End cover assembly and secondary battery comprising same

Abstract

The utility model belongs to the technical field of batteries, and mainly relates to an end cover assembly, which is provided with a liquid supplementing cavity for storing electrolyte and a through groove, the through groove penetrates through two opposite sides of the end cover assembly in the thickness direction and is communicated with the liquid supplementing cavity, a first sealing element is arranged in the through groove and is used for sealing the liquid supplementing cavity, the part, located in the liquid supplementing cavity, of the first sealing piece does not react with the electrolyte. According to the design, the internal space of the battery shell is fully utilized, and the use of external equipment such as an infusion pump is avoided. In addition, the utility model further designs the secondary battery comprising the end cover assembly, and the liquid supplementing method simplifies the liquid supplementing process and improves the liquid supplementing efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to an end cover assembly and a secondary battery comprising the end cover assembly. Background Art

[0002] In modern electronic devices, batteries are crucial energy suppliers, and their performance directly impacts the operational stability and lifespan of the devices. However, after two electrolyte injections, the battery cannot be replenished. When the electrolyte is depleted to a certain level, the battery's charge and discharge capacity plummets, leading to the end of its lifespan.

[0003] In the current technological context, to solve the problem of electrolyte not being replenished in time, a commonly used method is to replenish the electrolyte from the outside or a pre-set refill tank to the inside of the battery with the help of a liquid pump. However, this solution faces a significant limitation in practical application, namely, it does not fully consider the limited space inside the battery shell and battery pack. In addition, when the liquid pump fails or fails to operate normally, the battery refill process will be forced to be interrupted, which may have an adverse impact on battery performance and the stable operation of the overall system.

[0004] Based on this, there is an urgent need for an end cap assembly that can achieve fluid replenishment and a secondary battery including the end cap assembly to solve the above technical defects. Utility Model Content

[0005] One of the purposes of the present invention is to address the deficiencies of the prior art and to provide a structure that can directly replenish the battery with an end cover assembly, without the need for a liquid pump to directly replenish the battery electrolyte.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] An end cap assembly is provided with a refill cavity for storing electrolyte. The end cap assembly is provided with a through groove, which runs through two opposite sides of the end cap assembly in the thickness direction and is connected to the refill cavity. A first seal is provided in the through groove, and the first seal is used to seal the refill cavity, wherein the portion of the first seal located in the refill cavity does not react with the electrolyte.

[0008] The beneficial effects of the above technical solution of the utility model are:

[0009] Directly refilling the battery through the end cap assembly fully utilizes the internal space of the battery housing, avoids the use of external equipment such as a pump, simplifies the refill process, and improves refill efficiency. It also reduces the risk of battery performance degradation and system instability caused by refill equipment failure.

[0010] As a further improvement to the end cover assembly of the present invention, the material of the first sealing member includes PPHJ400 material and Vistamaxx6202 material;

[0011] The rehydration chamber is used for storing lithium ion electrolyte or sodium ion electrolyte.

[0012] As a further improvement to the end cover assembly of the present invention, the ratio of PPHJ400 material to Vistamaxx6202 material is 1:1.

[0013] As a further improvement to the end cap assembly of the present invention, the lithium ion electrolyte includes a lithium salt, a first solvent and a first additive, the lithium salt is lithium difluorophosphate, the first solvent includes at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, and dimethyl carbonate, and the first additive includes at least one of ethylene carbonate and fluoroethylene carbonate; or,

[0014] The sodium ion electrolyte includes a sodium salt, a second solvent and a second additive, the sodium salt is at least one of sodium difluorophosphate, sodium hexafluorophosphate and sodium bis(fluorosulfonyl)imide, the second solvent is at least one of fluoroethylene carbonate, ethyl methyl carbonate, diethyl carbonate and propylene carbonate, and the second additive is at least one of vinylene carbonate, succinic anhydride, vinyl sulfate, 1,3-propylene sultone and isocyanate.

[0015] As a further improvement to the end cover assembly of the utility model, the end cover assembly includes:

[0016] The cover plate is provided with a fluid replenishing tank;

[0017] The insulating unit is disposed on one side of the cover in the thickness direction, the insulating unit is provided with a mounting groove, the mounting groove is communicated with the fluid replenishing cavity, at least a portion of the first sealing member is disposed in the mounting groove, the mounting groove is used to seal the fluid replenishing cavity, and the first sealing member is exposed in the fluid replenishing groove;

[0018] The liquid replenishing groove and the installation groove together constitute a through groove.

[0019] As a further improvement to the end cover assembly of the present invention, a second sealing member is sealed in the liquid replenishing tank, and the first sealing member is located on a side of the second sealing member facing the insulating unit.

[0020] As a further improvement to the end cover assembly of the present invention, a notch is provided on the surface of the first sealing member adjacent to the second sealing member.

[0021] As a further improvement to the end cap assembly of the present invention, the insulating unit includes:

[0022] The first plastic part is provided with a first groove;

[0023] The liquid storage top plate is provided on a side of the first plastic component facing away from the cover plate, and the liquid storage top plate is provided with a second groove;

[0024] The liquid storage bottom plate is arranged on the side of the liquid storage top plate away from the cover plate, and the liquid storage bottom plate is provided with a third groove;

[0025] A liquid storage tank is provided on the surface of the liquid storage top plate facing the liquid storage bottom plate, or a liquid storage tank is provided on the surface of the liquid storage bottom plate facing the liquid storage top plate;

[0026] The liquid storage top plate and the liquid storage bottom plate are enclosed to form a liquid replenishing cavity, and the first groove, the second groove and the third groove together constitute an installation groove.

[0027] As a further improvement to the end cover assembly of the utility model, the end cover assembly includes:

[0028] The pole is provided with a column body and a connector, and the column body is interference-connected to the cover plate through a second plastic part.

[0029] The second purpose of the present invention is to provide a secondary battery that can simplify the battery refilling process in response to the deficiencies of the prior art.

[0030] To achieve the above objectives, this application adopts the following technical solutions:

[0031] A secondary battery comprises a bare cell and any of the above-mentioned end cap assemblies connected to the bare cell, wherein the bare cell comprises a shell, a positive electrode, a diaphragm and a negative electrode housed in the shell, and an electrolyte filled in the shell; and a fluid replenishing chamber is connected to the shell.

[0032] The refill method used in this utility model simplifies the refill process, improves battery production efficiency, and ensures the stability and reliability of the battery during use. By optimizing the design of the end cap assembly, the refill process of the secondary battery can be operated more conveniently, reducing dependence on complex equipment, thereby reducing production costs and maintenance difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0034] Figure 1 This is a schematic structural diagram of implementation mode 1 of the present invention;

[0035] Figure 2 for Figure 1 Section along AA;

[0036] Figure 3 for Figure 2 A partial enlarged view of point B in the middle;

[0037] Figure 4 Schematic diagram of the structure of the first sealing member in Example 1;

[0038] Figure 5 This is one of the structural diagrams of the insulation unit in Example 3;

[0039] Figure 6 This is the second structural diagram of the insulation unit in Example 3.

[0040] in:

[0041] 1-end cover assembly;

[0042] 11-Fluid infusion chamber;

[0043] 12-through slot;

[0044] 121-first sealing member;

[0045] 1211 - notch;

[0046] 13-cover plate;

[0047] 131- fluid replenishment tank;

[0048] 132 - second sealing member;

[0049] 14-Insulation unit;

[0050] 141-mounting slot;

[0051] 142-first plastic part;

[0052] 1421 - first slot;

[0053] 143-liquid storage top plate;

[0054] 1431-Second slot;

[0055] 144-liquid storage bottom plate;

[0056] 1441-third slot;

[0057] 15-pole;

[0058] 151- column;

[0059] 152-connector;

[0060] 153-Second plastic part. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0062] In the description of this utility model, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0063] Although the present application is disclosed as above in terms of a preferred embodiment, it is not intended to limit the claims. Any person skilled in the art may make several possible changes and modifications without departing from the concept of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

[0064] The present invention will be described in further detail below in conjunction with specific implementation methods, but the implementation methods of the present invention are not limited thereto.

[0065] Implementation Method 1

[0066] like Figure 1-3 As shown, in order to solve the technical problem of complicated battery refilling process in the prior art, the end cover assembly 1 in this embodiment is provided with a refilling chamber 11 for storing electrolyte, and the end cover assembly 1 is provided with a through groove 12. The through groove 12 runs through the two opposite sides of the end cover assembly 1 in the thickness direction and is connected to the refilling chamber 11. A first sealing member 121 is provided in the through groove 12. The first sealing member 121 is used to seal the refilling chamber 11, wherein the portion of the first sealing member 121 located in the refilling chamber 11 does not react with the electrolyte.

[0067] Specifically, the current sodium ion or lithium ion square aluminum shell battery, after undergoing two electrolyte injection processes, the battery cell is sealed and completely isolated from the outside. However, since the battery gradually consumes the electrolyte during recycling, when the amount of electrolyte is reduced to a certain level, it cannot be replenished, which will cause the battery's charge and discharge capacity to drop sharply, and ultimately lead to the end of the battery life. Taking the above problems into consideration, the present application proposes an end cap assembly 1, which can not only store electrolyte, but also makes the replenishment of electrolyte simple and efficient through a specific structural design.

[0068] Specifically, the working principle of the rehydration chamber 11 is: before the end cap assembly 1 is packaged with the bare cell and the battery structure, the rehydration chamber 11 is filled with an electrolyte of the same material as the electrolyte to be introduced subsequently through its through groove 12. When the above-mentioned electrolyte fills the entire rehydration chamber 11, the electrolyte can be sealed into the end cap assembly 1 by sealing the hole position of the through groove 12 through the first seal 121 (in the specific embodiment, the first seal 121 shown is a glue nail). When the battery needs to be rehydrated, the battery can be rehydrated through the rehydration chamber 11 by removing the first seal 121 in the through groove 12. Among them, it should be noted that the process of injecting electrolyte into the battery can be completed through the injection hole in the battery shell or through the injection hole in the end cap assembly 1. Preferably, the end cap assembly 1 in this embodiment also has an injection groove for injecting electrolyte.

[0069] Furthermore, the first seal 121 has two operating modes. One is that when the battery top cover has been installed, the first seal 121 is completely pulled out from the through groove 12 by a tool. At this time, the air pressure and gravity act together on the electrolyte in the rehydration chamber 11 to replenish the electrolyte in the battery shell; the second is to directly use a tool to apply external force to the first seal 121, so that it directly enters the interior of the battery shell, thereby replenishing the electrolyte in the rehydration chamber 11 into the battery. Among them, the rehydration chamber 11 is designed to store lithium ion or sodium ion electrolyte. Since the first seal 121 is made of materials that do not react with lithium ion or sodium ion electrolyte, it will not have an adverse effect on the battery.

[0070] Specifically, the first sealant 121 is made of PPHJ400 and Vistamaxx 6202. PPHJ400 offers excellent chemical resistance and mechanical strength, while Vistamaxx 6202 offers superior sealing performance and flexibility. This combination of materials ensures that the first sealant 121 can withstand chemical reactions and temperature fluctuations within the battery while maintaining a secure seal, thereby extending the battery's lifespan.

[0071] Furthermore, the ratio of PPHJ400 to Vistamaxx6202 in first sealant 121 is 1:1. This 1:1 ratio fully leverages the strengths of both materials, ensuring the stability and reliability of first sealant 121 in various environments. In practical applications, this ratio can be adjusted appropriately based on the battery's operating environment and requirements to achieve optimal sealing and extend battery life.

[0072] Furthermore, the lithium ion electrolyte includes a lithium salt, a first solvent and a first additive, the lithium salt is lithium difluorophosphate, the first solvent includes at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate and dimethyl carbonate, and the first additive includes at least one of ethylene carbonate and fluoroethylene carbonate; and the materials of the electrolyte do not react with the first sealant 121, thereby ensuring the stability and safety of the lithium ion battery.

[0073] The sodium ion electrolyte includes a sodium salt, a second solvent, and a second additive. The sodium salt is at least one of sodium difluorophosphate, sodium hexafluorophosphate, and sodium bis(fluorosulfonyl)imide. The second solvent is at least one of fluoroethylene carbonate, ethyl methyl carbonate, diethyl carbonate, and propylene carbonate. The second additive is at least one of vinylene carbonate, succinic anhydride, vinyl sulfate, 1,3-propylene sultone, and isocyanate. The materials of the electrolyte do not react with the first seal 121, further ensuring the stability and safety of the sodium ion battery.

[0074] Furthermore, a notch 1211 is provided on the surface of the first seal 121 near the second seal 132. The notch 1211 can be flat, circular, or multi-slot, with its shape corresponding to the tools used in actual production. This design reduces the complexity of battery refilling and improves product usability.

[0075] Implementation Method 2

[0076] like Figure 3-4 As shown, the difference from embodiment 1 is that: in order to further solve the structural complexity of battery electrolyte replenishment in the prior art, the end cap assembly 1 in this embodiment includes:

[0077] The cover plate 13 may be made of metal to maintain the strength of the end cap assembly 1. A refilling groove 131 is provided in the top cover to ensure air flow after the first seal 121 is removed, thereby exerting downward pressure on the electrolyte in the refilling chamber 11.

[0078] The insulating unit 14 is disposed on one side of the cover plate 13 in the thickness direction. The insulating unit 14 is provided with a mounting slot 141 that communicates with the refill chamber 11. At least a portion of the first sealing member 121 is disposed within the mounting slot 141, sealing the refill chamber 11. The first sealing member 121 is exposed from the refill chamber 131. Specifically, the first sealing member 121 is partially embedded in the mounting slot 141, and its primary function is to prevent electrolyte in the refill chamber 11 from flowing into the battery. When the first sealing member 121 is fully embedded in the mounting slot 141, electrolyte leakage from the through-holes at both ends of the sealing slot is eliminated, achieving an optimal sealing effect. This prevents electrolyte from splashing out of the refill chamber 11 due to battery shaking when the first sealing member 121 is partially embedded in the mounting slot 141.

[0079] The liquid replenishing groove 131 and the installation groove 141 together constitute the through groove 12 .

[0080] Furthermore, a second seal 132 is sealed in the refill tank 131, and the first seal 121 is located on the side of the second seal 132 facing the insulating unit 14. In a specific embodiment, the second seal 132 is a sealing nail, and the material of the second seal 132 can be a material with excellent chemical stability, high temperature resistance and corrosion resistance. Since the second seal 132 does not react with the electrolyte at the same time, it can ensure that the electrolyte in the refill tank 131 will not leak, thereby further improving the safety and reliability of the battery. In a specific embodiment, the second seal 132 seals the refill tank 131, so that the refill chamber 11 can only communicate with the outside world through the side of the mounting groove 141 away from the refill tank 131, and when the end cover assembly 1 has not yet been sealed with the battery shell, the refill chamber 11 is directly refilled through the side away from the refill tank 131.

[0081] Furthermore, a refill port is provided on the other side of the refill tank 131 for replenishing electrolyte into the refill chamber 11 during battery use. The refill port is sealed by a third sealing member, which can be made of a material with good elasticity and temperature resistance to adapt to the battery's operating environment at different temperatures.

[0082] Furthermore, to ensure battery stability during charge and discharge, the end cap assembly 1 also includes a pressure relief valve. This pressure relief valve is located on the cover plate 13. When the internal pressure of the battery exceeds a set value, the pressure relief valve automatically opens to release excess gas, preventing the battery from exploding or leaking due to excessive internal pressure.

[0083] In summary, this embodiment, by optimizing the design of the end cap assembly 1, not only improves the battery's sealing performance but also enhances its safety and reliability. Through rational material selection and structural design, the battery maintains stable operating conditions in a variety of operating environments, thus meeting the high performance requirements of modern electronic devices.

[0084] Other differences from Implementation 1 will not be repeated in this application.

[0085] Implementation 3

[0086] like Figure 5-6 As shown, different from Example 1, in order to further reflect the design principle of the fluid infusion chamber 11 of the present application, in this embodiment, the insulating unit 14 (in the specific embodiment, the lower plastic part) includes:

[0087] The first plastic component 142 is provided with a first groove 1421. The first plastic component serves as a bridge connecting the cover plate 13 and the refill chamber 11, preventing contact between the electrolyte and the top cover. Furthermore, the first groove 1421 accommodates the first sealing component 121, ensuring that it does not shift during the refill process.

[0088] The liquid storage top plate 143 is disposed on the side of the first plastic component 142 away from the cover plate 13 and has a second groove 1431 . The second groove 1431 is also used to accommodate the second sealing component 132 to ensure that the sealing effect is maintained during battery use.

[0089] like Figure 5 As shown, a liquid storage tank is provided on the surface of the liquid storage top plate 143 facing the liquid storage bottom plate 144. The specific shape and size of the liquid storage tank can be designed according to actual needs to meet the requirements of different battery capacities for liquid storage cavities.

[0090] like Figure 6 As shown, a liquid reservoir is provided on the surface of the liquid reservoir bottom plate 144 facing the liquid reservoir top plate 143. Specifically, the shape and size of the reservoir can be designed based on actual needs to meet the requirements of different battery capacities for the liquid reservoir cavity. The depth and width of the reservoir can be adjusted to accommodate different volumes of electrolyte replenishment. Furthermore, the edges of the reservoir can be designed with a smooth transition to reduce turbulence that may occur during the charge and discharge process of the electrolyte, thereby reducing wear and tear within the battery.

[0091] Furthermore, the liquid storage top plate 143 and the liquid storage bottom plate 144 enclose the liquid replenishing chamber 11, and the first groove 1421, the second groove 1431 and the third groove 1441 together constitute the mounting groove 141. Furthermore, the pole 15 is provided with a column 151 and a connector 152, and the column 151 is interference-connected to the cover plate 13 via a second plastic part.

[0092] Other details that are the same as those in Implementation 1 will not be repeated in this application.

[0093] Implementation 4

[0094] To address the shortcomings of the existing technology, the present application further provides a secondary battery that simplifies the battery refill process, comprising a bare cell and any of the aforementioned end cap assemblies 1 connected to the bare cell. The bare cell includes a housing, a positive electrode, a separator, and a negative electrode housed within the housing, and electrolyte perfused within the housing; and a refill chamber communicates with the housing. By optimizing the design of the end cap assembly 1, the present application achieves greater operational convenience during the refill process, reduces reliance on complex equipment, and thereby reduces production costs and maintenance.

[0095] Further addressing the deficiencies of the prior art, the present application also provides a refilling method that can simplify the refilling process of a secondary battery, the steps of which are as follows:

[0096] S101, removing the sealant covering the second sealing member in the end cover assembly 1, and removing the second sealing member from the end cover assembly 1;

[0097] S202: Using a designated tooling member to act on one side of the surface of the first sealing member 121 close to the second sealing member 132, the first sealing member 121 is pushed into the battery, so that the electrolyte stored in the liquid replenishing chamber 11 is replenished into the electrolyte of the secondary battery housing;

[0098] S303, reassemble the liquid infusion chamber 11 into the end cover assembly 1 and reseal it.

[0099] The rehydration method adopted by the present invention simplifies the rehydration process, reduces production costs, and reduces the risk of battery performance degradation due to improper operation.

[0100] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An end cap assembly, characterized in that: The end cap assembly (1) is provided with a refill chamber (11) for storing electrolyte, and the end cap assembly is provided with a through groove (12), the through groove (12) passes through two opposite sides of the end cap assembly (1) in a thickness direction and is in communication with the refill chamber (11), a first sealing member (121) is provided in the through groove (12), the first sealing member (121) is used to seal the refill chamber (11), wherein a portion of the first sealing member (121) located in the refill chamber (11) does not react with the electrolyte.

2. The end cap assembly according to claim 1, wherein: The end cap assembly (1) comprises: The cover plate (13) is provided with a fluid replenishing tank (131); an insulating unit (14) disposed on one side of the cover plate (13) in a thickness direction, the insulating unit (14) being provided with a mounting groove (141), the mounting groove (141) being in communication with the fluid replenishing cavity (11), at least a portion of the first sealing member (121) being disposed within the mounting groove (141), the mounting groove (141) being used to seal the fluid replenishing cavity (11), and the first sealing member (121) being exposed from the mounting groove (141); The liquid replenishing groove (131) and the installation groove (141) together constitute the through groove (12).

3. The end cap assembly according to claim 2, wherein: A second sealing member (132) is sealed in the fluid replenishing tank (131), and the first sealing member (121) is located on a side of the second sealing member (132) facing the insulating unit (14).

4. The end cap assembly according to claim 3, wherein: A notch (1211) is provided on a surface of the first sealing member (121) close to the second sealing member (132).

5. The end cap assembly according to claim 2, wherein: The insulating unit (14) comprises: A first plastic part (142) is provided with a first groove (1421); A liquid storage top plate (143) is provided on a side of the first plastic part (142) facing away from the cover plate (13), and the liquid storage top plate (143) is provided with a second groove (1431); A liquid storage bottom plate (144) is provided on a side of the liquid storage top plate (143) facing away from the cover plate (13), and the liquid storage bottom plate (144) is provided with a third groove (1441); A liquid storage tank (145) is provided on the surface of the liquid storage top plate (143) facing the liquid storage bottom plate (144), or a liquid storage tank (145) is provided on the surface of the liquid storage bottom plate facing the liquid storage top plate; The liquid storage top plate (143) and the liquid storage bottom plate (144) enclose the liquid infusion cavity (11), and the first groove (1421), the second groove (1431) and the third groove (1441) together constitute the installation groove (141).

6. The end cap assembly according to claim 2, wherein: The end cap assembly (1) comprises: The pole (15) is provided with a column (151) and a connector (152), wherein the column (151) is interference-connected to the cover plate (13) via a second plastic part (153).

7. A secondary battery, characterized in that: A bare battery cell and an end cap assembly (1) as claimed in any one of claims 1 to 6 connected to the bare battery cell, wherein the bare battery cell comprises a shell, a positive electrode, a diaphragm and a negative electrode accommodated in the shell, and an electrolyte injected into the shell; and the refill chamber (11) is connected to the shell.

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