethane rubber, thermoplastic elastomer (TPE), or EPDM (a copolymer of ethylene, propylene, and a small amount of non-conjugated diene, a type of EPDM rubber). In the embodiments of this application, the volumetric compression ratio of the restraint structure 30 is preferably ≥10%.

[0080] In some embodiments of this application, the binding structure 30 is a component made of a porous material, for example, the binding structure 30 has a porous structure space including but not limited to honeycomb pores. Thus, while the binding structure 30 constrains and restricts the electrode assembly 20, when electrolyte is injected into the receiving space 15 of the housing 10 and wets the electrode assembly 20, the porous structure space formed by the binding structure 30 can store the electrolyte. During long-term use of the battery cell 100 for charging and discharging, electrolyte loss is inevitable. At this time, the electrolyte stored in the porous structure space of the binding structure 30 can be released to replenish the lost electrolyte, improving the situation where the electrode plates of the electrode assembly 20 suffer from localized lithium dendrite formation due to difficulty in Z-axis liquid creep, thereby extending the service life of the battery cell 100.

[0081] Generally, the casing 10 of the battery cell 100 is made of aluminum, which is lightweight and has high strength.

[0082] In the battery cell 100 provided in the embodiments of this application, such as Figure 2 and Figure 11 As shown, the battery cell 100 also includes an insulating film 40 (commonly known as Mylar film), which has a covering space 41. The binding structure 30 and the electrode assembly 20 are both disposed in the covering space 41. Furthermore, the end cap assembly 50 includes an end cap body 51 and a terminal post structure 52 disposed on the end cap body 51. The end cap body 51 covers the housing 10, and the circumferential edge of the end cap body 51 is sealed to the insulating film 40. The terminal post structure 52 is electrically connected to the tabs of the electrode assembly 20. The terminal post structure 52 includes a positive terminal post and a negative terminal post. The positive electrode of the electrode assembly 20 has a positive tab, and the negative electrode of the electrode assembly 20 has a negative tab. The positive terminal post is electrically connected to the positive tab, and the negative terminal post is electrically connected to the negative tab. The restraint structure 30 and the electrode assembly 20 will not wobble relative to the housing 10 within the accommodating space 15, thereby ensuring that the electrical connection between the tab and the pole structure 52 will not become loose or broken, and ensuring normal conduction.

[0083] like Figure 1 , Figure 2 and Figure 11As shown, the end cap body 51 is provided with an injection hole 53, which connects to the encapsulation space 41. Electrolyte is injected into the encapsulation space 41 through the injection hole 53, and then the electrolyte wets the electrode assembly 20 and penetrates into the porous structure space of the binding structure 30. The injection hole 53 is then sealed. Because the circumferential edge of the end cap body 51 is sealed with the insulating film 40, electrolyte leakage into the housing 10 is prevented from causing an internal short circuit and thermal runaway, thus improving the safety performance of the battery cell 100.

[0084] And, as Figure 1 , Figure 2 and Figure 11 As shown, the end cap body 51 is also provided with a pressure relief mechanism 54 to release high-temperature flue gas inside the battery cell 100 in the event of thermal runaway. The pressure relief mechanism 54 is a component or part that is activated to release internal pressure when the internal pressure or temperature of the battery cell 100 reaches a predetermined threshold. "Activation" means that the pressure relief mechanism 54 performs an action, thereby releasing the internal pressure and temperature of the battery cell 100. The action of the pressure relief mechanism 54 may include, but is not limited to, at least a portion of the pressure relief mechanism 54 rupturing, tearing, or melting. After activation, the high-temperature flue gas inside the battery cell 100 will be discharged outward from the pressure relief mechanism 54. The predetermined threshold can be adjusted according to different design requirements. The predetermined threshold may depend on one or more of the materials of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 100. The pressure relief mechanism 54 may employ elements or components that are sensitive to pressure or temperature. That is, when the internal pressure or temperature of the battery cell 100 reaches a predetermined threshold, the pressure relief mechanism 54 is actuated to form a channel for releasing internal pressure.

[0085] In some embodiments of this application, the battery cell 100 further includes a base plate 62, such as Figure 2 As shown, the bottom support plate 62 is disposed between the bottom wall and the insulating film 40, and the bottom wall and the bottom support plate 62 together support the bottom end of the electrode assembly 20. The bottom support plate 62 and the insulating film 40 separate the bottom end of the electrode assembly 20 from the bottom wall of the housing 10, ensuring the insulation between the bottom end of the electrode assembly 20 and the bottom wall of the housing 10.

[0086] In some embodiments of this application, the battery cell 100 provided, such as Figure 11As shown, the binding structure 30 also includes a bottom 33, which is connected to the body portion 31 and the side portion 32. The bottom 33s of the two binding structures 30 are aligned and abut against the bottom wall. Thus, when the electrode assembly 20 is assembled between the two binding structures 30, the bottom end of the electrode assembly 20 is supported by the bottom 33s of the two binding structures 30. At this time, the two aligned bottom 33s of the two binding structures 30 can replace the aforementioned bottom support plate 62. The bottom 33s of the two binding structures 30 and the insulating film 40 separate the bottom end of the electrode assembly 20 from the bottom wall of the housing 10, ensuring insulation between the bottom end of the electrode assembly 20 and the bottom wall of the housing 10.

[0087] In this application, two binding structures 30 are integrally formed to create a rectangular frame structure that opens toward the end cap assembly 50. Some embodiments of this application employ injection molding to fabricate the two binding structures 30 of the integral component; in this case, the two binding structures 30 are two components of the integral component.

[0088] Alternatively, in other embodiments of this application, two binding structures 30 are injection molded separately, that is, the two binding structures 30 are set separately, and then the side parts 32 of the two binding structures 30 are joined and fixed by means of adhesive bonding, snap-fit ​​connection or mechanical connection (such as screw connection), so that the two binding structures 30 are connected into a modular component (i.e., an integral part).

[0089] In the embodiments of this application, the battery cell 100 can be a secondary battery, which refers to a battery cell 100 that can be recharged after discharge to activate the active materials and continue to be used. The battery cell 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0090] According to a second aspect of the embodiments of this application, embodiments of this application also provide a battery device 200, such as... Figure 12 As shown, the battery device 200 includes a main body 201, a cover 202, and multiple battery cells 100 as described above. The cover 202 closes onto the open end of the main body 201, forming an assembly space 203. Multiple battery cells 100 are arrayed and assembled within the assembly space 203. The battery cells 100 are used for storing electrical energy or supplying power.

[0091] According to a third aspect of the embodiments of this application, embodiments of this application also provide an electrical device 400, which includes an electrical load 410.

[0092] Electrical equipment 400 includes, but is not limited to, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys may include, but are not limited to, stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft may include, but are not limited to, airplanes, rockets, space shuttles, and spacecraft.

[0093] In some embodiments of this application, the electrical device 400 further includes a battery device 200 as described above. That is, the electrical device 400 uses one battery device 200 or multiple battery devices 200 connected in series, parallel, or mixed connection, and the electrical load 410 is electrically connected to the battery device 200. The battery device 200 is used to store electrical energy or to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0094] Alternatively, in some other embodiments of this application, the electrical device 400 further includes a plurality of battery cells 100 as described above. That is, the electrical device 400 uses a plurality of battery cells 100 connected in series, parallel, or in a mixed configuration, and the electrical load 410 is electrically connected to the plurality of battery cells 100. The plurality of battery cells 100 are used to store electrical energy, or the plurality of battery cells 100 are used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0095] Among them, the electrical equipment 400 is an electric vehicle, and it is assembled using a battery device 200, such as Figure 13 As shown, the battery device 200 is mounted on the frame 430 of the electric vehicle. The electric vehicle includes the frame 430, a drive motor, and wheels 440. The battery device 200 and the drive motor are both fixedly mounted on the frame 430, and the wheels 440 are rotatably connected to the frame 430. The battery device 200 is electrically connected to the drive motor, and the drive motor is driven by the wheels 440. When the battery device 200 provided in this application supplies power to the drive motor (the drive motor is one of the electrical loads 410 of the electrical equipment 400), the drive motor drives the wheels 440 to rotate, enabling the electric vehicle to drive normally. Furthermore, the electric vehicle includes a control device 420, which is mounted on the frame 430 and electrically connected to the battery device 200. The control device 420 is used to control and monitor the charging and discharging status of the battery device 200. In some electric vehicles, the battery housing of the battery device 200 can be part of the chassis structure of the electric vehicle. For example, a portion of the battery box can be at least part of the floor of the electric vehicle, or a portion of the battery box can be at least part of the crossbeams and longitudinal beams of the electric vehicle.

[0096] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The housing includes a bottom wall and two large side walls and two small side walls connected to the bottom wall. The bottom wall, the two large side walls and the two small side walls form an accommodating space. There is a corner between the large side walls and the adjacent small side walls. Electrode assembly, housed in the housing space; The restraint structure includes a main body and side portions connected to both ends of the main body. The main body is disposed between the large sidewall and the electrode assembly. The side portions fill the corner and extend to the small sidewall.

2. The battery cell according to claim 1, characterized in that, The battery cell includes two binding structures, which are respectively disposed on both sides of the electrode assembly along its thickness direction, and each corner is filled with a side portion.

3. The battery cell according to claim 2, characterized in that, The two binding structures are integrally formed to create a rectangular frame structure; Alternatively, the two binding structures are separately configured, with the two binding structures extending to the two side portions of the same small sidewall that are either connected to each other or spaced apart.

4. The battery cell according to claim 2, characterized in that, The electrode assembly includes a straight portion and a corner portion. The straight portion is disposed opposite to the main body portion, and the corner portion is disposed opposite to the corner position. The side portion has an arc-shaped surface on the side facing the electrode assembly, and the arc-shaped surface is adapted to fit the corner portion.

5. The battery cell according to claim 4, characterized in that, The portion of the side extending to the small sidewall also has an abutting surface on the side opposite to the small sidewall. The abutting surface is adjacent to the arc-shaped surface and is parallel to the inner surface of the small sidewall. The battery cell includes a plurality of electrode assemblies, which are stacked in the receiving space. One end of each electrode assembly facing the small sidewall abuts against the corresponding abutting surface.

6. The battery cell according to claim 5, characterized in that, The battery cell includes at least two electrode assemblies, which are stacked together. Two binding structures extend to two side portions of the same small sidewall that are in contact with each other. Each side portion is also provided with at least one abutting arc surface. The abutting arc surface is located at one end of the abutting surface away from the arc surface. The abutting arc surface is adapted to fit and adhere to the arc surface of the electrode assembly that is offset from the corner.

7. The battery cell according to claim 2, characterized in that, The two binding structures are separately arranged, and the two binding structures extend to the two side portions of the same small sidewall that are spaced apart; The battery cell includes only one electrode assembly, with one end of the electrode assembly facing the small sidewall abutting against the small sidewall; or, the battery cell includes multiple electrode assemblies, which are stacked in the receiving space, with one end of each electrode assembly facing the small sidewall abutting against the small sidewall.

8. The battery cell according to any one of claims 1-7, characterized in that, Along the height direction of the battery cell, the height of the binding structure is less than or equal to the height of the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The restraint structure is made of an elastic material that can deform elastically.

10. The battery cell according to claim 9, characterized in that, The elastic material is one of polytetrafluoroethylene, silicone, polyurethane rubber, thermoplastic elastomer, and EPDM rubber.

11. The battery cell according to claim 8, characterized in that, The binding structure is a component made of porous material.

12. The battery cell according to claim 8, characterized in that, The battery cell also includes an insulating film, which has a covering space, and the binding structure and the electrode assembly are both disposed in the covering space.

13. The battery cell according to claim 12, characterized in that, The battery cell also includes an end cap assembly that covers the housing, and the circumferential edge of the end cap assembly is sealed to the insulating film.

14. The battery cell according to claim 13, characterized in that, The binding structure abuts against the end cap assembly and the bottom wall at both ends along the height direction of the battery cell, respectively.

15. The battery cell according to any one of claims 2-7, characterized in that, The restraint structure also includes a bottom, which is connected to the body and the side, with the bottoms of the two restraint structures facing each other and abutting against the bottom wall.

16. A battery device, characterized in that, Includes a battery cell as described in any one of claims 1-15, the battery cell being used to store or provide electrical energy.

17. An electrical appliance, characterized in that, Including electrical loads; The electrical equipment further includes a plurality of battery cells as described in any one of claims 1-15, and the electrical load is electrically connected to the plurality of battery cells; Alternatively, the electrical equipment may further include the battery device as described in claim 16, wherein the electrical load is electrically connected to the battery device; The battery cell is used to store or provide electrical energy.

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