Lithium battery shell and self-sealing structure of lithium battery liquid injection port

Abstract

The utility model relates to battery liquid injection device technical field, concretely relates to a lithium battery shell and self -sealing structure of lithium battery liquid injection mouth. The utility model provides a lithium battery shell, including the casing, the casing is provided with the liquid injection mouth, still including the cover, the cover is fixed in the casing and covers the liquid injection mouth, is provided with the cover cavity in the cover, the cover cavity is linked together with the liquid injection mouth, the wall of cover is provided with the first through -hole that passes through the cover cavity and the outside space of cover, is provided with the reset spring in the cover cavity, the seal plug is installed in the liquid injection mouth department of casing, the seal plug includes upper sealing member and lower sealing member, upper sealing member can pass through the liquid injection mouth and is sealedly connected with the casing, lower sealing member sets up in the cover cavity and is sealedly slidably connected with the cover, lower sealing member can slide up and down along the cover cavity to push reset spring and produce the deformation, the free length of reset spring is greater than the axial height of cover cavity. The utility model does not need additional temporary plugging, and the protection is strong after the automatic sealing of liquid injection.

Description

Technical Field

[0001] This utility model relates to the field of battery liquid filling device technology, specifically to a self-sealing structure for a lithium battery casing and a lithium battery liquid filling port. Background Technology

[0002] In lithium battery production, electrolyte injection is a crucial step in filling the battery with electrolyte. Existing electrolyte injection port structures have the following drawbacks: 1. When the electrolyte filling is completed, the inner electrode of the battery cell may not be wetted in time, and the electrolyte overflows and contaminates the filling port when the filling nozzle is withdrawn. It is necessary to wipe it to avoid the electrolyte crystallization affecting the sealing welding. 2. Temporary sealing is cumbersome and unreliable. After the electrolyte is injected, tools such as chemical bonding nails need to be inserted for temporary sealing, which increases the process cost. In addition, the bonding nails are easy to leave residues and the seal is not tight, which leads to electrolyte leakage. 3. Weak environmental protection: From the time of liquid injection to the time of formation, the injection port is exposed to the air, which makes it easy to attract foreign objects such as dust and moisture, thus degrading the electrochemical performance of the battery. 4. Insufficient sealing durability: Traditional sealing pins are easily corroded and contaminated by electrolytes, and the seals fail after repeated use, resulting in a high risk of leakage. Utility Model Content

[0003] To address the technical problems of existing liquid injection port structures, such as overflow pollution, cumbersome repeated wiping and pin insertion / removal, poor sealing, and high equipment and product costs, this utility model provides a self-sealing structure for lithium battery casing and lithium battery liquid injection port, which eliminates the need for additional temporary sealing, automatically seals after liquid injection, and provides strong protection.

[0004] This utility model provides a lithium battery casing, including a casing with an injection port, and further including: an outer cover, which is fixed to the casing and covers the injection port, and has a cavity inside the outer cover that communicates with the injection port. The outer cover has a first through hole in its wall that connects the cavity to the outside space of the outer cover, and a return spring is disposed inside the cavity; and a sealing plug, which is installed at the injection port of the casing, and includes an upper sealing member and a lower sealing member. The upper sealing member can pass through the injection port and is sealed to the casing, while the lower sealing member is disposed in the cavity and is slidably sealed to the outer cover. The return spring is disposed on the side of the lower sealing member opposite to the upper sealing member, and the lower sealing member can slide up and down along the cavity to push the return spring to deform. The free length of the return spring is greater than the axial height of the cavity.

[0005] Furthermore, the sealing plug has a slide rail on its side wall and a groove that matches the slide rail on its outer cover; or, the sealing plug has a groove on its side wall and a slide rail that matches the slide rail on its outer cover.

[0006] Furthermore, the lower seal includes a connecting part and a sliding part. The connecting part is connected to the upper seal, the outer wall of the sliding part is in sealing contact with the wall of the cover cavity, and a cavity is provided inside the sliding part. The upper part of the return spring is disposed in the cavity.

[0007] This utility model provides a self-sealing structure for a lithium battery filling port, including a lithium battery shell and a filling nozzle. The filling nozzle includes a push part that cooperates with an upper sealing member. A filling channel is provided in the push part. The push part has a second through hole that penetrates the wall of the push part and communicates with the filling channel. During the process of the push part pressing down the sealing plug, the push part is sealed to the shell.

[0008] Furthermore, the injection port is provided with a limiting groove, and the injection nozzle includes a limiting part adapted to the limiting groove. The limiting part is located on the side of the pushing part facing away from the sealing plug. The injection port is provided with a guide hole, and the pushing part is slidably sealed to the guide hole.

[0009] Furthermore, the jacking section is conical or stepped.

[0010] Furthermore, the lower seal includes a connecting portion that connects to the upper seal. Along the axial direction of the outer cover, the connecting portion can contact the inner wall of the housing to limit the sealing position of the sealing plug.

[0011] Furthermore, when the injection nozzle is pressed down and the return spring is compressed into the injection state, the sealing plug moves down to form a guide channel connecting the first through hole and the second through hole. The second through hole is located on the side of the housing facing the outer cover. When the sealing plug is pushed up by the return spring to the injection port in the initial state, the lower seal can cover the first through hole to keep the cavity sealed.

[0012] Furthermore, the first through hole is a conical hole or a round hole, and the first through holes are evenly distributed along the circumference of the outer cover.

[0013] Furthermore, the sealing surface of the injection nozzle is covered with a sealing layer.

[0014] The beneficial effects of this utility model are as follows: This invention employs a linked conduction and sealing structure. The up-and-down movement of the injection nozzle directly drives the sealing plug, eliminating the need for additional tools (such as chemically formed glue pins) and simplifying the injection process. After injection, the sealing plug automatically resets and seals, eliminating inconsistencies caused by manual operation.

[0015] This invention features double sealing protection. The sealing part of the sealing plug forms a first seal with the inner wall of the outer cover, and the injection nozzle forms a second seal with the sealing surface of the sealing plug. During injection, both channels are open, and under normal conditions, both channels are closed, effectively preventing electrolyte overflow and the intrusion of foreign matter (dust, moisture).

[0016] This invention has strong adaptability. By adjusting the spring force and the sealing surface material of the sealing plug, it can be adapted to different electrolyte systems (such as liquid and solid) and battery models such as cylindrical, square, and blade types, making it highly versatile. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of one embodiment of a lithium battery casing; Figure 2 A schematic diagram of the structure of one embodiment of a lithium battery casing; Figure 3 A schematic diagram of one embodiment of a self-sealing structure for a lithium battery filling port; Figure 4 This is a schematic diagram of one embodiment of a self-sealing structure for a lithium battery filling port.

[0019] Explanation of main reference numerals: 1-shell, 2-injection port, 21-limiting groove, 22-guide hole, 3-outer cover, 31-first through hole, 4-cover cavity, 5-reset spring, 6-sealing plug, 61-upper seal, 62-lower seal, 71-connecting part, 72-sliding part, 8-injection nozzle, 81-push part, 82-second through hole, 83-limiting part. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0021] like Figure 1 and Figure 2As shown, one embodiment of this utility model provides a lithium battery casing, including a housing 1 with a liquid injection port 2, and an outer cover 3. The outer cover 3 is fixed to the housing 1 and covers the liquid injection port 2. A cavity 4 is provided inside the outer cover 3, which communicates with the liquid injection port 2. A first through hole 31 is provided in the wall of the outer cover 3, which connects the cavity 4 and the external space of the outer cover 3. A return spring 5 is provided inside the cavity 4. In a preferred embodiment, the first through hole 31 is a conical hole or a circular hole, and the first through holes 31 are evenly distributed along the circumference of the outer cover 3.

[0022] A sealing plug 6 is installed at the injection port 2 of the housing 1. The sealing plug 6 includes an upper sealing element 61 and a lower sealing element 62. The upper sealing element 61 can pass through the injection port 2 and is sealed to the housing 1. The lower sealing element 62 is disposed in the cover cavity 4 and is slidably sealed to the outer cover 3. A return spring 5 is disposed on the side of the lower sealing element 62 opposite to the upper sealing element 61. The lower sealing element 62 can slide up and down along the cover cavity 4 to push the return spring 5 to deform. The free length of the return spring 5 is greater than the axial height of the cover cavity 4. In the initial position, the free length of the return spring 5 is greater than the axial height of the cover cavity 4, and the return spring 5 deforms. The return spring 5 generates an elastic force that pushes the sealing plug 6 to seal the injection port 2, so that the sealing plug 6 is stably sealed to the housing 1. The lower seal 62 includes a connecting part 71 and a sliding part 72. The connecting part 71 is connected to the upper seal 61. The outer wall of the sliding part 72 is in sealing contact with the wall of the cover cavity 4. The sliding part 72 has a cavity inside. The upper part of the return spring 5 is disposed in the cavity. The part of the return spring 5 is located in the cavity of the sliding part 72. During the up and down movement of the sealing plug 6, the relative position of the return spring 5 and the sealing plug 6 is kept stable and will not move, thus ensuring the stability of the movement state.

[0023] like Figure 3 and Figure 4 As shown, one embodiment of this utility model provides a self-sealing structure for a lithium battery filling port 2, including a lithium battery shell and a filling nozzle 8. The filling nozzle 8 includes a push part 81 that cooperates with an upper sealing member 61. A filling channel is provided inside the push part 81. The push part 81 has a second through hole 82 that penetrates the wall of the push part 81 and communicates with the filling channel. During the process of the push part 81 pressing down on the sealing plug 6, the push part 81 is sealed to the shell 1. The sealing surface of the filling nozzle 8 is covered with a sealing layer. By adjusting the spring force and the sealing layer material, it can be adapted to different electrolyte systems (such as liquid and solid) and battery models such as cylindrical, square, and blade types, with high versatility. The sealing layer material can be fluororubber or polytetrafluoroethylene.

[0024] During the injection process, the injection nozzle 8 pushes the sealing plug 6 away from the housing 1. The sealing plug 6 moves away from the injection port 2, maintaining a seal between the injection nozzle 8 and the housing 1. After the sealing plug 6 moves, the electrolyte is injected into the housing 1. The injection port 2 is provided with a limiting groove 21. The injection nozzle 8 includes a limiting part 83 adapted to the limiting groove 21. The limiting part 83 is located on the side of the pushing part 81 facing away from the sealing plug 6. The limiting groove 21 and the limiting part 83 cooperate to control the final position of the injection nozzle 8 pressing down on the sealing plug 6. In a preferred embodiment, the pushing part 81 is conical or stepped. The injection port 2 is provided with a guide hole 22, and the pushing part 81 is slidably and sealingly connected to the guide hole 22.

[0025] The lower seal 62 includes a connecting portion 71, which connects to the upper seal 61. Along the axial direction of the outer cover 3, the connecting portion 71 can contact the inner wall of the housing 1 to limit the sealing position of the sealing plug 6. When the injection nozzle 8 is pressed down and the return spring 5 is compressed into the injection state, the sealing plug 6 moves down to form a guide channel connecting the first through hole 31 and the second through hole 82. The injection nozzle 8 is pressed down to the end position of the sealing plug 6. The second through hole 82 is located on the side of the housing 1 facing the outer cover 3. At this time, the electrolyte enters from the injection channel, passes through the second through hole 82, the guide channel, and the first through hole 31, and is injected into the housing 1. After the injection nozzle 8 is removed, the sealing plug 6 is pushed up by the return spring 5 to the injection port 2 in the initial state. The sliding portion 72 of the lower seal 62 can cover the first through hole 31 to keep the cavity 4 sealed.

[0026] like Figure 3 and Figure 4 As shown, the working process of the self-sealing structure of the lithium battery filling port 2 in one embodiment is as follows: Preparation for electrolyte filling: The filling nozzle 8 is connected to the supply device, and the sealing plug 6 is in an initial sealed state under the action of the return spring 5 (the sealing part is attached to the inner wall of the outer cover 3, and the hole of the outer cover 3 is closed). Injection operation: The supply device drives the filling nozzle 8 to move downwards → the pushing part 81 pushes the sealing plug 6 → the sealing plug 6 moves downwards along the guide rail → the sealing part disengages from the inner wall of the outer cover 3 (the hole of the outer cover 3 is exposed), the guide channel connects with the injection channel / first through hole 31 → the electrolyte is injected into the battery through "supply device → injection channel → guide channel → first through hole 31". Sealing reset: After injection, the supply device drives the filling nozzle 8 to move upwards → the pushing part 81 separates from the sealing plug 6 → the sealing plug 6 moves upwards and resets under the elastic force of the return spring 5 → the lower sealing part 62 is attached to the inner wall of the outer cover 3 (the first through hole 31 is closed), the upper sealing part 61 separates from the pushing part 81 → the filling port 2 is restored to a sealed state.

[0027] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the present invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be included within the protection scope of the present invention.

Claims

1. A lithium battery casing, comprising a casing, characterized in that, The casing is provided with a liquid injection port and also includes: The outer cover is fixed to the shell and covers the injection port. The outer cover has a cavity inside, which is connected to the injection port. The wall of the outer cover has a first through hole that connects the cavity to the external space of the outer cover. A return spring is installed inside the cavity. A sealing plug is installed at the liquid injection port of the housing. The sealing plug includes an upper sealing element and a lower sealing element. The upper sealing element can pass through the liquid injection port and is sealed to the housing. The lower sealing element is set in the cover cavity and is slidably sealed to the outer cover. A return spring is set on the side of the lower sealing element away from the upper sealing element. The lower sealing element can slide up and down along the cover cavity to push the return spring to deform. The free length of the return spring is greater than the axial height of the cover cavity.

2. A lithium battery casing as described in claim 1, characterized in that, The sealing plug has a slide rail on its side wall and a slide groove that matches the slide rail on its outer cover. Alternatively, the sealing plug has a groove on its side wall and a slide rail that matches the slide rail on its outer cover.

3. A lithium battery casing as described in claim 1, characterized in that, The lower seal includes a connecting part and a sliding part. The connecting part is connected to the upper seal. The outer wall of the sliding part is in sealing contact with the wall of the cover cavity. The sliding part has a cavity inside, and the upper part of the return spring is located in the cavity.

4. A self-sealing structure for a lithium battery electrolyte filling port, characterized in that, The lithium battery casing as described in any one of claims 1 or 3 further includes an injection nozzle, the injection nozzle including a push part that cooperates with the upper seal, the push part having an injection channel, the push part having a second through hole that penetrates the wall of the push part and communicates with the injection channel, and the push part being sealed to the casing during the process of the push part pressing down the sealing plug.

5. The self-sealing structure of the lithium battery filling port as described in claim 4, characterized in that, The injection port is provided with a limiting groove, and the injection nozzle includes a limiting part that is adapted to the limiting groove. The limiting part is located on the side of the pushing part facing away from the sealing plug. The injection port is provided with a guide hole, and the pushing part is slidably and sealingly connected to the guide hole.

6. The self-sealing structure of the lithium battery filling port as described in claim 5, characterized in that, The jacking section is conical or stepped.

7. The self-sealing structure of the lithium battery filling port as described in claim 4, characterized in that, The lower seal includes a connecting part that connects to the upper seal. Along the axial direction of the outer cover, the connecting part can contact the inner wall of the housing to limit the sealing position of the sealing plug.

8. The self-sealing structure of the lithium battery filling port as described in claim 4, characterized in that, When the injection nozzle is pressed down, the return spring is compressed and the injection state is in progress. The sealing plug moves down to form a guide channel connecting the first through hole and the second through hole. The second through hole is located on the side of the housing facing the outer cover. When the sealing plug is lifted by the return spring to the initial state of the injection port, the lower seal can cover the first through hole to keep the cavity sealed.

9. The self-sealing structure of the lithium battery filling port as described in claim 4, characterized in that, The first through hole is a conical hole or a round hole, and the first through holes are evenly distributed along the circumference of the outer cover.

10. The self-sealing structure of the lithium battery filling port as described in claim 4, characterized in that, The sealing surface of the injection nozzle is covered with a sealing layer.

Images