Battery and energy storage device

Abstract

Battery (01), wherein the battery (01) comprises: a housing (10), wherein the housing (10) has a receiving space (11); an electrode arrangement (20), wherein the electrode arrangement (20) is arranged in the receiving space (11) and has a first surface (21), wherein the first surface (21) extends perpendicular to an inner wall (12) of the housing (10);and a cover plate (40), wherein the cover plate (40) is at least partially arranged in the receiving space (11) and is located on one side of the first surface (21), wherein the cover plate (40) comprises a cover plate overlap connection section (42) which is rigidly connected to the housing (10), wherein the cover plate overlap connection section (42) comprises a first part (421), a second part (422) and a curved section (423) which are formed in one piece, wherein the first part (421) is arranged opposite the inner wall (12) of the housing (10) and the second part (422) is arranged opposite an upper wall (323) of the housing (10), wherein the curved section (423) is connected to the first part (421) and the second part (422), and wherein a side of the curved section (423) facing the housing (10) is provided with a deflection structure. (4231) is provided.;

Description

Technical FieldThe present application relates to the technical field of batteries, particularly to a battery and an energy storage device.Prior ArtWith the rapid development of electric automobiles and battery energy storage, traction batteries have become a focus of research as a core technology. As regards the structure, drive batteries are divided into wound and stacked configurations. Because of high production efficiency, wound drive batteries have previously become a prevailing variant of the drive batteries.A wound battery generally comprises a steel housing and a jellyroll, a negative current collector disc and a cover plate, which are arranged one above the other in the steel housing. In this case, the steel housing is electrically connected to the cover plate and the jellyroll is electrically connected to the negative current collector plate. In order to produce an electrical connection of the steel housing to the jellyroll, the cover plate must be firmly welded to the negative current collector plate. In order to ensure the reliability of the firm welding during the firm welding of the cover plate to the negative current collector plate, the cover plate must be pressed so that the negative current collector plate closely abuts the cover plate. The pressing further causes the jellyroll to be pressed by the negative current collector plate, so that in the completed battery product, both the top plate and the jellyroll are respectively in close contact with the negative current collector plate.However, during a charge-discharge cycle of the battery, the jellyroll extends, pushing the negative current collector disc and the top plate further, so that the top plate is exposed to a large voltage, resulting in a risk of leakage and burst of the battery and poor safety performance. This problem is to be solved urgent.Disclosure of the InventionProblem SettingEmbodiments of the present application provide a battery and an energy storage device, whereby the technical problem of high risk of leakage and burst and poor safety performance in batteries in the related art can be solved.Technical SolutionAccording to a first aspect, an embodiment of the present application provides a battery, comprising: a housing having a housing space; an electrode assembly disposed in the housing space and having a first surface, the first surface being perpendicular to an inner wall of the housing; anda cover plate disposed at least partially in the accommodating space and located on a side of the first surface.The cover plate comprises a cover plate overlap connecting section which is firmly connected to the housing. The cover plate overlap joint portion includes a first part, a second part, and a bent portion formed integrally. The first part is arranged opposite the inner wall of the housing and the second part is arranged opposite the upper wall of the housing. The bent portion is connected to the first part and the second part. In this case, a side of the bent portion facing the housing is provided with an escape structure.In an embodiment, the battery further includes a current collector plate disposed in the accommodation space and located on a side of the first surface, the cover plate disposed on a side of the current collector plate opposite to the electrode assembly, the current collector plate including a current collector plate body portion and a current collector plate bent portion formed integrally, and the current collector plate body portion abuts against the first surface and the current collector plate bent portion abuts against the inner wall.In one exemplary embodiment, it is provided that the current collector plate bending section comprises a first side wall and a second side wall which are arranged opposite one another, wherein the first side wall bears against the first part and the second side wall bears against the inner wall, wherein the current collector plate bending section further comprises the upper wall which is connected to the first side wall and the second side wall, wherein the upper wall bears against the second part and a corner section is formed at the interface of the upper wall and the second side wall, which corner section is associated with the bent section, wherein the corner section has an angle, wherein the avoidance structure is associated with the corner section, and wherein the avoidance structure is a recess.In one embodiment, it is provided that the current collector plate bending portion comprises a first side wall and a second side wall which are arranged opposite to one another, wherein the first side wall abuts against the first part and the second side wall abuts against the inner wall,wherein the current collector plate bent portion further comprises the top wall connected to the first side wall and the second side wall, the top wall abutting against the second part, and a corner portion is formed at the intersection of the top wall and the second side wall, the corner portion being associated with the bent portion, the corner portion having a first chamfer,and wherein the avoidance structure has a second chamfer which is smaller than or equal to the first chamfer.In one exemplary embodiment, it is provided that the cover plate further comprises a cover plate body section which is formed integrally with the cover plate overlap connection section, wherein the cover plate body section is placed over the cover plate overlap connection section on a side of the current collector plate body section facing away from the electrode arrangement, and wherein the cover plate body section is arranged at a distance from the current collector plate body section.In one exemplary embodiment, it is provided that the electrode arrangement is firmly welded to the current collector plate body section via a first welding section and the housing is firmly welded to the cover plate overlap connection section and the current collector plate bending section via a second welding section, respectively.In an embodiment, it is provided that the second welding portion is disposed on the same side as the current collector plate bending portion and the cover plate overlap joint portion and covers a joining gap between the current collector plate bending portion and the housing.In one exemplary embodiment, it is provided that a side of the second welding section facing away from the housing is firmly connected to the second part.In an embodiment, it is provided that, in a direction parallel to the first surface, the extension length of the second welding portion is greater than the extension length of the case and less than the sum of the extension length of the case and the extension length of the current collector plate bending portion.In one exemplary embodiment, it is provided that the second welding section is arranged in the joining gap between the current collector plate bending section and the housing and the top wall terminates flush with an end section of the housing.In one exemplary embodiment, it is provided that the current collector plate body portion comprises an escape hole and a plurality of buffer elements, wherein the plurality of buffer elements are arranged at a distance on the circumferential side of the escape hole, wherein the current collector plate body portion further comprises a plurality of connecting portions and in each case two adjacent buffer elements are connected to one another via the respective connecting portion, and wherein the single connecting portion has a width of 0.2 to 1 mm in a direction facing the circle center of the escape hole.According to a second aspect, an exemplary embodiment of the present application provides an energy storage device comprising at least one battery according to one of the configurations described above.Advantageous EffectsAdvantageous Effects of the Embodiments of the Present Application:In embodiments of the present application, the present application provides a battery and an energy storage device. The battery includes a housing, an electrode assembly, and a cover plate. The housing has a receiving space. The electrode assembly is arranged in the receiving space and has a first surface, which first surface runs perpendicular to an inner wall of the housing. The cover plate is at least partially disposed in the receiving space and is located on a side of the first surface. The cover plate comprises a cover plate overlap connecting section which is firmly connected to the housing. The cover plate overlap joint portion includes a first part, a second part, and a bent portion formed integrally. The first part is arranged opposite the inner wall of the housing and the second part is arranged opposite the upper wall of the housing. The bent portion is connected to the first part and the second part. In this case, a side of the bent portion facing the housing is provided with an escape structure. In the battery and the energy storage device according to the present application, the first part of the cover plate overlap connection portion of the cover plate is disposed opposite to the inner wall of the case and the second part is disposed opposite to the upper wall of the case, the bent portion is connected to the first part and the second part, and the case facing side of the bent portion is provided with the escape structure. Thus, the cover plate can be directly electrically connected to the housing and the electrode assembly, thereby solving the problem of high risk of leakage and burst and poor safety performance of the battery due to the need for fastening the cover plate and the current collector plate in a battery architecture in which the cover plate is indirectly connected to the current collector plate and the housing.Brief Description of the FiguresIn order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed for describing the embodiments will be briefly presented below. Obviously, the drawings in the following description represent only some embodiments of the present application. A person skilled in the art can also obtain further drawings based on these drawings without performing inventive effort. Shown therein are: FIG. 1 is a schematic structural view of a battery according to some embodiments of the present application; FIG. 2 shows an enlarged detail of the location A according to FIG. 1 ; FIG. 3 is a cutaway enlarged view of a boundary area between a cover plate overlap joint portion and a current collector plate bending portion and a case, respectively, according to some embodiments of the present application; FIG. 4 is a schematic three-dimensional representation of the current collector disc according to some embodiments of the present application; and FIG. 5 is an enlarged sectional view of the boundary area between the cover plate overlap connection portion and the current collector plate bending portion and the case according to some embodiments of the present application.List of reference numbers:Battery 01; case 10; accommodation space 11; inner wall 12; electrode assembly 20; first surface 21; current collector plate 30; current collector plate body portion 31; escape hole 311; buffer member 312; connection portion 313; current collector plate bending portion 32; first side wall 321; second side wall 322; top wall 323; corner portion 324; cover plate 40; cover plate body portion 41; cover plate overlap connection portion 42; first part 421; second part 422; bent portion 423; escape structure 4231; first welding portion 101; second welding portion 102.DETAILED EMBODIMENTSEmbodiment IFIG. 1 is a schematic structural view of a battery according to some embodiments of the present application; and FIG. 2 is a cutaway enlarged view of the location A of FIG. 1 ; reference is made to FIGS. 1 and 2. According to a first aspect, Embodiment I of the present application provides a battery 01. The battery 01 includes a housing 10, an electrode assembly 20, and a cover plate 40. The electrode arrangement 20 is arranged in the receiving space 11 and has a first surface 21, which first surface 21 runs perpendicular to an inner wall 12 of the housing 10. The cover plate 40 is at least partially disposed in the accommodation space 11 and is located on one side of the first surface 21, and the cover plate 40 includes a cover plate overlap connection portion 42 fixedly connected to the housing 10. The cover plate overlap joint portion 42 includes a first part 421, a second part 422 and a bent portion 423 which are integrally formed. The first part 421 is arranged opposite the inner wall 12 of the housing 10 and the second part 422 is arranged opposite an upper wall 323 of the housing 10. The bent portion 423 is connected to the first part 421 and the second part 422. Here, a side of the bent portion 423 facing the housing 10 is provided with an escape structure 4231.In the battery 01 according to the present application, by integrally forming the first part 421, the second part 422 and the bent portion 423 of the cover plate overlap connection portion 42, that is, by bending the first part 421 and the second part 422 via the bent portion 423, the bent portion 423 is associated with a corner formed by the top wall 323 and the inner wall 12 of the case 10. By providing the side of the bent portion 423 facing the housing 10 with the escape structure 4231, a joining gap between the bent portion 423 and an object to be joined can be reduced or eliminated, so that subsequent welding is facilitated, welding yield is increased, the risk of leakage of the battery 01 is decreased, and safety performance of the battery 01 is improved.In some embodiments of the present application, the battery 01 further includes a current collector plate 30, which current collector plate 30 is disposed in the accommodation space 11 and is located on a side of the first surface 21. The cover plate 40 is arranged on a side of the current collector plate 30 facing away from the electrode arrangement 20. The current collector plate 30 includes a current collector plate body portion 31 and a current collector plate bending portion 32 that are integrally molded. The current collector plate body portion 31 abuts against the first surface 21, and the current collector plate bending portion 32 abuts against the inner wall 12.In the battery 01 according to the present application, the current collector plate 30 disposed in the accommodation space 11 is located between the electrode assembly 20 and the cover plate 40, and the current collector plate 30 is electrically conductive. By the current collector plate body portion 31 abutting against the first surface 21 and the current collector plate bending portion 32 abutting against the inner wall 12, the current collector plate 30 can be electrically connected to the electrode assembly 20 via the current collector plate body portion 31, and the current collector plate 30 can be electrically connected to the case 10 via the current collector plate bending portion 32. By integrally forming the current collector plate body portion 31 and the current collector plate bending portion 32, the current collector plate 30 can directly electrically connect the housing 10 to the electrode assembly 20, thus improving the problem of high risk of leakage and burst and poor safety performance of the battery 01 due to the need for fastening the cover plate 40 and the current collector plate 30 in an architecture of the battery 01 in which the cover plate 40 is indirectly connected to the current collector plate 30 and the housing 10.In some embodiments of the application, the current collector plate bending portion 32 includes a first side wall 321 and a second side wall 322 that are disposed opposite to each other. The first side wall 321 abuts against the first part 421 and the second side wall 322 abuts against the inner wall 12. Here, the current collector plate bending portion 32 further includes the top wall 323 connected to the first side wall 321 and the second side wall 322. The top wall 323 abuts against the second part 422 and at the intersection of the top wall 323 and the second side wall 322 is formed a corner portion 324, which corner portion 324 is associated with the bent portion 423. The corner portion 324 has an angled portion. In this case, the avoidance structure 4231 is assigned to the corner section 324 and the avoidance structure 4231 is a recess.By integrally forming the first part 421, the second part 422 and the bent portion 423 connected to the first part 421 and the second part 422, the bent portion 423 inevitably forms a curved chamfer (also known as a rounded corner). Since the corner portion 324 at the intersection of the top wall 323 and the second side wall 322 is an end portion of the current collector disc 30, the corner portion 324 has an angle in an untreated state, which leads to a large clearance between the bent portion 423 and the corner portion 324 before the tight welding, thereby causing a large clearance between the first part 421 and the first side wall 321 and a large clearance between the second part 422 and the top wall 323 and the case 10, respectively, so that the welding failure rate is significantly increased and the risk of the battery 01 leaking is increased.In the battery 01 according to the present application, by forming the escape structure 4231 at a position associated with the bent portion 423 and the corner portion 324, the recess in the escape structure 4231 can receive the bend in the corner portion 324, so that when the battery 01 is firmly welded, the first part 421 can abut against the first side wall 321 and the second part 422 can abut against the top wall 323 and the housing 10, thus facilitating subsequent welding, increasing the welding yield, decreasing the risk of leakage of the battery 01, and improving the safety performance of the battery 01.In some embodiments of the application, the cover plate 40 further includes a cover plate body portion 41 integrally formed with the cover plate overlap joint portion 42. The cover plate body portion 41 is fitted over the cover plate overlap connection portion 42 on a side of the current collector plate body portion 31 facing away from the electrode assembly 20. The cover plate body portion 41 is disposed spaced apart from the current collector plate body portion 31.In the battery 01 according to the present application, by forming the cover plate body portion 41 integrally with the cover plate overlap joint portion 42, the cover plate body portion 41 can be fitted on the opposite side of the current collector plate body portion 31 from the electrode assembly 20 via the cover plate overlap joint portion 42 fixedly connected to the case 10 and the current collector plate bending portion 32, respectively, so that the cover plate 40 is spaced apart from the current collector plate body portion 31. By disposing the cover plate 40 spaced apart from the current collector plate body portion 31, a space can be formed between the cover plate 40 and the current collector plate body portion 31 that can function as a buffer space upon subsequent expansion of the electrode assembly 20, thus reducing the risk of leakage and burst of the battery 01 and improving the safety performance of the battery 01.FIG. 3 shows a cutout enlargement of a boundary region between the cover plate overlap connection portion and the current collector plate bending portion or the housing according to some exemplary embodiments of the present application. Reference is made to FIGS. 1 to 3. In some embodiments of the application, the cover plate overlap joint portion 42 includes the first part 421, the second part 422 and the bent portion 423 connected to the first part 421 and the second part 422 which are integrally formed. Here, the current collector plate bending portion 32 includes the first side wall 321 and the second side wall 322 that are disposed opposite to each other. The first side wall 321 abuts against the first part 421 and the second side wall 322 abuts against the inner wall 12. Here, the current collector plate bending portion 32 further includes the top wall 323 connected to the first side wall 321 and the second side wall 322. The top wall 323 abuts against the second part 422 and at the intersection of the top wall 323 and the second side wall 322, the corner portion 324 is formed, which corner portion 324 is associated with the bent portion 423. The corner portion 324 has an angled portion. The bent section 423 comprises: the avoidance structure 4231, which avoidance structure 4231 is assigned to the corner section 324.By integrally forming the first part 421, the second part 422 and the bent portion 423 connected to the first part 421 and the second part 422, the bent portion 423 inevitably forms a curved chamfer (also known as a rounded corner). Since the corner portion 324 at the intersection of the top wall 323 and the second side wall 322 is an end portion of the current collector disc 30, the corner portion 324 has an angle in an untreated state, which leads to a large clearance between the bent portion 423 and the corner portion 324 before the tight welding, thereby causing a large clearance between the first part 421 and the first side wall 321 and a large clearance between the second part 422 and the top wall 323 and the case 10, respectively, so that the welding failure rate is significantly increased and the risk of the battery 01 leaking is increased.In the battery 01 according to the present application, by forming the escape structure 4231 at the position associated with the bent portion 423 and the corner portion 324, a cavity in the escape structure 4231 can accommodate the bend in the corner portion 324, so that when the battery 01 is firmly welded, the first part 421 can abut against the first side wall 321 and the second part 422 can abut against the top wall 323 and the housing 10, thus facilitating subsequent welding, increasing the welding yield, decreasing the risk of leakage of the battery 01, and improving the safety performance of the battery 01.In some embodiments of the application, the electrode assembly 20 is firmly welded to the current collector plate body portion 31 via a first welding portion 101, and the housing 10 is firmly welded to the current collector plate bending portion 32 via a second welding portion 102.In the battery 01 according to the present application, by the current collector plate body portion 31 abutting against the first surface 21 and the current collector plate bending portion 32 abutting against the inner wall 12, the current collector plate body portion 31 and the first surface 21 can be fixed relative to each other and the current collector plate bending portion 32 and the inner wall 12 can be held fixed relative to each other, thus facilitating the formation of the first welding portion 101 between the electrode assembly 20 and the current collector plate body portion 31 and the formation of the second welding portion 102 between the case 10 and the current collector plate bending portion 32 by solid welding, and thereby ensuring the stability of the electrical connection.In some embodiments of the application, the second welding portion 102 is disposed on the same side as the current collector plate bending portion 32 and the housing 10, and covers a joining gap between the current collector plate bending portion 32 and the housing 10.In the battery 01 according to the present application, by disposing the second welding portion 102 on the same side as the current collector plate bending portion 32 and the case 10 and covering the joining gap between the current collector plate bending portion 32 and the case 10, the sealing ability of the battery 01 can be further improved.In some exemplary embodiments of the application, a side of the second welding section 102 facing away from the housing 10 is firmly connected to the second part 422.In the battery 01 according to the present application, by firmly connecting the side of the second welding portion 102 facing away from the case 10 to the second part 422, that is, in the battery 01, by filling the gap between the case 10 and the second part 422 with solder, the case 10 is firmly connected to the cover plate overlap connection portion 42, and the second welding portion 102 is disposed on the same side as the current collector plate bending portion 32 and the case 10 and covers the joint gap between the current collector plate bending portion 32 and the case 10, a firm connection of the case 10 and the cover plate overlap connection portion 42 to the current collector plate bending portion 32 can be made and the assembly stability of the battery 01 can be enhanced.It should be understood that in the present application, there is no limitation on the position at which the second welding portion 102 is formed. In another embodiment of the application, the second welding portion 102 is disposed in the joint gap between the current collector plate bending portion 32 and the housing 10, and the top wall 323 is flush with an end portion of the housing 10. By thus disposing the second welding portion 102, the total thickness of the battery 01 can be reduced to some extent and the volume of the battery 01 can be reduced.In some embodiments of the application, in a direction parallel to the first surface 21, the extension length of the second welding portion 102 is greater than the extension length of the case 10 and less than the sum of the extension length of the case 10 and the extension length of the current collector plate bending portion 32.In the battery 01 according to the present application, by making the extension length of the second welding portion 102 longer than the extension length of the case 10, a single welding operation can already achieve firm assembly of the case 10, the current collector plate 30, and the cover plate 40, and ensure the stability of the electrical connection of the case 10 to the current collector plate 30.In the battery 01 according to the present application, by making the extension length of the second welding portion 102 less than the sum of the extension length of the case 10 and the extension length of the current collector plate bending portion 32, the sealing ability is secured while minimizing the welding depth, thus reducing the welding device performance requirements and lowering the welding cost. Further, the penetration of the second welding portion 102 through the current collector plate bending portion 32 is prevented, and the penetration of the welding slag generated when forming the second welding portion 102 into the inside of the battery 01 via the joint gap between the current collector plate bending portion 32 and the cover plate overlap joint portion 42 is prevented.FIG. 4 shows a schematic three-dimensional representation of the current collector disc according to some embodiments of the present application. As can be seen from FIGS. 1 to 4, in some embodiments of the application, the current collector disc 30 includes a body portion including an escape hole 311 and a plurality of buffer members 312. The plurality of buffer members 312 are spaced apart on the circumferential side of the escape hole 311. The current collector plate body portion 31 further includes a plurality of connecting portions 313, and every two adjacent buffer members 312 are connected to each other via the respective connecting portion 313. The single connecting portion 313 has a width of 0.2 to 1 mm in a direction facing the circle center of the escape hole 311.In the battery 01 according to the present application, by the buffer members 312 covering the electrode assembly 20 from above, the buffer members 312 are pressed by the buffer members 312 when the electrode assembly 20 expands in later use. By the single connecting portion 313, which connects each two adjacent buffer elements 312 to one another, having a width of 0.2 to 1 mm in the direction facing the circle center of the escape hole 311, a connection of two adjacent buffer elements 312 can be produced and at the same time the connection strength of two adjacent buffer elements 312 can be kept low, so that the single connecting portion 313 can be separated during the later use when the electrode arrangement 20 is expanded. Thus, the single buffer member 312 may be displaced away from the electrode assembly 20 to release pressure generated by expansion of the electrode assembly 20 in the battery 01, thus ensuring the safety performance of the battery 01.In detail, the width of the single connecting portion 313 in the direction facing the circle center of the escape hole 311 is, among other things, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm and 1 mm.In some embodiments of the application, the battery 01 is a cylindrical battery. The electrode assembly 20 includes a positive terminal and a negative terminal. The current collector disc 30 is electrically connected to the negative terminal of the electrode assembly 20. The housing 10 is a steel housing or other electrically conductive housing. Both the cover plate 40 and the current collector disc 30 consist of an electrically conductive material. The technique for solid welding forming the first welding portion 101 and the second welding portion 102 may be a resistance welding technique and / or a laser welding technique.According to a second aspect, the application further provides an energy storage device including at least one battery 01 according to any one of the above configurations.Working Example IIFIG. 5 shows a cutout enlargement of the boundary region between the cover plate overlap connection portion and the current collector plate bending portion or the housing according to some exemplary embodiments of the present application. Reference is made to FIGS. 1, 2, 3 and 5. Embodiment II of the present application provides a battery 01 and an energy storage device. The battery 01 includes a housing 10, an electrode assembly 20, and a current collector plate 30. The electrode arrangement 20 is arranged in the receiving space 11 and has a first surface 21, which first surface 21 runs perpendicular to an inner wall 12 of the housing 10. The current collector plate 30 is disposed in the accommodation space 11 and is located on a side of the first surface 21, and the current collector plate 30 includes a current collector plate body portion 31 and a current collector plate bending portion 32 that are integrally formed. The current collector plate body portion 31 abuts against the first surface 21, and the current collector plate bending portion 32 abuts against the inner wall 12. The energy storage device includes at least one battery 01 described above.Note that the battery 01 and the energy storage device provided by Embodiment II of the present application are configured similarly to the battery 01 and the energy storage device provided by Embodiment I of the present application. In the present application, detailed description thereof will be omitted. The difference is that the cover plate overlap joint portion 42 includes the first part 421, the second part 422 and the bent portion 423 connected to the first part 421 and the second part 422 which are integrally formed. Here, the current collector plate bending portion 32 includes the first side wall 321 and the second side wall 322 that are disposed opposite to each other. The first side wall 321 abuts against the first part 421 and the second side wall 322 abuts against the inner wall 12. Here, the current collector plate bending portion 32 further includes the top wall 323 connected to the first side wall 321 and the second side wall 322. The top wall 323 abuts against the second part 422 and at the intersection of the top wall 323 and the second side wall 322, the corner portion 324 is formed, which corner portion 324 is associated with the bent portion 423. The corner portion 324 has a first chamfer. Bent section 423 includes an avoidance structure 4231, which avoidance structure 4231 has a second chamfer that is smaller than or equal to the first chamfer.In the battery 01 according to the present application, by forming the second chamfer smaller than or equal to the first chamfer in the bent portion 423, when the battery 01 is firmly welded, the first part 421 can abut against the first side wall 321 and the second part 422 can abut against the top wall 323 and the housing 10, thus facilitating subsequent welding, increasing welding yield, decreasing the risk of leakage of the battery 01, and improving the safety performance of the battery 01.As stated above, the present application provides a battery and an energy storage device. The battery includes a housing, an electrode assembly, and a cover plate. The housing has a receiving space. The electrode assembly is arranged in the receiving space and has a first surface, which first surface runs perpendicular to an inner wall of the housing. The cover plate is at least partially disposed in the receiving space and is located on a side of the first surface. The cover plate comprises a cover plate overlap connecting section which is firmly connected to the housing. The cover plate overlap joint portion includes a first part, a second part, and a bent portion formed integrally. The first part is arranged opposite the inner wall of the housing and the second part is arranged opposite the upper wall of the housing. The bent portion is connected to the first part and the second part. In this case, a side of the bent portion facing the housing is provided with an escape structure. In the battery and the energy storage device according to the present application, the first part of the cover plate overlap connection portion of the cover plate is disposed opposite to the inner wall of the case and the second part is disposed opposite to the upper wall of the case, the bent portion is connected to the first part and the second part, and the case facing side of the bent portion is provided with the escape structure. Thus, the cover plate can be directly electrically connected to the housing and the electrode assembly, thereby solving the problem of high risk of leakage and burst and poor safety performance of the battery due to the need for fastening the cover plate and the current collector plate in a battery architecture in which the cover plate is indirectly connected to the current collector plate and the housing.

Claims

A battery (01), the battery (01) comprising: a housing (10), the housing (10) having an accommodation space (11); an electrode assembly (20), the electrode assembly (20) being disposed in the accommodation space (11) and having a first surface (21), the first surface (21) being perpendicular to an inner wall (12) of the housing (10); and a cover plate (40), the cover plate (40) being at least partially disposed in the accommodation space (11) and being on a side of the first surface (21), the cover plate (40) comprising a cover plate overlap joint portion (42) fixedly connected to the housing (10), the cover plate overlap joint portion (42) comprising a first part (421), a second part (422), and a bent portion (423) integrally formed, wherein the first part (421) is arranged opposite the inner wall (12) of the housing (10) and the second part (422) is arranged opposite an upper wall (323) of the housing (10), wherein the bent portion (423) is connected to the first part (421) and the second part (422), and wherein a side of the bent portion (423) facing the housing (10) is provided with an escape structure (4231).The battery (01) according to claim 1, wherein the battery (01) further comprises a current collector disc (30), the current collector disc (30) is disposed in the accommodation space (11) and is located on a side of the first surface (21), the cover plate (40) is disposed on a side of the current collector disc (30) opposite to the electrode assembly (20), the current collector disc (30) comprises a current collector disc body portion (31) and a current collector disc bending portion (32) which are integrally formed, and wherein the current collector disc body portion (31) abuts against the first surface (21) and the current collector disc bending portion (32) abuts against the inner wall (12).The battery (01) according to claim 2, wherein the current collector plate bending portion (32) comprises a first side wall (321) and a second side wall (322) arranged opposite to each other, the first side wall (321) abuts against the first part (421) and the second side wall (322) abuts against the inner wall (12), the current collector plate bending portion (32) further comprises the top wall (323) connected to the first side wall (321) and the second side wall (322), the top wall (323) abuts against the second part (422), and a corner portion (324) is formed at an intersection of the top wall (323) and the second side wall (322), the corner portion (324) being associated with the bent portion (423), and the corner portion (324) having a bend, wherein the avoidance structure (4231) is assigned to the corner portion (324), and wherein the avoidance structure (4231) is a recess.The battery (01) according to claim 2, wherein the current collector plate bending portion (32) comprises a first side wall (321) and a second side wall (322) arranged opposite to each other, the first side wall (321) abutting against the first part (421) and the second side wall (322) abutting against the inner wall (12), the current collector plate bending portion (32) further comprising the top wall (323) connected to the first side wall (321) and the second side wall (322), the top wall (323) abutting against the second part (422), and a corner portion (324) is formed at the intersection of the top wall (323) and the second side wall (322), which corner portion (324) is associated with the bent portion (423), the corner portion (324) having a first chamfer, and wherein the avoidance structure (4231) has a second chamfer which is smaller than or equal to the first chamfer.The battery (01) according to any one of claims 2 to 4, wherein the cover plate (40) further comprises a cover plate body portion (41) integrally formed with the cover plate overlap connection portion (42), wherein the cover plate body portion (41) is fitted over the cover plate overlap connection portion (42) on a side of the current collector plate body portion (31) facing away from the electrode assembly (20), and wherein the cover plate body portion (41) is spaced apart from the current collector plate body portion (31).The battery (01) according to claim 5, wherein the electrode assembly (20) is firmly welded to the current collector plate body portion (31) via a first welding portion (101), and the case (10) is firmly welded to the cover plate overlap joint portion (42) and the current collector plate bending portion (32) via a second welding portion (102), respectively.The battery (01) according to claim 6, wherein the second welding portion (102) is disposed on the same side as the current collector plate bending portion (32) and the cover plate overlap connecting portion (42), and covers a joining gap between the current collector plate bending portion (32) and the case (10).The battery (01) according to claim 7, wherein a side of the second welding portion (102) facing away from the housing (10) is fixedly connected to the second part (422).The battery (01) according to claim 8, wherein in a direction parallel to the first surface (21), the extension length of the second welding portion (102) is greater than the extension length of the case (10) and less than the sum of the extension length of the case (10) and the extension length of the current collector plate bending portion (32).The battery (01) according to any one of claims 6 to 9, wherein the second welding portion (102) is disposed in the joint gap between the current collector plate bending portion (32) and the case (10), and the top wall (323) is flush with an end portion of the case (10).The battery (01) according to any one of claims 2 to 10, wherein the current collector plate body portion (31) comprises an escape hole (311) and a plurality of buffer members (312), wherein the plurality of buffer members (312) are spacedly arranged on the circumferential side of the escape hole (311), wherein the current collector plate body portion (31) further comprises a plurality of connection portions (313), and every two adjacent buffer members (312) are connected to each other via the respective connection portion (313), and wherein the single connection portion (313) has a width of 0.2 to 1 mm in a direction facing the circle center of the escape hole (311).An energy storage device, wherein the energy storage device comprises at least one battery (01) according to any one of claims 1 to 11.

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