Liquid injection and replacement and explosion venting component and lithium ion battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a liquid injection and replacement and explosion venting component and a lithium ion battery. When the lithium ion battery is lack of liquid, the electrolyte can be injected through the liquid injection and replacement component. The liquid injection and replacement and explosion venting component comprises a liquid injection and replacement component and an explosion venting pipe component; the liquid injection and change component comprises a liquid injection and change component main body and a plugging piece; the liquid injection and replacement component body is used for being fixed to a shell, and a first channel used for being communicated with an electrolyte area of an inner cavity of the shell is formed in the liquid injection and replacement component body. The plugging piece is used for plugging the first channel; the plugging piece is separated from the first channel under the action of thermal runaway pressure or temperature of the lithium ion battery; the explosion venting pipe component comprises an explosion venting pipe and an explosion venting film fixed in the explosion venting pipe; and the explosion venting pipe is coaxially and hermetically sleeved with the liquid injection and replacement component main body in a detachable manner. Three functions of liquid injection, liquid change and explosion venting of the lithium ion battery can be completed based on the liquid injection, liquid change and explosion venting component, so that the lithium ion battery with the functional component is simple in structure and relatively low in cost.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, in particular to a liquid injection and explosion relief 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 and explosion relief component and a lithium-ion battery, wherein the liquid injection and explosion relief component are 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 lithium-ion single cell or a lithium-ion battery module.

[0004] The technical solution of the utility model is to provide a liquid injection and explosion relief 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 explosion relief components include liquid injection components and explosion relief pipe components;

[0006] The liquid injection component includes a columnar liquid injection component body and a plugging component; the liquid injection component body is used to be fixed on the shell, and a first channel for communicating with the electrolyte area in the inner cavity of the shell is opened on the liquid injection component body; the plugging component is used to plug the first channel; and the plugging component can be separated from the first channel under the action of thermal runaway pressure or temperature of the lithium-ion battery;

[0007] The explosion-relief pipe component comprises an explosion-relief pipe and an explosion-relief membrane fixed in the explosion-relief pipe; the explosion-relief pipe is coaxially sealed and sleeved with the main body of the liquid injection and replacement component in a detachable manner.

[0008] After a period of charge and discharge cycles of lithium-ion batteries, the performance is reduced due to the decomposition and consumption of the electrolyte. The explosion relief tube component can be disassembled, the plugging component can be opened, and the electrolyte can be added to the inner cavity of the shell through the first channel on the main body of the liquid injection component to improve the performance of the lithium-ion battery; or, after a period of charge and discharge cycles of lithium-ion batteries, the performance of lithium-ion batteries is affected by the appearance of impurities in the electrolyte. The electrolyte in the inner cavity of the shell can also be replaced by the liquid injection component to improve the performance of lithium-ion batteries. The replacement here can be a partial replacement or a complete replacement. After completing the liquid replenishment or liquid replacement operation, the first channel is blocked from the outside of the shell with the plugging component, and the explosion relief tube component is installed. The operation is simple and convenient, and the liquid injection and replacement operation can be performed multiple times.

[0009] When a lithium-ion battery experiences thermal runaway, the sealing member detaches from the first channel under the action of internal pressure or temperature, and enters the explosion venting pipe through the first channel along with the thermal runaway smoke and part of the electrolyte, breaking through the explosion venting membrane and being discharged.

[0010] The utility model can complete the three functions of liquid injection, liquid replacement and explosion relief of lithium ion batteries based on the liquid injection and explosion relief components, so that the lithium ion battery with the functional components does not need to be provided with three corresponding components for the three functions, the structure is simple and the cost is low.

[0011] Furthermore, the main body of the fluid injection and replacement component is provided with a second channel that is connected to the gas area of ​​the inner cavity of the shell; the second channel is isolated from the first channel; and the blocking member is also used to block the second channel. The second channel can be used to connect the gas area of ​​the inner cavity of the shell with the external environment to facilitate smooth fluid injection or fluid replacement.

[0012] Furthermore, the blocking member is solid paraffin filled in the first channel and the second channel.

[0013] Furthermore, the liquid injection and explosion relief component also includes an electrolyte connecting pipe and a gas connecting pipe;

[0014] The first channel is connected through the electrolyte connecting pipe and the electrolyte area in the inner cavity of the shell;

[0015] The second channel is connected through the gas connecting pipe and the gas zone in the inner cavity of the shell.

[0016] Further, the main body of the liquid injection and replacement component is a cylinder;

[0017] A first blind hole is formed along the axial direction of the cylinder;

[0018] A second blind hole and a third blind hole isolated from each other are provided at the bottom of the blind hole along the axial direction of the cylinder; a second through hole and a third through hole connected to the second blind hole and the third blind hole are provided along the radial direction of the cylinder respectively; the second blind hole and the second through hole constitute a second channel; the third blind hole and the third through hole constitute a first channel;

[0019] The explosion relief pipe is sealed and sleeved in the first blind hole.

[0020] Furthermore, the outer wall of the explosion relief pipe is threadedly connected to the inner wall of the first blind hole.

[0021] 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;

[0022] The above-mentioned liquid injection and explosion relief components are 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.

[0023] The utility model also provides a lithium ion battery, which is special in that it comprises a shell and m single cells arranged in the shell, where m>1;

[0024] The inner cavity of the shell is connected with the inner cavity of each single battery;

[0025] The above-mentioned liquid injection and explosion relief components are 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.

[0026] 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.

[0027] Furthermore, a liquid channel extending along the arrangement direction of the single cells is provided between the bottom plate of the housing and each single cell;

[0028] One end of the electrolyte connecting tube is fixed to one end of the first channel, and the other end port is close to the bottom plate of the shell; and in the height direction of the shell, the highest position of the electrolyte connecting tube is higher than the electrolyte liquid level in the inner cavity of the shell.

[0029] The beneficial effects of the utility model are:

[0030] 1. The utility model provides a first channel connected to the inner cavity of the shell on the main body of the liquid injection component, and connects the explosion relief pipe component to the main body of the liquid injection component, fixes the liquid injection component and the explosion relief component to the lithium ion battery shell, and the first channel is connected to the electrolyte area in the shell. The plugging member 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;

[0031] After a period of charge and discharge cycles of lithium-ion batteries, the performance is reduced due to the decomposition and consumption of the electrolyte. The explosion relief tube component can be disassembled, the plugging component can be opened, and the electrolyte can be added to the inner cavity of the shell through the first channel on the main body of the liquid injection component to improve the performance of the lithium-ion battery; or, after a period of charge and discharge cycles of lithium-ion batteries, the performance of lithium-ion batteries is affected by the appearance of impurities in the electrolyte. The electrolyte in the inner cavity of the shell can also be replaced by the liquid injection component to improve the performance of lithium-ion batteries. The replacement here can be a partial replacement or a complete replacement. After completing the liquid replenishment or liquid replacement operation, the first channel is blocked from the outside of the shell with the plugging component, and the explosion relief tube component is installed. The operation is simple and convenient, and the liquid injection and replacement operation can be performed multiple times.

[0032] When a lithium-ion battery experiences thermal runaway, the sealing member detaches from the first channel under the action of internal pressure or temperature, and enters the explosion venting pipe through the first channel along with the thermal runaway smoke and part of the electrolyte, breaking through the explosion venting membrane and being discharged.

[0033] The utility model can complete the three functions of liquid injection, liquid replacement and explosion relief of lithium ion batteries based on the liquid injection and explosion relief components, so that the lithium ion battery with the functional components does not need to be provided with three corresponding components for the three functions, and has a simple structure and is easy to operate.

[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 It is a schematic diagram of the structure of the liquid injection and explosion relief component in Example 1;

[0036] Figure 2 It is a schematic diagram of the explosion of the liquid injection and explosion relief component in Example 1;

[0037] Figure 3 It is a cross-sectional view of the fluid injection and explosion relief component in Example 1;

[0038] Figure 4 It is a schematic diagram of the structure of the liquid injection and explosion relief component provided with the electrolyte connecting pipe in Example 1;

[0039] Figure 5 It is a structural schematic diagram of the explosion relief pipe component in Example 1;

[0040] Figure 6 is a schematic diagram of the structure of the lithium ion battery in Example 1;

[0041] Figure 7This is a schematic diagram of a partial explosion of a lithium-ion battery in Example 1;

[0042] Figure 8 This is a schematic structural diagram of a lithium-ion battery provided with a heat transfer tube in Example 1;

[0043] Fig. 9 is a partial cross-sectional view of the lithium-ion battery in Example 1;

[0044] Fig.10 It is a schematic diagram of the explosion structure of the liquid injection and explosion relief component and the end plate in Example 1;

[0045] Fig.11 It is a schematic diagram of the installation structure of the liquid injection and explosion relief component and the end plate in Example 1;

[0046] Fig.12 is a cross-sectional view of the fluid injection component in Example 2;

[0047] Fig.13 This is a schematic diagram of the structure of the liquid injection and replacement component in Example 2;

[0048] Fig.14 It is a cross-sectional view of the fluid injection and explosion relief component in Example 2;

[0049] Fig.15 This is a schematic diagram of the structure of the electrolyte connecting pipe and the gas connecting pipe in Example 2;

[0050] Fig.16 This is a partial cross-sectional view of the lithium-ion battery in Example 2.

[0051] The accompanying drawings in the figure are marked as follows:

[0052] 1. Liquid injection and replacement component; 11. Liquid injection and replacement component body; 111. Annular limiting boss; 112. First channel; 113. Second channel; 114. First blind hole; 115. Second blind hole; 116. Third blind hole; 117. Second through hole; 118. Third through hole; 12. Blocking member; 13. Electrolyte connecting pipe; 14. Gas connecting pipe; 2. Explosion-proof pipe component; 21. Explosion-proof pipe; 22. Explosion-proof membrane; 3. Shell; 31. Shell top plate; 32. Shell bottom plate; 33. End plate; 331. Mounting hole; 34. Support member; 35. Electrolyte shared chamber; 36. Gas shared chamber; 4. Single cell; 5. Heat transfer tube. DETAILED DESCRIPTION

[0053] 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.

[0054] 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.

[0055] 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, rather than indicating or implying 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, third, etc." are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] The utility model provides a functional component for a lithium ion battery. Based on the functional component, liquid injection, liquid replacement and explosion relief of the lithium ion battery can be completed. For ease of understanding, the functional component is defined as a liquid injection, liquid replacement and explosion relief component.

[0057] The lithium-ion battery may be a lithium-ion single cell or a lithium-ion battery module with a housing.

[0058] If it is a lithium-ion single cell battery (including a shell and at least one group of electrode assemblies located in the shell), the injection and replacement fluid and the explosion relief component can be fixed at any position of the lithium-ion single cell battery shell. Preferably, the injection and replacement fluid and the explosion relief component are fixed on the original injection port of the lithium-ion single cell battery to achieve the function of injecting electrolyte or replacing electrolyte. At the same time, when the lithium-ion single cell battery has thermal runaway, part of the electrolyte in the inner cavity of the shell and the thermal runaway smoke will be discharged from the injection and replacement fluid and the explosion relief component.

[0059] 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 it can also be called a lithium-ion battery pack or a large-capacity battery), the injection and replacement fluid and the explosion-proof component can also be fixed at any part of the shell of the lithium-ion battery module. Based on the injection and replacement fluid and the explosion-proof component, the injection or replacement of the electrolyte in the inner cavity of the shell can be achieved; at the same time, when any single cell has thermal runaway, part of the electrolyte in the inner cavity of the shell and the thermal runaway smoke will be discharged from the injection and replacement fluid and the explosion-proof component.

[0060] The utility model can realize the above three functions based on one component, so that the lithium ion battery with the functional component does not need to be provided with three corresponding components for the three functions, and has a simple structure and convenient operation.

[0061] Specifically, the fluid injection and explosion relief component of the present invention is mainly composed of a fluid injection component and an explosion relief pipe component. The fluid injection component and the explosion relief pipe component are connected to each other. The fluid injection operation is realized based on the fluid injection component, and the explosion relief function is realized based on the explosion relief pipe component.

[0062] Among them, the fluid injection and replacement component includes a columnar fluid injection and replacement component body and a sealing component; 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 inner cavity of the shell is opened on the fluid injection and replacement component body; during the charging and discharging operation of the lithium-ion battery, the sealing component is used to block the first channel. When the fluid injection and replacement operation is performed, the sealing component needs to be removed and the fluid injection and replacement operation is performed based on the first channel.

[0063] The explosion relief pipe component includes an explosion relief pipe and an explosion relief membrane fixed in the explosion relief pipe; the explosion relief pipe is coaxially sealed and sleeved with the main body of the injection and replacement component in a detachable manner, and can be connected in a threaded connection or an interference fit manner.

[0064] After a period of charge and discharge cycles of lithium-ion batteries, the performance is reduced due to the decomposition and consumption of the electrolyte. The explosion relief tube component can be disassembled, the sealing component can be removed, and the electrolyte can be injected into the inner cavity of the shell through the first channel to improve the performance of the lithium-ion battery. Or, after a period of charge and discharge cycles of lithium-ion batteries, the performance of lithium-ion batteries is affected by the appearance of impurities in the electrolyte. The performance of lithium-ion batteries can also be improved by replacing the electrolyte in the inner cavity of the shell through the injection and replacement of the liquid and the explosion relief component. The replacement here can be a partial replacement or a complete replacement. After completing the injection or replacement operation, the first channel can be blocked with the sealing component, and the explosion relief tube component can be connected to the main body of the injection and replacement component. The operation is simple and convenient.

[0065] When a lithium-ion battery experiences thermal runaway, the sealing member detaches from the first channel under the action of internal pressure or temperature, and enters the explosion venting pipe through the first channel along with the thermal runaway smoke and part of the electrolyte, breaking through the explosion venting membrane and being discharged.

[0066] It should be noted here that the blocking member is usually a solid material located in the first channel and does not react with the electrolyte; the above-mentioned blocking member is separated from the first channel, including at least the following two situations:

[0067] 1. Under the action of thermal runaway pressure, the plugging part directly detaches from the first channel, and enters the explosion-proof pipe through the first channel along with the thermal runaway smoke and part of the electrolyte, breaking through the explosion-proof membrane and being discharged.

[0068] 2. Under the action of thermal runaway temperature, the solid plugging part melts, forms a molten state or a liquid state, and leaves the first channel, and enters the explosion relief pipe through the first channel along with the thermal runaway smoke and part of the electrolyte, and breaks through the explosion relief membrane to be discharged. In this case, the plugging part is solid to block the first channel during the normal charge and discharge cycle of the lithium-ion battery, and becomes molten or liquid at the thermal runaway temperature of the lithium-ion battery, and loses the plugging function. Generally, phase change materials can be selected. Such phase change materials are solid at the normal charge and discharge cycle temperature of the lithium-ion battery; liquid or gas at the thermal runaway temperature of the lithium-ion battery; for example: paraffin (melting point is usually between 50℃-70℃), the temperature of the normal charge and discharge cycle of the lithium-ion battery is about 20℃-30℃, at which temperature the paraffin is solid and seals the first channel; the thermal runaway temperature of the lithium-ion battery is much higher than 70℃, so when the lithium-ion battery is thermally runaway, the paraffin melts and becomes liquid, and loses the plugging function.

[0069] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0070] Example 1

[0071] like Figure 1 , which is a schematic structural diagram of the fluid injection and explosion relief component of this embodiment, including a fluid injection component 1 and an explosion relief pipe component 2.

[0072] Combination Figure 2 and Figure 3 It can be seen that the fluid injection and replacement component 1 includes a fluid injection and replacement component body 11 and a sealing member 12.

[0073] The main body 11 of the liquid injection component is used to be fixed on the lithium-ion battery shell 3. In this embodiment, the main body 11 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 lithium-ion battery shell 3, this embodiment provides an annular limiting boss 111 on the outer peripheral surface of the main body 11 of the liquid injection component along the circumference. A mounting hole 331 is opened on the lithium-ion battery shell 3, and the main body 11 of the liquid injection component is fixed in the mounting hole 331. The annular limiting boss 111 is welded to the area of ​​the shell 3 around the mounting hole 331 to achieve fixation while sealing the mounting hole 331 (see details). Fig.10 and Fig.11 ).

[0074] A through hole is provided on the main body 11 of the liquid injection and replacement component as the first channel 112. The first channel 112 may be a straight through hole or an L-shaped through hole (such as Figure 2 and Figure 3 As shown, this embodiment is an L-shaped through hole). After the liquid injection component body 11 is fixed on the lithium-ion battery housing 3, one end of the first channel 112 ( Figure 3 The port shown in 112a) is located outside the housing 3, and the other end ( Figure 3 The port shown as 112b in the figure is located inside the shell 3 and is connected to the electrolyte area in the inner cavity of the shell 3.

[0075] In order to prevent the blocking member 12 from opening, the electrolyte in the inner cavity of the housing 3 leaks from the first channel 112. Figure 4 As shown, in this embodiment, the first channel 112 is connected to the electrolyte area of ​​the inner cavity of the shell 3 through the electrolyte connecting pipe 13. In the height direction of the shell 3, the highest position of the electrolyte connecting pipe 13 ( Figure 4 The position shown in h in the figure is higher than the electrolyte level in the inner cavity of the shell 3, and the end of the electrolyte connecting pipe 13 connected to the electrolyte area in the inner cavity of the shell 3 ( Figure 4 1) is extended into the bottom of the inner cavity of the shell 3 as much as possible and is always immersed in the electrolyte. When the liquid needs to be replaced, as much electrolyte as possible can be drawn out of the inner cavity of the shell 3, so that the liquid replacement is more thorough.

[0076] The electrolyte connecting tube 13 and the liquid injection component body 11 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 11 by welding or screwing. The electrolyte connecting tube 13 is generally made of the same aluminum material as the liquid injection component body 11.

[0077] The blocking member 12 of this embodiment is made of solid paraffin wax and blocks the first channel 112. When blocking, liquid paraffin wax is directly poured into the first channel 112, and after cooling, solid paraffin wax is formed to block the first channel 112.

[0078] In some other embodiments, the sealing member 12 may also be made of other phase change materials that meet the requirements (solid at the normal charge and discharge cycle temperature of the lithium-ion battery; liquid or gaseous at the thermal runaway temperature of the lithium-ion battery) and do not react with the electrolyte.

[0079] In some other embodiments, the plugging member 12 may also be a rubber member, but the bonding strength between the rubber member and the first channel needs to be limited. Only under the action of thermal runaway pressure can the plugging member 12 directly detach from the first channel 112, and enter the explosion relief pipe 21 through the first channel 112 along with the thermal runaway smoke and part of the electrolyte, and break through the explosion relief membrane 22 to be discharged. The first channel 112 corresponding to this solution is preferably a straight hole.

[0080] like Figure 5 As shown, the explosion-proof pipe component 2 of this embodiment includes an explosion-proof pipe 21 and an explosion-proof membrane 22 fixed in the explosion-proof pipe 21;

[0081] Combination Figure 3 It can be seen that the explosion relief pipe 21 of this embodiment is sleeved inside one end of the first channel 112 and can be fixed and sealed by a threaded connection.

[0082] In other embodiments, the explosion relief pipe 21 and the first channel 112 may be connected by interference fit;

[0083] In other embodiments, the explosion-proof tube 21 can also be sleeved on the outside of one end of the first channel 112, and can be fixed and sealed by means of threads or interference fit. The position of the explosion-proof membrane 22 in the explosion-proof tube 21 can be adjusted according to the connection position of the explosion-proof tube 21 and the first channel 112. If the explosion-proof tube 21 is sleeved in the first channel 112, the position of the explosion-proof membrane 22 is not specifically limited, and it can be located at any position in the explosion-proof tube 21, preferably at one end of the explosion-proof tube 21 close to the plugging member 12, to avoid the explosion-proof membrane 22 being exposed and damaged. If the explosion-proof tube 21 is sleeved outside the first channel 112, the explosion-proof membrane 22 needs to be fixed at one end of the explosion-proof tube 21 away from the plugging member 12, and the explosion-proof membrane 22 is easily damaged by external forces.

[0084] like Figure 6 , which is a schematic diagram of the structure of a lithium-ion battery according to the present embodiment, specifically a large-capacity battery, including a housing 3 and a plurality of single cells 4 arranged in the housing 3 .

[0085] The single cells 4 in this embodiment are square shell cells, the number of which is 13, and the inner cavity of each single cell 4 includes an electrolyte area and a gas area. In other embodiments, the number of single cells 4 can be adjusted according to actual needs, and the shape of single cells 4 can also be adjusted according to actual needs.

[0086] A rectangular housing 3 is usually used. For ease of description, the length direction of the housing 3 is defined as the x direction, the width direction of the housing 3 is defined as the y direction, and the height direction of the housing 3 is defined as the z direction.

[0087] The utility model does not specifically limit the structure of the housing 3, and at least the following two structures can be adopted:

[0088] 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);

[0089] 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).

[0090] In the following description, the cover plates in the housing 3 parallel to the xy plane are respectively defined as the housing top plate 31 and the housing bottom plate 32 , and the cover plate parallel to the yz plane is referred to as the end plate 33 .

[0091] The inner cavity of the housing 3 is connected to the inner cavities of all the single cells 4. Preferably, a shared cavity can be provided in the housing 3, so that the inner cavity of the shared cavity is connected to the inner cavities of all the single cells 4 to achieve the above-mentioned connection effect.

[0092] It should be noted that:

[0093] The above-mentioned shared chamber can be an electrolyte shared chamber 35 (see 7). Through the electrolyte shared chamber 35, each single cell 4 can be placed in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single cell 4; improving the performance and charge-discharge cycle life of large-capacity batteries. The electrolyte shared chamber 35 described here is a liquid channel extending along the length direction (x direction) of the shell 3 between the shell bottom plate 32 and each single cell 4. The liquid channel can be integrally formed with the shell bottom plate 32, or can be formed by setting a support member 34 between the lower cover plate of the single cell 4 and the shell bottom plate 32.

[0094] A gas sharing chamber 36 is provided along the x direction on the housing top plate 31, and the inner cavity of the gas sharing chamber 36 is connected to the inner gas area of ​​each single cell 4. The gas sharing chamber is used to achieve gas balance of each single cell, and the performance and charge-discharge cycle life of the large-capacity battery can also be improved.

[0095] In some other embodiments, only the electrolyte sharing chamber 35 may be provided.

[0096] In order to improve the heat dissipation performance of such large-capacity batteries, avoidance holes can be opened on the outer shell top plate 31 to allow the polarity terminals of each single battery 4 to extend out; the polarity terminals of each single battery 4 extend out of the avoidance holes and the outer shell top plate 31 area around the avoidance holes is fixedly sealed with the shell of the single battery 4.

[0097] It should be noted that the single cell battery 4 polarity terminal described here can be a single cell battery 4 pole. In order to avoid the single cell battery 4 pole being unable to smoothly extend out of the avoidance hole as a polarity terminal, a pole adapter can also be connected to the single cell battery 4 pole, and the overall structure of the single cell battery 4 pole and the pole adapter can be used as the single cell battery 4 polarity terminal.

[0098] In order to further improve the heat dissipation performance of the large-capacity battery in the above embodiment, Figure 8 As shown, the large-capacity battery in this embodiment further includes a heat transfer tube 5 .

[0099] In this embodiment, a heat transfer tube 5 clamping part is provided at the part where the polarity terminal extends out of the avoidance hole, and the heat transfer tube 5 is fixed in the heat transfer tube 5 clamping part, so that the heat transfer tube 5 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, a heat transfer medium with a higher temperature is introduced into the heat transfer tube 5 to increase the temperature of the large-capacity battery; 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.

[0100] The above-mentioned injection and explosion relief components are fixed on the housing end plate 33. In this embodiment, the injection and explosion relief components are close to the housing bottom plate 32. Therefore, in order to avoid opening the blocking member 12, the electrolyte in the inner cavity of the housing 3 leaks from the first channel 112, such as Fig. 9 As shown, in this embodiment, the first channel 112 is connected to the electrolyte area in the inner cavity of the shell 3 through the electrolyte connecting tube 13. In the height direction of the shell 3, the highest position of the electrolyte connecting tube 13 is higher than the electrolyte level in the inner cavity of the shell 3, and the end of the electrolyte connecting tube 13 connected to the electrolyte area in the inner cavity of the shell 3 extends as far as possible into the bottom of the inner cavity of the shell 3 and is always immersed in the electrolyte. When the liquid needs to be replaced, the electrolyte in the inner cavity of the shell 3 can be extracted as much as possible, so that the liquid replacement is more thorough.

[0101] Combination Fig.10 and Fig.11 In this embodiment, a mounting hole 331 matching the cross-sectional shape of the liquid injection body is provided on the shell end plate 33, the liquid injection component body 11 is coaxially located in the mounting hole 331, and the annular limiting boss 111 is sealed and welded to the surrounding area of ​​the mounting hole 331. 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 33 of each large-capacity battery are exposed, and when the liquid injection and explosion relief components are arranged on the end plate 33, the liquid injection operation can be conveniently performed.

[0102] After a period of charge and discharge cycles of a large-capacity battery, the performance of the large-capacity battery is reduced due to the decomposition and consumption of the electrolyte. The electrolyte can be added to the inner cavity of the shell 3 and the inner cavity of each single cell 4 by injecting and exploding components to improve the performance of the large-capacity battery; or, after a period of charge and discharge cycles of a large-capacity battery, 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 3 and the inner cavity of each single cell 4 by injecting and exploding components. The replacement here can be partial replacement or full replacement. In addition, after the electrolyte area in the inner cavity of each single cell 4 is connected to the electrolyte shared chamber 35, the electrolyte can be injected into the inner cavity of each single cell 4 and the electrolyte shared chamber 35 again by injecting and exploding components to ensure the continuity of the electrolyte.

[0103] When a lithium-ion battery experiences thermal runaway, the solid paraffin melts and detaches from the first channel 112 under the action of internal pressure or temperature, and enters the explosion venting pipe 21 along with the thermal runaway smoke and part of the electrolyte through the electrolyte connecting pipe 13 and the first channel 112, breaking through the explosion venting membrane 22 and being discharged.

[0104] In some other embodiments, a high-temperature (thermal runaway temperature) fusible material may be selected as the electrolyte connecting tube 13. At the thermal runaway temperature, the electrolyte connecting tube 13 melts and enters the explosion-proof tube 21 along with the thermal runaway smoke and part of the electrolyte through the first channel 112, breaking through the explosion-proof membrane 22 and being discharged.

[0105] The following describes the fluid replacement process:

[0106] When injection is required, follow these steps:

[0107] Disassemble the explosion relief pipe component 2, heat it, melt the paraffin, and extract the liquid paraffin;

[0108] Extend the electrolyte injection tube into the first channel 112 and inject the electrolyte, and after the injection is completed, withdraw the electrolyte injection tube;

[0109] Liquid paraffin is poured into the first channel 112 , and after the paraffin solidifies, the explosion relief pipe component 2 is fixed on the liquid injection component body 11 .

[0110] When the fluid needs to be changed, follow these steps:

[0111] Disassemble the explosion relief pipe component 2, heat it, melt the paraffin, and extract the liquid paraffin;

[0112] Insert the electrolyte extraction tube into the first channel 112 and extract the electrolyte; then, insert the electrolyte injection tube into the first channel 112 and inject new electrolyte; after the injection is completed, remove the electrolyte injection tube;

[0113] Liquid paraffin is poured into the first channel 112 , and after the paraffin solidifies, the explosion relief pipe component 2 is fixed on the liquid injection component body 11 .

[0114] It should be noted that, in this embodiment, during the liquid injection process, if the pressure in the inner cavity of the shell 3 is too high, the problem of liquid injection difficulty may occur.

[0115] Example 2

[0116] This embodiment is based on the embodiment 1. Figure 12 to Figure 14 As shown, a second channel 113 is opened on the liquid injection and replacement component body 11 , and the blocking member 12 in the above embodiment is also used to block the second channel 113 .

[0117] In this embodiment, a first blind hole 114 is provided along the axial direction of the cylinder; a second blind hole 115 and a third blind hole 116 isolated from each other are provided at the bottom of the blind hole along the axial direction of the cylinder; a second through hole 117 and a third through hole 118 respectively connected with the second blind hole 115 and the third blind hole 116 are provided along the radial direction of the cylinder; the second blind hole 115 and the second through hole 117 constitute a second channel 113; the third blind hole 116 and the third through hole 118 constitute a first channel 112; and the explosion relief pipe 21 is sealed and sleeved in the first blind hole 114.

[0118] In some other embodiments, the second channel 113 may also be a straight through hole, and the cross section may be adjusted according to actual needs. As long as it is ensured that the second channel 113 is connected to the gas zone of the inner cavity of the shell 3, the protective gas can be injected into the inner cavity of the shell 3 or the gas in the inner cavity of the shell 3 can be discharged through the second channel 113.

[0119] After the liquid injection and replacement component body 11 is fixed on the lithium-ion battery housing 3, one end of the second channel 113 is located outside the housing 3, and the other end is located inside the housing 3 and communicates with the gas area of ​​the inner cavity of the housing 3. Specifically, the second channel 113 can also be connected to the gas area of ​​the inner cavity of the housing 3 through the gas connecting pipe 14 (see Fig.15 ).

[0120] like Fig.16 , which is a partial cross-sectional view of the large-capacity battery of this embodiment. Different from the large-capacity battery of Embodiment 1, this embodiment adopts the above-mentioned fluid injection and explosion relief components, and the rest of the structure is the same as that of Embodiment 1, which will not be repeated here.

[0121] The following describes the fluid injection and replacement process of this embodiment:

[0122] When injection is required, follow these steps:

[0123] Disassemble the explosion relief pipe component 2, heat it, melt the paraffin, and extract the liquid paraffin;

[0124] When there is gas in the inner cavity of the housing 3, the gas will overflow from the second channel 113, making it easy to inject liquid into the inner cavity of the housing 3. In order to inject liquid more smoothly, in this step, an air extraction pipe can be inserted into the second channel 113, 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 3;

[0125] Afterwards, the electrolyte injection tube is extended into the first channel 112 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 3, and then the injection can be carried out;

[0126] After the rehydration is completed, remove the electrolyte injection tube and the air extraction tube;

[0127] Afterwards, liquid paraffin is poured into the first channel 112 and the second channel 113 , and after the paraffin solidifies, the explosion relief pipe component 2 is fixed on the liquid injection component body 11 .

[0128] When the fluid needs to be changed, follow these steps:

[0129] Disassemble the explosion relief pipe component 2, heat it, melt the paraffin, and extract the liquid paraffin;

[0130] The electrolyte extraction tube is inserted into the first channel 112 to extract the electrolyte; when the electrolyte cannot be extracted, a gas injection tube can be inserted into the second channel 113 to inject protective gas into the inner cavity of the shell 3 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 inserted into the first channel 112 and new electrolyte is injected; after the injection is completed, the electrolyte injection tube is pulled out;

[0131] Afterwards, liquid paraffin is poured into the first channel 112 and the second channel 113 , and after the paraffin solidifies, the explosion relief pipe component 2 is fixed on the liquid injection component body 11 .

[0132] After the second channel is added, it is easier to perform liquid injection or liquid replacement operations compared to Example 1.

Claims

1. A liquid injection and explosion relief component, applied to a lithium ion battery, wherein the lithium ion battery comprises a shell, and the inner cavity of the shell comprises an electrolyte area and a gas area; characterized in that: The liquid injection and explosion relief components include liquid injection components and explosion relief pipe components; The liquid injection component includes a columnar liquid injection component body and a plugging component; the liquid injection component body is used to be fixed on the shell, and a first channel for communicating with the electrolyte area in the inner cavity of the shell is opened on the liquid injection component body; the plugging component is used to plug the first channel; and the plugging component can be separated from the first channel under the action of thermal runaway pressure or temperature of the lithium-ion battery; The explosion-relief pipe component comprises an explosion-relief pipe and an explosion-relief membrane fixed in the explosion-relief pipe; the explosion-relief pipe is coaxially sealed and sleeved with the main body of the liquid injection and replacement component in a detachable manner.

2. The liquid injection and explosion relief component according to claim 1, characterized in that: The main body of the liquid injection and replacement component is also provided with a second channel which is in communication with the gas area in the inner cavity of the shell; the second channel is isolated from the first channel; and the blocking member is also used to block the second channel.

3. The liquid injection and explosion relief component according to claim 2, characterized in that: The blocking member is solid paraffin filled in the first channel and the second channel.

4. The liquid injection and explosion relief component according to claim 3, characterized in that: It also includes an electrolyte connecting pipe and a gas connecting pipe; The first channel is connected through the electrolyte connecting pipe and the electrolyte area in the inner cavity of the shell; The second channel is connected through the gas connecting pipe and the gas zone in the inner cavity of the shell.

5. The liquid injection and explosion relief component according to claim 2, characterized in that: The main body of the liquid injection and replacement component is a cylinder; A first blind hole is formed along the axial direction of the cylinder; A second blind hole and a third blind hole isolated from each other are provided at the bottom of the blind hole along the axial direction of the cylinder; a second through hole and a third through hole connected to the second blind hole and the third blind hole are provided along the radial direction of the cylinder respectively; the second blind hole and the second through hole constitute a second channel; the third blind hole and the third through hole constitute a first channel; The explosion relief pipe is sealed and sleeved in the first blind hole.

6. The liquid injection and explosion relief component according to claim 5, characterized in that: The outer wall of the explosion relief pipe is threadedly connected to the inner wall of the first blind hole.

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 explosion relief 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 is connected to the electrolyte area in the inner cavity of the shell.

8. 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 explosion relief 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 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. The lithium-ion battery according to claim 8, characterized in that: A liquid channel extending along the arrangement direction of the single cells is provided between the bottom plate of the housing and each single cell; One end of the electrolyte connecting tube is fixed to one end of the first channel, and the other end port is close to the bottom plate of the shell; and in the height direction of the shell, the highest position of the electrolyte connecting tube is higher than the electrolyte liquid level in the inner cavity of the shell.

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