Injection molded cylindrical battery structure

Abstract

This invention proposes an injection-molded cylindrical battery structure, relating to the technical field of lithium batteries. It includes a casing and positive and negative electrode caps installed at both ends of the casing. Both the positive and negative electrode caps have annular grooves on their sides. The positive and negative electrode caps are inserted into the casing at their respective ends. The positive and negative electrode caps approach each other, pressing the casing and causing a portion of the casing to bend into the grooves. Both the positive and negative electrode caps have injection channels communicating with the grooves. These channels are used to inject a solidifiable solid to fill the gap formed between the groove and the inner wall of the casing. This invention fixes the positive and negative electrode caps by bending the casing itself and fills and seals the gap between the electrode caps and the casing by injecting a solidifiable solid. This invention reduces battery production costs through injection molding. This invention can cope with short-circuit damage to the battery cell and prevent short-circuit explosions.

Description

Technical Field

[0001] This invention relates to the technical field of lithium batteries, and more particularly to an injection-molded cylindrical battery structure. Background Technology

[0002] With the development of power lithium batteries in my country, battery technology is constantly being updated and iterated, and battery safety requirements are becoming increasingly stringent. As a result, battery costs are gradually decreasing. Currently, the top covers at both ends of the battery are made by laser welding, which has relatively high process requirements and associated equipment costs, thus affecting the cost of battery production. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an injection-molded cylindrical battery structure to solve the problem of high cost in battery cell manufacturing process.

[0004] Based on the technical problems existing in the background art, the present invention proposes an injection-molded cylindrical battery structure, including a shell and a positive electrode cap and a negative electrode cap installed at both ends of the shell. The positive electrode cap and the negative electrode cap are provided with annular grooves on their sides. The positive electrode cap and the negative electrode cap are inserted into the shell at their respective ends. The positive electrode cap and the negative electrode cap approach each other and squeeze the shell, causing a part of the shell to bend into the groove. The positive electrode cap and the negative electrode cap are provided with injection channels that communicate with the grooves. The injection channels are used to inject solidifiable solids to fill the interlayer formed between the groove and the inner wall of the shell.

[0005] Preferably, the positive electrode cover includes a first plug body, a metal cover, an explosion-proof sheet, and a first current-collecting plate. The first plug body has a first circular groove at the end away from the housing. A first ring gasket with the same diameter as the first circular groove is placed in the first circular groove. The explosion-proof sheet is installed in the first circular groove and contacts the top of the first ring gasket. A first hole penetrating the first plug body is provided at the center of the first plug body. The first current-collecting plate is located on the side of the first plug body away from the first circular groove and passes through the first hole to connect with the explosion-proof sheet. The metal cover is installed on the side of the explosion-proof sheet away from the first current-collecting plate and is connected to the first current-collecting plate.

[0006] Preferably, the opening of the first plug is provided with an annular, bendable first seal at the edge of the first circular groove, and the first seal can be bent to abut against the upper surface of the metal cover.

[0007] Preferably, the first concentrator includes a first disc body and a first connecting post. The first connecting post is located at the center of the side of the first disc body facing the first plug body. The first connecting post passes through the first hole and is welded to the center of the explosion-proof sheet. The first disc body is connected to a first support foot, and the first support foot abuts against the side of the first plug body away from the metal cover.

[0008] Preferably, the explosion-proof sheet is bowl-shaped with its opening facing the metal cover. The outer ring of the explosion-proof sheet is bent to form a clamping groove with the inner wall of the first circular groove. The metal cover is bent and then embedded into the clamping groove for installation.

[0009] Preferably, the bottom of the first plug is provided with multiple explosion-proof holes, and an expansion body is provided inside the explosion-proof holes, with the expansion body bending toward the first flow-gathering plate.

[0010] Preferably, the negative electrode cover includes a second plug, a negative electrode plate, and a second current-collecting plate. The end of the second plug away from the housing is provided with a second circular groove. A second annular pad with the same diameter as the second circular groove is placed in the second circular groove. A second hole penetrating the second plug is provided at the center of the second plug. The second current-collecting plate is located on the side of the second plug away from the second circular groove. The second current-collecting plate passes through the second hole and is connected to the negative electrode plate through a conductive plate. The negative electrode plate is installed in the second circular groove and contacts the side of the second annular pad away from the second current-collecting plate. The negative electrode plate and the second circular groove can form a placement space for placing the conductive plate.

[0011] Preferably, the second plug opening is provided with an annular, bendable second seal at the edge of the second circular groove, and the negative electrode sheet is provided with an annular sealing groove that matches the second seal. The second seal can be bent into the annular sealing groove to fix the negative electrode sheet, and the side of the negative electrode cover away from the positive electrode is flat.

[0012] Preferably, the inner walls at both ends of the shell are provided with two bending grooves, and the outer walls at both ends of the shell are provided with one bending groove, thereby forming a W bending area. When the positive electrode cover and the negative electrode cover approach each other and press the W bending area, the W bending area can be made to bulge into the groove.

[0013] Preferably, the second current collector includes a second disk body and a second connecting post. The second connecting post is located at the center of the side of the second disk body facing the second plug body. The second connecting post passes through the second hole and is welded to the negative electrode plate through a conductive sheet. The second disk body is connected to a second support foot, and the second support foot abuts against the side of the second plug body away from the negative electrode plate.

[0014] Compared with existing technologies, the injection-molded cylindrical battery structure proposed in this invention, employing the above-mentioned technical solution, achieves the following technical effects:

[0015] This invention fixes the positive and negative electrode caps by bending the shell itself, and fills and seals the gap between the electrode caps and the shell by injecting a solid that can solidify. This invention can reduce the cost of battery production through injection molding. This invention can cope with short circuit damage to the battery cell and prevent short circuit explosions. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the battery of the present invention before the positive and negative electrode caps are fixed.

[0017] Figure 2 This is a cross-sectional view of the battery of the present invention after the positive electrode cap and the negative electrode cap are fixed.

[0018] Figure 3This is an exploded view of the positive electrode cap of the present invention;

[0019] Figure 4 This is an exploded view of the negative electrode cap of the present invention;

[0020] Figure 5 This is a schematic diagram of the W-bending area before bending according to the present invention;

[0021] Figure 6 This is a schematic diagram of the W-bending area after bending according to the present invention.

[0022] In the diagram: 1. Shell; 2. Positive electrode cap; 3. Negative electrode cap; 4. Groove; 5. Injection channel; 21. First plug; 22. Metal cap; 23. Explosion-proof plate; 24. First current-collecting plate; 211. First circular groove; 25. First annular gasket; 212. First hole; 213. First seal; 241. First disc; 242. First connecting post; 243. First support foot; 26. Clamping groove; 214. Explosion-proof hole; 215. Expansion body; 31. Second plug; 32. Negative electrode plate; 33. Second current-collecting plate; 311. Second circular groove; 312. Second annular gasket; 313. Second hole; 314. Conductive plate; 315. Second seal; 321. Annular sealing groove; 101. Bending groove; 102. W-bending area; 331. Second disc; 332. Second connecting post; 333. Second support foot. Detailed Implementation

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] Example

[0026] Please refer to Figures 1 to 6 This invention proposes an injection-molded cylindrical battery structure, including a housing 1 and positive electrode caps 2 and negative electrode caps 3 installed at both ends of the housing 1. Both the positive electrode caps 2 and 3 have annular grooves 4 on their sides. The positive electrode caps 2 and 3 are inserted into the housing 1 at their respective ends. The positive electrode caps 2 and 3 approach each other, pressing the housing 1 so that a portion of the housing 1 bends into the grooves 4. Both the positive electrode caps 2 and 3 have injection channels 5 communicating with the grooves 4. The injection channels 5 are used to inject a solidifiable substance to fill the interlayer formed between the grooves 4 and the inner wall of the housing 1. In this design, electrode rolls can be inserted into the housing 1, with both ends of the electrode rolls contacting the positive electrode caps 2 and 3, respectively. During battery manufacturing, the positive electrode cap 2 and the negative electrode cap 3 are inserted into both ends. By squeezing the two electrode caps, the two ends of the casing 1 collapse. The collapsed areas bend into the grooves 4 of the two electrode caps, allowing the two electrode caps to be confined within the casing 1. There will be a layer between the inner wall of the casing 1 and the grooves 4, which may cause instability between the two electrode caps and the casing 1. At this time, molten plastic or other solidifiable substances are injected into the injection channel 5 to fill the grooves 4. After filling, it can prevent the electrode caps from shaking on the casing 1. When the filled plastic solidifies, it can seal the layer and limit the separation of the electrode caps from the casing 1, making it more stable.

[0027] In a specific embodiment, refer to Figure 1 , Figure 2 , Figure 3 The positive electrode cover 2 includes a first plug body 21, a metal cover 22, an explosion-proof sheet 23, and a first current-concentrating plate 24. The first plug body 21 has a first circular groove 211 at the end away from the housing 1. A first ring gasket 25 with the same diameter as the first circular groove 211 is placed in the first circular groove 211. The explosion-proof sheet 23 is installed in the first circular groove 211 and contacts the top of the first ring gasket 25. A first hole 212 is provided at the center of the first plug body 21, penetrating the first plug body 21. The first current-concentrating plate 24 is located on the side of the first plug body 21 away from the first circular groove 211 and passes through the first hole 212 to connect with the explosion-proof sheet 23. The metal cover 22 is installed on the side of the explosion-proof sheet 23 away from the first current-concentrating plate 24 and is connected to the first current-concentrating plate 24.

[0028] In the above scheme, the positive electrode cover 2 serves as a safety protection function. In this application, the first ring gasket 25 is used to elevate the explosion-proof sheet 23, so that there is a certain gap between the explosion-proof sheet 23 and the bottom of the first circular groove 211. The explosion-proof sheet 23 can deform. Under normal conditions, the center of the explosion-proof sheet 23 will connect with the center of the first current-collecting plate 24 to conduct electricity. After the electrode roll is placed inside the shell, the end will have multiple folded electrode pieces. The electrode pieces can be concentrated and conducted to the explosion-proof sheet 23 through the current-collecting plate. The edge of the metal cover 22 is connected to the edge of the explosion-proof sheet 23, and a gap is reserved between the middle of the metal cover 22 and the explosion-proof sheet 23. The space for the deformation of the explosion-proof sheet 23 is provided. Multiple explosion-proof holes 214 are provided at the bottom of the first plug body 21. An expansion body 215 is provided in the explosion-proof hole 214. Under normal conditions, the expansion body 215 bends toward the first current-collecting plate 24. When the battery is short-circuited, gas will be generated inside the casing 1 and expand. At this time, the expansion body 215 will deform toward the outside of the battery. The expansion body 215 will push out of the explosion-proof hole 214 and push the explosion-proof sheet 23. At this time, the welding point between the explosion-proof sheet 23 and the current-collecting plate will detach or separate, which can prevent the current-collecting plate and the explosion-proof sheet 23 from conducting electricity, thereby preventing the cell from continuing to short-circuit.

[0029] In a specific embodiment, refer to Figure 1 , Figure 2 , Figure 3 The opening of the first plug 21 is located at the edge of the first circular groove 211 and is provided with an annular bendable first seal 213. The first seal 213 can be bent to abut against the upper surface of the metal cover 22. In this solution, the metal cover 22 is not enough to achieve a fixed function by placing it in the first circular groove 211. By bending the first seal 213, a sealing edge can be set on the top of the metal cover 22 and the metal cover 22 can be fastened in the first circular groove 211. Furthermore, a positive electrode is installed in the center part of the metal cover 22 by means of rivets.

[0030] In a specific embodiment, refer to Figure 1 , Figure 3The first concentrator 24 includes a first disc body 241 and a first connecting post 242. The first connecting post 242 is located at the center of the side of the first disc body 241 facing the first plug 21 and is connected to the center of the explosion-proof sheet 23 through the first hole 212. The first disc body 241 is connected to a first support foot 243, which abuts against the side of the first plug 21 away from the metal cover 22. In this scheme, the first disc body 241 of the first concentrator 24 is used to abut against the positive electrode of the electrode roll. The connecting post at the center of the first disc 241 is used to connect with the center of the explosion-proof sheet 23 by electric welding. When necessary, the expansion body 215 can easily push the explosion-proof sheet 23 to detach from the connection post. When the first plug 21 squeezes the first concentrator 24 towards the electrode roll, the first disc 241 will come into contact with the positive electrode of the electrode roll. When the squeezing continues, the first support foot 243 will deform and exert a certain thrust on the first disc 241, which can improve the stability of the contact between the first disc 241 and the positive electrode of the electrode roll.

[0031] In a specific embodiment, refer to Figure 2 , Figure 3 The explosion-proof plate 23 is bowl-shaped with its opening facing the metal cover 22. The outer ring of the explosion-proof plate 23 is bent to form a clamping groove 26 with the inner wall of the first circular groove 211. The metal cover 22 is bent and embedded in the clamping groove 26 for installation. In this solution, the explosion-proof plate 23 is shaped like a diaphragm. The center of the explosion-proof plate 23 can move along the central axis of the explosion-proof plate 23 to generate deformation. The inside of the battery is usually in a constant pressure state and will not deform. Only when the gas inside the battery expands, when the expansion body 215 pushes the explosion-proof plate 23, the explosion-proof plate 23 can be disengaged from the connection with the connecting post.

[0032] In a specific embodiment, refer to Figure 1 , Figure 2 , Figure 4The negative electrode cover 3 includes a second plug body 31, a negative electrode plate 32, and a second current-collecting plate 33. A second circular groove 311 is provided at the end of the second plug body 31 away from the housing 1. A second annular gasket 312 with the same diameter as the second circular groove 311 is placed inside the second circular groove 311. A second hole 313 penetrating the second plug body 31 is provided at the center of the second plug body 31. The second current-collecting plate 33 is located on the side of the second plug body 31 away from the second circular groove 311. The second current-collecting plate 33 passes through the second hole 313 and is connected to the negative electrode plate 32 via a conductive sheet 314. The negative electrode plate 32 is installed in the second circular groove 311 and connected to the second... The side of the ring pad 312 away from the second current-collecting disk 33 is in contact, and the negative electrode sheet 32 ​​and the second circular groove 311 can form a placement space for placing the conductive sheet 314. In this scheme, the second plug 31 is installed on the negative end of the corresponding electrode roll of the housing 1. The effect of the second current-collecting disk 33 is the same as that of the first current-collecting disk 24. It is used to connect with the negative electrode of the electrode roll. The second current-collecting disk 33 and the negative electrode sheet 32 ​​are connected by the folded conductive sheet 314, which provides more operating space for the installation of the negative electrode and facilitates the installation of the negative electrode sheet 32. In this application, the electrode roll can be inserted from the negative electrode of the entire battery for installation and sealing.

[0033] In a specific embodiment, refer to Figure 1 , Figure 2 , Figure 4 The second plug 31 has an opening located at the edge of the second circular groove 311, and is provided with an annular, bendable second seal 315. The negative electrode 32 is provided with an annular sealing groove 321 that matches the second seal 315. The second seal 315 can be bent into the annular sealing groove 321 to fix the negative electrode 32, and make the side of the negative electrode cover 3 away from the positive electrode flat. In this solution, the function of the second seal 315 is the same as that of the first seal 213. The second seal 315 is used to seal the negative electrode 32. After the second seal 315 is bent, it can be fixed in the annular sealing groove 321 to secure the negative electrode 32, and can also keep the bottom of the negative electrode 32 in a complete flat plane, which facilitates the installation and use of the entire battery.

[0034] In a specific embodiment, refer to Figure 5 , Figure 6 The inner walls at both ends of the housing 1 are provided with two bending grooves 101, and the outer walls at both ends of the housing 1 are provided with one bending groove 101, thus forming a bending area 102. When the positive electrode cover 2 and the negative electrode cover 3 approach each other and press against the bending area 102, the bending area 102 can be made to bulge into the groove 4. In this solution, when the positive electrode cover 2 and the negative electrode cover 3 press against each other, the entire pressure will act on the housing 1, and bending and folding will occur at the bending groove 101. The bending area 102 will bulge into the housing 1 and be exactly in the groove 4, which can limit the position of the positive electrode cover 2 and the negative electrode cover 3. Then, by injecting a solidifiable solid to fill the gap area, a low-cost fixing effect can be achieved.

[0035] In a specific embodiment, refer to Figure 1 , Figure 2 , Figure 4 The second current-collecting disk 33 includes a second disk body 331 and a second connecting post 332. The second connecting post 332 is located at the center of the side of the second disk body 331 facing the second plug body 31 and is connected to it. The second connecting post 332 passes through the second hole 313 and is welded to the negative electrode plate 32 through a conductive sheet 314. The second disk body 331 is connected to a second support foot 333, which abuts against the side of the second plug body 31 away from the negative electrode plate 32. In this solution, the second current-collecting disk 33 has the same function as the first current-collecting disk 24, and it is used for the negative electrode current-collecting connection of the electrode roll.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A structure for an injection-molded cylindrical battery, characterized in that, Includes a shell (1) and a positive electrode cap (2) and a negative electrode cap (3) installed at both ends of the shell (1). Both the positive electrode cap (2) and the negative electrode cap (3) have annular grooves (4) on their sides. The positive electrode cap (2) and the negative electrode cap (3) are inserted into the shell (1) respectively. The positive electrode cap (2) and the negative electrode cap (3) approach each other and squeeze the shell (1) so that a part of the shell (1) bends into the groove (4). Both the positive electrode cap (2) and the negative electrode cap (3) have injection channels (5) that connect to the groove (4). The injection channels (5) are used to inject solids to fill the interlayer formed between the groove (4) and the inner wall of the shell (1). Two bending grooves (101) are provided on the inner walls at both ends of the shell (1), and one bending groove (101) is provided on the outer walls at both ends of the shell (1), thereby forming a W bending area (102). The positive electrode cover (2) and the negative electrode cover (3) approach each other and squeeze the W bending area (102), which can cause the W bending area (102) to bulge into the groove (4).

2. The injection-molded cylindrical battery structure according to claim 1, characterized in that, The positive electrode cover (2) includes a first plug body (21), a metal cover (22), an explosion-proof plate (23), and a first current-collecting plate (24). The first plug body (21) has a first circular groove (211) at one end away from the shell (1). A first ring pad (25) with the same diameter as the first circular groove (211) is placed in the first circular groove (211). The explosion-proof plate (23) is installed in the first circular groove (211) and contacts the top of the first ring pad (25). A first hole (212) penetrating the first plug body (21) is provided at the center of the first plug body (21). The first current-collecting plate (24) is located on the side of the first plug body (21) away from the first circular groove (211) and passes through the first hole (212) to connect with the explosion-proof plate (23). The metal cover (22) is installed on the side of the explosion-proof plate (23) away from the first current-collecting plate (24) and is connected with the first current-collecting plate (24).

3. The injection-molded cylindrical battery structure according to claim 2, characterized in that, The opening of the first plug (21) is located at the edge of the first circular groove (211) and is provided with an annular bendable first seal (213). The first seal (213) can be bent to abut the upper surface of the metal cover (22).

4. The injection-molded cylindrical battery structure according to claim 2, characterized in that, The first concentrator (24) includes a first disc body (241) and a first connecting post (242). The first connecting post (242) is located at the center of the side of the first disc body (241) facing the first plug body (21). The first connecting post (242) passes through the first hole (212) and is welded to the center of the explosion-proof plate (23). The first disc body (241) is connected to a first support foot (243). The first support foot (243) abuts against the side of the first plug body (21) away from the metal cover (22).

5. The injection-molded cylindrical battery structure according to claim 2, characterized in that, The explosion-proof plate (23) is bowl-shaped and the opening faces the metal cover (22). The outer ring of the explosion-proof plate (23) is bent and forms a clamping groove (26) with the inner wall of the first circular groove (211). The metal cover (22) is bent and embedded in the clamping groove (26) for installation.

6. The injection-molded cylindrical battery structure according to claim 2, characterized in that, The bottom of the first plug (21) is provided with multiple explosion-proof holes (214), and an expansion body (215) is provided inside the explosion-proof hole (214). The expansion body (215) bends toward the first flow-gathering plate (24).

7. The injection-molded cylindrical battery structure according to claim 1, characterized in that, The negative electrode cover (3) includes a second plug (31), a negative electrode plate (32), and a second current-collecting plate (33). The second plug (31) has a second circular groove (311) at one end away from the shell (1). A second ring pad (312) with the same diameter as the second circular groove (311) is placed in the second circular groove (311). A second hole (313) penetrating the second plug (31) is provided at the center of the second plug (31). The second current-collecting plate (33) is located on the side of the second plug (31) away from the second circular groove (311). The second current-collecting plate (33) passes through the second hole (313) and is connected to the negative electrode plate (32) through the conductive plate (314). The negative electrode plate (32) is installed in the second circular groove (311) and contacts the side of the second ring pad (312) away from the second current-collecting plate (33). The negative electrode plate (32) and the second circular groove (311) can form a space for placing the conductive plate (314).

8. The injection-molded cylindrical battery structure according to claim 7, characterized in that, The second plug (31) has an opening located at the edge of the second circular groove (311) and is provided with an annular bendable second seal (315). The negative electrode (32) is provided with an annular sealing groove (321) that matches the second seal (315). The second seal (315) can be bent into the annular sealing groove (321) to fix the negative electrode (32) and make the side of the negative electrode cover (3) away from the positive electrode flat.

9. The injection-molded cylindrical battery structure according to claim 7, characterized in that, The second current collector (33) includes a second plate (331) and a second connecting post (332). The second connecting post (332) is located at the center of the side of the second plate (331) facing the second plug (31). The second connecting post (332) passes through the second hole (313) and is welded to the negative electrode plate (32) through a conductive sheet (314). The second plate (331) is connected to a second support foot (333). The second support foot (333) abuts against the side of the second plug (31) away from the negative electrode plate (32).

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