Liquid injection and replacement component and lithium ion battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a liquid injection and replacement component and a lithium ion battery. The liquid injection and change component comprises a liquid injection and change component main body and a plugging piece; a first channel communicated with the electrolyte region of the inner cavity of the shell is formed in the liquid injection and replacement component main body; the plugging piece comprises at least one group of sealing units; each sealing unit comprises a first sealing plug and a sealing coating which are sequentially stacked in the axial direction of the first channel, the first sealing plug is located on the side close to the inner cavity of the shell, and the sealing coating is located on the side away from the inner cavity of the shell. When the lithium ion battery is lack of liquid, electrolyte can be injected into the lithium ion battery through the liquid injection and replacement component. When impurities appear in the electrolyte of the lithium ion battery, the electrolyte in the inner cavity of the shell can be replaced through the electrolyte injection and replacement component. According to the utility model, the first channel can be sealed twice based on each group of sealing units, so that the first channel part is ensured to have higher sealing reliability in the charge-discharge cycle process of the lithium ion battery.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, in particular to a liquid injection and replacement component and a lithium ion battery. Background Art

[0002] The main function of the electrolyte in lithium-ion batteries is to transport lithium ions. Too little electrolyte will prevent some active substances from being wetted, which is not conducive to the battery capacity. However, during the operation of lithium-ion batteries, due to the continuous redox reaction, the electrolyte will be continuously consumed, which is one of the important reasons for the reduction of the cycle life of lithium-ion batteries. Utility Model Content

[0003] The purpose of the utility model is to provide a liquid injection component and a lithium-ion battery, wherein the liquid injection component is used to cooperate with the lithium-ion battery, and when the lithium-ion battery is short of liquid during operation, the electrolyte can be injected into the lithium-ion battery through the liquid injection component. The lithium-ion battery described herein can be a single cell or a lithium-ion battery module.

[0004] The technical solution of the utility model is to provide a liquid injection and replacement component, which is applied to a lithium ion battery. The lithium ion battery comprises a shell, and the inner cavity of the shell comprises an electrolyte area and a gas area. The utility model is special in that:

[0005] The liquid injection and replacement component includes a liquid injection and replacement component body and a blocking member;

[0006] The main body of the liquid injection and replacement component is columnar and is used to be fixed on the shell, and a first channel that is connected to the electrolyte area in the inner cavity of the shell is opened on the main body of the liquid injection and replacement component;

[0007] The blocking member includes n groups of sealing units, wherein n is an integer greater than or equal to 1;

[0008] n is equal to 1, and the sealing unit is disposed in the first channel to seal the first channel;

[0009] n is greater than 1, and n groups of sealing units are sequentially stacked in the first channel along the axial direction of the first channel to seal the first channel;

[0010] Each group of sealing units includes a first sealing plug and a sealing coating which are sequentially stacked along the axial direction of the first channel. The first sealing plug is located on a side close to the inner cavity of the shell, and the sealing coating is located on a side away from the inner cavity of the shell.

[0011] When the lithium-ion battery is charged and discharged for a period of time, the electrolyte is decomposed and consumed, resulting in reduced performance. The sealing units can be taken out one by one, and the sealing coating in each sealing unit can be removed by dissolving, tearing, etc. The sealing plug can be pulled out using the tool, and then the electrolyte is injected into the inner cavity of the shell through the first channel to improve the performance of the lithium-ion battery; or, when the lithium-ion battery is charged and discharged for a period of time, the performance of the lithium-ion battery is affected by impurities in the electrolyte. The sealing unit can also be taken out through the above process, and the electrolyte in the inner cavity of the shell is replaced based on the first channel to improve the performance of the lithium-ion battery. After completing the injection or replacement operation, the first channel can be blocked from the outside of the shell using at least one group of sealing units, which is simple and convenient to operate.

[0012] The utility model can realize two seals on the first channel based on each set of sealing units, ensuring that the first channel has high sealing reliability during the charging and discharging cycle of the lithium ion battery. In addition, the sealing unit of the utility model has a simple structure, convenient processing and manufacturing and sealing process, and low cost.

[0013] Furthermore, in order to prevent the blocking member from falling out of the first channel due to the pressure in the inner cavity of the housing, the utility model provides an annular groove on the inner wall of the first channel along its circumference; a limit ring is installed in the annular groove;

[0014] The end face of the outermost sealing unit in the first channel abuts against the limit ring, which limits the axial movement of n groups of sealing units in the first channel; wherein the outermost sealing unit in the first channel is the sealing unit farthest from the inner cavity of the shell in the axial direction of the first channel.

[0015] Furthermore, the blocking member further includes a second sealing plug;

[0016] The second sealing plug is stacked along the axial direction of the first channel outside the outermost sealing unit, and the end face of the second sealing plug abuts against the limit retaining ring. After the second sealing plug is added, the limit retaining ring abuts against the second sealing plug, which can avoid the limit retaining ring abutting against the sealing coating and damaging the sealing performance of the sealing coating.

[0017] Furthermore, a second channel communicating with the gas area in the inner cavity of the shell is provided on the main body of the liquid injection and replacement component;

[0018] The first channel is a stepped through hole opened along the main body of the liquid injection and replacement component;

[0019] The second channel is isolated from the small hole of the step through hole and is connected to the large hole of the step through hole;

[0020] The blocking piece is arranged in the large hole of the step through hole.

[0021] The gas area in the inner cavity of the housing can be connected to the external environment based on the second channel, so as to facilitate the smooth injection or replacement of liquid. At the same time, after the first channel is designed as a stepped through hole, the blocking member can block the first channel and the second channel at the same time, with a simple structure and convenient operation.

[0022] Further, the large hole of the step through hole is a tapered hole, and the small end of the tapered hole is close to the small hole of the step through hole. It can be understood that the blocking piece adopts a tapered column structure adapted to the tapered hole, and such a design facilitates the disassembly of the blocking piece.

[0023] Furthermore, the above-mentioned liquid injection and replacement component also includes an electrolyte connecting pipe section; one end of the electrolyte connecting pipe section is fixed on the liquid injection and replacement component body and is connected to the first channel; the other end of the electrolyte connecting pipe section is used to communicate with the electrolyte area in the inner cavity of the shell.

[0024] Furthermore, the sealing coating layer adopts a sealing paint that does not react with the electrolyte.

[0025] The utility model also provides a lithium ion battery, which is special in that it comprises a shell and an electrode assembly and an electrolyte located in the shell;

[0026] The above-mentioned liquid injection and replacement component is fixed on the shell, and one end of the first channel is located in the inner cavity of the shell and is connected with the electrolyte area in the inner cavity of the shell.

[0027] The utility model also provides another lithium ion battery, which is special in that it comprises a shell and m single cells arranged in the shell, where m>1;

[0028] The inner cavity of the shell is connected with the inner cavity of each single battery;

[0029] The above-mentioned liquid injection and replacement component is fixed on the shell, and one end of the first channel is located in the inner cavity of the shell and is connected with the electrolyte area in the inner cavity of the shell.

[0030] Furthermore, one end of the second channel is located in the inner cavity of the shell and is communicated with the gas zone in the inner cavity of the shell.

[0031] The beneficial effects of the utility model are:

[0032] 1. The utility model opens a first channel on the main body of the liquid injection and replacement component, fixes the liquid injection and replacement component on the lithium-ion battery shell, communicates with the inner cavity of the shell through the first channel, and blocks the first channel from the outside of the shell to ensure the sealing of this part during the normal charge and discharge cycle of the lithium-ion battery; after the lithium-ion battery is charged and discharged for a period of time, the electrolyte is decomposed and consumed and reduced, resulting in reduced performance. The blocking member can be opened to replenish electrolyte into the inner cavity of the shell through the first channel on the main body of the liquid injection and replacement component to improve the performance of the lithium-ion battery; or, after the lithium-ion battery is charged and discharged for a period of time, the electrolyte appears in the electrolyte and affects the performance of the lithium-ion battery. The electrolyte in the inner cavity of the shell can also be replaced by the liquid injection and replacement component to improve the performance of the lithium-ion battery. The replacement here can be partial replacement or full replacement. After completing the liquid replenishment or liquid replacement operation, the first channel can be blocked by the blocking member. The operation is simple and convenient, and the liquid injection and replacement operation can be performed multiple times.

[0033] The utility model adopts at least one group of sealing units as a plugging member, and each group of sealing units can realize two-way sealing of the first channel. At the same time, the sealing coating is coated on the outer end face of the first sealing plug and the joint between the first sealing plug and the inner wall of the first channel. The sealing coating area coated on the outer end face of the first sealing plug fully blocks the first channel from the axial direction, and the sealing coating area coated at the joint between the first sealing plug and the inner wall of the first channel seals the first channel from the radial direction, ensuring that the first channel has a high sealing reliability during the charging and discharging cycle of the lithium-ion battery. In addition, each group of sealing units of the utility model includes the first sealing plug and the sealing coating, which has a simple structure, convenient processing and manufacturing and sealing processes, and low cost.

[0034] 2. When the internal pressure of the battery is not conducive to the operation of injecting and replacing the liquid, the utility model opens a second channel on the main body of the liquid injection and replacement component. During the liquid injection and replacement process, the second channel connects the gas area in the inner cavity of the shell with the external environment. Through the second channel, the internal pressure of the battery is changed, so that the electrolyte flows smoothly during the liquid injection and replacement process, and the electrolyte can also fully infiltrate the pole pieces of each single battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic structural diagram of the fluid injection and replacement component of Example 1;

[0036] Figure 2 It is a cross-sectional view of the fluid injection component of Example 1;

[0037] Figure 3 for Figure 2 Enlarged view of area a in the middle;

[0038] Figure 4 This is a structural schematic diagram of a liquid injection and replacement component connected to an electrolyte connecting pipe section in Example 1;

[0039] Figure 5 This is a schematic diagram of the structure of the lithium-ion battery of Example 1;

[0040] Figure 6 A partial exploded view of the lithium-ion battery of Example 1;

[0041] Figure 7 This is a schematic structural diagram of a lithium-ion battery provided with a heat transfer tube in Example 1;

[0042] Figure 8 It is an exploded view of the liquid injection component and the end plate in Example 1;

[0043] Fig. 9 It is a cross-sectional view of the fluid injection component of Example 2;

[0044] Fig.10 for Fig. 9 Enlarged view of area b;

[0045] Fig.11 It is a cross-sectional view of the fluid injection component of Example 3;

[0046] Fig.12 A cross-sectional view of a liquid injection and replacement component provided with a second sealing plug in Example 3;

[0047] Fig.13 It is a cross-sectional view of the fluid injection component of Example 4;

[0048] The accompanying drawings in the figure are marked as follows:

[0049] 1. Liquid injection and replacement component body; 11. Annular limiting boss; 12. First channel; 120. Small hole; 122. Large hole; 121. Limit retaining ring; 13. Second channel; 2. Sealing unit; 21. First sealing plug; 22. Sealing coating; 23. Second sealing plug; 3. Electrolyte connecting pipe section; 4. Shell; 41. Shell top plate; 42. Shell bottom plate; 43. End plate; 44. Mounting hole; 5. Single cell; 6. Electrolyte shared chamber; 7. Gas shared chamber; 8. Support member; 9. Heat transfer tube; 10. Explosion relief mechanism. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and 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.

[0052] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second, etc." are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0053] The utility model provides a functional component for a lithium ion battery. Based on the functional component, the liquid injection and liquid replacement of the lithium ion battery can be completed. For the convenience of understanding, the functional component is defined as a liquid injection and replacement component.

[0054] The lithium-ion battery may be a single cell or a lithium-ion battery module with a housing.

[0055] If it is a single cell battery (including an outer shell and at least one set of electrode assemblies located inside the outer shell, and the inner cavity of the outer shell includes an electrolyte area and a gas area), the liquid injection and replacement component can be fixed at any position of the single cell battery outer shell, and the liquid injection and replacement component is preferably fixed on the original liquid injection port of the single cell battery to realize the function of injecting or replacing the electrolyte.

[0056] If it is a lithium-ion battery module with a shell (including the shell and at least two single cells located in the shell, the inner cavity of the shell and the inner cavity of the single cells are connected, and the inner cavity of the shell includes an electrolyte area and a gas area, which can also be called a lithium-ion battery pack or a large-capacity battery), the liquid injection and replacement component can also be fixed to any part of the lithium-ion battery module shell, and based on the liquid injection and replacement component, the electrolyte in the inner cavity of the shell can be injected or replaced.

[0057] Specifically, the liquid injection component of the present invention mainly includes a columnar liquid injection component body and a plugging member; the liquid injection component body is fixed on the lithium-ion battery shell, and a first channel that penetrates the electrolyte area of ​​the shell cavity is opened on the liquid injection component body.

[0058] During the charge and discharge cycle of the lithium-ion battery, the blocking member blocks the first channel from the outside of the shell; when the fluid injection and replacement operation is performed, the blocking member needs to be opened to implement the fluid injection and replacement operation based on the first channel.

[0059] The blocking member of the utility model includes at least one group of sealing units, and the sealing units can be arranged at the positions of the first channel according to the number of the sealing units:

[0060] 1. When there is a set of sealing units, the sealing units are arranged in the first channel to seal the first channel;

[0061] 2. When there are multiple groups (two or more groups) of sealing units, the multiple groups of sealing units are stacked in sequence in the first channel along the axial direction of the first channel to seal the first channel.

[0062] Specifically, each group of sealing units includes a first sealing plug and a sealing coating which are stacked in sequence along the axial direction of the first channel. The first sealing plug is located on the side close to the inner cavity of the shell to perform preliminary sealing on the first channel, and the sealing coating is located on the side away from the inner cavity of the shell to perform secondary sealing on the first channel.

[0063] After a period of charge and discharge cycles of the lithium-ion battery, the electrolyte is decomposed and consumed, resulting in reduced performance. The sealing units can be removed in sequence, and the sealing coating in each sealing unit can be removed by dissolving, tearing, etc. The first sealing plug can be pulled out using the tool (specifically, Figure 2 As shown, a threaded blind hole can be opened in the first sealing plug, and the first sealing plug can be pulled out based on a tool provided with a threaded rod adapted to the threaded blind hole, and then the electrolyte is injected into the inner cavity of the shell through the first channel to improve the performance of the lithium-ion battery; or, when the lithium-ion battery is charged and discharged for a period of time, the performance of the lithium-ion battery is affected due to the appearance of impurities in the electrolyte, and the sealing unit can be taken out through the above process, and the electrolyte in the inner cavity of the shell can be replaced based on the first channel to improve the performance of the lithium-ion battery. The replacement here can be a partial replacement or a complete replacement. After completing the injection or liquid replacement operation, the first channel can be blocked from the outside of the shell using at least one group of sealing units, which is simple and convenient to operate.

[0064] The utility model can realize two seals on the first channel based on each set of sealing units, ensuring that the first channel has high sealing reliability during the charging and discharging cycle of the lithium ion battery. In addition, the sealing unit of the utility model has a simple structure, convenient processing and manufacturing and sealing process, and low cost.

[0065] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0066] Example 1

[0067] like Figure 1 , which is a schematic diagram of the structure of the fluid injection and replacement component of this embodiment. The fluid injection and replacement component of this embodiment comprises a fluid injection and replacement component body 1 and a blocking member arranged on the fluid injection and replacement component body 1.

[0068] The liquid injection and replacement component body 1 is used to be fixed on the lithium-ion battery housing 4. Figure 2 It can be seen that the main body 1 of the liquid injection component in this embodiment is a cylinder. In some other embodiments, a rectangular column, a semi-cylinder, etc. can also be selected. In order to facilitate its fixation on the lithium-ion battery housing 4, an annular limiting boss 11 is provided on the outer circumference of the main body 1 of the liquid injection component in this embodiment. A mounting hole 44 is provided on the lithium-ion battery housing 4 (see Figure 8 ), fix the liquid injection and replacement component body 1 in the mounting hole 44, weld the annular limiting boss 11 to the area of ​​the shell 4 around the mounting hole 44, and seal the mounting hole 44 while achieving fixation.

[0069] A through hole is provided on the main body 1 of the liquid injection and replacement component as the first channel 12. The first channel 12 can be a straight through hole or an L-shaped through hole (such as Figure 1 and Figure 2 As shown, this embodiment is an L-shaped through hole).

[0070] After the liquid injection and replacement component body 1 is fixed on the lithium-ion battery housing 4 , one end of the first channel 12 is located outside the housing 4 , and the other end is located inside the housing 4 , for communicating with the electrolyte area in the inner cavity of the housing 4 .

[0071] like Figure 4 As shown, in this embodiment, an electrolyte connecting pipe section 3 is added to realize the connection between the first channel 12 and the electrolyte area of ​​the inner cavity of the shell 4. One end of the electrolyte connecting pipe section 3 is fixed on the liquid injection component body 1 and passes through the first channel 12; the other end is used to communicate with the electrolyte area of ​​the inner cavity of the shell 4.

[0072] It should be noted that the end of the electrolyte connecting pipe section 3 connected to the electrolyte area in the inner cavity of the shell 4 can be directly extended into the bottom of the inner cavity of the shell 4 and is always immersed in the electrolyte. When the liquid needs to be replaced, as much electrolyte as possible in the inner cavity of the shell 4 can be extracted, so that the liquid replacement is more thorough.

[0073] In some other embodiments, an electrolyte flow channel may be provided on the housing 4 to communicate with the first channel 12, so that the first channel 12 communicates with the electrolyte area in the housing 4. However, compared with this embodiment, the structure is more complicated, and when the electrolyte flow channel cannot extend to the bottom of the inner cavity of the housing 4, incomplete liquid replacement may occur.

[0074] In this embodiment, the electrolyte connecting pipe section 3 and the liquid injection and replacement component body 1 can be an integral part or a separate part. When it is a separate part, it can be connected to the liquid injection and replacement component body 1 by welding or screwing.

[0075] The material of the electrolyte connecting pipe section 3 is generally selected from the same aluminum material as the liquid injection component body 1. It can also be an organic material such as rubber that does not react with the electrolyte.

[0076] The blocking member of this embodiment, such as Figure 2 and Figure 3 As shown, it includes a group of sealing units 2, which include a first sealing plug 21 and a sealing coating 22 axially stacked along the first channel 12; the first sealing plug 21 is located on the side close to the inner cavity of the shell 4, and performs primary sealing on the first channel 12, and the sealing coating 22 is located on the side away from the inner cavity of the shell 4, and performs secondary sealing on the sealing channel.

[0077] In this embodiment, the first sealing plug 21 is generally made of rubber materials that do not react with the electrolyte, such as fluororubber, nitrile rubber, natural rubber or EPDM rubber. The sealing coating 22 is generally made of sealing paint or sealing varnish that does not react with the electrolyte, and is coated on the outer end face of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12 (the inner wall of the L-shaped through hole) based on the coating method; wherein the outer end face of the first sealing plug 21 refers to the end face of the first sealing plug 21 away from the inner cavity of the housing 4 in the length direction of the first channel 12.

[0078] When it is necessary to inject or replace the fluid, use a paint remover to remove the coating and pull out the first sealing plug 21; perform the fluid injection or replacement operation through the first channel 12. After completing the fluid injection or replacement operation, insert the first sealing plug 21 into the first channel 12, and apply the sealing coating 22 on the outer end surface of the first sealing plug 21 and at the joint between the first sealing plug 21 and the inner wall of the first channel 12.

[0079] like Figure 5 and Figure 6 , which is a schematic structural diagram of a lithium-ion battery according to the present embodiment, specifically a large-capacity battery, including a housing 4 and a plurality of single cells 5 arranged in the housing 4 .

[0080] The single cells 5 in this embodiment are square shell cells, and the number is 13. The inner cavity of each single cell 5 includes an electrolyte area and a gas area. In other embodiments, the number of single cells 5 can be adjusted according to actual needs, and the shape of single cells 5 can also be adjusted according to actual needs.

[0081] A rectangular shell is usually used. For ease of description, the length direction of the shell 4 is defined as the x direction, the width direction of the shell 4 is defined as the y direction, and the height direction of the shell 4 is defined as the z direction.

[0082] The utility model does not specifically limit the structure of the housing 4, and at least the following two structures can be adopted:

[0083] The first structure includes a cylinder with open ends at both ends (i.e., the end parallel to the yz plane is the open end) and end plates respectively fixed to the two open ends of the cylinder (i.e., the end plates are parallel to the yz plane);

[0084] The second structure includes a cylinder with open ends at the top and bottom (i.e., the ports parallel to the xy plane are open ends) and an upper cover plate and a lower cover plate respectively fixed to the open ends of the top and bottom of the cylinder (i.e., the upper cover plate and the lower cover plate are parallel to the xy plane).

[0085] In the following description, the cover plates in the housing 4 parallel to the xy plane are respectively defined as the housing top plate 41 and the housing bottom plate 42 , and the cover plate parallel to the yz plane is referred to as the end plate 43 .

[0086] The inner cavity of the housing 4 is connected to the inner cavities of all the single cells 5. Preferably, a shared cavity can be provided in the housing 4, so that the inner cavity of the shared cavity is connected to the inner cavities of all the single cells 5 to achieve the above-mentioned connection effect.

[0087] It should be noted that:

[0088] The above-mentioned shared chamber can be an electrolyte shared chamber 6 (see Figure 6 As shown in the figure, the electrolyte sharing chamber 6 can make each single cell 5 in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single cell 5; improving the performance and charge-discharge cycle life of the large-capacity battery. The electrolyte sharing chamber 6 described here is a liquid channel extending along the length direction (x direction) of the shell 4 between the shell bottom plate 42 and each single cell 5. The liquid channel can be integrally formed with the shell bottom plate 42, or can be formed by setting a support member 8 between the lower cover plate of the single cell 5 and the shell bottom plate 42.

[0089] A gas sharing chamber 7 is provided on the top plate 41 of the housing along the x direction (see Figure 6 As shown in FIG. 1 , the inner cavity of the gas sharing chamber 7 is connected to the inner gas area of ​​each single cell 5. The gas sharing chamber 7 is used to achieve gas balance of each single cell 5, and the performance and charge-discharge cycle life of the large-capacity battery can also be improved.

[0090] In some other embodiments, only the electrolyte sharing chamber 6 may be provided.

[0091] In order to improve the heat dissipation performance of such large-capacity batteries, avoidance holes can be opened on the outer shell top plate 41 to allow the polarity terminals of each single battery 5 to extend out; the polarity terminals of each single battery 5 extend out of the avoidance holes and the outer shell top plate 41 area around the avoidance holes is fixedly sealed with the shell of the single battery 5.

[0092] It should be noted that the polarity terminal of the single cell battery 5 described here can be a pole of the single cell battery 5. In order to avoid that the pole of the single cell battery 5 cannot be smoothly extended out of the avoidance hole as a polarity terminal or the extended height does not meet the set requirements, a pole adapter can also be connected to the pole of the single cell battery 5, and the overall structure of the single cell battery 5 pole and the pole adapter can be used as the polarity terminal of the single cell battery 5.

[0093] In order to further improve the heat dissipation performance of the large-capacity battery in the above embodiment, Figure 7 As shown, the large-capacity battery in this embodiment further includes a heat transfer tube 9.

[0094] In this embodiment, a heat transfer tube 9 clamping part is provided at the part where the polarity terminal extends out of the avoidance hole, and the heat transfer tube 9 is fixed in the heat transfer tube 9 clamping part, so that the heat transfer tube 9 is directly connected to the polarity terminal of the large-capacity battery, and the heat on the polarity terminal where the heat is relatively concentrated can be timely conducted out, thereby improving the heat dissipation effect of the large-capacity battery. In addition, when the temperature of the large-capacity battery is lower than the set threshold, the large-capacity battery is heated by passing a heat transfer medium with a higher temperature into the heat transfer tube 9; by controlling the temperature of the heat transfer medium, it can be ensured that the large-capacity battery always operates at a normal operating temperature.

[0095] Combination Figures 5 to 7 It can be seen that in this embodiment, the explosion relief mechanism 10 is fixed on the end plate 43 of the housing 4. The explosion relief mechanism 10 in this embodiment is close to the housing bottom plate 42, and preferably faces the electrolyte shared chamber 6. When any single battery 5 has thermal runaway, the thermal runaway smoke and part of the electrolyte break through the explosion relief membrane of the explosion relief mechanism 10 and are discharged through the explosion relief mechanism 10.

[0096] In this embodiment, the above-mentioned liquid injection and replacement component is fixed on the end plate 43 of the outer shell 4. In this embodiment, the liquid injection and replacement component is close to the top plate 41 of the outer shell, and the first channel 12 and the electrolyte area of ​​the inner cavity of the outer shell 4 are connected through the electrolyte connecting pipe section 3. The end of the electrolyte connecting pipe section 3 connected to the electrolyte area of ​​the inner cavity of the outer shell 4 extends as far as possible into the bottom of the inner cavity of the outer shell 4 and is always immersed in the electrolyte. When the liquid needs to be replaced, the electrolyte in the inner cavity of the outer shell 4 can be extracted as much as possible, so that the liquid replacement is more thorough.

[0097] Combination Figure 8 As shown, in this embodiment, a mounting hole 44 matching the cross-sectional shape of the liquid injection body is provided on the end plate 43 of the housing 4, the liquid injection component body 1 is coaxially located in the mounting hole 44, and the annular limiting boss 11 is sealed and welded to the surrounding area of ​​the mounting hole 44. When such large-capacity batteries are assembled into energy storage devices, multiple large-capacity batteries are arranged along the width direction of the large-capacity batteries, so that the end plates 43 of each large-capacity battery are exposed, and when the liquid injection component is set on the end plate 43, the liquid injection operation can be conveniently performed.

[0098] When the large-capacity battery is charged and discharged for a period of time, the performance of the large-capacity battery is reduced due to the decomposition and consumption of the electrolyte. The performance of the large-capacity battery can be improved by injecting electrolyte into the inner cavity of the shell 4 and the inner cavity of each single cell 5 through the liquid injection component; or, when the large-capacity battery is charged and discharged for a period of time, the performance of the large-capacity battery is affected by the appearance of impurities in the electrolyte. The performance of the large-capacity battery can also be improved by replacing the electrolyte in the inner cavity of the shell 4 and the inner cavity of each single cell 5 through the liquid injection component. The replacement here can be a partial replacement or a complete replacement. In addition, after the electrolyte area in the inner cavity of each single cell 5 and the electrolyte shared chamber 6 are connected, the electrolyte can be injected into the inner cavity of each single cell 5 and the electrolyte shared chamber 6 again through the liquid injection component to ensure the continuity of the electrolyte.

[0099] The following describes the process of injecting and replacing the liquid of the large-capacity battery in this embodiment:

[0100] When injection is required, follow these steps:

[0101] Remove the sealing coating 22 by using a paint remover, and take out the first sealing plug 21;

[0102] Insert the electrolyte injection tube into the first channel 12 and inject the electrolyte. After the injection is completed, remove the electrolyte injection tube;

[0103] The first sealing plug 21 is inserted into the first channel 12 , and a sealing coating 22 is applied to the outer end surface of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12 .

[0104] When the fluid needs to be changed, follow these steps:

[0105] Remove the sealing coating 22 by using a paint remover, and take out the first sealing plug 21;

[0106] The electrolyte extraction tube is connected to the first channel 12, and the electrolyte is extracted; then, the electrolyte injection tube is connected to the first channel 12, and new electrolyte is injected; after the injection is completed, the electrolyte injection tube is extracted;

[0107] The first sealing plug 21 is inserted into the first channel 12 , and a sealing coating 22 is applied to the outer end surface of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12 .

[0108] It should be noted that, in this embodiment, during the liquid injection process, if the pressure in the inner cavity of the shell 4 is too high, the problem of liquid injection difficulty may occur.

[0109] Example 2

[0110] like Fig. 9As shown, different from the first embodiment, the blocking member of this embodiment includes two groups of sealing units 2 , and the two groups of sealing units 2 are sequentially stacked and arranged in the first channel 12 along the axial direction of the first channel 12 .

[0111] like Fig.10 As shown, the sealing unit 2 in this embodiment is the same as the sealing unit 2 in Embodiment 1, and both include a first sealing plug 21 and a sealing coating 22 which are axially stacked along the first channel 12; the first sealing plug 21 is located on a side close to the inner cavity of the shell 4, and performs primary sealing on the first channel 12, and the sealing coating 22 is located on a side away from the inner cavity of the shell 4, and performs secondary sealing on the sealing channel.

[0112] In this embodiment, four sealings are performed on the first channel 12 based on two groups of sealing units 2. In some other embodiments, the blocking member may also include three or more groups of sealing units 2. Four or more sealings are performed on the first channel 12. In this embodiment, by increasing the number of sealing units 2 in the first channel 12, compared with embodiment 1, during the charge and discharge cycle of the lithium-ion battery, the first channel portion has a higher sealing reliability.

[0113] The large-capacity battery of this embodiment is different from the large-capacity battery of Embodiment 1 in that this embodiment adopts the above-mentioned liquid injection and replacement component, and the rest of the structure is the same as that of Embodiment 1, which will not be described again here.

[0114] The process of injecting and replacing the liquid of the large-capacity battery is similar to that of Example 1, except that: before injecting and replacing the liquid, two sets of sealing units 2 need to be taken out, and after the injection and replacement of the liquid is completed, the first channel 12 is sealed with two sets of sealing units 2.

[0115] Example 3

[0116] like Fig.11 , which is a cross-sectional view of the fluid injection component of this embodiment. Unlike Embodiment 2, this embodiment provides a limiting structure in the first channel 12 to limit the blocking member in the first channel 12 in the axial direction of the first channel 12 to prevent the blocking member from falling off from the first channel 12 under the pressure of the inner cavity of the shell 4.

[0117] In this embodiment, an annular groove is formed on the inner wall of the first channel 12 along its circumference, and a limit ring 121 is installed in the annular groove; the limit ring 121 abuts against the sealing coating 22 in the outermost sealing unit 2 in the first channel 12. The outermost sealing unit 2 in the first channel 12 is the sealing unit 2 farthest from the inner cavity of the housing 4 in the axial direction of the first channel 12. Fig.11 The sealing unit 2 is located at the rightmost side. When the pressure in the inner cavity of the housing 4 is relatively high, the blocking member will not fall off from the first channel 12 due to the blocking of the limit stopper ring 121.

[0118] The limit ring 121 in this embodiment can adopt a retaining spring, and the sealing coating 22 adopts sealing paint. Since the coating thickness is relatively thin, when the limit ring 121 directly abuts against the sealing coating 22, the integrity of the sealing coating 22 may be destroyed, thereby affecting the sealing effect of the sealing coating 22.

[0119] To solve this problem, Fig.12 As shown, a second sealing plug 23 is added outside the outermost sealing unit 2 in the first channel 12, so that the stop ring 121 abuts against the second sealing plug 23. The second sealing plug 23 can not only seal the first channel 12 again, but also prevent the stop ring 121 from affecting the sealing coating 22.

[0120] The large-capacity battery of this embodiment is different from the large-capacity battery of Embodiment 2 in that this embodiment adopts the above-mentioned liquid injection and replacement component, and the rest of the structure is the same as that of Embodiment 2, which will not be described again here.

[0121] The process of filling and replacing the liquid of a large-capacity battery is similar to that of Example 1, with the only difference being that before filling and replacing the liquid, it is necessary to take out the limit retaining ring 121, the second sealing plug 23, and the two sets of sealing units 2 in sequence; after the filling and replacement of the liquid is completed, the two sets of sealing units 2 and the second sealing plug 23 are used to seal the first channel 12, and the limit retaining ring 121 is installed to limit the entire sealing component.

[0122] Example 4

[0123] like Fig.13 , which is a cross-sectional view of the liquid injection component of this embodiment. Different from the above-mentioned embodiment, this embodiment is based on the above-mentioned embodiment, and a second channel 13 that penetrates the gas area of ​​the inner cavity of the shell 4 is opened on the liquid injection component body 1. The blocking member in the above-mentioned embodiment is also used to block the second channel 13, and the gas area of ​​the inner cavity of the shell 4 is connected with the external environment through the second channel 13, so as to change the internal pressure of the battery, so that the electrolyte flows smoothly during the liquid injection process, and the electrolyte can also fully infiltrate the pole pieces of each single battery 5.

[0124] Fig.13 The following description will be given by taking the liquid replacement component in Example 3 as an example.

[0125] In this embodiment, another through hole is provided on the main body 1 of the liquid injection and replacement component along the axial direction thereof as the second channel 13. The second channel 13 may be a straight through hole or an L-shaped through hole (such as Fig.13 The second channel 13 is connected to the gas area of ​​the inner cavity of the shell 4, and the protective gas can be injected into the inner cavity of the shell 4 or the gas in the inner cavity of the shell 4 can be discharged through the second channel 13.

[0126] from Fig.13It can be seen that in order to use the blocking member in Example 3 to block the first channel 12 and the second channel 13 at the same time, the first channel 12 is designed as a step through hole opened along the axial direction of the injection and replacement component body 1 in this embodiment. The second channel 13 is isolated from the small hole 120 of the step through hole and is connected to the large hole 122 of the step through hole; the blocking member is arranged in the large hole 122 of the step through hole. The first channel 12 and the second channel 13 are blocked at the same time.

[0127] In order to facilitate the disassembly of the plugging piece, the large hole of the step through hole is a tapered hole, and the small end of the tapered hole is close to the small hole of the step through hole. Correspondingly, the plugging piece adopts a tapered column structure adapted to the tapered hole.

[0128] The large-capacity battery of this embodiment is different from the large-capacity battery of Embodiment 3 in that this embodiment adopts the above-mentioned liquid injection and replacement component, and the rest of the structure is the same as that of Embodiment 3, which will not be described again here.

[0129] The following describes the process of injecting and replacing the liquid of the large-capacity battery in this embodiment:

[0130] When injection is required, follow these steps:

[0131] Removing the blocking parts:

[0132] Remove the limit retaining ring, pull out the second sealing plug 23, remove the right sealing unit and the left sealing unit in turn, remove the sealing coating 22 in each sealing unit with a paint remover, and pull out the first sealing plug 21 with a corresponding tool;

[0133] Injection:

[0134] When there is gas in the inner cavity of the housing 4, the gas will overflow from the second channel 13 in sequence, making it easy to inject liquid into the inner cavity of the housing 4. In order to inject liquid more smoothly, in this step, an exhaust pipe can be inserted into the second channel 13, and an external exhaust device connected to the exhaust pipe can be started to exhaust gas, so that a certain negative pressure is formed in the inner cavity of the housing 4;

[0135] Afterwards, the electrolyte injection tube is inserted into the first channel 12, and the electrolyte is injected. During the injection process, if there is a problem of injection difficulty, the external air extraction device can be started to form a certain negative pressure in the inner cavity of the shell 4, and then the injection can be carried out;

[0136] After the injection is completed, remove the electrolyte injection tube and the air extraction tube;

[0137] Use the blocking piece to block the first channel and the second channel:

[0138] First, the first two sealing steps of the first channel and the second channel are performed using the left sealing unit, specifically, the first sealing plug 21 is inserted into the first channel 12, and the sealing coating 22 is applied to the outer end surface of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12; then, the second two sealing steps of the first channel and the second channel are performed using the right sealing unit, specifically, the first sealing plug 21 on the right is inserted into the first channel 12, and the sealing coating 22 is applied to the outer end surface of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12 close to the sealing coating 22 of the left sealing unit. Finally, the second sealing plug is inserted into the first channel 12, and the limit retaining ring 121 is installed in the annular groove to tighten the second sealing plug 23.

[0139] When the fluid needs to be changed, follow these steps:

[0140] Removing the blocking parts:

[0141] Remove the limit retaining ring, pull out the second sealing plug 23, remove the right sealing unit and the left sealing unit in turn, remove the sealing coating 22 in each sealing unit with a paint remover, and pull out the first sealing plug 21 with a corresponding tool;

[0142] Fluid exchange:

[0143] Insert the electrolyte extraction tube into the first channel 12 and extract the electrolyte; when the electrolyte cannot be extracted, insert the gas injection tube into the second channel 13, inject the protective gas into the inner cavity of the shell 4, and extract the electrolyte; after the extraction is completed, take out the electrolyte extraction tube and the gas injection tube, insert the electrolyte injection tube into the first channel 12, and inject new electrolyte; after the injection is completed, remove the electrolyte injection tube;

[0144] Use the blocking piece to block the first channel and the second channel:

[0145] First, the first two sealing steps of the first channel and the second channel are performed using the left sealing unit, specifically, the first sealing plug 21 is inserted into the first channel 12, and the sealing coating 22 is applied to the outer end surface of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12; then, the second two sealing steps of the first channel and the second channel are performed using the right sealing unit, specifically, the first sealing plug 21 on the right is inserted into the first channel 12, and the sealing coating 22 is applied to the outer end surface of the first sealing plug 21 and the joint between the first sealing plug 21 and the inner wall of the first channel 12 close to the sealing coating 22 of the left sealing unit. Finally, the second sealing plug is inserted into the first channel 12, and the limit retaining ring 121 is installed in the annular groove to tighten the second sealing plug 23.

[0146] This embodiment is provided with a second channel 13, which makes it easier to perform liquid injection or liquid replacement operations compared to the above embodiments.

Claims

1. A liquid injection component, applied to a lithium-ion battery, wherein the lithium-ion battery comprises a shell, and an inner cavity of the shell comprises an electrolyte area and a gas area; characterized in that: The liquid injection and replacement component includes a liquid injection and replacement component body and a blocking member; The main body of the liquid injection and replacement component is columnar and is used to be fixed on the shell, and a first channel that is connected to the electrolyte area in the inner cavity of the shell is opened on the main body of the liquid injection and replacement component; The blocking member includes n groups of sealing units, wherein n is an integer greater than or equal to 1; n is equal to 1, and the sealing unit is disposed in the first channel to seal the first channel; n is greater than 1, and n groups of sealing units are sequentially stacked in the first channel along the axial direction of the first channel to seal the first channel; Each group of sealing units includes a first sealing plug and a sealing coating which are sequentially stacked along the axial direction of the first channel. The first sealing plug is located on a side close to the inner cavity of the shell, and the sealing coating is located on a side away from the inner cavity of the shell.

2. The liquid injection component according to claim 1, characterized in that: An annular groove is provided on the inner wall of the first channel along its circumference; a limit retaining ring is installed in the annular groove; The end face of the outermost sealing unit in the first channel abuts against the limit ring, which limits the axial movement of n groups of sealing units in the first channel; wherein the outermost sealing unit in the first channel is the sealing unit farthest from the inner cavity of the shell in the axial direction of the first channel.

3. The liquid injection component according to claim 2, characterized in that: The blocking member also includes a second sealing plug; The second sealing plug is stacked along the axial direction of the first channel on the outside of the outermost sealing unit, and the end surface of the second sealing plug is in contact with the limit retaining ring.

4. The liquid injection and replacement component according to any one of claims 1 to 3, characterized in that: The main body of the liquid injection and replacement component is provided with a second channel which is in communication with the gas area of ​​the inner cavity of the shell; The first channel is a stepped through hole opened along the main body of the liquid injection and replacement component; The second channel is isolated from the small hole of the step through hole and is connected to the large hole of the step through hole; The blocking piece is arranged in the large hole of the step through hole.

5. The liquid injection and replacement component according to claim 4, characterized in that: The large hole of the step through hole is a tapered hole, and the small end of the tapered hole is close to the small hole of the step through hole.

6. The liquid injection component according to claim 4, characterized in that: It also includes an electrolyte connecting pipe section; one end of the electrolyte connecting pipe section is fixed on the liquid injection and replacement component body and is connected with the first channel; the other end of the electrolyte connecting pipe section is used to communicate with the electrolyte area in the inner cavity of the shell.

7. The liquid injection and replacement component according to claim 4, characterized in that: The sealing coating adopts sealing paint which does not react with the electrolyte.

8. A lithium ion battery, characterized in that: It includes a housing and an electrode assembly and an electrolyte located in the housing; The liquid injection and replacement component according to any one of claims 1 to 7 is fixed on the shell, and one end of the first channel is located in the inner cavity of the shell and is connected to the electrolyte area in the inner cavity of the shell.

9. The lithium-ion battery according to claim 8, characterized in that: One end of the second channel is located in the inner cavity of the shell and is communicated with the gas zone in the inner cavity of the shell.

10. A lithium ion battery, characterized in that: It includes a housing and m single cells arranged in the housing, where m>1; The inner cavity of the shell is connected with the inner cavity of each single battery; The liquid injection and replacement component according to any one of claims 1 to 7 is fixed on the shell, and one end of the first channel is located in the inner cavity of the shell and is connected to the electrolyte area in the inner cavity of the shell.

11. The lithium-ion battery according to claim 10, characterized in that: One end of the second channel is located in the inner cavity of the shell and is communicated with the gas zone in the inner cavity of the shell.

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