A rechargeable lithium battery and a method for manufacturing the same

Abstract

The present application relates to a rechargeable lithium battery and a manufacturing method thereof, wherein the lithium battery comprises a voltage regulating circuit assembly, a plastic frame, a first metal shell, a lithium battery cell and an insulating outer skin; the lithium battery cell comprises a winding battery cell assembly, a high-voltage positive electrode cap assembly and a second metal shell, an annular rolling groove is provided on the upper portion of the second metal shell, the second metal shell is divided into a main body portion and a contraction portion, the contraction portion of the second metal shell is embedded in the first metal shell, and the outer surfaces of the first metal shell and the second metal shell are flush. The present application first produces a complete and independent lithium battery cell, and then performs fractionation, selects qualified lithium batteries and then places them in the first metal shell, so it can solve the technical problem that the capacity of lithium batteries in the prior art does not meet the requirements, and greatly reduces the defective rate of the product; the first metal shell and the second metal shell are very convenient to disassemble and repair, and the voltage regulating circuit assembly can be reused after repair.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a rechargeable lithium battery and a method for manufacturing the same. Background Art

[0002] Low-voltage lithium batteries convert the high voltage of lithium batteries into a low voltage of 1.5V through a voltage drop circuit board. They are made according to the sizes of No. 5 batteries, No. 7 batteries, etc., and can replace common alkaline batteries and nickel-metal hydride batteries.

[0003] A step-down lithium battery is disclosed in a Chinese patent application with publication number CN118315645A. Since a process of packaging before formation is adopted, defective products that do not meet the capacity requirements will inevitably exist in the subsequent capacity division process. The packaged lithium battery cannot be disassembled without loss, and the internal high-value voltage regulating circuit components are difficult to reuse, which needs to be improved. Summary of the invention

[0004] In order to solve the technical problem that the existing low-voltage lithium battery adopts the process of first packaging and then forming, and defective products will appear in the subsequent capacity division process, the present invention provides a rechargeable lithium battery and a manufacturing method thereof.

[0005] On the one hand, the technical solution provided by the present application is as follows: a rechargeable lithium battery, comprising a voltage regulating circuit assembly, a plastic frame, a first metal shell, a lithium battery cell and an insulating outer skin; the voltage regulating circuit assembly and the plastic frame are arranged in the first metal shell, and the plastic frame is used to fix the voltage regulating circuit assembly; the lithium battery cell comprises a wound battery cell assembly, a high-voltage positive electrode cap assembly and a second metal shell, an annular rolling groove is provided on the upper part of the second metal shell, the wound battery cell assembly is arranged in the second metal shell, and its position is limited by the annular rolling groove, the second metal shell is divided into a main body portion below and a contraction portion above by the annular rolling groove, the outer diameter of the first metal shell is the same as the outer diameter of the main body portion of the second metal shell, the inner diameter of the first metal shell is the same as the outer diameter of the contraction portion of the second metal shell, the contraction portion of the second metal shell is embedded in the first metal shell, the outer surfaces of the first metal shell and the second metal shell are flush, and the insulating outer skin covers the first metal shell and the second metal shell.

[0006] By adopting the above technical solution, the voltage regulating circuit component of the rechargeable lithium battery of the present application is provided with necessary circuits such as a step-down circuit, a voltage stabilizing circuit, a charging circuit, and an over-discharge protection circuit, which are electrically connected to the lithium battery cell. The low-voltage positive electrode cap serves as the positive electrode of the battery, and the second metal shell serves as the negative electrode of the battery, which can stably output a low voltage.

[0007] The present application first produces a complete and independent lithium battery cell, and then performs chemical composition, selects qualified lithium batteries and then places them into the first metal shell, so it can solve the technical problem that the capacity of lithium batteries in the prior art does not meet the requirements, and greatly reduces the defective rate of the product; the contraction part of the second metal shell is embedded in the first metal shell, and when the size is appropriate, the outer wall of the contraction part of the second metal shell and the inner wall of the first metal shell are tightly matched to produce a large static friction force, which can better prevent the first metal shell and the second metal shell from separating, and the insulating outer skin is coated on the outside of the first metal shell and the second metal shell, further ensuring that the first metal shell and the second metal shell cannot separate, and ensuring the integrity of the lithium battery. If a defect is found during the detection process, the first metal shell and the second metal shell can be pulled out and separated after removing the insulating outer skin, and the disassembly is very convenient. If there is a problem with the lithium battery cell, the lithium battery cell can be replaced, and if there is a problem with the voltage regulating circuit component, the voltage regulating circuit component can be replaced. The defective voltage regulating circuit component can be reused after repair. Of course, the electrical performance qualification test can also be carried out before the insulating outer skin is coated. Only lithium batteries that have passed the test are coated with the insulating outer skin, which can avoid unnecessary consumption of the insulating outer skin.

[0008] Optionally, the first metal shell and the second metal shell are fixedly connected by spot welding, or the lower edge of the first metal shell shrinks inward to form a shrinkage to define a shrinkage portion of the second metal shell.

[0009] Optionally, the voltage regulating circuit assembly includes a low-voltage positive electrode cap, a PCB board, a charging interface, a high-voltage positive electrode spring clip, a negative electrode spring clip and an elastic ejector pin, wherein the charging interface, the high-voltage positive electrode spring clip, the negative electrode spring clip and the elastic ejector pin are all arranged on the PCB board, the plastic frame and the low-voltage positive electrode cap are limited by the top wall of the first metal shell, a positive and negative electrode isolation sheet is also provided between the low-voltage positive electrode cap and the top wall of the first metal shell, a through hole is provided on the top of the first metal shell, and a first charging avoidance hole is provided on the side, the low-voltage positive electrode cap extends out of the through hole, and the charging avoidance hole is used to expose the charging interface of the voltage regulating circuit assembly, the elastic ejector pin abuts against the inner wall of the low-voltage positive electrode cap, the negative electrode spring clip abuts against the inner wall of the first metal shell, the high-voltage positive electrode spring clip abuts against the high-voltage positive electrode cap assembly, the first metal shell and the second metal shell are in contact and conductive, and a second charging avoidance hole is provided at the corresponding position on the side of the insulating outer skin.

[0010] Optionally, the plastic frame includes an upper frame and a lower frame, the upper frame and the lower frame are fixed by snapping, and the PCB board is fixed between the upper frame and the lower frame.

[0011] Optionally, the plastic frame is bonded to the inner wall of the first metal shell by glue.

[0012] Optionally, the plastic frame is disposed in the first metal shell in a floating manner, and the high-voltage positive electrode spring is also used to press the plastic frame against the top wall of the first metal shell.

[0013] Optionally, the low-voltage positive electrode cap is glued to the plastic frame, and the positive and negative electrode separators are glued to the plastic frame and the low-voltage positive electrode cap.

[0014] Optionally, a protruding vertical guide strip is provided on the outer peripheral surface of the plastic frame to reduce the friction between the plastic frame and the inner wall of the first metal shell.

[0015] Optionally, the negative electrode spring sheet is provided with a convex bump protruding outward, and the convex bump contacts the inner wall of the first metal shell through the inner wall of the first metal shell to reduce the friction between the negative electrode spring sheet and the inner wall of the first metal shell.

[0016] On the other hand, the present application also provides another technical solution: a method for manufacturing the above-mentioned rechargeable lithium battery, comprising the following steps:

[0017] S1, placing the wound battery cell assembly into the second metal shell, making an annular rolling groove on the upper part of the second metal shell, welding the negative electrode tab of the wound battery cell assembly to the bottom wall of the second metal shell, welding the positive electrode tab to the high-voltage positive electrode cap assembly, injecting electrolyte, placing the high-voltage positive electrode cap assembly into the second metal shell, making a contraction portion on the upper part of the second metal shell, and then making a spinning edge on the upper edge of the second metal shell, fixing the high-voltage positive electrode cap assembly in the contraction portion to form a lithium battery cell, and performing chemical composition processing on the lithium battery cell;

[0018] S2, fixing the voltage regulating circuit assembly on the plastic frame, and then installing them together into the first metal housing;

[0019] S3, embedding the upper end of the lithium battery cell into the first metal shell;

[0020] S4, putting on an insulating outer skin, heating and shrinking the insulating outer skin so that the insulating outer skin wraps around the first metal shell and the lithium battery core.

[0021] In summary, the present application includes at least one of the following beneficial technical effects:

[0022] 1. The rechargeable lithium battery of the present application is provided with a voltage regulating circuit assembly, which can stably output low voltage;

[0023] 2. The present application first produces a complete and independent lithium battery cell, then performs chemical composition and capacity analysis, selects qualified lithium batteries and places them into the first metal shell, thereby solving the technical problem that the capacity of lithium batteries in the prior art does not meet the requirements, and greatly reduces the defective rate of products;

[0024] 3. The outer wall of the contraction part of the second metal shell and the inner wall of the first metal shell are tightly matched to generate a large static friction force, which can better prevent the first metal shell and the second metal shell from separating. The insulating outer skin further ensures that the first metal shell and the second metal shell cannot separate, thereby ensuring the integrity of the lithium battery; the first metal shell and the second metal shell are very convenient to disassemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a three-dimensional diagram of the lithium battery described in Example 1 of the present application;

[0026] Figure 2 is a schematic diagram of a half-section structure of a lithium battery according to Embodiment 1 of the present application;

[0027] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0028] Figure 4 is a schematic diagram of a half-section structure of the lithium battery described in Example 1 of the present application from another angle;

[0029] Figure 5 yes Figure 4 Enlarged view of point B in the middle;

[0030] Figure 6 It is a schematic diagram of the assembly action of the voltage regulating circuit component and the plastic frame in the first embodiment of the present application;

[0031] Figure 7 It is a schematic diagram of the assembly action of installing the voltage regulating circuit component and the plastic frame into the first metal housing in the first embodiment of the present application;

[0032] Figure 8 This is a schematic diagram of the assembly action of placing a wound battery cell assembly into a second metal housing according to an embodiment of the present application;

[0033] Fig. 9 It is a schematic diagram of making an annular rolling groove on the upper part of the second metal shell in the first embodiment of the present application;

[0034] Fig.10 This is a schematic diagram of the assembly action of installing the high-voltage positive electrode cap assembly into the second metal shell in the first embodiment of the present application;

[0035] Fig.11 is a schematic diagram of manufacturing a contraction portion on the upper part of the second metal shell in the first embodiment of the present application;

[0036] Fig.12 It is a schematic diagram of manufacturing a spinning edge on the upper part of the second metal shell in the first embodiment of the present application;

[0037] Fig.13This is a schematic diagram of the assembly action of installing a lithium battery cell into a first metal housing in an embodiment of the present application;

[0038] Fig.14 This is a schematic diagram of the assembly action of applying an insulating outer skin and performing heating and shrinking according to an embodiment of the present application;

[0039] Fig.15 It is a schematic diagram of the assembly action of installing the voltage regulating circuit component and the plastic frame into the first metal housing in the second embodiment of the present application;

[0040] Fig.16 is a comparison diagram of the voltage regulating circuit assembly and the plastic frame before and after expansion and contraction in the second embodiment of the present application;

[0041] Fig.17 is a three-dimensional diagram of the lithium battery described in Example 3 of the present application;

[0042] Fig.18 yes Fig.17 Enlarged view of point C in the middle (the voltage regulator circuit components and the plastic frame are in a compressed state);

[0043] Fig.19 It is a partial schematic diagram of the charging port rotated to a hidden state;

[0044] Fig. 20 It is a schematic diagram of the assembly action of installing the voltage regulating circuit component and the plastic frame into the first metal housing in the third embodiment of the present application.

[0045] Explanation of the reference numerals in the accompanying drawings: 1. voltage regulating circuit assembly; 11. low-voltage positive electrode cap; 12. PCB board; 13. charging interface; 14. high-voltage positive electrode spring; 15. negative electrode spring; 151. convex bump; 16. elastic ejector pin; 17. positive and negative electrode separator; 2. plastic frame; 21. upper frame; 22. lower frame; 23. vertical guide bar; 24. annular tooth; 3. first metal shell; 31. through hole; 32. first charging avoidance hole; 4. lithium battery cell; 41. wound battery cell assembly; 42. high-voltage positive electrode cap assembly; 43. second metal shell; 431. annular rolling groove; 432. main body; 433. contraction part; 434. spun edge; 5. insulating outer skin; 51. second charging avoidance hole. DETAILED DESCRIPTION

[0046] The following is combined with Figures 1 to 20 This application is described in further detail. Embodiment 1:

[0047] Reference Figures 1 to 5 This embodiment discloses a rechargeable lithium battery, including a voltage regulating circuit assembly 1, a plastic frame 2, a first metal shell 3, a lithium battery cell 4 and an insulating outer shell 5. This embodiment specifically uses an AAA battery (No. 7 battery), but this application is not limited to AAA batteries.

[0048] Reference Figure 4 , Figure 6 and Figure 7 The voltage regulating circuit assembly 1 and the plastic frame 2 are arranged in the first metal shell 3, and the plastic frame 2 is used to fix the voltage regulating circuit assembly 1. The plastic frame 2 includes an upper frame 21 and a lower frame 22, and the upper frame 21 and the lower frame 22 are fixed by snapping, and the PCB board 12 is fixed between the upper frame 21 and the lower frame 22. The plastic frame 2 can effectively prevent the PCB board 12 from contacting and short-circuiting with the first metal shell 3, and at the same time better fix the PCB board 12 to prevent the PCB board 12 from changing position.

[0049] Reference Fig.12 The lithium battery cell 4 includes a wound battery cell assembly 41, a high-voltage positive electrode cap assembly 42 and a second metal shell 43. The second metal shell 43 has an annular rolling groove 431 on its upper portion. The wound battery cell assembly 41 is arranged in the second metal shell 43 and its position is limited by the annular rolling groove 431. The second metal shell 43 is divided into a main body portion 432 at the bottom and a contraction portion 433 at the top by the annular rolling groove 431.

[0050] Reference Figure 3 , Figure 5 and Fig.13 The outer diameter of the first metal shell 3 is the same as the outer diameter of the main body 432 of the second metal shell 43, the inner diameter of the first metal shell 3 is the same as the outer diameter of the contraction portion 433 of the second metal shell 43, the contraction portion 433 of the second metal shell 43 is embedded in the first metal shell 3, the outer surfaces of the first metal shell 3 and the second metal shell 43 are flush, and the insulating outer skin 5 is covered outside the first metal shell 3 and the second metal shell 43.

[0051] Reference Figure 3 , Figure 5 and Figure 6The voltage regulating circuit assembly 1 includes a low-voltage positive electrode cap 11, a PCB board 12, a charging interface 13, a high-voltage positive electrode spring 14, a negative electrode spring 15 and an elastic ejector pin 16. The charging interface 13, the high-voltage positive electrode spring 14, the negative electrode spring 15 and the elastic ejector pin 16 are all arranged on the PCB board 12. The plastic frame 2 and the low-voltage positive electrode cap 11 are limited by the top wall of the first metal shell 3. A positive and negative electrode separator 17 is also arranged between the low-voltage positive electrode cap 11 and the top wall of the first metal shell 3. The top of the first metal shell 3 is provided with a through hole 3 1, a first charging avoidance hole 32 is provided on the side, the low-voltage positive cap 11 extends out of the through hole 31, the charging avoidance hole is used to expose the charging interface 13 of the voltage regulating circuit assembly 1, the elastic ejector 16 abuts against the inner wall of the low-voltage positive cap 11, the negative spring 15 abuts against the inner wall of the first metal shell 3, the high-voltage positive spring 14 abuts against the high-voltage positive cap assembly 42, the first metal shell 3 and the second metal shell 43 are in contact and conductive, and a second charging avoidance hole 51 is provided at the corresponding position on the side of the insulating outer skin 5. The positive and negative electrode separators 17 are used to prevent the low-voltage positive cap 11 and the first metal shell 3 from short-circuiting to ensure electrical safety.

[0052] In this embodiment, the plastic frame 2 is glued to the inner wall of the first metal shell 3 to prevent the plastic frame 2 from rotating on the first metal shell 3 and avoid misalignment, so that the charging port 13 cannot be fully exposed.

[0053] The manufacturing method of the rechargeable lithium battery described in this embodiment comprises the following steps:

[0054] S1, place the wound battery cell assembly 41 into the second metal shell 43, make an annular rolling groove 431 on the upper part of the second metal shell 43, weld the negative pole ear of the wound battery cell assembly 41 to the bottom wall of the second metal shell 43, weld the positive pole ear to the high-voltage positive cap assembly 42, inject electrolyte, place the high-voltage positive cap assembly 42 into the second metal shell 43, make a contraction part 433 on the upper part of the second metal shell 43, and then make a spinning edge 434 on the upper edge of the second metal shell 43, fix the high-voltage positive cap assembly 42 in the contraction part 433, form a lithium battery cell 4, and perform a chemical composition treatment on the lithium battery cell 4;

[0055] S2, fix the voltage regulating circuit assembly 1 on the plastic frame 2, and then install them together into the first metal housing 3;

[0056] S3, embedding the upper end of the lithium battery cell 4 into the first metal shell 3;

[0057] S4, putting on the insulating outer skin 5, heating and shrinking it, so that the insulating outer skin 5 wraps around the first metal shell 3 and the lithium battery core 4.

[0058] The manufacturing method described in the present application has reasonable procedures, high yield rate, can be industrialized, and is particularly suitable for large-scale production.

[0059] The specific connection principle of the circuit of the present application is as follows: the positive pole tab of the wound battery cell assembly 41 is welded to the lower surface of the high-voltage positive electrode cap assembly 42, and is connected to the PCB board 12 through the high-voltage positive electrode spring 14; the negative pole tab of the wound battery cell assembly 41 is welded to the bottom wall of the second metal shell 43, and is connected to the PCB board 12 through the second metal shell 43, the first metal shell 3 and the negative electrode spring 15; after the circuit on the PCB board 12 is reduced in voltage, the positive low voltage is output from the low-voltage positive electrode cap 11, and the negative electrode of the lithium battery is output from the second metal shell 43.

[0060] The voltage regulating circuit assembly 1 of the rechargeable lithium battery of the present application is provided with necessary circuits such as a step-down circuit, a voltage stabilizing circuit, a charging circuit, and an over-discharge protection circuit, and is electrically connected to the lithium battery cell 4. The low-voltage positive electrode cap 11 serves as the positive electrode of the battery, and the second metal shell 43 serves as the negative electrode of the battery, and can stably output a low voltage.

[0061] The present application first produces a complete and independent lithium battery cell 4, and then performs the chemical composition, selects the qualified lithium battery and then places it in the first metal shell 3, so it can solve the technical problem that the capacity of the lithium battery in the prior art does not meet the requirements, and greatly reduces the defective rate of the product; the contraction part 433 of the second metal shell 43 is embedded in the first metal shell 3, and when the size is appropriate, the outer wall of the contraction part 433 of the second metal shell 43 and the inner wall of the first metal shell 3 are tightly matched to generate a large static friction force, which can better prevent the first metal shell 3 and the second metal shell 43 from separating, and the insulating outer skin 5 is coated on the outside of the first metal shell 3 and the second metal shell 43, further ensuring that the first metal shell 3 and the second metal shell 43 cannot separate, and ensuring the integrity of the lithium battery. If a defect is found during the detection process, the first metal shell 3 and the second metal shell 43 can be pulled out and separated after removing the insulating outer skin 5, and the disassembly is very convenient. If there is a problem with the lithium battery cell 4, the lithium battery cell 4 is replaced, and if there is a problem with the voltage regulating circuit component 1, the voltage regulating circuit component 1 is replaced, and the defective voltage regulating circuit component 1 can be reused after repair. Of course, the electrical performance qualification test can also be carried out before the insulating outer sheath 5 is coated, and only the lithium batteries that have passed the test are coated with the insulating outer sheath 5, which can avoid unnecessary consumption of the insulating outer sheath 5.

[0062] In this embodiment, when there are further requirements for the structural strength of the lithium battery shell, the connection relationship between the first metal shell 3 and the second metal shell 43 can also be strengthened. For example, the first metal shell 3 and the second metal shell 43 can be fixedly connected by spot welding, or the lower edge of the first metal shell 3 is contracted inward to form a shrinkage to limit the contraction portion 433 of the second metal shell 43. Both are feasible, but will affect the convenience of disassembly and assembly, and can be reasonably selected according to the user's usage scenario. Embodiment 2:

[0063] Since the rear end of the cylindrical battery needs to contact the negative elastic element of the external battery compartment to achieve electrical connection, sometimes the negative elastic element is deformed or the spring falls off, which can easily lead to poor electrical contact of the cylindrical battery.

[0064] Reference Fig.15 and Fig.16 , as the second embodiment of the rechargeable lithium battery of the present application, the difference from the first embodiment is that the plastic frame 2 can be arranged in the first metal shell 3 in a floating manner, and the floating distance is D, and the high-voltage positive electrode spring 14 is also used to push the plastic frame 2 against the top wall of the first metal shell 3. First, the low-voltage positive electrode cap 11 is raised by 1-4mm, so that the lithium battery of the present application is 1-4mm longer than the existing lithium battery as a whole. When installed in the battery compartment, the low-voltage positive electrode cap 11 is compressed and retracted, so it does not affect the installation of the lithium battery, but the installation effect of the lithium battery will be tighter. If the negative electrode elastic element of the battery compartment is deformed or the elasticity becomes poor, the low-voltage positive electrode cap 11 will only partially retract, or even not retract, thereby making up for the space where the elasticity of the negative electrode elastic element of the battery compartment is missing, ensuring excellent electrical contact.

[0065] In this embodiment, the low-voltage positive electrode cap 11 is glued to the plastic frame 2, and the positive and negative electrode separators 17 are glued to the plastic frame 2 and the low-voltage positive electrode cap 11. In this way, the low-voltage positive electrode cap 11, the plastic frame 2 and the voltage regulating circuit assembly float up and down as a whole without being dispersed.

[0066] Reference Fig.15, the high-voltage positive electrode spring clip 14 needs to select appropriate elasticity, and it must have sufficient elastic force to lift up the low-voltage positive electrode cap 11, the plastic frame 2 and the voltage regulating circuit assembly 1, but the elastic force cannot be too strong, which may easily lead to the inability to be installed in the battery compartment. The plastic frame 2 must be able to float freely up and down, and the friction between it and the inner wall of the first metal shell 3 must be as small as possible. To this end, the present application has made the following improvements. First, a protruding vertical guide strip 23 is provided on the outer peripheral surface of the plastic frame 2. Since the contact area between the two is greatly reduced, the friction between it and the inner wall of the first metal shell 3 can be reduced; second, an outwardly protruding bulge 151 is provided on the negative electrode spring clip 15. The bulge 151 contacts the inner wall of the first metal shell 3, which can also reduce the contact area between the two, thereby reducing the friction between the inner wall of the first metal shell 3. Other structures and beneficial effects are consistent with those of Example 1 and will not be repeated here. Embodiment three:

[0067] Reference Figures 17 to 20 The difference from the second embodiment is that the plastic frame 2 can not only float up and down in the first metal shell 3, but also rotate in the first metal shell 3, so that the charging port 13 will be hidden in the first metal shell 3 after rotating a certain angle, which makes the lithium battery more beautiful in appearance and can effectively protect the charging port 13 and improve safety.

[0068] Reference Fig. 20 Since the low-voltage positive electrode cap 11 is relatively smooth and small in size, it is not easy to twist it manually. Therefore, in this embodiment, an annular tooth 24 is set on the upper frame 21 of the plastic frame 2. The annular tooth 24 is located on the upper edge of the charging interface 13. By turning the annular tooth 24, the plastic frame 2 drives the charging interface 13 to rotate so as to be hidden. Normally, when the low-voltage positive electrode cap 11 is not compressed, the annular tooth 24 cannot be exposed. When the low-voltage positive electrode cap 11 is compressed, the annular tooth 24 moves down and is exposed. At this time, you can use fingernails, toothpicks, screwdrivers and other objects to turn it to expose or hide the charging interface 13, thereby achieving the technical effect described above. Other structures and beneficial effects are consistent with those of Example 2 and will not be repeated here.

[0069] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A rechargeable lithium battery, characterized in that: It comprises a voltage regulating circuit assembly, a plastic frame, a first metal shell, a lithium battery cell and an insulating outer skin; the voltage regulating circuit assembly and the plastic frame are arranged in the first metal shell, and the plastic frame is used to fix the voltage regulating circuit assembly; the lithium battery cell comprises a wound battery cell assembly, a high-voltage positive electrode cap assembly and a second metal shell, an annular rolling groove is arranged on the upper part of the second metal shell, the wound battery cell assembly is arranged in the second metal shell, and the position is limited by the annular rolling groove, the second metal shell is divided into a main body part below and a contraction part above by the annular rolling groove, the outer diameter of the first metal shell is the same as the outer diameter of the main body part of the second metal shell, the inner diameter of the first metal shell is the same as the outer diameter of the contraction part of the second metal shell, the contraction part of the second metal shell is embedded in the first metal shell, the outer surfaces of the first metal shell and the second metal shell are flush, and the insulating outer skin is coated on the outside of the first metal shell and the second metal shell; The voltage regulating circuit assembly comprises a low-voltage positive electrode cap, a PCB board, a charging interface, a high-voltage positive electrode spring, a negative electrode spring and an elastic ejector pin. The charging interface, the high-voltage positive electrode spring, the negative electrode spring and the elastic ejector pin are all arranged on the PCB board. The plastic frame and the low-voltage positive electrode cap are limited by the top wall of the first metal shell. A positive and negative electrode separator is also arranged between the low-voltage positive electrode cap and the top wall of the first metal shell. A through hole is arranged on the top of the first metal shell, and a first charging avoidance hole is arranged on the side. The low-voltage positive electrode cap extends out of the through hole. The charging avoidance hole is used to expose the charging interface of the voltage regulating circuit assembly. The elastic ejector pin abuts against the inner wall of the low-voltage positive electrode cap, the negative electrode spring abuts against the inner wall of the first metal shell, the high-voltage positive electrode spring abuts against the high-voltage positive electrode cap assembly, the first metal shell and the second metal shell are in contact and conductive, and a second charging avoidance hole is arranged at a corresponding position on the side of the insulating outer skin; The plastic frame is arranged in the first metal shell in a floating manner, and the high-voltage positive electrode spring is also used to press the plastic frame against the top wall of the first metal shell; The outer peripheral surface of the plastic frame is provided with a protruding vertical guide strip, which is used to reduce the friction between the plastic frame and the inner wall of the first metal shell; The negative electrode spring sheet is provided with a convex bump protruding outward, and the convex bump contacts the inner wall of the first metal shell through the inner wall of the first metal shell to reduce the friction between the negative electrode spring sheet and the inner wall of the first metal shell.

2. The rechargeable lithium battery according to claim 1, characterized in that: The first metal shell and the second metal shell are fixedly connected by spot welding, or the lower edge of the first metal shell shrinks inward to form a shrinkage to define a shrinkage portion of the second metal shell.

3. The rechargeable lithium battery according to claim 1, characterized in that: The plastic frame comprises an upper frame and a lower frame, the upper frame and the lower frame are fixed by snap connection, and the PCB board is fixed between the upper frame and the lower frame.

4. The rechargeable lithium battery according to claim 1, characterized in that: The low-voltage positive electrode cap is glued to the plastic frame, and the positive and negative electrode separators are glued to the plastic frame and the low-voltage positive electrode cap.

5. A method for manufacturing a rechargeable lithium battery according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, placing the wound battery cell assembly into the second metal shell, making an annular rolling groove on the upper part of the second metal shell, welding the negative electrode tab of the wound battery cell assembly to the bottom wall of the second metal shell, welding the positive electrode tab to the high-voltage positive electrode cap assembly, injecting electrolyte, placing the high-voltage positive electrode cap assembly into the second metal shell, making a contraction portion on the upper part of the second metal shell, and then making a spinning edge on the upper edge of the second metal shell, fixing the high-voltage positive electrode cap assembly in the contraction portion to form a lithium battery cell, and performing chemical composition processing on the lithium battery cell; S2, fixing the voltage regulating circuit assembly on the plastic frame, and then installing them together into the first metal housing; S3, embedding the upper end of the lithium battery cell into the first metal shell, and the high-voltage positive electrode spring pushes the plastic frame against the top wall of the first metal shell, so that the plastic frame can float up and down in the first metal shell; S4, putting on an insulating outer skin, heating and shrinking the insulating outer skin so that the insulating outer skin wraps around the first metal shell and the lithium battery core.

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