Open formation cap

Abstract

The utility model relates to the technical field of lithium ion batteries, and discloses an opening formation cap which comprises a ring-shaped outer wrapping ring and a conducting ring, the conducting ring is fixed on the inner side of the outer wrapping ring through a sealing ring, the middle of the conducting ring is provided with an upper through hole, the bottom of the conducting ring abuts against an insulating sheet, and the middle of the insulating sheet is provided with a lower through hole. A connecting piece is tightly attached to the bottom of the insulating piece, a vent hole is formed in the connecting piece, and the vent hole is connected with the upper through hole through a lower through hole; the cap is used for conveniently discharging gas generated in the formation process through the upper through hole, so that opening formation can be realized, the gas pressure in the battery cell is reduced, and meanwhile, the negative influence on the electrical property caused by gas generated in the battery cell is reduced; the connecting piece is communicated with the upper through hole through the vent hole, so that gas generated in the battery cell in the formation process is discharged to the outside through the vent hole in the connecting piece and the upper through hole of the conducting ring, and the problem that gas generated in the formation of the cylindrical lithium ion battery cannot be discharged is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to an open formation cap. Background Art

[0002] As the energy density of lithium-ion batteries continues to increase, high-nickel positive electrode materials and silicon-based negative electrode materials have become the preferred options for improving energy density; the structural characteristics of cylindrical batteries with uniform stress make them the preferred battery cell structure for high-nickel positive electrodes with silicon-based negative electrodes; on the other hand, with the high residual alkali content of high-nickel positive electrode materials and the repeated film formation of SEI films on silicon-based negative electrodes, the gas production problem of high-nickel positive electrode materials and silicon-based negative electrode materials is inevitable in the preparation process of lithium-ion batteries.

[0003] The hard shell structure of cylindrical batteries can alleviate the volume change caused by gas production to a certain extent. Square batteries can be formed by opening the battery, and soft-pack batteries can be formed by cutting off the airbag to discharge most of the gas generated during the formation process. However, the existing process route of one-time liquid injection and sealing of cylindrical batteries cannot reduce gas production or alleviate the negative impact caused by gas production. Utility Model Content

[0004] The utility model aims to provide an open formation cap, aiming to solve the problem in the prior art that the gas produced by the formation of a cylindrical lithium ion battery cannot be discharged.

[0005] The utility model is implemented as follows: an open chemical cap comprises a ring-shaped outer ring and a conductive ring, wherein the conductive ring is fixed on the inner side of the outer ring through a sealing ring, and the sealing ring is arranged around the outer side of the conductive ring, wherein the middle part of the conductive ring has an upper through hole, and the bottom of the conductive ring abuts against an insulating sheet, wherein the insulating sheet is arranged in a ring shape, and the middle part of the insulating sheet has a lower through hole, and the bottom of the insulating sheet is tightly fitted with a connecting sheet, and the insulating sheet is fixed to the bottom of the conductive ring through the connecting sheet, and a vent hole is opened on the connecting sheet, and the vent hole is connected to the upper through hole through the lower through hole; a top cover is welded on the conductive ring, and the top cover is sealed on the upper through hole.

[0006] Furthermore, the outer peripheral edge of the connecting piece has a plurality of welding points extending toward the conductive ring, the plurality of welding points are arranged around and spaced along the outer peripheral edge of the connecting piece, and the connecting piece is welded to the conductive ring through the welding points.

[0007] Furthermore, the diameter of the upper through hole of the conductive ring is consistent with the diameter of the lower through hole of the insulating sheet.

[0008] Furthermore, the diameter of the insulating sheet is smaller than the diameter of the connecting sheet.

[0009] Furthermore, the bottom edge of the top cover is recessed upward to form a lower step with an outward opening, the lower step is arranged around the bottom of the top cover, and the lower step abuts against the inner side wall of the upper through hole.

[0010] Furthermore, the top of the lower step has a lower flat surface, and the lower flat surface abuts against the top surface of the conductive ring; the outer periphery of the lower step has a lower outer peripheral surface, and the lower outer peripheral surface abuts against the inner side wall of the upper through hole.

[0011] Furthermore, the bottom of the top cover has a plurality of inwardly recessed grooves, and the grooves are exposed in the upper through hole.

[0012] Furthermore, the top edge of the conductive ring is recessed downward to form an upper step opening outward, the bottom of the upper step has an upper flat surface, the upper flat surface abuts against the inner side of the sealing ring, and the outer periphery of the upper step has an upper outer peripheral surface, the upper outer peripheral surface abuts against the bottom of the sealing ring.

[0013] Furthermore, it also includes a cylindrical shell, which has a accommodating cavity with a top opening, a winding core is arranged in the accommodating cavity, the outer ring seals and connects the accommodating cavity in the shell through a sealing ring, the winding core is welded to the connecting plate through a pole ear, and the accommodating cavity is connected to the vent hole.

[0014] Furthermore, the outer side of the sealing ring has a wrapping ring extending downward, and the wrapping ring is arranged circumferentially along the outer side of the sealing ring. The inner side of the outer wrapping ring is arranged on the outer sides of the sealing ring and the wrapping ring. The inner side of the wrapping ring is provided with an inwardly recessed gap, and the opening edge of the shell is inserted into the gap of the wrapping ring, and the accommodating cavity of the shell is sealed and covered by the outer wrapping ring.

[0015] Compared with the prior art, the utility model provides an open formation cap, and the cap is used to conveniently discharge the gas generated in the formation process through the upper through hole, so that open formation can be realized, the gas pressure inside the battery cell can be reduced, and the negative impact of the gas generated inside the battery cell on the electrical performance can be reduced; the conductive ring is sealed and connected to the outer ring through the sealing ring, and the connecting piece is connected to the upper through hole through the vent hole, so that the gas generated inside the battery cell in the formation process can be discharged to the outside through the vent hole on the connecting piece and the upper through hole of the conductive ring; after the formation is completed, the top cover is inserted into the upper through hole of the conductive ring, and the top cover is connected to the conductive ring by welding to realize the sealing of the battery cell, thereby solving the problem that the gas generated by the formation of the cylindrical lithium ion battery cannot be discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the cross-section structure of the open forming cap provided by the utility model;

[0017] Figure 2 It is a schematic diagram of the top view structure of the connecting piece provided by the utility model;

[0018] Figure 3 It is a schematic diagram of the cutaway structure of the cap and the shell provided by the utility model.

[0019] In the figure: outer ring 10, conductive ring 20, sealing ring 30, insulating sheet 40, connecting sheet 50, top cover 60, shell 70, winding core 80, upper through hole 21, upper step 22, upper flat surface 23, upper outer peripheral surface 24, wrapping ring 31, gap 32, lower through hole 41, vent hole 51, welding point 52, lower step 61, lower flat surface 62, lower outer peripheral surface 63, groove 64. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0021] The implementation of the present utility model is described in detail below in conjunction with specific embodiments.

[0022] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present utility model, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present utility model. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0023] Reference Figure 1-3 As shown, it is a preferred embodiment provided by the utility model.

[0024] The open chemical forming cap comprises a ring-shaped outer ring 10 and a conductive ring 20. The conductive ring 20 is fixed on the inner side of the outer ring 10 through a sealing ring 30. The sealing ring 30 is arranged around the outer side of the conductive ring 20. The middle part of the conductive ring 20 has an upper through hole 21. The bottom of the conductive ring 20 abuts against an insulating sheet 40. The insulating sheet 40 is arranged in a ring shape. The middle part of the insulating sheet 40 has a lower through hole 41. The bottom of the insulating sheet 40 is tightly fitted with a connecting sheet 50. The insulating sheet 40 is fixed to the bottom of the conductive ring 20 through the connecting sheet 50. A vent hole 51 is opened on the connecting sheet 50. The vent hole 51 is connected to the upper through hole 21 through the lower through hole 41. A top cover 60 is welded on the conductive ring 20, and the top cover 60 is sealed on the upper through hole 21.

[0025] The open formation cap provided above is used to conveniently discharge the gas generated in the formation process through the upper through hole 21, so as to realize open formation, reduce the gas pressure inside the battery cell, and reduce the negative impact of the gas production inside the battery cell on the electrical performance; the conductive ring 20 is sealed and connected to the outer ring 10 through the sealing ring 30, and the connecting piece 50 is connected to the upper through hole 21 through the vent hole 51, so that the gas generated inside the battery cell in the formation process passes through the vent hole 51 on the connecting piece 50 and is discharged to the outside through the upper through hole 21 of the conductive ring 20. After the formation is completed, the top cover 60 is inserted into the upper through hole 21 of the conductive ring 20, and the top cover 60 is connected to the conductive ring 20 by welding to realize the sealing of the battery cell, thereby solving the problem that the gas produced by the formation of the cylindrical lithium-ion battery cannot be discharged.

[0026] The sealing ring 30 is made of insulating material and is arranged in a ring shape.

[0027] After formation, the battery cell is in a charged state, and the battery cell can be directly welded and sealed with the top cover 60 and the conductive ring 20 on the tray, without the need to transfer a single battery cell, thus avoiding the possible occurrence of a short circuit outside the battery cell during the transfer process;

[0028] If a single battery cell needs to be transferred, even if the battery cell falls over, since the top of the cap has the same polarity, no external short circuit will occur due to the top of the cap contacting other conductive materials.

[0029] In this embodiment, the outer peripheral edge of the connecting piece 50 has a plurality of welding points 52 extending toward the conductive ring 20 . The plurality of welding points 52 are arranged around and spaced apart along the outer peripheral edge of the connecting piece 50 . The connecting piece 50 is welded to the conductive ring 20 via the welding points 52 .

[0030] When an abnormality occurs in the battery cell and the current passing through the connecting piece 50 is too large, the limited welding point 52 of the connecting piece 50 will be disconnected, cutting off the circuit to prevent the battery cell from further failure.

[0031] In this embodiment, the upper through hole 21 of the conductive ring 20 has the same diameter as the lower through hole 41 of the insulating sheet 40. In this way, it is convenient to discharge the gas generated during the formation process, reduce the gas pressure inside the battery cell, and reduce the negative impact of gas generation inside the battery cell on the electrical performance.

[0032] In this embodiment, the diameter of the insulating sheet 40 is smaller than the diameter of the connecting sheet 50. In this way, it is convenient to weld the connecting sheet 50 to the conductive ring 20 through the welding points 52 on the connecting sheet 50.

[0033] In this embodiment, the bottom edge of the top cover 60 is recessed upward to form a lower step 61 opening outward. The lower step 61 is arranged around the bottom of the top cover 60 and abuts against the inner wall of the upper through hole 21 .

[0034] The top of the lower step 61 has a lower flat surface 62 which abuts against the top surface of the conductive ring 20 ; the outer periphery of the lower step 61 has a lower outer peripheral surface 63 which abuts against the inner side wall of the upper through hole 21 .

[0035] The design of the top cover 60 being inserted into the conductive ring 20 can reduce the requirements for the humidity of the formation and sealing environment and reduce the manufacturing cost; the specific structural arrangement is that the lower outer peripheral surface 63 abuts against the inner wall of the upper through hole 21, so that the top cover 60 is inserted into the upper through hole 21 of the conductive ring 20.

[0036] In this embodiment, the bottom of the top cover 60 has a plurality of inwardly recessed grooves 64 , and the grooves 64 are exposed in the upper through hole 21 .

[0037] The design of the groove 64 on the inner surface of the top cover 60 is that when the battery cell experiences thermal runaway and generates a large amount of gas, when a certain pressure is reached, the groove 64 on the inner surface of the top cover 60 can rupture to release the internal pressure of the battery cell and prevent the battery cell from further failure.

[0038] In this embodiment, the top edge of the conductive ring 20 is concave downward to form an upper step 22 with an opening facing outward, the bottom of the upper step 22 has an upper flat surface 23, the upper flat surface 23 abuts against the inner side of the sealing ring 30, and the outer periphery of the upper step 22 has an upper outer peripheral surface 24, the upper outer peripheral surface 24 abuts against the bottom of the sealing ring 30. In this way, the connection relationship between the sealing ring 30 and the conductive ring 20 can be increased, and the outer ring 10 can be isolated and connected with the conductive ring 20 through the sealing ring 30.

[0039] In this embodiment, a cylindrical shell 70 is also included, and a receiving cavity with a top opening is provided in the shell 70, and a winding core 80 is arranged in the receiving cavity. The outer ring 10 seals and connects the receiving cavity in the shell 70 through a sealing ring 30, and the winding core 80 is welded to the connecting piece 50 through a tab, and the receiving cavity is connected to the vent hole 51. In this way, the gas generated inside the battery cell in the shell 70 during the formation process passes through the vent hole 51 on the connecting piece 50 and is discharged to the outside through the upper through hole 21 of the conductive ring 20.

[0040] In this embodiment, the outer side of the sealing ring 30 has a wrapping ring 31 extending downward, and the wrapping ring 31 is arranged around the outer side of the sealing ring 30. The inner side of the outer wrapping ring 10 is arranged around the outer sides of the sealing ring 30 and the wrapping ring 31. The inner side of the wrapping ring 31 is provided with an inwardly recessed slit 32. The opening edge of the housing 70 is inserted into the slit 32 of the wrapping ring 31, and the accommodating cavity of the housing 70 is sealed and covered by the outer wrapping ring 10. In this way, the top opening edge of the housing 70 penetrates into the slit 32 of the sealing ring 30, and the sealing is achieved by the outer wrapping ring 10 wrapping the sealing ring 30 and the housing 70.

[0041] A plurality of ventilation holes 51 are arranged at intervals around the circumference of the connecting plate 50 , and at least a portion of the ventilation holes 51 are communicated with the lower through hole 41 .

[0042] Specific implementation method one, the cylindrical battery is openly formed with a cap, the top cover 60 is in an open state, the winding core 80 pole ear is welded to the connecting piece 50, and after the battery cell is baked, injected with liquid and other processes, the top opening edge of the shell 70 is inserted into the gap 32 of the sealing ring 30, and the outer ring 10 wraps the sealing ring 30 and the shell 70 to achieve the shell opening sealing; the battery cell is aged in a low dew point environment, and then transferred to a test cabinet for open formation in a low dew point environment. During the formation, the battery cell is connected to the external circuit through the conductive ring 20 and the shell 70. The gas generated inside the battery cell during the formation process is discharged to the outside through the vent 51 on the connecting piece 50 and the upper through hole 21 of the conductive ring 20. After the formation is completed, the top cover 60 is inserted into the upper through hole 21 of the conductive ring 20, and the top cover 60 is connected to the conductive ring 20 by welding to achieve the sealing inside the battery cell.

[0043] Specific implementation method II, the cylindrical battery is openly formed with a cap, the top cover 60 is in a state of being inserted into the conductive ring 20, the winding core 80 pole ear is welded to the connecting piece 50, and after the battery cell has been baked, injected with liquid and other processes, the top opening edge of the shell 70 is inserted into the gap 32 of the sealing ring 30, and the outer ring 10 wraps the sealing ring 30 and the shell 70 to achieve the shell opening sealing; the battery cell is aged under a normal environment, and then transferred to a test cabinet for open formation under a normal environment. During the formation, the battery cell is connected to the external circuit through the conductive ring 20 and the shell 70. During the formation, the gas generated inside the battery cell passes through the vent hole 51 on the connecting piece 50, passes through the upper through hole 21 of the conductive ring 20, and is discharged to the outside from the gap between the top cover 60 and the conductive ring 20 that is not completely sealed. After the formation is completed, the sealing of the top cover 60 and the conductive ring 20 is achieved by welding.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Opening forming cap, characterized in that: It comprises a ring-shaped outer ring and a conductive ring, wherein the conductive ring is fixed on the inner side of the outer ring through a sealing ring, and the sealing ring is arranged around the outer side of the conductive ring, wherein the middle part of the conductive ring has an upper through hole, and the bottom of the conductive ring abuts against an insulating sheet, and the insulating sheet is arranged in a ring shape, wherein the middle part of the insulating sheet has a lower through hole, and the bottom of the insulating sheet is tightly fitted with a connecting sheet, and the insulating sheet is fixed to the bottom of the conductive ring through the connecting sheet, and a vent hole is opened on the connecting sheet, and the vent hole is connected to the upper through hole through the lower through hole; a top cover is welded on the conductive ring, and the top cover is sealed on the upper through hole.

2. The open chemical formation cap according to claim 1, characterized in that: The outer peripheral edge of the connecting piece has a plurality of welding points extending toward the conductive ring. The plurality of welding points are arranged around and spaced along the outer peripheral edge of the connecting piece. The connecting piece is welded to the conductive ring through the welding points.

3. The open chemical formation cap according to claim 2, characterized in that: The diameter of the upper through hole of the conductive ring is consistent with the diameter of the lower through hole of the insulating sheet.

4. The open chemical formation cap according to claim 3, characterized in that: The diameter of the insulating sheet is smaller than the diameter of the connecting sheet.

5. The open chemical formation cap according to claim 4, characterized in that: The bottom edge of the top cover is recessed upwards to form a lower step with an outward opening. The lower step is arranged around the bottom of the top cover and abuts against the inner side wall of the upper through hole.

6. The open chemical formation cap according to claim 5, characterized in that: The top of the lower step has a lower flat surface, and the lower flat surface abuts against the top surface of the conductive ring; the outer periphery of the lower step has a lower outer peripheral surface, and the lower outer peripheral surface abuts against the inner side wall of the upper through hole.

7. The open chemical formation cap according to any one of claims 1 to 6, characterized in that: The bottom of the top cover is provided with a plurality of inwardly recessed grooves, and the grooves are exposed in the upper through hole.

8. The open chemical formation cap according to claim 7, characterized in that: The top edge of the conductive ring is recessed downward to form an upper step with an opening facing outward, the bottom of the upper step has an upper flat surface, the upper flat surface abuts against the inner side of the sealing ring, and the outer periphery of the upper step has an upper outer peripheral surface, the upper outer peripheral surface abuts against the bottom of the sealing ring.

9. The open chemical formation cap according to any one of claims 1 to 6, characterized in that: It also includes a cylindrical shell, which has a accommodating cavity with a top opening, a winding core is arranged in the accommodating cavity, the outer ring seals and connects the accommodating cavity in the shell through a sealing ring, the winding core is welded to the connecting plate through a pole ear, and the accommodating cavity is connected to the vent hole.

10. The open formation cap according to claim 9, characterized in that: The outer side of the sealing ring has a wrapping ring extending downward, and the wrapping ring is arranged circumferentially along the outer side of the sealing ring. The inner side of the outer wrapping ring is arranged on the outer sides of the sealing ring and the wrapping ring. The inner side of the wrapping ring is provided with an inwardly recessed gap, and the opening edge of the shell is inserted into the gap of the wrapping ring, and the accommodating cavity of the shell is sealed and covered by the outer wrapping ring.

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