Sealing assembly, upper cover plate assembly, lithium ion battery and large-capacity battery

Abstract

The present invention belongs to the field of lithium ion batteries, and specifically provides a sealing assembly, an upper cover plate assembly, a lithium ion battery and a large-capacity battery. The technical problem in the prior art whereby during the operation of a lithium ion battery, due to continuous redox reactions, an electrolyte is continuously depleted, leading to a decline in the cycle life of the lithium ion battery is solved. The sealing assembly comprises an injection-molded member, a first sealing member, and a second sealing member, wherein the injection-molded member is formed on the basis of an injection molding process and is fixed in an electrolyte injection port, and an opening in communication with an inner cavity of a casing is provided in the injection-molded member; the first sealing member is inserted into the opening for initial sealing of the opening; and the second sealing member is detachably fixed to the injection-molded member and covers the opening for secondary sealing of the opening. Using the sealing assembly in the present invention can perform electrolyte replenishment on the lithium ion battery at any time as needed, thus helping to prolong the cycle life of the lithium ion battery.

Description

Sealing assembly, upper cover assembly, lithium-ion battery and high-capacity battery Technical Field

[0001] The present invention belongs to the field of lithium-ion batteries, and specifically relates to a sealing assembly, an upper cover assembly, a lithium-ion battery, and a large-capacity battery. Background Art

[0002] Lithium-ion batteries consist of an outer shell, a battery cell inside the shell, and an electrolyte. During the operation of lithium-ion batteries, due to the continuous redox reaction, the electrolyte will be continuously consumed, making some active substances unable to penetrate. This is one of the important reasons for the reduction in the cycle life of lithium-ion batteries. Summary of the Invention

[0003] The present invention aims to provide a sealing assembly, an upper cover assembly, a lithium-ion battery, and a high-capacity battery, which overcome the technical problem in the prior art that during the operation of lithium-ion batteries, electrolyte is continuously consumed due to the ongoing redox reaction, resulting in a reduced cycle life of the lithium-ion battery.

[0004] The technical solution of the present invention is to provide a sealing assembly for use in a lithium-ion battery. The lithium-ion battery comprises a housing with a liquid injection port provided on the housing. The special feature of the sealing assembly is that the sealing assembly comprises an injection molded part, a first sealing part, and a second sealing part.

[0005] The injection molded part is formed based on the injection molding process and fixed in the liquid injection port, and an opening is opened on the injection molded part to communicate with the inner cavity of the shell;

[0006] The first sealing member is inserted into the opening to initially seal the opening;

[0007] The second sealing member is detachably fixed to the injection molded part and covers the opening to secondary seal the opening.

[0008] The present invention has an injection molded part at the liquid injection port of the lithium-ion battery, and an opening that penetrates the inner cavity of the lithium-ion battery shell is opened on the injection molded part. The liquid injection operation can be realized based on the opening. The present invention uses the opening on the injection molded part as a new liquid injection port. The sealing part only needs to cooperate with the new liquid injection port and does not need to cooperate with the original liquid injection port of the lithium-ion battery. Therefore, when the sealing part is removed, the structure of the lithium-ion battery itself is not damaged. A first sealing part is inserted into the opening to perform a first seal on the opening, and a second sealing part is used to cover the opening to perform a second seal on the opening, which has high sealing reliability. The second sealing part is detachably covered on the opening. When liquid replenishment is required, the second sealing part is first removed, and then the first sealing part is taken out using a tool to replenish liquid. After the liquid replenishment is completed, the first sealing part is inserted into the opening, and the second sealing part is fixed to the injection molded part to cover the opening.

[0009] It can be seen that by using the sealing assembly of the present invention, the lithium-ion battery can be replenished at any time as needed, thereby helping to improve the cycle life of the lithium-ion battery. In addition, due to the provision of the sealing assembly of the present invention, the lithium-ion battery can be reused, which is more energy-saving and environmentally friendly.

[0010] Furthermore, the injection port includes a first through hole, which is a stepped through hole, and the small hole of the first through hole is opened near the outer surface of the shell; the injection molded part includes a first component and a second component; the first component is molded in the first through hole, and the second component is located on the outer surface of the shell. By molding the first component in the large hole of the first through hole, the entire injection molded part can be firmly fixed to the shell; in addition, since the thickness of the lithium-ion battery shell (z-direction dimension) is relatively thin, if only the first seal is inserted into the injection port, the contact surface between the first seal and the injection port is very small, and it is difficult to achieve a good sealing effect; the present invention fixes the injection molded part with a z-direction dimension larger than the shell size at the injection port, and opens an opening in the injection molded part as a new injection port, and inserts the first seal into the new injection port. Since the new injection port has a larger z-direction dimension, the contact surface between the first seal and the new injection port is larger, which can achieve a better sealing effect.

[0011] Furthermore, the liquid injection port further includes at least one second through hole; the second through hole is located in the peripheral area of ​​the small hole of the first through hole and is connected to the large hole of the first through hole;

[0012] The injection molded part also includes a third component integral with the first and second components; the third component is formed in the second through hole. By cooperating with the first component formed in the first through hole and the third component, the injection molded part can be more securely combined with the housing.

[0013] Furthermore, the opening is formed on the first component and the second component, and is coaxial with the original liquid injection port of the lithium-ion battery.

[0014] Furthermore, there are multiple second through holes, which are evenly distributed in the peripheral area of ​​the small hole of the first through hole.

[0015] Furthermore, the second sealing member is fixed to the injection molded part based on a hot melt process, which can further improve the sealing reliability of the liquid injection port.

[0016] Furthermore, the injection molded part opening is a stepped through hole, with the small hole of the opening close to the inner cavity of the shell; the first seal includes a sealing portion and an operating portion; the sealing portion is inserted into the small hole of the opening and has an interference fit with the wall of the small hole of the opening; the operating portion is located in the large hole of the opening and has a clearance fit with the wall of the large hole of the opening; along the depth direction of the opening, the top of the operating portion is lower than the large hole mouth of the opening, and the projection of the operating portion on the stepped surface of the opening completely covers the small hole of the opening. The opening is designed as a stepped through hole, and the stepped surface is used as the axial limiting surface of the first seal, that is, the lower end face of the operating portion of the first seal contacts the stepped surface, which can limit the axial position of the first seal within the opening.

[0017] The present invention also provides an upper cover plate assembly, including an upper cover plate, which is special in that: a liquid injection port is provided on the upper cover plate, and a sealing component is provided at the liquid injection port, and the sealing component is the above-mentioned sealing component.

[0018] The present invention also provides a lithium-ion battery, comprising an upper cover plate assembly, the special feature of which is that the upper cover plate assembly is the above-mentioned upper cover plate assembly.

[0019] The present invention also provides a large-capacity battery, which is special in that it comprises an outer shell and a plurality of single cells arranged in the outer shell;

[0020] At least one shared chamber is provided in the outer shell, and the inner cavity of the shared chamber is connected to the inner cavities of all the single batteries;

[0021] The outer shell is provided with avoidance holes corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the avoidance holes, and the outer shell area corresponding to the avoidance holes is fixedly sealed with the single battery shell;

[0022] The outer shell is provided with a liquid injection port, and a sealing component is provided at the liquid injection port, and the sealing component is the sealing component mentioned above.

[0023] The beneficial effects of the present invention are:

[0024] The present invention has an injection molded part at the liquid filling port of the lithium ion battery, and an opening penetrating the inner cavity of the lithium ion battery shell is provided on the injection molded part, and the liquid injection operation can be realized based on the opening; a first sealing part is inserted into the opening to perform a first sealing on the opening, and a second sealing part is used to cover the opening to perform a second sealing on the opening, which has high sealing reliability; wherein the second sealing part covers the opening in a detachable manner, when liquid replenishment is required, the second sealing part is first removed, and then the first sealing part is taken out using a tool to replenish liquid; after the liquid replenishment is completed, the first sealing part is inserted into the opening, and the second sealing part is fixed on the injection molded part to cover the opening.

[0025] It can be seen that by using the sealing assembly of the present invention, the lithium-ion battery can be replenished at any time as needed, thereby helping to improve the cycle life of the lithium-ion battery. In addition, due to the provision of the sealing assembly of the present invention, the lithium-ion battery can be reused, which is more energy-saving and environmentally friendly.

[0026] In addition, the present invention uses the opening on the injection molded part as a new liquid injection port, and the seal only needs to cooperate with the new liquid injection port and does not need to cooperate with the original liquid injection port of the lithium-ion battery. Therefore, when the seal is removed, the lithium-ion battery structure itself is not damaged.

[0027] In addition, after a period of charge and discharge cycles, impurities in the electrolyte may affect the performance of the lithium-ion battery. This sealing assembly can be used to replace the electrolyte in the inner cavity of the shell to improve the performance of the lithium-ion battery. The replacement here can be partial or complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a schematic structural diagram of a sealing assembly of Example 1 fixed to a lithium-ion battery housing;

[0029] FIG2 is a cross-sectional view of the sealing assembly of Example 1 fixed to the lithium-ion battery housing;

[0030] FIG3 is a cross-sectional view of the liquid injection port in Example 1;

[0031] FIG4 is a schematic structural diagram of the injection molded part in Example 1;

[0032] FIG5 is a cross-sectional view of the injection molded part fixed to the lithium-ion battery housing in Example 1;

[0033] FIG6 is a schematic structural diagram of another liquid injection port in Example 1;

[0034] FIG7 is a cross-sectional view of the fixed sealing assembly at the liquid injection port shown in FIG6 in Example 1;

[0035] FIG8 is a schematic structural diagram of another injection molded part in Example 1;

[0036] FIG9 is a schematic structural diagram of the upper cover assembly of Example 2;

[0037] FIG10 is a schematic structural diagram of a lithium-ion battery according to Example 3;

[0038] FIG11 is a schematic structural diagram of a large-capacity battery according to Example 4;

[0039] FIG12 is a cross-sectional view of a large-capacity battery according to Example 4;

[0040] The reference numerals in the figure are: 1. Sealing assembly; 11. Injection molded part; 111. Opening; 112. First component; 1121. First sub-component; 1122. Second sub-component; 113. Second component; 114. Third component; 12. First sealing member; 121. Operating part; 122. Sealing part; 13. Second sealing member; 2. Shell; 21. Liquid filling port; 211. First through hole; 212. Second through hole; 3. Upper cover; 4. Pole; 5. Shell; 51. Shared chamber; 52. Shell top plate; 53. First side wall; 6. Single cell; 61. Single cell pole; 62. Pole adapter. DETAILED DESCRIPTION

[0041] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] In the description of the present invention, it should be noted that the terms "top," "upper," and "lower" and other references to orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and so on, are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] The present invention provides a sealing assembly for sealing a liquid filling port of a lithium-ion battery. The liquid filling port is generally provided on an upper cover plate of the lithium-ion battery, but the present invention does not exclude the possibility of being provided on other parts of the lithium-ion battery housing, such as on a cylindrical body constituting the housing or on a lower cover plate constituting the housing. When the liquid filling port is provided on the lower cover plate, in order to prevent electrolyte from overflowing from the inner cavity of the housing during liquid filling, the placement direction of the lithium-ion battery can be adjusted so that the liquid filling port faces upward.

[0045] The sealing assembly of the present invention includes an injection molded part, a first seal and a second seal; the injection molded part is formed in the liquid injection port based on the injection molding process, and an opening that penetrates the inner cavity of the shell is opened on the injection molded part, serving as a new liquid injection port; the first seal is inserted into the opening to initially seal the opening; the second seal is fixed to the injection molded part in a detachable manner and covers the opening to secondary seal the opening.

[0046] The present invention has an injection molded part at the liquid injection port of the lithium-ion battery, and an opening penetrating the inner cavity of the lithium-ion battery shell is formed on the injection molded part. The opening is used as a new liquid injection port. The first seal and the second seal only need to cooperate with the new liquid injection port, and do not need to cooperate with the original liquid injection port of the lithium-ion battery. Therefore, when the first seal and the second seal are removed, the structure of the lithium-ion battery itself is not damaged. The first seal and the second seal are used to seal the opening in two steps, thereby improving the sealing reliability of the liquid injection port. The second seal is fixed to the injection molded part in a detachable manner. When liquid replenishment is required, the second seal is first removed, and then the first seal is taken out using a tool to replenish liquid. After the liquid replenishment is completed, the first seal is inserted into the opening, and the second seal is fixed to the injection molded part to cover the opening.

[0047] From the above description, it can be seen that the sealing assembly of the present invention can be used to replenish the lithium-ion battery at any time as needed, which helps to improve the cycle life of the lithium-ion battery and also allows the lithium-ion battery to be reused.

[0048] In addition, after a period of charge and discharge cycles, impurities in the electrolyte may affect the performance of the lithium-ion battery. This sealing assembly can be used to replace the electrolyte in the inner cavity of the shell to improve the performance of the lithium-ion battery. The replacement here can be partial or complete.

[0049] The present invention also provides an upper cover plate assembly. The above-mentioned liquid injection port is opened on the upper cover plate assembly, generally located between two poles, and the above-mentioned sealing assembly is provided at the position of the liquid injection port.

[0050] In addition, the present invention also provides a lithium-ion battery having the upper cover plate assembly.

[0051] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] Referring to Figures 1 and 2 , a schematic diagram of the structure of a sealing assembly 1 secured to a lithium-ion battery housing 2 according to this embodiment is shown. The lithium-ion battery comprises a housing 2, which is enclosed by an upper cover 3, a cylindrical body, and a lower cover. A liquid injection port 21 can be located anywhere within the housing 2; the figure shows a portion of the housing 2 where the sealing assembly 1 is secured.

[0054] The sealing assembly 1 of this embodiment includes an injection molded part 11 , a first sealing part 12 and a second sealing part 13 .

[0055] The injection molded part 11 is formed based on the injection molding process and fixed in the liquid injection port 21, and an opening 111 that penetrates the inner cavity of the shell 2 is opened on the injection molded part 11; the first sealing part 12 is inserted into the opening 111 to initially seal the opening 111; the second sealing part 13 is detachably fixed on the injection molded part 11 and covers the opening 111 to secondary seal the opening 111.

[0056] As can be seen from Figure 2, in the depth direction of the liquid injection port 21 (for the convenience of description, the depth direction of the liquid injection port 21 can be defined as the z direction), the size of the injection molded part 11 is larger than the size of the shell 2, that is, part of the structure of the injection molded part 11 is located inside the liquid injection port 21, and the other part of the structure is located outside the liquid injection port 21 and on the outer surface of the shell 2.

[0057] Adding the injection molded part 11 can have the following two advantages:

[0058] First, the opening 111 on the injection molded part 11 is used as a new liquid injection port, and the seal only needs to cooperate with the new liquid injection port and does not need to cooperate with the original liquid injection port 21 of the lithium-ion battery. Therefore, when the seal is removed, the structure of the lithium-ion battery itself is not damaged.

[0059] Secondly, the difficulty of sealing the liquid injection port 21 is reduced. Since the thickness (z-direction dimension) of the lithium-ion battery shell 2 is relatively thin, if only the first sealing member 12 is inserted into the liquid injection port 21, the contact surface between the first sealing member 12 and the liquid injection port 21 is very small, and it is difficult to achieve a good sealing effect. In this embodiment, an injection molded part 11 whose z-direction dimension is larger than that of the shell 2 is fixed at the liquid injection port 21, and an opening is opened in the injection molded part 11 as a new liquid injection port, and the first sealing member 12 is inserted into the new liquid injection port. Since the new liquid injection port has a larger z-direction dimension, the contact surface between the first sealing member 12 and the new liquid injection port is larger, which can achieve a better sealing effect.

[0060] In order to improve the bonding strength between the injection molded part 11 and the original liquid injection port 21 of the lithium-ion battery, the structure of the liquid injection port 21 is also optimized in this embodiment:

[0061] As shown in Figure 3, the liquid injection port 21 includes a first through hole 211, which is in communication with the inner cavity of the housing 2. In this embodiment, the first through hole 211 is a stepped through hole; the small hole of the first through hole 211 is located near the outer surface of the housing 2. The first through hole 211 can be a circular hole, a square hole, or other polygonal hole, and the specific selection can be based on actual needs. In this embodiment, a circular hole is selected.

[0062] The injection molded part 11 is injection molded into the liquid injection port 21 using a non-metallic material. The material of the injection molded part 11 includes PP (polypropylene), PE (polyethylene), PC (polycarbonate), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PPO (polyphenylene oxide), etc. PP is preferred in this embodiment due to its better molding performance.

[0063] The structure of the injection molded part 11 is shown in Figures 4 and 5. For ease of description, the injection molded part 11 can be divided into two parts. The part molded in the first through hole 211 is defined as a first component 112, and the part located on the outer surface of the housing 2 is defined as a second component 113. The first component 112 is further divided into two parts. The part located in the small hole of the first through hole 211 is defined as a first sub-component 1121, and the part located in the large hole of the first through hole 211 is defined as a second sub-component 1122.

[0064] The diameter of the first sub-component 1121 is smaller than that of the second component 113 and the second sub-component 1122 ; the injection molded part 11 can be well fixed in the liquid injection port 21 based on the second sub-component 1122 .

[0065] To further enhance the stability of the injection molded part 11 on the housing 2, as shown in FIG6 , this embodiment may further include a plurality of second through holes 212 formed in the housing 2. The plurality of second through holes 212 are evenly distributed in the area surrounding the small holes of the first through hole 211 and are in communication with the large holes of the first through hole 211. The corresponding structure of the injection molded part 11 can be seen in FIG7 and FIG8 . Compared to the structure shown in FIG5 , the injection molded part 11 further includes a third member 114 formed within the second through hole 212.

[0066] In some other embodiments, there may be one second through hole 212, which is simpler in structure than the present embodiment. However, the bonding strength between the injection molded part 11 and the outer shell 2 is weaker. When there is a slight pressure in the inner cavity of the lithium-ion battery, the entire injection molded part 11 may fall off from the liquid injection port 21, or cracks may form between the injection molded part 11 and the outer shell 2, thereby damaging the battery performance.

[0067] As can be seen from Figures 2, 5 and 7, the opening 111 in this embodiment is a stepped through hole, which is opened at the axial center position of the injection molded part 11, that is, coaxial with the original liquid filling port 21 of the battery; the large hole of the opening 111 is set close to the top of the injection molded part 11.

[0068] In order to match the shape of the opening 111, the first sealing member 12 of this embodiment is a cylinder with a T-shaped axial cross-section. For the convenience of description, the cylinder with a larger diameter can be defined as the operating portion 121, and the cylinder with a smaller diameter can be defined as the sealing portion 122. As can be seen from Figure 7, the sealing portion 122 is inserted into the small hole of the opening 111 and has an interference fit with the wall of the small hole. The operating portion 121 is located in the large hole of the opening 111 and has a clearance fit with the wall of the large hole.

[0069] Along the z direction, the top of the operating part 121 is lower than the large opening of the opening 111. That is, there should be a certain gap between the top of the operating part 121 and the second sealing member 13 to avoid interference between the two when the second sealing member 13 is removed later.

[0070] In other embodiments, the opening 111 may be a through hole, and the diameter of the corresponding operating portion 121 of the first sealing member 12 should be smaller than the diameter of the sealing portion 122. In other words, the sealing portion 122 and the opening 111 have an interference fit, while the operating portion 121 and the opening 111 have a clearance fit, so as to facilitate the subsequent removal of the first sealing member 12 based on the operating portion 121. However, compared to this embodiment, the axial position of the first sealing member 12 in the opening 111 cannot be limited.

[0071] As can be seen from FIG7 , the second sealing member 13 is detachably fixed to the injection molded part 11 and covers the opening 111 ;

[0072] The second sealing member 13 is usually fixed to the injection molded part 11 by threaded connection, screw connection or hot melt;

[0073] If a threaded connection is adopted, the structure of the second sealing member 13 can be a structure similar to a nut. In this case, an external thread needs to be provided on the outer peripheral surface of the injection molded part 11 to be threadedly connected to the second sealing member 13.

[0074] If screw connection is adopted, the structure of the second sealing member 13 can be a circular sealing plate, and the sealing plate and the injection molded part 11 can be fixed with screws;

[0075] If hot melt is used, the second sealing member 13 can be formed of a circular sealing plate, which is generally made of a rubber material that does not react with the electrolyte, such as fluororubber, nitrile rubber, natural rubber or EPDM.

[0076] By comparing the above three connection methods, considering the sealing effect and the simplicity of the structure, this embodiment preferably fixes the second sealing member 13 by hot melting.

[0077] According to the above structural description, the sealing portion 122 of the first sealing member 12 is interference-fitted with the opening 111, which ensures the sealing of the opening 111 to a certain extent, that is, forming a primary seal, and the subsequent covering of the second sealing member 13 forms a secondary seal.

[0078] The operating portion 121 of the first sealing member 12 is in clearance fit with the opening 111, that is, there is a certain gap between the outer peripheral surface of the operating portion 121 and the inner wall of the opening 111. Then, after removing the second sealing member 13, a tool such as pliers can be used in conjunction with the operating portion 121 to remove the first sealing member 12 from the opening 111. The operation is simple and convenient.

[0079] Based on the above description, the installation and removal process of the sealing assembly 1 of this embodiment is as follows:

[0080] Installation steps: Based on the injection molding process, the injection molded part 11 is first installed in the original liquid injection port 21 of the lithium-ion battery. Then, the first sealing part 12 is inserted into the opening 111 of the injection molded part 11. Then, the second sealing part 13 is fixed to the injection molded part 11 by hot melting to cover the opening 111 to achieve sealing.

[0081] Disassembly steps: First, use local high-temperature heating at the second seal 13 to melt the hot-melt second seal 13, and use a cutter to scrape off the second seal 13. In order to prevent the injection molded part 11 from melting during heating, a protective device can be installed on the injection molded part 11 during heating to prevent the injection molded part 11 from deforming due to high temperature.

[0082] Then use the tool to take out the first sealing member 12 and perform fluid replenishment. After the fluid replenishment is completed, the installation can be performed according to the above-mentioned installation steps.

[0083] It can also be seen from the above steps that the first sealing member 12 not only performs a sealing function but also prevents impurities from falling into the inner cavity of the housing 2 through the opening 111 during the disassembly of the second sealing member 13 .

[0084] In summary, the sealing assembly 1 provided in this embodiment realizes multiple refills of lithium-ion batteries, which can effectively avoid the problem of lithium-ion batteries being scrapped due to insufficient electrolyte after multiple cycles, and enables lithium-ion batteries to develop in a more energy-saving and environmentally friendly direction.

[0085] Example 2

[0086] 9 , this embodiment is an upper cover plate assembly, including an upper cover plate 3 and the sealing assembly 1 of embodiment 1 fixed thereon.

[0087] That is to say, in this embodiment, the liquid injection port 21 is opened on the upper cover plate 3. The position of the liquid injection port 21 on the upper cover plate 3 is not limited, but for the symmetry of the structure, the liquid injection port 21 can be opened in the central area of ​​the upper cover plate 3, located between the two poles 4.

[0088] The structures of the liquid injection port 21 and the sealing assembly 1 are the same as those in Example 1, and will not be described in detail in this embodiment.

[0089] Example 3

[0090] Referring to Figure 10 , this embodiment illustrates a lithium-ion battery (similar in structure to commercially available prismatic lithium-ion batteries). The upper cover plate 3 of this lithium-ion battery is the upper cover plate assembly of Example 2. The sealing assembly 1 allows for multiple refills within the lithium-ion battery, thereby helping to extend the battery's service life. Furthermore, since lithium-ion batteries are reusable, they are more energy-efficient and environmentally friendly.

[0091] Example 4

[0092] 11 and 12 , this embodiment is a large-capacity battery, comprising an outer shell 5 and a plurality of single cells 6 ; the multiple single cells 6 are arranged in the same direction and placed in the outer shell; the single cells here are commercially available square-shell lithium-ion batteries;

[0093] A shared chamber 51 is provided in the outer shell 5 , and the inner cavity of the shared chamber 51 is connected to the inner cavities of all the single batteries 6 ;

[0094] It should be noted that:

[0095] The shared chamber 51 may be an electrolyte shared chamber, which allows each single cell to be placed in a unified electrolyte environment, thereby ensuring the uniformity of the electrolyte in each single cell and improving the performance and charge-discharge cycle life of large-capacity batteries.

[0096] The shared chamber 51 may also be a gas shared chamber, which can achieve gas balance in each single battery and improve the performance and charge-discharge cycle life of large-capacity batteries.

[0097] The shared chamber 51 may also be a gas-liquid shared chamber. Through the gas-liquid shared chamber, each single cell can be placed in a unified electrolyte environment and gas environment, thereby improving the performance and charge-discharge cycle life of large-capacity batteries.

[0098] In order to improve the heat dissipation performance of such large-capacity batteries, avoidance holes are opened on the top plate 52 of the outer shell corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the corresponding avoidance hole, and the area of ​​the top plate of the outer shell corresponding to the avoidance hole is fixedly sealed with the single battery shell, so that the gap between the polarity terminal and the avoidance hole is sealed.

[0099] It should be noted that the single cell polarity terminal described here can be a single cell pole 61. In order to prevent the single cell pole 61 from being unable to smoothly extend out of the avoidance hole as a polarity terminal, a pole adapter 62 can also be connected to the single cell pole, and the overall structure of the single cell pole and the pole adapter can be used as the single cell polarity terminal.

[0100] For the convenience of description, the length direction of the outer shell is defined as the x direction, the width direction of the outer shell is defined as the y direction, and the height direction of the outer shell is defined as the z direction.

[0101] As can be seen from Figure 11, a sealing assembly 1 is provided on the first side wall 53 of this embodiment (wherein the first side wall 53 is the side wall of the outer shell parallel to the yz plane), that is, the liquid injection port 21 of this embodiment is opened on the first side wall 53.

[0102] The structures of the liquid injection port 21 and the sealing assembly 1 are the same as those in Example 1 and will not be described in detail in this embodiment. In this embodiment, the liquid injection port 21 and the sealing assembly 1 are provided on the outer shell of the large-capacity battery. After the large-capacity battery has been charged and discharged for a period of time, the electrolyte decomposes and is consumed, resulting in a decrease in the performance of the large-capacity battery. The sealing assembly 1 can be opened to replenish the electrolyte into the inner cavity of the large-capacity battery to improve the performance of the large-capacity battery. Alternatively, after the large-capacity battery has been charged and discharged for a period of time, the electrolyte appears in the electrolyte, which affects the performance of the large-capacity battery. The sealing assembly 1 can also be opened to replace the electrolyte in the inner cavity to improve the performance of the large-capacity battery.

Claims

1. A sealing component is applied to a lithium-ion battery. The lithium-ion battery includes a housing (2), and a liquid injection port (21) is provided on the housing (2). It is characterized in that: The sealing assembly includes an injection molded part (11), a first seal (12), and a second seal (13); The injection molded part (11) is formed based on an injection molding process and fixed within the liquid injection port (21), and an opening (111) communicating with the inner cavity of the outer shell (2) is provided on the injection molded part (11); The first seal (12) is inserted into the opening (111) to initially seal the opening (111); The second seal (13) is detachably fixed to the injection molded part (11) and covers the opening (111) to secondarily seal the opening (111).

2. The sealing assembly according to claim 1, wherein: The liquid injection port (21) includes a first through hole (211), the first through hole (211) is a stepped through hole, and the small hole of the first through hole (211) is provided near the outer surface of the outer shell (2); the injection molded part (11) includes a first member (112) and a second member (113); the first member (112) is formed within the first through hole (211), and the second member (113) is located on the outer surface of the outer shell (2).

3. The sealing assembly according to claim 2, characterized in that: The liquid injection port (21) further includes at least one second through hole (212); the second through hole (212) is located in the peripheral area of the small hole of the first through hole (211) and communicates with the large hole of the first through hole (211); The injection molded part (11) further includes a third member (114) integrated with the first member (112) and the second member (113); the third member (114) is formed within the second through hole (212).

4. The sealing assembly according to claim 3, characterized in that: The opening (111) is provided on the first member (112) and the second member (113).

5. The sealing assembly according to claim 3, wherein: There are multiple second through holes (212), which are evenly distributed in the peripheral area of the small hole of the first through hole (211); there are multiple third members (114) in the injection molded part (11), and each is formed within a second through hole (212).

6. The sealing assembly according to any one of claims 1 to 5, characterized in that: The second seal (13) is fixed to the injection molded part (11) based on a hot melt process.

7. The sealing assembly according to claim 6, wherein: The opening (111) of the injection molded part (11) is a stepped through hole, and the small hole of the opening (111) is near the inner surface of the outer shell (2); The first seal (12) includes a sealing portion (122) and an operating portion (121); the sealing portion (122) is inserted into the small hole of the opening (111) and is in interference fit with the hole wall of the small hole of the opening (111), the operating portion (121) is located within the large hole of the opening (111) and is in clearance fit with the hole wall of the large hole of the opening (111), along the hole depth direction of the opening (111), the top of the operating portion (121) is lower than the large hole opening of the opening (111), and the projection of the operating portion (121) on the stepped surface of the opening (111) completely covers the small hole of the opening (111).

8. An upper cover plate assembly, comprising an upper cover plate (3), characterized in that: The upper cover plate (3) is provided with a liquid injection port (21), and a sealing assembly (1) is provided at the liquid injection port (21), and the sealing assembly (1) is the sealing assembly (1) according to any one of claims 1 to 7.

9. A lithium-ion battery, comprising an upper cover plate assembly, characterized in that: The upper cover plate assembly is the upper cover plate assembly according to claim 8.

10. A large-capacity battery, characterized in that: It includes an outer shell body and a plurality of single cells arranged within the outer shell body; At least one shared chamber is provided within the outer shell body, and the inner cavity of the shared chamber is communicated with the inner cavities of all single cells; Avoidance holes are provided on the outer housing corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the avoidance holes, and the area of the outer housing corresponding to the avoidance holes is fixedly sealed with the housing of the single battery (6). A liquid injection port (21) is provided on the outer housing, and a sealing assembly (1) is arranged at the liquid injection port (21), and the sealing assembly (1) is the sealing assembly (1) according to any one of claims 1 to 7.

Images