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 replacement component comprises a columnar liquid injection and replacement component main body; the liquid injection and replacement component body is used for being fixed to a shell, a first channel communicated with an electrolyte area of an inner cavity of the shell is formed in the liquid injection and replacement component body, and a first pipe fitting is arranged in the first channel in a sleeved mode. The end, located outside the shell, of the first pipe fitting is sealed. When liquid injection or liquid change is needed, the end part, positioned outside the shell, of the first pipe fitting can be opened, and electrolyte is injected into or changed into the inner cavity of the shell through the first pipe fitting and the first channel, so that the performance of the lithium ion battery is improved; after liquid injection or liquid change operation is completed, the end, located outside the shell, of the first pipe fitting is sealed, operation is easy and convenient, and meanwhile liquid injection and liquid change operation can be executed repeatedly.

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 columnar liquid injection and replacement component body;

[0006] The main body of the liquid injection and replacement component is used to be fixed on the shell, and a first channel communicating with the electrolyte area in the inner cavity of the shell is opened on the main body of the liquid injection and replacement component, and a first pipe is sleeved in the first channel; the end of the first pipe outside the shell is sealed.

[0007] When the lithium-ion battery is charged and discharged for a period of time, the performance is reduced due to the decomposition and consumption of the electrolyte. The end of the first tube outside the shell can be opened, and the electrolyte can be injected into the inner cavity of the shell through the first tube and 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 the appearance of impurities in the electrolyte. The electrolyte in the inner cavity of the shell can be replaced by a liquid replacement component 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 replacement operation, the end of the first tube outside the shell can be sealed. The operation is simple and convenient, and the injection and replacement operation can be performed multiple times.

[0008] Furthermore, a second channel is provided on the main body of the liquid injection and replacement component, which is connected to the gas area of ​​the inner cavity of the shell. A second pipe is sleeved in the second channel; the end of the second pipe located outside the shell is sealed. The gas area of ​​the inner cavity of the shell can be connected to the external environment based on the second pipe and the second channel, so that liquid injection or liquid replacement can be carried out smoothly.

[0009] Furthermore, the first pipe and the second pipe are made of plastic tubes that do not react with the electrolyte, and the ends outside the shell are sealed by heat shrink extrusion sealing, which has high sealing reliability and a relatively simple sealing method and structure.

[0010] In order to further improve the sealing reliability of the liquid injection component body during the charge and discharge cycle of the lithium-ion battery, the liquid injection component also includes a sealing rubber plug;

[0011] The first channel is a stepped through hole opened along the main body of the liquid injection and replacement component;

[0012] 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;

[0013] Ends of the first pipe member and the second pipe member located outside the housing are located in the large hole of the step through hole;

[0014] The sealing rubber plug is inserted into the large hole of the step through hole to seal the first channel and the second channel.

[0015] Furthermore, a sealing layer is provided on the step surface of the first channel, and the ends of the first pipe and the second pipe located outside the shell extend out of the sealing layer. The sealing layer can improve the stability of the first pipe and the second pipe in the first channel and the second channel respectively, and can also play a sealing role between the pipe and the corresponding channel.

[0016] Furthermore, the above-mentioned fluid injection and replacement component also includes a sealing end cover; the sealing end cover is detachably fixed to the fluid injection and replacement component body to reseal the first channel and the second channel, which can further improve the sealing reliability of the fluid injection and replacement component body during the charge and discharge cycle of the lithium-ion battery.

[0017] The utility model also discloses a lithium ion battery, which is special in that it comprises a shell and an electrode assembly and an electrolyte located in the shell;

[0018] 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.

[0019] The utility model also discloses a lithium ion battery, which is special in that it comprises a shell and m single cells arranged in the shell, where m>1;

[0020] The inner cavity of the shell is connected with the inner cavity of each single battery;

[0021] 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.

[0022] 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.

[0023] The beneficial effects of the utility model are:

[0024] 1. The utility model opens a first channel on the main body of the liquid replenishing and changing component, and sets a first pipe in the first channel, fixes the liquid replenishing and changing component on the lithium-ion battery shell, one end of the first channel is connected to the electrolyte area in the shell, and the end of the first pipe outside the shell is sealed to ensure the sealing of this part during the normal charge and discharge cycle of the lithium-ion battery; when 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 end of the first pipe outside the shell can be opened, and the electrolyte is injected into the inner cavity of the shell through the first pipe and 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 electrolyte appears in the electrolyte and affects the performance of the lithium-ion battery, and the electrolyte in the inner cavity of the shell can also be replaced by the liquid replenishing and changing component to improve the performance of the lithium-ion battery. The replacement here can be partial replacement or full replacement. After completing the injection or liquid replacement operation, the end of the first pipe outside the shell can be sealed, which is simple and convenient to operate, and the injection and replacement operation can be performed multiple times.

[0025] 2. When the internal pressure of the battery is not conducive to the operation of filling and replacing the fluid, the utility model opens a second channel on the main body of the liquid replacement component, and sets a second pipe in the second channel. During the normal charge and discharge cycle of the lithium-ion battery, the end of the second pipe outside the shell is sealed. During the liquid replacement process, the end of the second pipe outside the shell is opened, and the gas area in the inner cavity of the shell is connected to the external environment through the second pipe and the second channel. The internal pressure of the battery is changed through the second pipe and the second channel, so that the electrolyte flows smoothly during the liquid replacement process, and the electrolyte can also fully infiltrate the pole pieces of each single battery.

[0026] 3. The utility model can use three seals (the first seal: the end seals of the first tube and the second tube located outside the shell; the second seal: the first channel and the second channel are initially sealed by a sealing rubber plug; the third seal: the first channel and the second channel are re-sealed by a sealing end cover;) to seal the main body of the liquid replacement component, so that the sealing reliability of the liquid replacement component is ensured during the normal charge and discharge cycle of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of the fluid injection and replacement component of Example 1;

[0028] Figure 2 It is a cross-sectional view of the fluid injection component of Example 1;

[0029] Figure 3This is a schematic structural diagram of a liquid injection and replacement component provided with an electrolyte connecting pipe in Example 1;

[0030] Figure 4 This is a schematic diagram of the structure of a large-capacity battery in Example 1;

[0031] Figure 5 This is a partial exploded view of the large-capacity battery of Example 1;

[0032] Figure 6 This is a schematic diagram of the structure of a large-capacity battery provided with a heat transfer tube in Example 1;

[0033] Figure 7 This is a schematic diagram of the installation structure of the liquid injection and replacement component and the end plate in Example 1;

[0034] Figure 8 It is an exploded view of the liquid injection component and the end plate in Example 1;

[0035] Fig. 9 This is a schematic structural diagram of the fluid injection and replacement component of Example 2;

[0036] Fig.10 It is a cross-sectional view of the fluid injection component of Example 2;

[0037] Fig.11 This is a schematic structural diagram of the liquid injection and replacement component of Example 3;

[0038] Fig.12 It is a cross-sectional view of the fluid injection component of Example 3;

[0039] Fig.13 It is a partial exploded view of the fluid injection component of Example 3;

[0040] Fig.14 This is a schematic diagram of the structure of a large-capacity battery in Example 3;

[0041] Fig.15 This is a schematic structural diagram of the liquid injection and replacement component of Example 4;

[0042] Fig.16 It is a partial exploded view of the liquid injection component of Example 4;

[0043] Fig.17 It is a cross-sectional view of the liquid injection component of Example 4;

[0044] Fig.18 This is a schematic diagram of the structure of a large-capacity battery in Example 4;

[0045] The accompanying drawings in the figure are marked as follows:

[0046] 1. Injection and replacement component body; 11. Annular limiting boss; 12. First channel; 121. Large hole; 122. Small hole; 13. First pipe; 131. Free end of first pipe; 14. Electrolyte connecting pipe; 15. Sealant layer; 17. Second channel; 18. Second pipe; 181. Free end of second pipe; 2. Lithium-ion battery; 21. Shell; 211. Shell top plate; 212. Shell bottom plate; 213. End plate; 2131. Mounting hole; 214. Electrolyte shared chamber; 215. Gas shared chamber; 216. Support; 22. Single cell; 23. Heat transfer tube; 24. Explosion relief mechanism; 3. Sealing rubber plug; 31. O-ring; 32. Blind hole; 4. Sealing end cover; 41. Sealing gasket. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The lithium-ion battery may be a single cell or a lithium-ion battery module with a housing.

[0052] 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.

[0053] 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.

[0054] Specifically, the fluid injection and replacement component of the utility model mainly includes a columnar fluid injection and replacement component body; the fluid injection and replacement 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 fluid injection and replacement component body; a first pipe is sleeved in the first channel.

[0055] After the liquid injection and replacement component body is fixed on the lithium-ion battery shell, the free end of the first tube extends to the outside of the shell, and the end of the first channel where the first tube is not fixed is located inside the shell and communicated with the electrolyte area in the inner cavity of the shell.

[0056] During the charging and discharging operation of the lithium-ion battery, the end of the first tube located outside the shell (i.e., the free end of the first tube) is sealed; when performing fluid injection and replacement operations, it is necessary to open the end of the first tube located outside the shell, and the fluid injection and replacement operations are performed based on the first tube and the first channel.

[0057] When the lithium-ion battery is charged and discharged for a period of time, the performance is reduced due to the decomposition and consumption of the electrolyte. The end of the first tube outside the shell can be opened, and the electrolyte can be injected into the inner cavity of the shell through the first tube and 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 the appearance of impurities in the electrolyte. The electrolyte in the inner cavity of the shell can be replaced by a liquid injection component 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 replacement operation, the end of the first tube outside the shell can be sealed, which is simple and convenient to operate.

[0058] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0059] Example 1

[0060] like Figure 1 , which is a schematic structural diagram of the fluid injection and replacement component of this embodiment, including a fluid injection and replacement component main body 1.

[0061] The main body 1 of the liquid injection component is used to be fixed on the outer shell of the lithium-ion battery 2. In this embodiment, the main body 1 of the liquid injection component is a cylinder. In some other embodiments, a rectangular column, a semi-cylinder, etc. can also be used. In order to facilitate its fixation on the outer shell of the lithium-ion battery 2, this embodiment provides an annular limiting boss 11 on the outer circumferential surface of the main body 1 of the liquid injection component along the circumference. A mounting hole 2131 is opened on the outer shell of the lithium-ion battery 2, and the main body 1 of the liquid injection component is fixed in the mounting hole 2131. The annular limiting boss 11 is welded to the outer shell 21 area around the mounting hole 2131 to achieve fixation while sealing the mounting hole 2131 (see details). Figure 8 ).

[0062] 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 2 As shown, this embodiment is an L-shaped through hole).

[0063] In this embodiment, the first pipe 13 is sleeved in the first channel 12. After the liquid injection component body 1 is fixed to the outer shell of the lithium-ion battery 2, the free end 131 of the first pipe is located outside the outer shell 21. The first channel 12 does not fix the end of the first pipe 13 ( Figure 2 The port shown in 12a is located inside the shell 21 and is connected to the electrolyte area in the inner cavity of the shell 21.

[0064] During the charging and discharging operation of the lithium-ion battery 2 , the free end 131 of the first tube is sealed; when the fluid injection operation is performed, the free end 131 of the first tube needs to be opened, and the fluid injection operation is performed based on the first tube 13 and the first channel 12 .

[0065] In this embodiment, the first tube 13 is made of PP (polypropylene) material that does not react with the electrolyte, and the free end 131 of the first tube is sealed by heat shrink extrusion sealing.

[0066] In some other embodiments, the first tube 13 may also be made of other materials such as plastic or rubber that do not react with the electrolyte.

[0067] In some other embodiments, the first tube 13 may also be made of other hard materials that do not react with the electrolyte, such as metal materials such as aluminum and copper. Correspondingly, a sealing plug or sealing cover may be fixed to the free end 131 of the first tube for sealing.

[0068] In order to further improve the stability of the first tube 13 on the injection and replacement component body 1 and ensure the sealing between the first tube 13 and the first channel 12, as shown in FIG. Figure 2As shown, in this embodiment, the first channel is designed as a stepped through hole opened along the main body of the liquid injection and replacement component; sealant is poured on the step surface of the first channel, and a sealant layer 15 is formed after solidification. The sealant layer can fix the first pipe 13 and seal the gap between the first pipe 13 and the first channel 12.

[0069] It should be noted that the free end 131 of the first pipe needs to extend out of the sealant layer 15 .

[0070] In order to be able to change the fluid more thoroughly, Figure 3 As shown, in this embodiment, an electrolyte connecting pipe 14 is connected to one end of the first channel 12 located inside the shell, and the first channel 12 is connected to the electrolyte area in the inner cavity of the shell through the electrolyte connecting pipe 14.

[0071] One end of the electrolyte connecting tube 14 is fixed on the liquid injection and replacement component body 1 and is connected with the first channel 12; the other end is used to communicate with the electrolyte area in the inner cavity of the shell.

[0072] It should be noted that the end of the electrolyte connecting tube 14 connected to the electrolyte area in the inner cavity of the shell can be directly extended into the bottom of the inner cavity of the shell 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 can be extracted to make the liquid replacement more thorough.

[0073] The electrolyte connecting tube 14 and the liquid injection 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 component body 1 by welding or screwing. The electrolyte connecting tube 14 is generally made of the same aluminum material as the liquid injection component body 1.

[0074] like Figure 4 , which is a schematic diagram of the structure of a lithium-ion battery 2 of this embodiment, specifically a large-capacity battery, including a housing 21 and a plurality of single cells 22 arranged in the housing 21 .

[0075] The single cells 22 in this embodiment are square shell cells, and the number is 13. The inner cavity of each single cell 22 includes an electrolyte area and a gas area. In other embodiments, the number of single cells 22 can be adjusted according to actual needs, and the shape of the single cells 22 can also be adjusted according to actual needs.

[0076] A rectangular housing 21 is generally used. For ease of description, the length direction of the housing 21 is defined as the x direction, the width direction of the housing 21 is defined as the y direction, and the height direction of the housing 21 is defined as the z direction.

[0077] The present invention does not specifically limit the structure of the housing 21, and at least the following two structures can be adopted:

[0078] 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);

[0079] 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).

[0080] In the following description, the cover plates in the housing 21 parallel to the xy plane are respectively defined as the housing top plate 211 and the housing bottom plate 212 , and the cover plate parallel to the yz plane is referred to as the end plate 213 .

[0081] The inner cavity of the housing 21 is connected to the inner cavities of all the single cells 22. Preferably, a shared cavity may be provided in the housing 21, so that the inner cavity of the shared cavity is connected to the inner cavities of all the single cells 22 to achieve the above-mentioned connection effect.

[0082] It should be noted that:

[0083] The shared chamber may be an electrolyte shared chamber 214 (see Figure 5 As shown in the figure, the electrolyte sharing chamber 214 can make each single cell 22 in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single cell 22; improving the performance and charge-discharge cycle life of the large-capacity battery. The electrolyte sharing chamber 214 described here is a liquid channel extending along the length direction (x direction) of the shell 21 between the shell bottom plate 212 and each single cell 22. The liquid channel can be integrally formed with the shell bottom plate 212, or can be formed by setting a support member 216 between the lower cover plate of the single cell 22 and the shell bottom plate 212.

[0084] A gas sharing chamber 215 is provided on the housing top plate 211 along the x direction (see Figure 5 As shown in FIG. 2 , the inner cavity of the gas sharing chamber 215 is connected to the inner gas area of ​​each single battery 22. The gas sharing chamber 215 is used to achieve gas balance of each single battery 22, and the performance and charge-discharge cycle life of the large-capacity battery can also be improved.

[0085] In some other embodiments, only the electrolyte sharing chamber 214 may be provided.

[0086] In order to improve the heat dissipation performance of such large-capacity batteries, avoidance holes can be opened on the outer shell top plate 211 to allow the polarity terminals of each single battery 22 to extend out; the polarity terminals of each single battery 22 extend out of the avoidance holes and the outer shell top plate 211 area around the avoidance holes is fixedly sealed with the shell of the single battery 22.

[0087] It should be noted that the polarity terminal of the single cell battery 22 described here can be a single cell battery 22 pole. In order to avoid the single cell battery 22 pole being unable to smoothly extend out of the avoidance hole as a polarity terminal or the extension height not meeting the set requirements, a pole adapter can also be connected to the single cell battery 22 pole, and the overall structure of the single cell battery 22 pole and the pole adapter can be used as the single cell battery 22 polarity terminal.

[0088] In order to further improve the heat dissipation performance of the large-capacity battery in the above embodiment, Figure 6 As shown, the large-capacity battery in this embodiment further includes a heat transfer tube 23 .

[0089] In this embodiment, a heat transfer tube 23 clamping part is provided at the part where the polarity terminal extends out of the avoidance hole, and the heat transfer tube 23 is fixed in the heat transfer tube 23 clamping part, so that the heat transfer tube 23 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 23; 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.

[0090] Combination Figures 4 to 7 It can be seen that in this embodiment, the explosion relief mechanism 24 is fixed to the end plate 213 of the housing 21. The explosion relief mechanism 24 of this embodiment is close to the housing bottom plate 212, and preferably faces the electrolyte shared chamber 214. When any single battery 22 has thermal runaway, the thermal runaway smoke and part of the electrolyte break through the explosion relief membrane of the explosion relief mechanism 24 and are discharged through the explosion relief mechanism 24.

[0091] In this embodiment, the above-mentioned liquid injection and replacement component is fixed on the end plate 213 of the outer shell 21. In this embodiment, the liquid injection and replacement component is close to the top plate 211 of the outer shell, and the first channel 12 and the electrolyte area of ​​the inner cavity of the outer shell 21 are connected through the electrolyte connecting tube 14. The end of the electrolyte connecting tube 14 connected to the electrolyte area of ​​the inner cavity of the outer shell 21 extends as far as possible into the bottom of the inner cavity of the outer shell 21 and is always immersed in the electrolyte. When the liquid needs to be replaced, the electrolyte in the inner cavity of the outer shell 21 can be extracted as much as possible, so that the liquid replacement is more thorough.

[0092] Combination Figure 8 As shown, in this embodiment, a mounting hole 2131 matching the cross-sectional shape of the liquid injection and replacement body is provided on the end plate 213 of the housing 21, the liquid injection and replacement component body 1 is coaxially located in the mounting hole 2131, and the annular limiting boss 11 is sealed and welded to the surrounding area of ​​the mounting hole 2131. 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 213 of each large-capacity battery are exposed, and when the liquid injection and replacement component is set on the end plate 213, the liquid injection and replacement operation can be conveniently performed.

[0093] 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 electrolyte can be injected into the inner cavity of the shell 21 and the inner cavity of each single cell 22 through the liquid injection component to improve the performance of the large-capacity battery; 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 electrolyte in the inner cavity of the shell 21 and the inner cavity of each single cell 22 can be replaced by the liquid injection component to improve the performance of the large-capacity battery. The replacement here can be a partial replacement or a full replacement. In addition, after the electrolyte area in the inner cavity of each single cell 22 is connected to the electrolyte shared chamber 214, the electrolyte can be injected into the inner cavity of each single cell 22 and the electrolyte shared chamber 214 again through the liquid injection component to ensure the continuity of the electrolyte.

[0094] The following describes the process of injecting and replacing the liquid of the large-capacity battery in this embodiment:

[0095] When injection is required, follow these steps:

[0096] The end of the first pipe member 13 located outside the housing 21 is opened by cutting the heat-shrinkable extruded section of the first pipe member 13;

[0097] Connect the electrolyte injection tube to the first pipe member 13 and inject the electrolyte. After the injection is completed, remove the electrolyte injection tube;

[0098] The end of the first pipe 13 outside the housing 21 is sealed by heat shrink extrusion sealing.

[0099] When the fluid needs to be changed, follow these steps:

[0100] The end of the first pipe member 13 located outside the housing 21 is opened by cutting the heat-shrinkable extruded section of the first pipe member 13;

[0101] Connect the electrolyte extraction tube to the first tube 13 and extract the electrolyte; then, connect the electrolyte injection tube to the first tube 13 and inject new electrolyte; after the injection is completed, extract the electrolyte injection tube;

[0102] The end of the first pipe 13 outside the housing 21 is sealed by heat shrink extrusion sealing.

[0103] It should be noted that, in this embodiment, during the liquid injection process, if the pressure in the inner cavity of the housing 21 is too high, the problem of liquid injection difficulty may occur.

[0104] Example 2

[0105] like Fig. 9 and Fig.10As shown, in this embodiment, based on embodiment 1, a second channel 17 communicating with the gas zone in the inner cavity of the shell is opened on the main body 1 of the liquid injection and replacement component, and a second pipe 18 is sleeved in the second channel 17; the end of the second pipe 18 located outside the shell (the cover end can be defined as the free end 181 of the second pipe) is sealed.

[0106] Similar to the first channel 12 , the second channel 17 may be a straight through hole or an L-shaped through hole.

[0107] Fig.10 In the figure, the first channel is a stepped through hole opened along the main body of the fluid injection and replacement component; the second channel is an L-shaped through hole, which is isolated from the small hole 122 of the stepped through hole and is connected to the large hole 121 of the stepped through hole; the ends of the first pipe 13 and the second pipe 18 located outside the shell are located in the large hole 121 of the stepped through hole.

[0108] It should be noted that when a sealant layer 15 is provided on the step surface of the first channel, the free end 181 of the second pipe also needs to extend out of the sealant layer 15 .

[0109] After the liquid injection and replacement component body 1 is fixed on the outer shell of the lithium-ion battery 2, the free end 181 of the second tube is located outside the outer shell, and the second channel 17 is not fixed to the end of the second tube 18 ( Fig.10 The port shown in 17a is located inside the shell and is connected to the gas area of ​​the inner cavity of the shell.

[0110] During the charging and discharging operation of the lithium-ion battery 2, the free end 181 of the second tube is sealed; when the liquid injection and replacement operation is performed, the free end 181 of the second tube needs to be opened, and a protective gas is injected into the inner cavity of the shell or the gas in the inner cavity of the shell is discharged through the second tube 18 and the second channel 17 to change the internal pressure of the battery, 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 22.

[0111] In this embodiment, the second pipe 18 is made of PP (polypropylene) material that does not react with the electrolyte, and is sealed by heat shrink extrusion sealing.

[0112] In some other embodiments, the second tube 18 may also be made of other materials such as plastic or rubber that do not react with the electrolyte.

[0113] In some other embodiments, the second tube 18 may also be made of other hard materials that do not react with the electrolyte, such as metal materials such as aluminum and copper. Correspondingly, a sealing plug or sealing cover may be fixed to the free end 181 of the second tube for sealing.

[0114] 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.

[0115] The following describes the process of injecting and replacing the liquid of the large-capacity battery in this embodiment:

[0116] When injection is required, follow these steps:

[0117] By cutting the heat-shrinkable extrusion sections of the first pipe member 13 and the second pipe member 18, the ends of the first pipe member 13 and the second pipe member 18 located outside the housing 21 are opened;

[0118] When there is gas in the inner cavity of the housing 21, the gas will overflow from the second channel 17 and the second pipe 18 in sequence, making it easy to inject liquid into the inner cavity of the housing 21. In order to inject liquid more smoothly, in this step, an air extraction pipe can be inserted into the second pipe 18 (or the air extraction pipe can be connected to the second pipe 18), and an external air extraction device connected to the air extraction pipe can be started to extract gas, so that a certain negative pressure is formed in the inner cavity of the housing 21;

[0119] Afterwards, the electrolyte injection pipe is connected to the first pipe member 13, 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 21, and then the injection can be carried out;

[0120] After the injection is completed, remove the electrolyte injection tube and the air extraction tube;

[0121] Afterwards, the ends of the first pipe member 13 and the second pipe member 18 located outside the housing 21 are sealed by heat shrink extrusion sealing.

[0122] When the fluid needs to be changed, follow these steps:

[0123] By cutting the heat-shrinkable extrusion sections of the first pipe member 13 and the second pipe member 18, the ends of the first pipe member 13 and the second pipe member 18 located outside the housing 21 are opened;

[0124] The electrolyte extraction tube is connected to the first pipe fitting 13, and the electrolyte is extracted; when the electrolyte cannot be extracted, a gas injection tube can be inserted into the second pipe fitting 18, or the second pipe fitting 18 can be connected to the gas injection tube, and a protective gas can be injected into the inner cavity of the shell 21 to extract the electrolyte; after the extraction is completed, the electrolyte extraction tube and the gas injection tube are taken out, and the electrolyte injection tube is connected to the first pipe fitting 13, and new electrolyte is injected; after the injection is completed, the electrolyte injection tube is extracted;

[0125] Afterwards, the ends of the first pipe member 13 and the second pipe member 18 located outside the housing 21 are sealed by heat shrink extrusion sealing.

[0126] Compared with the first embodiment, the second embodiment is more convenient to perform the liquid injection or liquid replacement operation after the second channel 17 and the second pipe 18 are added.

[0127] Example 3

[0128] like Figures 11 to 13 As shown, different from the above-mentioned embodiment, this embodiment further adopts a sealing rubber plug 3 to seal the first channel and the second channel.

[0129] from Fig.12 As can be seen in the figure, the ends of the first pipe 13 and the second pipe 18 located outside the housing 21 are located in the large hole 121 of the first channel; the sealing rubber plug 3 is inserted into the large hole 121 to seal the first channel and the second channel. In order to further improve the sealing performance, an O-ring 31 is provided between the sealing rubber plug 3 and the wall of the large hole 121.

[0130] The sealing rubber plug 3 in this embodiment is made of polytetrafluoroethylene rubber material that does not react with the electrolyte. In some other embodiments, other rubber materials that do not react with the electrolyte may also be used.

[0131] In addition, a blind hole 32 may be provided on the sealing rubber plug 3 to facilitate the use of tools to pull it out of the large hole 121 .

[0132] like Fig.14 As shown, it is a schematic diagram of the structure of the large-capacity battery of the embodiment. Different from the large-capacity battery in the embodiment 2, this embodiment adopts the above-mentioned liquid injection and replacement component, and the rest of the structure is the same as that of the embodiment 2, which will not be repeated here.

[0133] For the large-capacity battery corresponding to this embodiment, the process of filling and replacing the liquid is similar to that of Embodiment 2, except that, when filling or replacing the liquid is required, the sealing rubber plug 3 needs to be pulled out first, and then the ends of the first pipe 13 and the second pipe 18 located outside the housing 21 are opened by cutting the heat shrink extrusion sections of the first pipe 13 and the second pipe 18; after the filling and replacement of the liquid is completed and the ends of the first pipe 13 and the second pipe 18 located outside the housing 21 are sealed by heat shrink extrusion sealing, the large hole 121 needs to be blocked by the sealing rubber plug 3. The remaining steps are similar to those of Embodiment 2 and will not be repeated here.

[0134] Example 4

[0135] Different from the above-mentioned embodiment, Figures 15 to 17 As shown, this embodiment also uses a sealing end cover 4 to perform secondary sealing on the large hole 121. Fig.16 and Fig.17 Take the example of adding a sealing end cover 4 on the basis of embodiment 3.

[0136] In order to further ensure the sealing performance, a sealing gasket 41 may be further provided between the sealing end cover 4 and the end of the blind hole 32 .

[0137] The sealing end cap 4 is detachably fixed to the fluid injection and exchange component body 1. For example, it can be fastened to the fluid injection and exchange component body 1 by a threaded connection, or it can be fixed to the fluid injection and exchange component body 1 by an interference fit. However, compared with the threaded connection, the interference fit is more difficult to assemble and disassemble. Therefore, this embodiment uses a threaded connection to fix the sealing end cap 4 to the fluid injection and exchange component body 1.

[0138] like Fig.18 As shown, it is a schematic diagram of the structure of the large-capacity battery of this embodiment. What is different from the large-capacity battery of Example 3 is that this embodiment adopts the above-mentioned liquid injection and replacement component, and the rest of the structure is the same as that of Example 3, which will not be repeated here.

[0139] For the large-capacity battery corresponding to this embodiment, the process of filling and replacing the liquid is similar to that of Embodiment 3, except that when filling or replacing the liquid is required, the sealing end cap 4 needs to be removed first, and after the sealing rubber plug 3 is pulled out, the ends of the first pipe 13 and the second pipe 18 located outside the housing 21 are opened by cutting the heat shrink extrusion sections of the first pipe 13 and the second pipe 18; after the filling and replacement of the liquid is completed, the ends of the first pipe 13 and the second pipe 18 located outside the housing 21 are sealed by heat shrink extrusion sealing, and after the large hole 121 is blocked by the sealing rubber plug 3, the large hole 121 needs to be sealed again by the sealing end cap 4. The remaining steps are similar to those of Embodiment 3 and will not be repeated here.

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 columnar liquid injection and replacement component body; The main body of the liquid injection and replacement component is used to be fixed on the shell, and a first channel that is connected to the electrolyte area of ​​the inner cavity of the shell is opened on the main body of the liquid injection and replacement component, and a first pipe is sleeved in the first channel; The end of the first tube located outside the housing is sealed.

2. The liquid injection component according to claim 1, 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 in the inner cavity of the shell. A second pipe is sleeved in the second channel. The end of the second pipe located outside the shell is sealed.

3. The liquid injection component according to claim 2, characterized in that: The first pipe and the second pipe are made of plastic pipes that do not react with the electrolyte, and the ends located outside the shell are sealed by heat shrink extrusion sealing.

4. The liquid injection and replacement component according to claim 3, characterized in that: Also includes a sealing rubber plug; 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; Ends of the first pipe member and the second pipe member located outside the housing are located in the large hole of the step through hole; The sealing rubber plug is inserted into the large hole of the step through hole to seal the first channel and the second channel.

5. The liquid injection and replacement component according to claim 4, characterized in that: A sealing rubber layer is arranged on the step surface of the first channel, and ends of the first pipe member and the second pipe member located outside the shell extend out of the sealing rubber layer.

6. The liquid injection component according to claim 4, characterized in that: It also includes a sealing end cover; the sealing end cover is detachably fixed to the main body of the liquid injection and replacement component to reseal the first channel and the second channel.

7. 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 6 is fixed on the shell, and one end of the first channel is located in the inner cavity of the shell and communicated with the electrolyte area in the inner cavity of the shell.

8. The lithium-ion battery according to claim 7, 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.

9. 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 6 is fixed on the shell, and one end of the first channel is located in the inner cavity of the shell and communicated with the electrolyte area in the inner cavity of the shell.

10. The lithium-ion battery according to claim 9, 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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