Secondary battery and battery pack

Abstract

The application discloses a secondary battery and a battery pack, and belongs to the technical field of batteries. The secondary battery comprises a first shell, an electrode assembly, a second shell and an elastic piece. The first shell has a containing cavity. The electrode assembly is arranged in the containing cavity. The second shell is arranged outside the first shell. At least part of the second shell is arranged in a spaced manner with the first shell, and a spacing cavity is formed between the second shell and the first shell. The elastic piece is arranged between the first shell and the second shell, and the elastic piece connects the first shell and the second shell. According to the application, the first shell is arranged in the second shell, and the elastic piece is arranged between the first shell and the second shell. Thus, the first shell can be deformed to a certain extent, and excessive deformation of the first shell can be prevented.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a secondary battery and battery pack. Background Technology

[0002] A cylindrical battery includes a casing and an electrode assembly, with the electrode assembly located inside the casing.

[0003] However, the electrode assembly expands during charging and discharging. After expanding, the electrode assembly comes into contact with the housing. The housing can constrain the expansion of the electrode assembly, but as the expansion of the electrode assembly intensifies, the expanded electrode assembly may cause deformation of the housing, and the electrode assembly may also deform and fail. Utility Model Content

[0004] The purpose of this utility model is to provide a secondary battery to solve the technical problem of lack of support when the electrode assembly expands; another purpose of this application is to provide a battery pack.

[0005] Technical solution: This application provides a secondary battery, comprising:

[0006] A first housing, the first housing having a receiving cavity;

[0007] An electrode assembly disposed in the receiving cavity;

[0008] A second housing is fitted over the first housing, at least a portion of the second housing is spaced apart from the first housing, and a spacer cavity is formed between the second housing and the first housing;

[0009] An elastic element is disposed between a first housing and a second housing, and the elastic element connects the first housing and the second housing.

[0010] In some embodiments, the secondary battery has a first direction, the first housing includes a first housing body, the first housing body is a circular cylinder, the second housing includes a second housing body, the second housing body is a polygonal cylinder, the first housing body and the second housing body both extend along the first direction; the polygonal cylinder has a cylinder wall, the cylinder wall has a plurality of cylinder walls connected sequentially along the circumference of the first housing body, and the elastic element connects the first housing body and the cylinder wall.

[0011] Two adjacent cylindrical walls are connected to the first shell body to form a spacer cavity. There are multiple spacer cavities, and multiple elastic elements are provided, with at least two spacer cavities provided with the elastic elements.

[0012] In some embodiments, the secondary battery further includes a support member disposed in the spacer cavity, the support member being disposed at the connection between two adjacent cylindrical walls and connected to the two adjacent cylindrical walls, the support member having a support portion located on the side of the support member facing the cylindrical body; multiple support members are provided, and the elastic member is connected to the support portion of the corresponding support member.

[0013] In some embodiments, at least one of the spacer cavities is provided with a plurality of elastic members arranged at intervals along the first direction, and the support extends along the first direction. In the spacer cavity provided with the plurality of elastic members, the support connects the plurality of elastic members.

[0014] In some embodiments, the support portion extends along the first direction and is connected to at least two of the elastic elements; or, the same support element has a plurality of support portions, the plurality of support portions being spaced apart along the first direction, and each support portion being connected to one of the elastic elements.

[0015] In some embodiments, both the support member and the elastic member extend along the first direction, and the support member and the elastic member correspond one-to-one; or, the support member is integrally formed with the cylinder wall; or, the support member and the elastic member are integrally formed.

[0016] In some embodiments, the second housing further includes a first end cap and a second end cap, the second housing body having a first opening and a second opening disposed opposite to each other in the first direction, the first end cap being connected to the second housing body and sealing the first opening, and the second end cap being connected to the second housing body and sealing the second opening.

[0017] In some embodiments, the first shell body has a third opening and a fourth opening disposed opposite to each other in the first direction, both the third opening and the fourth opening communicating with the receiving cavity, the first end cap further covering the third opening, and the second end cap further covering the fourth opening;

[0018] The first shell body is provided with a plurality of connecting holes, the connecting holes connecting the receiving cavity and the spacer cavity, and at least two of the connecting holes are spaced apart in the first direction.

[0019] In some embodiments, the first shell body has a first end face in the first direction, and the wall of at least one of the communicating holes overlaps with the first end face.

[0020] Accordingly, this application also provides a battery pack, including a secondary battery as described in any of the above embodiments.

[0021] Beneficial Effects: Compared with the prior art, the secondary battery provided in this application includes a first shell, an electrode assembly, a second shell, and an elastic member. The first shell has a receiving cavity; the electrode assembly is disposed in the receiving cavity; the second shell is sleeved outside the first shell, at least a portion of the second shell is spaced apart from the first shell, and a spacer cavity is formed between the second shell and the first shell; the elastic member is disposed between the first shell and the second shell, and the elastic member connects the first shell and the second shell. In this application, by disposing the first shell inside the second shell and providing the elastic member between the first shell and the second shell, when the first shell is subjected to the expansion force generated by the electrode assembly, the first shell further transmits this force to the elastic member. The elastic member can resist this force, and as the elastic member continuously compresses, the resistance force of the elastic member to the first shell also increases. This allows the first shell to deform to a certain extent, preventing the electrode assembly from collapsing, and also prevents the first shell from excessively deforming. Attached Figure Description

[0022] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of a secondary battery provided in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of the first and second casings in the secondary battery provided in the embodiments of this application;

[0025] Figure 3 for Figure 2 A magnified view of a section at point A in the middle circle;

[0026] Figure 4 A cross-sectional view of a secondary battery provided in an embodiment of this application;

[0027] Figure 5 After the secondary battery electrode assembly provided in one embodiment of this application is removed, Figure 4 Sectional view at point AA.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100-First housing; 110-Receiving cavity; 120-First housing body; 121-Third opening; 122-Fourth opening; 123-Communication hole; 124-First end face; 200-Electrode assembly; 300-Second housing; 310-Spacer cavity; 320-Second housing body; 321-Cylinder wall; 322-First opening; 323-Second opening; 330-First end cap; 340-Second end cap; 400-Elastic element; 500-Supporting element; 510-Supporting part; X-First direction. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0032] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure of this application, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit this application.

[0033] The cylindrical battery includes a housing and an electrode assembly 200, the electrode assembly 200 being disposed inside the housing.

[0034] However, the electrode assembly 200 will expand during charging and discharging. After expanding, the electrode assembly 200 will come into contact with the housing. The housing can constrain the expansion of the electrode assembly 200. However, as the expansion of the electrode assembly 200 intensifies, the expanded electrode assembly 200 may cause the housing to deform, and the electrode assembly 200 may be deformed and fail.

[0035] To address the technical problem of insufficient support during expansion of the electrode assembly 200, leading to performance degradation or even failure, the first embodiment of this application provides a secondary battery. (See attached image.) Figure 1 , Figure 2 , Figure 3 and Figure 4The secondary battery includes a first housing 100, an electrode assembly 200, a second housing 300, and an elastic member 400. The first housing 100 has a receiving cavity 110. The electrode assembly 200 is disposed in the receiving cavity 110. The second housing 300 is sleeved outside the first housing 100, and at least a portion of the second housing 300 is spaced apart from the first housing 100, forming a spacer cavity 310 between the second housing 300 and the first housing 100. The elastic member 400 is disposed between the first housing 100 and the second housing 300, and the elastic member 400 connects the first housing 100 and the second housing 300.

[0036] It is understandable that the electrode assembly 200 will expand after long-term operation. The force generated by the expansion will act on the first housing 100, which may cause the first housing 100 to be severely deformed or the electrode assembly 200 to collapse, resulting in a sharp decline in battery performance or even scrapping.

[0037] Specifically, the elastic element 400 is able to undergo elastic deformation when the electrode assembly 200 expands.

[0038] In the above embodiment, by placing the first housing 100 inside the second housing 300 and providing an elastic member 400 between the first housing 100 and the second housing 300, when the first housing 100 is subjected to the expansion force generated by the electrode assembly 200, the first housing 100 can further transmit the force to the elastic member 400. The elastic member 400 can resist the force under the support of the second housing 300. As the elastic member 400 is continuously compressed, the resistance force of the elastic member 400 to the first housing 100 also increases. This allows the first housing 100 to have a certain degree of deformation to prevent the electrode assembly 200 from collapsing, and also prevents the first housing 100 from further deforming and becoming excessively deformed after the elastic member 400 is compressed to a certain extent, thereby reducing the possibility of the secondary battery performance deteriorating or even becoming unusable.

[0039] In some embodiments, the elastic element 400 may be a spring, and the elastic element 400 may be able to generate elastic deformation in the direction from the first housing 100 to the second housing 300; in some embodiments, the first housing 100 has a radial direction, and the elastic element 400 may be able to generate elastic deformation in the radial direction. For example, the elastic element 400 may also be a fiber material, rubber material, etc., with elastic deformation capability.

[0040] In some embodiments, please refer to Figure 4 and Figure 5The secondary battery has a first direction X. The first housing 100 includes a first housing body 120, which is a cylindrical body. The second housing 300 includes a second housing body 320, which is a polygonal cylindrical body. Both the first housing body 120 and the second housing body 320 extend along the first direction X. The polygonal cylindrical body has a cylindrical wall 321. Multiple cylindrical walls 321 are connected sequentially along the circumference of the first housing body 120. An elastic member 400 connects the first housing body 120 and the cylindrical wall 321. A spacer cavity 310 is formed between two adjacent cylindrical walls 321 and the first housing body 120. Multiple spacer cavities 310 are provided. Multiple elastic members 400 are provided, and at least two spacer cavities 310 are provided with elastic members 400.

[0041] Wherein, the first direction X is the auxiliary direction. Figure 1 and Figure 2 The direction of the middle arrow X.

[0042] In some embodiments, the polygonal cylinder is a regular polygonal cylinder; in some embodiments, the second housing 300 is a regular hexagonal cylinder.

[0043] Compared to a circular second housing 300, a hexagonal cylindrical second housing 300 makes it easier to group multiple secondary batteries into a battery pack, improving the space utilization and overall energy density within the battery pack.

[0044] In some embodiments, each spacer cavity 310 is provided with an elastic element 400 so that the resistance of the second housing 300 to the first housing 100 by the multiple elastic elements 400 is more uniform in the circumferential direction of the first housing 100, resulting in better performance.

[0045] Optionally, multiple spacer cavities 310 are equally spaced along the circumference of the first housing 100.

[0046] By incorporating multiple elastic elements 400, the resistance of the second housing 300 to the first housing 100 during secondary battery expansion is further enhanced. Simultaneously, by providing elastic elements 400 in at least two spacer cavities 310, the resistance of the second housing 300 to the first housing 100 via the elastic elements 400 becomes more uniform and effective.

[0047] In some embodiments, please refer to Figure 4 The secondary battery also includes a support member 500, which is disposed in the spacer cavity 310 and at the connection of two adjacent cylindrical walls 321. The support member 500 is connected to the two adjacent cylindrical walls 321. The support member 500 has a support portion 510, which is located on the side of the support member 500 facing the cylindrical body. Multiple support members 500 are provided, and elastic members 400 are connected to the support portions 510 of the corresponding support members 500.

[0048] Firstly, in the above embodiments, by providing a support member 500 at the connection point of two adjacent cylindrical walls 321 facing the first housing 100, and by connecting the support member 500 to the adjacent cylindrical walls 321, the strength of the connection point of the adjacent cylindrical walls 321 is increased, thereby improving the strength of the second housing 300, and thus making the second housing 300 more effective in providing resistance through the elastic member 400.

[0049] Secondly, in the above embodiments, by providing a support member 500 that can connect two adjacent cylindrical walls 321 on the side of the elastic member 400 near the second shell body 320, when the electrode assembly 200 expands and transmits the expansion force to the elastic member 400 through the first shell 100, the expansion force can be transmitted to the two adjacent cylindrical walls 321 through the support member 500, so that the two adjacent cylindrical walls 321 can be subjected to uniform force, reducing the possibility of failure between the connection points of the cylindrical walls 321, and improving the reliability of the second shell body 320 and the secondary battery.

[0050] Since the cylindrical walls 321 of the polygonal second shell body 320 are connected sequentially along the circumference, and a spacer cavity 310 is formed between two adjacent cylindrical walls 321 and the first shell body 120, the elastic element 400 is disposed in the spacer cavity 310. At this time, if the elastic element 400 is directly connected to the cylindrical wall 321, the connection part is an inclined surface, which is not convenient for better connection. Therefore, the support part 510 can achieve a better connection with the elastic element 400, and also facilitates the further transmission of the force of the elastic element 400 to the cylindrical wall 321.

[0051] In some embodiments, the support portion 510 may be the side of the support member 500 facing the first housing 100, and the end of the elastic member 400 facing away from the first housing 100 is connected to the support portion 510.

[0052] In some embodiments, the support portion 510 may be a hole with an opening facing the first housing 100, and at least a portion of the elastic member 400 passes through the hole to position the elastic member 400.

[0053] In some embodiments, please refer to Figure 5 At least one spacer cavity 310 is provided with a plurality of elastic elements 400 arranged at intervals along the first direction X, and a support member 500 extends along the first direction X. In the spacer cavity 310 provided with a plurality of elastic elements 400, the support member 500 connects the plurality of elastic elements 400.

[0054] There may be multiple spacer cavities 310, but all spacer cavities 310 may contain at least two elastic elements 400, or only some may contain at least two elastic elements 400. In a spacer cavity 310 containing at least two elastic elements 400, a support member 500 connects all the elastic elements 400 located in that spacer cavity 310.

[0055] In some embodiments, the elastic members 400 in the same spacer cavity 310 are spaced apart along the first direction X and connected to the same support member 500.

[0056] In some embodiments, the two ends of the support member 500 along the first direction X may be flush with the two ends of the second shell body 320 along the first direction X.

[0057] Firstly, in the above embodiments, the support member 500 extends in the first direction X, which enables the support portion 510 to also extend in the first direction X or to have multiple support portions 510, thereby allowing one support member 500 to connect multiple elastic members 400, thereby reducing the number of parts in the secondary battery and reducing the assembly difficulty of the secondary battery.

[0058] Secondly, the support member 500 extending along the first direction X can provide better support for the connection of adjacent cylindrical walls 321 along the first direction X, thereby giving the second shell body 320 better strength and thus giving the secondary battery better reliability.

[0059] In some embodiments, please refer to Figure 5 The support portion 510 extends along the first direction X, and the support portion 510 connects to at least two elastic members 400.

[0060] In another embodiment, the same support member 500 has a plurality of support portions 510, which are spaced apart along a first direction X, and each support portion 510 is connected to an elastic member 400.

[0061] The above provides two implementations of the support portion 510. One is that the support portion 510 extends along the first direction X, thereby connecting multiple elastic members 400; the other is that there are multiple support portions 510, each corresponding to one elastic member 400.

[0062] In some embodiments, the support portion 510 is a support surface facing the first shell body 120, and the support surface extends along the first direction X to be able to connect with a plurality of elastic members 400 spaced apart along the first direction X.

[0063] In some embodiments, the support portion 510 is a support hole with an opening facing the first housing body 120, and a plurality of support holes are spaced apart along the first direction X so that a plurality of elastic members 400 spaced apart along the first direction X can pass through the support holes.

[0064] In the above embodiments, the support member 500 having a support portion 510 extending along the first direction X or having a plurality of support portions 510 spaced apart along the first direction X can allow one support member 500 to connect to a plurality of elastic members 400 spaced apart along the first direction X, reducing the number of support members 500 and the number of parts of the secondary battery, thereby reducing the assembly difficulty of the secondary battery.

[0065] In some embodiments, both the support member 500 and the elastic member 400 extend along a first direction X, and the support member 500 and the elastic member 400 correspond one-to-one. In another embodiment, the support member 500 is integrally formed with the cylinder wall 321; for example, the support member 500 and the cylinder wall 321 can be selected from the same material and can be integrally formed. In yet another embodiment, the support member 500 and the elastic member 400 are integrally formed; for example, both the support member 500 and the elastic member 400 can be made of materials with elastic deformation capabilities, such as rubber.

[0066] Specifically, the support member 500 and the elastic member 400 are in one-to-one correspondence, meaning that each elastic member 400 has a support member 500 connected to it, so that each elastic member 400 can be connected to the cylinder wall 321 through the support member 500, thereby allowing the force from each elastic member 400 to be distributed to two adjacent cylinder walls 321, thus enabling the second shell body 320 to have better strength.

[0067] In some embodiments, the support member 500 and the elastic member 400 are both parts independent of the first shell body 120 and the second shell body 320. The cylinder wall 321 and the support member 500 are connected only when needed, and the support member 500 and the elastic member 400 are connected only when needed.

[0068] In the above embodiments, the support member 500 and the elastic member 400 are set to be independent and connected and assembled only when needed, so as to reduce the transportation difficulty of secondary battery parts and improve the compatibility of parts in secondary batteries.

[0069] In some embodiments, the support member 500 is integrally formed with the cylindrical wall 321, that is, the cylindrical wall 321 and the support member 500 are both parts of the second shell body 320, and all the support members 500, the cylindrical wall 321 and the second shell body 320 are integrally connected together to form a single part. In some embodiments, the support member 500 and the cylindrical wall 321 are welded together.

[0070] In the above embodiments, by integrally configuring the support member 500 and the cylindrical wall 321, the connection reliability between the support member 500 and the cylindrical wall 321 is improved, thereby further enhancing the connection strength between adjacent cylindrical walls 321. Furthermore, the integral configuration of the support member 500 and the cylindrical wall 321 also reduces the number of parts in the secondary battery, lowering the assembly difficulty of the secondary battery.

[0071] In some embodiments, the support member 500 and the elastic member 400 are integrally disposed, that is, the support member 500 and the elastic member 400 are connected together to form a separate part. In some embodiments, one support member 500 is integrally connected with a plurality of elastic members 400 connected thereto to form a separate part; in some embodiments, the support member 500 and the elastic member 400 are welded together.

[0072] In the above embodiments, by integrating the support member 500 and the elastic member 400, the connection reliability between the support member 500 and the elastic member 400 is improved, thereby further enhancing the connection strength between adjacent cylinder walls 321. Furthermore, integrating the support member 500 and the elastic member 400 also reduces the number of parts in the secondary battery, lowering the assembly difficulty.

[0073] In some embodiments, please refer to Figure 1 and Figure 5 The second housing 300 also includes a first end cap 330 and a second end cap 340. The second housing body 320 has a first opening 322 and a second opening 323 that are disposed opposite to each other in the first direction X. The first end cap 330 is connected to the second housing body 320 and covers the first opening 322. The second end cap 340 is connected to the second housing body 320 and covers the second opening 323.

[0074] In the above embodiments, by providing a first end cap 330 and a second end cap 340, the receiving cavity 110 and the spacer cavity 310 can be exposed from the first opening 322 or the second opening 323 during the assembly of the secondary battery. This facilitates the placement and installation of components such as the electrode assembly 200, the elastic element 400, and the support member 500, reducing the assembly difficulty of the secondary battery. Furthermore, providing two end caps, namely the first end cap 330 and the second end cap 340, allows the receiving cavity 110 and the spacer cavity 310 to be exposed at both ends along the first direction X. This allows for selection of the opening exposed from the first end cap 330 or the second end cap 340 for the installation of the electrode assembly 200, the elastic element 400, and the support member 500, further reducing the assembly difficulty of the secondary battery.

[0075] In some embodiments, please refer to Figure 5 The first shell body 120 has a third opening 121 and a fourth opening 122 that are disposed opposite to each other in the first direction X. Both the third opening 121 and the fourth opening 122 are connected to the receiving cavity 110. The first end cap 330 also covers the third opening 121, and the second end cap 340 also covers the fourth opening 122. The first shell body 120 is provided with a plurality of connecting holes 123, which connect the receiving cavity 110 and the spacer cavity 310. At least two connecting holes 123 are spaced apart in the first direction X.

[0076] The connecting hole 123 allows the electrolyte in the first housing 100 to enter the second housing 300, and also allows electrolyte to be stored in the gap between the first housing 100 and the second housing 300, i.e., the spacer cavity 310, as an effective replenishment of the electrolyte in the first housing 100 after consumption. The connecting hole 123 enables both connection and replenishment. Of course, the elastic element 400 in this embodiment needs to be corrosion-resistant and not affect the effective components of the electrolyte. Furthermore, when the battery malfunctions and generates high-pressure gas, the connecting hole 123 near the upper side in the first direction X, which is not submerged in electrolyte, or the connecting hole 123 that is not submerged after partial electrolyte consumption, can also act as a vent, allowing the gas generated in the first housing 100 to be released into the spacer cavity 310, providing a new space for gas release and serving as a buffer against explosion.

[0077] On the one hand, by having the first end cap 330 and the second end cap 340 respectively seal the first opening 322 and the second opening 323, the electrode assembly 200 can be completely limited by the first shell body 120, the first end cap 330 and the second end cap 340, thereby reducing the possibility of the electrode assembly 200 shifting along the first direction X and improving the reliability and safety of the secondary battery.

[0078] Secondly, by providing a through hole connecting the spacer cavity 310 and the receiving cavity 110, the gas in the secondary battery can be connected in the spacer cavity 310 and the receiving cavity 110, so that the gas generated by the electrode assembly 200 in the receiving cavity 110 can be discharged from the secondary battery through the spacer cavity 310, thereby improving the safety performance of the secondary battery.

[0079] Thirdly, by providing a connecting hole 123 connecting the spacer cavity 310 and the receiving cavity 110, the electrolyte in the secondary battery can be connected in the spacer cavity 310 and the receiving cavity 110, so that the electrolyte in the spacer cavity 310 can flow to the receiving cavity 110 and contact the electrode assembly 200, thereby improving the utilization rate of the electrolyte and thus improving the performance of the secondary battery.

[0080] In some embodiments, please refer to Figure 5 The first shell body 120 has a first end face 124 in the first direction X, and the wall of at least one connecting hole 123 overlaps with the first end face 124.

[0081] It should be noted that, as Figure 5 As shown, the first end face 124 is the bottom end face when the battery is working. The wall of the connecting hole 123 overlaps with the first end face 124, so that the connecting hole 123 can effectively connect the receiving cavity 110 and the spacer cavity 310, so that the electrolyte at the bottom of the spacer cavity 310 can be effectively replenished into the receiving cavity 110.

[0082] Specifically, the first shell body 120 has a first end face 124 in the first direction X, a third opening 121 is disposed on the first end face 124, the first end face 124 is connected to the second end cover 340; at least one through hole 123 penetrates the first end face 124, and the hole wall of the through hole 123 is connected to the first end face 124.

[0083] In the above embodiment, when the through hole 123 penetrating the first end face 124 is a drain hole, the electrolyte at the bottom can also flow between the spacer cavity 310 and the receiving cavity 110, thereby maximizing the utilization rate of the electrolyte and improving the performance of the secondary battery.

[0084] Accordingly, this application also provides a battery pack including a secondary battery as described in any of the above embodiments.

[0085] The battery pack may include a housing and multiple secondary batteries, which are grouped together and housed within the housing.

[0086] The above provides a detailed description of a secondary battery and battery pack provided in the embodiments of this application. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A secondary battery, characterized in that, include: A first housing, the first housing having a receiving cavity; An electrode assembly disposed in the receiving cavity; A second housing is fitted over the first housing, at least a portion of the second housing is spaced apart from the first housing, and a spacer cavity is formed between the second housing and the first housing; An elastic element is disposed between the first housing and the second housing, and the elastic element connects the first housing and the second housing.

2. The secondary battery according to claim 1, characterized in that, The secondary battery has a first direction. The first housing includes a first housing body, which is a circular cylinder. The second housing includes a second housing body, which is a polygonal cylinder. Both the first housing body and the second housing body extend along the first direction. The polygonal cylinder has a cylinder wall, which has multiple cylinder walls that are sequentially connected along the circumference of the first housing body. The elastic element connects the first housing body and the cylinder wall. The two adjacent cylindrical walls are connected to the first shell body and form one of the spacer cavities; The spacer cavity has multiple spaces, the elastic element has multiple elastic elements, and at least two of the spacer cavities have the elastic element.

3. The secondary battery according to claim 2, characterized in that, The secondary battery also includes a support member disposed in the spacer cavity, the support member being located at the connection between two adjacent cylindrical walls and connected to the two adjacent cylindrical walls, the support member having a support portion located on the side of the support member facing the cylindrical body; multiple support members are provided, and the elastic member is connected to the support portion of the corresponding support member.

4. The secondary battery according to claim 3, characterized in that, At least one of the spacer cavities is provided with a plurality of elastic elements arranged at intervals along the first direction, and the support extends along the first direction. In the spacer cavity provided with the plurality of elastic elements, the support connects the plurality of elastic elements.

5. The secondary battery according to claim 4, characterized in that, The support portion extends along the first direction and is connected to at least two of the elastic elements; or, the same support element has multiple support portions, which are spaced apart along the first direction, and each support portion is connected to one of the elastic elements.

6. The secondary battery according to claim 3, characterized in that, Both the support member and the elastic member extend along the first direction, and the support member and the elastic member correspond one-to-one; or, the support member is integrally formed with the cylinder wall; or, the support member and the elastic member are integrally formed.

7. The secondary battery according to any one of claims 2-6, characterized in that, The second housing further includes a first end cap and a second end cap. The second housing body has a first opening and a second opening disposed opposite to each other in the first direction. The first end cap is connected to the second housing body and covers the first opening, and the second end cap is connected to the second housing body and covers the second opening.

8. The secondary battery according to claim 7, characterized in that, The first shell body has a third opening and a fourth opening that are disposed opposite to each other in the first direction. Both the third opening and the fourth opening are in communication with the receiving cavity. The first end cap also covers the third opening, and the second end cap also covers the fourth opening. The first shell body is provided with a plurality of connecting holes, the connecting holes connecting the receiving cavity and the spacer cavity, and at least two of the connecting holes are spaced apart in the first direction.

9. The secondary battery according to claim 8, characterized in that, The first shell body has a first end face in the first direction, and the wall of at least one of the communicating holes overlaps with the first end face.

10. A battery pack, characterized in that, Includes the secondary battery as described in any one of claims 1-9.

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