Injection molding cylindrical battery structure

Abstract

The invention provides an injection-molded cylindrical battery structure, and relates to the technical field of lithium batteries, the injection-molded cylindrical battery structure comprises a shell, and a positive electrode cover and a negative electrode cover which are mounted at two ends of the shell, annular grooves are formed in side edges of the positive electrode cover and the negative electrode cover, and the positive electrode cover and the negative electrode cover are respectively plugged in corresponding to two ends of the shell; the positive electrode cover and the negative electrode cover get close to each other to extrude the shell so that one part of the shell can be bent into the groove, the positive electrode cover and the negative electrode cover are each provided with an injection molding channel communicated with the groove, and the injection molding channels are used for injecting a solidifiable body to fill an interlayer formed by the groove and the inner wall of the shell; the positive electrode cover and the negative electrode cover are fixed through the bending of the shell, and the gap between the positive electrode cover and the negative electrode cover is filled and sealed by injecting the solidifiable body, so that the production cost of the battery can be reduced in an injection molding manner; according to the invention, short-circuit damage of the battery cell can be handled, and the phenomenon of short-circuit explosion can be prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to an injection-molded cylindrical battery structure. Background Art

[0002] With the development of power lithium batteries in my country, battery technology has been continuously updated and iterated, battery safety requirements have become increasingly higher, and the cost of batteries has gradually decreased. At this stage, the top covers at both ends of the battery are made by laser welding, which has relatively high process requirements and related equipment costs, 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 of battery cell manufacturing process.

[0004] Based on the technical problems existing in the background technology, the present invention proposes an injection-molded cylindrical battery structure, including a shell and a positive electrode cover and a negative electrode cover installed at both ends of the shell, the sides of the positive electrode cover and the negative electrode cover are both provided with annular grooves, the positive electrode cover and the negative electrode cover are respectively inserted into the two ends of the shell, the positive electrode cover and the negative electrode cover are close to each other to squeeze the shell so that a part of the shell is bent into the groove, the positive electrode cover and the negative electrode cover are both provided with an injection channel connected to the groove, and the injection channel is used to inject a solidifiable body to fill the interlayer formed by 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 plate and a first current collecting plate. A first circular groove is provided at the end of the first plug body away from the shell, a first ring gasket with the same diameter as the first circular groove is placed in the first circular groove, the explosion-proof plate is installed in the first circular groove and contacts with 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 a side of the first plug body away from the first circular groove and is connected to the explosion-proof plate through the first hole, and the metal cover is installed on a side of the explosion-proof plate away from the first current collecting plate and is connected to the first current collecting plate.

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

[0007] Preferably, the first focusing plate includes a first plate body and a first connecting column, the first connecting column is located at the center of the first plate body facing the first plug body, the first connecting column passes through the first hole and is welded to the center of the explosion-proof plate, the first plate body is connected to a first supporting foot, and the first supporting foot is in contact with a side of the first plug body away from the metal cover.

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

[0009] Preferably, a plurality of explosion-proof holes are arranged at the bottom of the first plug body, an expansion body is arranged in the explosion-proof hole, and the expansion body is bent toward the first focusing plate.

[0010] Preferably, the negative electrode cover includes a second plug body, a negative electrode sheet and a second current focusing disk, a second circular groove is provided at one end of the second plug body away from the shell, a second ring gasket with the same diameter as the second circular groove is placed in the second circular groove, a second hole penetrating the second plug body is provided at the center of the second plug body, the second current focusing disk is located on a side of the second plug body away from the second circular groove, the second current focusing disk is connected to the negative electrode sheet through the conductive sheet through the second hole, the negative electrode sheet is installed in the second circular groove and contacts with a side of the second ring gasket away from the second current focusing disk, and the negative electrode sheet and the second circular groove can form a placement space for placing the conductive sheet.

[0011] Preferably, the second plug opening is located at the edge of the second circular groove and is provided with a ring-shaped bendable second seal, and the negative electrode sheet is provided with an ring-shaped sealing groove matching the second seal position, and the second seal can be bent into the ring-shaped sealing groove to fix the negative electrode sheet and make the side of the negative electrode cover away from the positive electrode a flat surface.

[0012] Preferably, two bending grooves are provided on the inner walls at both ends of the shell, and one bending groove is provided on the outer walls at both ends of the shell, thereby forming a W-bending area. The positive electrode cover and the negative electrode cover are pressed close to each other to squeeze the W-bending area, so that the W-bending area can bulge into the groove.

[0013] Preferably, the second current collecting plate includes a second plate body and a second connecting column, the second connecting column is located at the center of the second plate body facing the second plug body, the second connecting column passes through the second hole and is welded to the negative electrode sheet through a conductive sheet, the second plate body is connected to a second supporting foot, and the second supporting foot is in contact with a side of the second plug body away from the negative electrode sheet.

[0014] Compared with the prior art, the injection-molded cylindrical battery structure proposed by the present invention adopts the above technical solution and achieves the following technical effects:

[0015] The present invention fixes the positive electrode cover and the negative electrode cover by bending the shell itself, and fills and seals the gap between the electrode cover and the shell by injecting a solidifiable solid. The present invention can reduce the cost of battery production by injection molding; the present invention can cope with short-circuit damage to the battery cell and prevent short-circuit explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of the positive electrode cover and the negative electrode cover of the battery of the present invention before being fixed;

[0017] Figure 2 It is a cross-sectional view of the battery of the present invention after the positive electrode cover and the negative electrode cover are fixed;

[0018] Figure 3It is a schematic diagram of the exploded positive electrode cover of the present invention;

[0019] Figure 4 It is a schematic diagram of the decomposition of the negative electrode cover of the present invention;

[0020] Figure 5 It is a schematic diagram of the W bending zone of the present invention before bending;

[0021] Figure 6 It is a schematic diagram of the W bending zone of the present invention after bending.

[0022] In the figure: 1. shell; 2. positive electrode cover; 3. negative electrode cover; 4. groove; 5. injection molding channel; 21. first plug body; 22. metal cover; 23. explosion-proof plate; 24. first current collecting plate; 211. first circular groove; 25. first ring gasket; 212. first hole; 213. first seal; 241. first disk body; 242. first connecting column; 243. first supporting foot; 26. clamping groove; 214. explosion-proof hole; 215. expansion body; 31. second plug body; 32. negative electrode plate; 33. second current collecting plate; 311. second circular groove; 312. second ring gasket; 313. second hole; 314. conductive plate; 315. second seal; 321. annular sealing groove; 101. bending groove; 102. W bending area; 331. second disk body; 332. second connecting column; 333. second supporting foot. DETAILED DESCRIPTION

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] Example

[0026] Please refer to Figures 1 to 6 The present invention proposes an injection-molded cylindrical battery structure, comprising a shell 1 and a positive electrode cover 2 and a negative electrode cover 3 installed at both ends of the shell 1. The sides of the positive electrode cover 2 and the negative electrode cover 3 are both provided with an annular groove 4, and the positive electrode cover 2 and the negative electrode cover 3 are respectively inserted into the two ends of the shell 1, and the positive electrode cover 2 and the negative electrode cover 3 are close to each other to squeeze the shell 1 so that a part of the shell 1 is bent into the groove 4. The positive electrode cover 2 and the negative electrode cover 3 are both provided with an injection channel 5 connected to the groove 4, and the injection channel 5 is used to inject a solidifiable solid to fill the interlayer formed by the groove 4 and the inner wall of the shell 1; in this scheme, a pole roll can be loaded into the shell 1, and the two ends of the pole roll are respectively in contact with the positive electrode cover 2 and the negative electrode cover 3, and the whole When manufacturing a battery, the positive electrode cover 2 and the negative electrode cover 3 are inserted into the two ends, and the two electrode covers are squeezed to make the two ends of the shell 1 collapse. The collapsed area will bend into the grooves 4 of the two electrode covers, so that the two electrode covers can be confined in the shell 1. There will be an interlayer between the inner wall of the shell 1 and the groove 4, which will make the two electrode covers and the shell 1 unstable. At this time, the dissolved plastic is injected into the injection channel 5 to fill the groove 4, or other solidifiable substances. After filling, the electrode covers can be prevented from shaking on the shell 1. When the filled plastic solidifies, the interlayer can be closed and the separation of the electrode covers and the shell 1 can be limited, which can be 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 plate 23 and a first flow collecting disk 24. A first circular groove 211 is provided at the end of the first plug body 21 away from the shell 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 plate 23 is installed in the first circular groove 211 and contacts the top of the first ring gasket 25. A first hole 212 that penetrates the first plug body 21 is provided at the center of the first plug body 21. The first flow collecting disk 24 is located on a side of the first plug body 21 away from the first circular groove 211 and is connected to the explosion-proof plate 23 through the first hole 212. The metal cover 22 is installed on a side of the explosion-proof plate 23 away from the first flow collecting disk 24 and is connected to the first flow collecting disk 24.

[0028] In the above scheme, the positive electrode cover 2 plays a role of safety protection. In the present application, the first ring gasket 25 is used to raise the explosion-proof plate 23 so that the explosion-proof plate 23 has a certain distance from the bottom of the first circular groove 211, and the explosion-proof plate 23 can be deformed. Under normal circumstances, the center of the explosion-proof plate 23 will be connected to the center of the first current collecting disk 24 for conduction; after the pole roll is placed in the shell, the end will have a plurality of folded pole pieces, which can be gathered and conducted through the current collecting disk and directed to the explosion-proof plate 23, the edge of the metal cover 22 is connected to the edge of the explosion-proof plate 23, and a space will be reserved between the middle of the metal cover 22 and the explosion-proof plate 23 To provide space for the explosion-proof plate 23 to deform, a plurality of explosion-proof holes 214 are arranged at the bottom of the first plug body 21, and an expansion body 215 is arranged in the explosion-proof hole 214. Under normal circumstances, the expansion body 215 bends toward the first focusing disk 24. When a short circuit occurs in the battery, gas will be generated and expanded inside the shell 1. At this time, the expansion body 215 will deform outward from the battery, and the expansion body 215 will push out of the explosion-proof hole 214 and push the explosion-proof plate 23. At this time, the welding point between the explosion-proof plate 23 and the focusing disk will be desoldered or detached, which can prevent the focusing disk and the explosion-proof plate 23 from conducting electricity, thereby preventing the battery 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 body 21 is located at the edge of the first circular groove 211 and is provided with a first annular bendable seal 213. The first seal 213 can be bent to contact the upper surface of the metal cover 22. In this solution, it is not enough to fix the metal cover 22 in the first circular groove 211. By bending the first seal 213, a sealing edge can be provided above 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 central part of the metal cover 22 by means of rivets.

[0030] In a specific embodiment, refer to Figure 1 , Figure 3The first flow collecting plate 24 includes a first plate body 241 and a first connecting column 242. The first connecting column 242 is located at the center of the first plate body 241 facing the first plug body 21 and is connected. The first connecting column 242 passes through the first hole 212 and is welded to the center of the explosion-proof plate 23. The first plate body 241 is connected to a first supporting foot 243. The first supporting foot 243 abuts against the side of the first plug body 21 away from the metal cover 22. In this solution, the first plate body 241 of the first flow collecting plate 24 is used to abut against the positive electrode of the pole coil. The connecting column in the center of the first disk body 241 is used to connect to the center of the explosion-proof plate 23 by electric welding. When necessary, the expansion body 215 can easily push the explosion-proof plate 23 out of the connection with the connecting column; when the first plug body 21 squeezes the first focusing disk 24 toward the pole roll, the first disk body 241 will contact the positive pole of the pole roll. When the squeezing continues, the first supporting leg 243 will be deformed, which has a certain thrust effect on the first disk body 241, and can improve the stability of the contact between the first disk body 241 and the positive pole of the pole roll.

[0031] In a specific embodiment, refer to Figure 2 , Figure 3 The explosion-proof piece 23 is bowl-shaped, and its opening faces the metal cover 22. The outer circle of the explosion-proof piece 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 scheme, the shape of the explosion-proof piece 23 is similar to the eardrum. The center of the explosion-proof piece 23 can move along the central axis of the explosion-proof piece 23 to produce deformation. The interior of the battery is usually in a constant pressure state and will not deform. Only when the gas expansion is generated inside the battery, the expansion body 215 pushes the explosion-proof piece 23, which can make the explosion-proof piece 23 detach from the connection with the connecting column.

[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 sheet 32 ​​and a second current collecting disk 33. The second plug body 31 is provided with a second circular groove 311 at one end away from the shell 1. A second ring gasket 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 body 31 is provided at the center of the second plug body 31. The second current collecting disk 33 is located on a side of the second plug body 31 away from the second circular groove 311. The second current collecting disk 33 passes through the second hole 313 and is connected to the negative electrode sheet 32 ​​through the conductive sheet 314. The negative electrode sheet 32 ​​is installed in the second circular groove 311 and connected to the second The annular gasket 312 contacts one side away from the second current collecting disk 33, and the negative electrode sheet 32 ​​and the second circular groove 311 can form a placement space for the conductive sheet 314; in the present scheme, the second plug body 31 is installed at the negative end of the pole coil corresponding to the shell 1, and the effect of the second current collecting disk 33 is the same as that of the first current collecting disk 24, which is used to connect with the negative pole of the pole coil. The second current collecting disk 33 is connected to the negative electrode sheet 32 ​​through a folded conductive sheet 314, which provides more operating space for the installation of the negative pole and can facilitate the installation of the negative electrode sheet 32. In the present application, the negative pole of the entire battery can be inserted into the pole coil for installation and sealing.

[0033] In a specific embodiment, refer to Figure 1 , Figure 2 , Figure 4 The opening of the second plug body 31 is located at the edge of the second circular groove 311 and is provided with a ring-shaped bendable second seal 315. The negative electrode sheet 32 ​​is provided with an annular sealing groove 321 matching the second seal 315. The second seal 315 can be bent into the annular sealing groove 321 to fix the negative electrode sheet 32 ​​and make the side of the negative electrode cover 3 away from the positive electrode a plane. In this scheme, 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 sheet 32. After the second seal 315 is bent, it can fix the negative electrode sheet 32 ​​in the annular sealing groove 321 and keep the bottom of the negative electrode sheet 32 ​​in a complete plane, which is convenient for the installation and use of the entire battery.

[0034] In a specific embodiment, refer to Figure 5 , Figure 6 , 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, and the positive electrode cover 2 and the negative electrode cover 3 are close to each other to squeeze the W-bending area 102, so that the W-bending area 102 can be protruded into the groove 4; in this scheme, when the positive electrode cover 2 and the negative electrode cover 3 are squeezed against each other, the entire pressure will act on the shell 1, and bending and folding will occur at the bending groove 101, and the W-bending area 102 will protrude partly into the shell 1 and just in the groove 4, which can realize the limitation of the positive electrode cover 2 and the negative electrode cover 3, and then by injecting a solidifiable body 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 converging disk 33 includes a second disk body 331 and a second connecting column 332. The second connecting column 332 is located at the center of the second disk body 331 facing the second plug body 31 and is connected. The second connecting column 332 passes through the second hole 313 and is welded to the negative electrode sheet 32 ​​through the conductive sheet 314. The second disk body 331 is connected with a second supporting foot 333. The second supporting foot 333 is in conflict with the side of the second plug body 31 away from the negative electrode sheet 32. In this solution, the second current converging disk 33 has the same function as the first current converging disk 24, and is used for the negative electrode current converging connection of the pole roll.

[0036] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An injection-molded cylindrical battery structure, characterized in that: The invention comprises a shell (1) and a positive electrode cover (2) and a negative electrode cover (3) mounted at both ends of the shell (1); the sides of the positive electrode cover (2) and the negative electrode cover (3) are both provided with an annular groove (4); the positive electrode cover (2) and the negative electrode cover (3) are respectively inserted into the two ends of the shell (1); the positive electrode cover (2) and the negative electrode cover (3) are mutually pressed to extrude the shell (1) so that a part of the shell (1) is bent into the groove (4); the positive electrode cover (2) and the negative electrode cover (3) are both provided with an injection channel (5) connected to the groove (4); the injection channel (5) is used to inject a solidifiable solid to fill the interlayer formed by the groove (4) and the inner wall of the shell (1).

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

3. The injection-molded cylindrical battery structure according to claim 2, characterized in that: An annular bendable first seal strip (213) is arranged at the edge of the first circular groove (211) where the opening of the first plug body (21) is located. The first seal strip (213) can be bent to contact the upper surface of the metal cover (22).

4. The injection-molded cylindrical battery structure according to claim 2, characterized in that: The first concentrating disk (24) comprises a first disk body (241) and a first connecting column (242). The first connecting column (242) is located at the center of the first disk body (241) facing the first plug body (21) and is connected. The first connecting column (242) passes through the first hole (212) and is welded to the center of the explosion-proof disk (23). The first disk body (241) is connected to a first supporting leg (243), and the first supporting leg (243) is in contact with a 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 disc (23) is bowl-shaped, and its opening faces the metal cover (22). The outer ring of the explosion-proof disc (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.

6. The injection-molded cylindrical battery structure according to claim 2, characterized in that: A plurality of explosion-proof holes (214) are arranged at the bottom of the first plug body (21), and an expansion body (215) is arranged inside the explosion-proof hole (214), and the expansion body (215) is bent toward the first focusing plate (24).

7. The injection-molded cylindrical battery structure according to claim 1, characterized in that: The negative electrode cover (3) comprises a second plug body (31), a negative electrode sheet (32) and a second current collecting plate (33); a second circular groove (311) is arranged at one end of the second plug body (31) away from the housing (1); a second ring gasket (312) having 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 body (31) is arranged at the center of the second plug body (31); and the second current collecting plate (33) is provided with a second circular groove (311). Located on a 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 the conductive sheet (314). The negative electrode plate (32) is installed in the second circular groove (311) and contacts with a side of the second ring gasket (312) away from the second current collecting plate (33). The negative electrode plate (32) and the second circular groove (311) can form a placement space for placing the conductive sheet (314).

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

9. The injection-molded cylindrical battery structure according to claim 1, characterized in that: Two bending grooves (101) are arranged on the inner walls at both ends of the shell (1), and one bending groove (101) is arranged 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) are brought close to each other to press the W-bending area (102), so that the W-bending area (102) can be protruded into the groove (4).

10. The injection-molded cylindrical battery structure according to claim 7, characterized in that: The second current collecting disk (33) comprises a second disk body (331) and a second connecting column (332). The second connecting column (332) is located at the center of the second disk body (331) and connected to the side facing the second plug body (31). The second connecting column (332) passes through the second hole (313) and is welded to the negative electrode sheet (32) via a conductive sheet (314). The second disk body (331) is connected to a second supporting foot (333), and the second supporting foot (333) contacts the side of the second plug body (31) away from the negative electrode sheet (32).

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