Cylindrical lithium battery cap, lithium battery with said cap, and battery manufacturing process

Abstract

To provide a cylindrical lithium battery cap with a built-in battery management system (BMS) board, which has a compact and rational structure, is convenient to produce, is small, and can minimize the effect of a reduced cell capacity for the need to install a BMS board, and a cylindrical lithium battery with the cylindrical lithium battery cap.SOLUTION: In a cylindrical lithium battery with a cylindrical lithium battery cap, a cap mechanism includes a cap case 11, a positive electrode conductive metal cap 12, a BMS component 13, and a plastic bracket 14 used to protect the BMS component. The BMS component includes a BMS motherboard portion 131 and a positive electrode insulating cap portion 132. The BMS motherboard portion is provided with a plurality of electronic components 133 that form a BMS management system, and the positive electrode insulating cap portion is installed facing a positive electrode 221 side of the cylindrical lithium battery.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to the technical field of cylindrical lithium batteries, and more particularly to a cylindrical lithium battery cap incorporating a BMS substrate and a cylindrical lithium battery with the cap. [Background technology]

[0002] Cylindrical lithium batteries, also known as lithium-ion batteries, are common secondary batteries. They consist of a cylindrical container containing a positive electrode, a negative electrode, and an electrolyte. The battery cap is a component of the cylindrical lithium battery and is used to seal the top of the battery.

[0003] Currently, cylindrical lithium batteries on the market are divided into those with and those without BMS systems. Battery Management Systems (BMS) are an important component of modern battery technology, playing a key role in electric vehicles and renewable energy storage systems in particular. The main function of a BMS is to ensure the safe and stable increase in the energy utilization rate of the battery pack.

[0004] Lithium batteries come in standard external dimensions, such as AA and AAA batteries. To install a BMS system on a cylindrical lithium battery, the lithium battery cell must be shrunk, and an independently sealed battery cell and an independent BMS system must be created before the two are placed in a battery case and electrically connected. Because the BMS system and the battery are installed separately in this cylindrical lithium battery with a BMS system, the battery cell is significantly shrunk, resulting in reduced battery capacity, increased overall battery weight, high manufacturing costs, and complicated installation during production and processing, limiting the battery's application range and performance. Therefore, how to manufacture a miniaturized rechargeable cylindrical lithium battery with a built-in BMS substrate has become a technical challenge in the field.

[0005] The applicant of the present invention has filed a patent application for an invention entitled "Cylindrical lithium battery cap with built-in BMS substrate" with application number CN202310996046.2, which comprises a steel case, a cap with a BMS substrate connected to the inside of the steel case, a plastic bracket at its lower end connected to the inside of the cap with the BMS substrate, a positive electrode conductive metal cap at its lower end connected to the inside of the plastic bracket, and a PCBA substrate connected to the upper outer edge of the positive electrode conductive metal cap, the center of the lower end of the PCBA substrate extending to the center of the positive electrode conductive metal cap, and the PCBA substrate comprising a BMS chip, a power management chip, a battery control chip, a display chip, and a multiplexer, a negative electrode metal ring connected to the upper outer edge of the PCBA substrate, and the entire opening of the steel case curls inward and contacts the negative electrode metal ring, providing electrical conductivity to the negative electrode. The positive electrode plastic cap is connected to the inner wall of the negative electrode metal ring, with a damping between them, and the center of the positive electrode plastic cap has an open structure to fit with the external positive electrode metal post. The present invention overcomes the cap structure of the conventional cylindrical lithium battery and has a built-in BMS for monitoring to meet usage needs and simplify the installation procedure.

[0006] However, in the above solution, due to the installation of a plastic bracket structure, the use of a negative electrode metal ring, and a positive electrode plastic cap, the overall cap structure is not the most compact, and there is still room for improvement. Summary of the Invention [Problem to be solved by the invention]

[0007] A first object of the present invention is to provide a cylindrical lithium battery cap with a built-in BMS substrate, which has a compact and reasonable structure, is convenient for production and manufacturing, and is advantageous for manufacturing a miniaturized cylindrical lithium battery with a built-in BMS substrate. With the cylindrical lithium battery cap with a built-in BMS substrate described in the present invention, the impact of the need to install a BMS substrate on the cell capacity can be minimized.

[0008] The second object of the present invention is to provide a cylindrical lithium-ion battery, in which a cylindrical lithium-ion battery cap with a BMS substrate inside has the advantages of a compact cylindrical lithium-ion battery with a built-in BMS substrate, minimizing the impact of the BMS substrate on the cell capacity, and having a simple and compact structure with good sealing properties, making the battery highly practical, safe, and reliable.

[0009] The third object of the present invention is to provide a manufacturing process for cylindrical lithium batteries, which can be manufactured in a simple and convenient manner. [Means for solving the problem]

[0010] A first invention to achieve the first object is a cylindrical lithium battery cap incorporating a BMS substrate, the cap mechanism including a cap case, a positive electrode conductive metal cap, a BMS component, and a plastic bracket used to protect the BMS component; The cap case is used to connect to the inside of a steel case of a cylindrical lithium battery, The positive electrode conductive metal cap is located inside the cap case and is used for electrical connection with the positive electrode of the lithium battery cell; The BMS component includes a BMS motherboard unit and a positive electrode insulating cap unit, the BMS motherboard unit is provided with a plurality of electronic components for forming a BMS management system, the positive electrode insulating cap unit is installed facing the positive electrode side of the cylindrical lithium battery and is hermetically connected to the cap case and the steel case of the cylindrical lithium battery, the motherboard unit and the positive electrode insulating cap unit are integrally molded or installed separately, the positive electrode conductive metal cap includes a body portion with a groove and a flange portion integrally molded with the body portion, electronic components on the BMS motherboard portion are installed facing the groove, and when a plastic bracket is used, the BMS motherboard portion and the plastic bracket are located between the positive electrode conductive metal cap and the positive electrode insulating cap portion, and the positive electrode insulating cap portion abuts and connects to the flange portion; When a metal conductive ring is used, the BMS motherboard, the metal conductive ring is located between the positive conductive metal cap and the positive insulating cap portion, and the metal conductive ring is located between the flange portion and the BMS motherboard portion.

[0011] Preferably, an embossed portion is provided on the flange portion on a side facing the positive electrode insulating cap portion. Preferably, the positive electrode conductive metal cap is hermetically connected to the positive electrode insulating cap portion and a cap case. Preferably, an explosion-proof relief portion is provided in the center of the positive electrode conductive metal cap on the side facing the positive electrode of the cell, the thickness of the explosion-proof relief portion is thinner than the thickness of other positions of the positive electrode conductive metal cap, and when the internal pressure of the cell exceeds a threshold value, the explosion-proof relief portion can prevent an explosion due to excessive pressure inside the battery. Preferably, the BMS motherboard part and the positive electrode insulating cap part are provided with an air-to-air slot for mutual communication with the outside air, and after the explosion-proof relief part explodes, the explosion-proof relief part is conductive with the slot.

[0012] A second invention for achieving the second object is a cylindrical lithium battery comprising a battery insulating case, a steel case placed inside the battery insulating case, and a cell placed inside the steel case, the negative electrode of the cell being electrically connected to the steel case, a cylindrical lithium battery cap with the BMS substrate built in being placed inside the steel case, the positive electrode of the cell being electrically connected to the positive electrode conductive metal cap, a solder portion being provided around the positive electrode insulating cap on the side facing the positive electrode conductive pillar of the battery, this solder portion being electrically connected to the steel case, and the positive electrode insulating cap on the side facing the positive electrode conductive pillar of the battery being another solder portion being electrically connected to the steel case. Preferably, the motherboard unit and the positive electrode insulating cap unit are provided with chemical formation holes that are used during a lithium battery chemical treatment to connect them and activate the lithium battery by charging and discharging the lithium battery.

[0013] A third invention for achieving the third object is a manufacturing process for a cylindrical lithium battery, which is used to produce the cylindrical lithium battery described above and comprises the following steps: The manufacturing process of the cap, including: Step 1: Install multiple electronic components on the BMS motherboard, and then complete the installation process on the BMS motherboard. Step 2: After applying waterproof paint to the plastic bracket, spray the sealant on it. After the sealant has dried, soften the plastic bracket. Step 3: Insert the positive electrode conductive metal cap into the plastic bracket with the sealant dried, and then install the BMS component to complete the manufacturing of the lithium battery cap with the built-in BMS component. A manufacturing process for a battery core, including: Step 1, mix ingredients, Step 2, application, Step 3, create a sheet, Step 4, winding, The final product assembly process includes: Step 1: Place the cell in the steel case, and laser weld the negative electrode of the cell to the bottom of the inside of the steel case. Step 2: Roll the grooves in the steel case to fix the cells inside and prevent them from falling. Step 3: Laser weld the positive electrode of the cell to the back edge of the positive electrode conductive metal cap. Step 4: Dry the components with the caps welded to remove moisture, then inject the electrolyte. Step 5: Roll the entire opening of the steel case inward, press it against the solder part of the positive electrode insulating cap, and seal it so that the negative electrode is conductive. Step 6: Cover the packaging with the corresponding printing sleeve according to the customer's requirements, and print the code. Step 7: Put it in the cabinet and perform chemical conversion treatment and aging treatment. Step 8: Fully charge the rechargeable lithium batteries after aging treatment, and separate batteries of different capacities and voltages. Step 9: Pack the battery in a special packaging box for rechargeable lithium batteries to ensure safe storage and transportation. [Effects of the Invention]

[0014] According to the first invention, by adopting the above technical solution, the structure and installation method of the plastic bracket are improved, the negative metal ring is eliminated, the overall cap structure is more compact, and the capacity of the battery cell can be further increased. In addition, the motherboard part and the positive insulating cap part can be integrally molded or separately installed, which makes the installation method more flexible. When they are integrally molded, the volume of the cap is further reduced, and when they are separately installed, the positive insulating cap part is thinner than the positive plastic cap in the prior art and can be more closely fitted to the motherboard part. The positive electrode conductive metal cap is provided with an explosion-proof relief part, and when the pressure inside the cell becomes abnormally high and exceeds a threshold, the metal of the explosion-proof relief part is thin and will burst first, preventing an explosion caused by excessive internal pressure. The BMS motherboard has one or more slots communicating with the outside, and after the explosion-proof relief part bursts, the high-pressure gas will be released through this hole. Therefore, the cap of the present invention has a more rational structure, employs fewer parts, has lower production costs, is easier to manufacture, is more compact, and the capacity of a lithium battery employing a cap of this structure is larger.

[0015] According to the second invention, by adopting the above technical solution, a more reasonable cap structure can be adopted, which can be used for small lithium batteries with different fixed voltages such as 1.5V for AA batteries and AAA batteries, and the solder part is electrically connected to the steel case, and the positive electrode conductive metal cap is electrically connected to the positive electrode of the cell, thereby forming an internal circuit circuit that can output different voltages such as 1.2V, 1.5V, 9V, etc. from the internal cell's 3.6V. The resulting lithium battery has better sealing performance, a high level of explosion-proof effect, and a larger battery capacity than the traditional cylindrical lithium battery with BMS board.

[0016] According to the third invention, all the above manufacturing processes are simple and convenient, and suitable for mass production of the lithium battery described in the present invention at low cost. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of a cylindrical lithium battery with a cylindrical lithium battery cap incorporating a BMS substrate according to Example 1 of the present invention (the battery insulating case is not shown). [Figure 2] FIG. 2 is an enlarged view of part A in FIG. [Figure 3] FIG. 3 is an exploded schematic diagram 1 (the battery insulating case is not shown) of a cylindrical lithium battery with a cylindrical lithium battery cap incorporating a BMS substrate according to Example 1 of the present invention. [Figure 4] FIG. 4 is an exploded schematic diagram 1 (the battery insulating case is not shown) of a cylindrical lithium battery with a cylindrical lithium battery cap incorporating a BMS substrate according to Example 1 of the present invention. [Figure 5] FIG. 5 is a cross-sectional view of a cylindrical lithium battery with a cylindrical lithium battery cap incorporating a BMS substrate according to Example 2 of the present invention (the battery insulating case is not shown). [Figure 6] FIG. 6 is an enlarged view of part B in FIG. [Figure 7]FIG. 7 is an exploded schematic diagram 1 (battery insulating case not shown) of a cylindrical lithium battery with a cylindrical lithium battery cap incorporating a BMS substrate according to Example 2 of the present invention. [Figure 8] FIG. 8 is an exploded schematic diagram 1 (battery insulating case not shown) of a cylindrical lithium battery with a cylindrical lithium battery cap incorporating a BMS substrate according to Example 2 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be further described below with reference to Figures 1 to 8. [Example]

[0019] Example 1 As shown in FIGS. 1 to 4 , a cylindrical lithium battery cap incorporating a BMS substrate is particularly suitable for AA batteries, and includes a cap mechanism 1, the cap mechanism 1 including a cap case 11, a positive electrode conductive metal cap 12, a BMS component 13, and a plastic bracket 14 used to protect the BMS component 13; The cap case 11 is used to connect to the inside of a steel case 21 of a cylindrical lithium battery, The positive electrode conductive metal cap 12 is located inside the cap case 11 and is used for electrical connection with the positive electrode 221 of the lithium battery cell. The positive electrode conductive metal cap 12 includes a grooved body portion 121 and a flange portion 122 integrally formed with the body portion 121. An explosion-proof relief part 123 is provided in the center of the positive electrode conductive metal cap 12 on the side facing the positive electrode of the cell, and the thickness of the explosion-proof relief part 123 is thinner than the thickness of other parts of the positive electrode conductive metal cap 12. When the internal pressure of the cell 22 exceeds a threshold value, the explosion-proof relief part 123 can prevent an explosion caused by excessive pressure inside the battery. The BMS component 13 includes a BMS motherboard part 131 and a positive electrode insulating cap part 132. The BMS motherboard part 131 is provided with a plurality of electronic components 133 that form a BMS management system. The positive electrode insulating cap part 132 is installed facing the positive electrode side of the cylindrical lithium battery and is hermetically connected to the cap case 11 and the steel case 21 of the cylindrical lithium battery. The motherboard and the positive electrode insulating cap part 132 are integrally molded or separately installed. The electronic components 133 and the plastic bracket 14 on the BMS motherboard part 131 are installed in the groove of the main body part 121, and the BMS motherboard part 131 and the positive electrode insulating cap part 132 are provided with an air-to-air slot 134 that communicates with the outside air. After the explosion-proof relief part 123 explodes, the explosion-proof relief part 123 is electrically connected to the slot 134, and the high-pressure gas is discharged from the inside of the cell 22 through the positive electrode conductive metal cap 12 and the slot 134 (the slot 134 here is the formation hole of the lithium battery). The positive electrode insulating cap portion 132 is located above the positive electrode conductive metal cap 12 and is abutted against the flange portion 122. The positive electrode conductive metal cap 132 is hermetically fitted into the cap case 11. An embossed portion 1221 is provided on the side of the flange portion 122 facing the positive electrode insulating cap portion 132. The protruding surface of the embossed portion 1221 abuts against the positive electrode insulating cap portion 132. The embossed portion 1221 makes the contact between the positive electrode conductive metal cap 12 and the BMS component (13) more stable, ensuring stable current conduction. The BMS motherboard part 131 and the plastic bracket 14 are located between the positive electrode conductive metal cap 12 and the positive electrode insulating cap part 132. The positive electrode insulating cap part 132 is located above the positive electrode conductive metal cap 12 and faces the positive electrode side of the battery. The positive electrode insulating cap part 132 is hermetically fitted into the cap case 11, and the BMS component 13 is electrically connected to the steel case 21. Specifically, a solder part 1321 is provided around the side of the positive electrode insulating cap part 132 facing the positive electrode conductive pillar of the battery, and the solder part 1321 is electrically connected to the steel case 21. The positive electrode conductive metal cap 12 is hermetically connected to the positive electrode insulating cap part 132 and the cap case 11, respectively. [Example]

[0020] Example 2 As shown in Figures 5 to 8, a cylindrical lithium battery cap with a built-in BMS motherboard is particularly suitable for an AA battery, and includes a cap mechanism 1, which includes a cap case 11, a positive electrode conductive metal cap 12, a BMS component 13, and a metal conductive ring 15 used to protect the BMS component 13. (The positive electrode conductive metal cap 12 is preferably made of soft aluminum material. Therefore, the positive electrode conductive metal cap 12 is soft and its space on an AA battery is too small. To increase the space, a support member needs to be added to increase the installation space for electronic components. In addition, a positive electrode metal conductive ring 15 needs to be installed to ensure the conductive function.) The cap case 11 is used to connect to the inside of a steel case 21 of a cylindrical lithium battery, The positive electrode conductive metal cap 12 is located in the cap case 11 and is used for electrical connection with the positive electrode 221 of the lithium battery cell. The positive electrode conductive metal cap 12 includes a grooved main body 121 and a flange 122 integrally molded with the main body 121. An explosion-proof relief part 123 is provided in the center of the side of the positive electrode conductive metal cap 12 facing the positive electrode of the cell. The thickness of the explosion-proof relief part 123 is thinner than the thickness of other parts of the positive electrode conductive metal cap 12. When the internal pressure of the cell 22 exceeds a threshold value, the explosion-proof relief part 123 can prevent an explosion caused by excessive pressure inside the battery. The BMS component unit 13 includes a BMS motherboard unit 131 and a positive electrode insulating cap unit 132. A plurality of electronic components 133 forming a BMS management system are installed on the BMS motherboard unit 131. The positive electrode insulating cap unit 132 is installed facing the positive electrode side of the cylindrical lithium battery and is hermetically connected to the cap case 11 and the steel case 21 of the cylindrical lithium battery. The BMS motherboard and the positive electrode insulating cap unit 132 are integrally molded or separately installed. The electronic components 133 on the BMS motherboard part 131 are installed facing the groove, and the metal conductive ring 15 is abutted and connected between the flange part 122 and the positive electrode insulating cap part 132. The BMS motherboard part 131 and the positive electrode insulating cap part 132 are provided with an air-to-air slot 134 that communicates with the outside air. After the explosion-proof relief part 123 explodes, the explosion-proof relief part 123 is conductive with the slot 134, and the high-pressure gas is discharged from the inside of the cell 22 through the positive electrode conductive metal cap 12 and the slot 134. The positive electrode insulating cap portion 132 is located above the positive electrode conductive metal cap 12 and abuts against the flange portion 122. The positive electrode insulating cap portion 132 is hermetically fitted into the cap case 11. An embossed portion 1221 is provided on the side of the flange portion 122 facing the positive electrode insulating cap portion 132. The protruding surface of the embossed portion 1221 abuts against the metal conductive ring 15. The embossed portion 1221 makes the contact between the positive electrode conductive metal cap 12 and the metal conductive ring 15 more stable, thereby ensuring the stability of current conduction of the BMS component 13.

[0021] The BMS motherboard part 131 and the metal conductive ring 15 are located between the positive electrode conductive metal cap 12 and the positive electrode insulating cap part 132. The positive electrode insulating cap part 132 is located above the positive electrode conductive metal cap 12 and is hermetically fitted into the cap case 11 facing the positive electrode side of the battery, and the BMS component 13 is electrically connected to the steel case 21. More specifically, a solder part 1321 is provided around the positive electrode insulating cap part 132 on the positive electrode conductive column side facing the battery, and this solder part 1321 is electrically connected to the steel case 21. The positive electrode conductive metal cap 12 is hermetically connected to the metal conductive ring 15 and the cap case 11 . [Example]

[0022] Example 3 This is a cylindrical lithium battery comprising a battery insulating case, a steel case 21 placed inside the battery insulating case, and a cell 22 placed inside the steel case 21, the negative electrode 222 of the cell is electrically connected to the steel case 21 so that the entire steel case 21 serves as the negative electrode of the cylindrical lithium battery, a cylindrical lithium battery cap incorporating the BMS substrate described in Example 1 is provided inside the steel case 21, the positive electrode 221 of the cell is electrically connected to the positive electrode conductive metal cap 12, and a solder portion 1321 is provided around the positive electrode conductive column side of the positive electrode insulating cap portion 132 facing the battery, and the solder portion 1321 is electrically connected to the steel case 21.

[0023] Here, the steel case is the negative electrode, and a steel case inner ring is provided on the side of the steel case facing the battery positive electrode. The steel case inner ring is crimped onto the solder part. The solder part has a certain thickness, and since the solder is a soft metal, after crimping, a part of the steel case inner ring is fitted into the solder part, which ensures reliable contact with the steel case and can meet the demand for overcurrent. The voltage range of the cell 22 itself is 3V-4.2V, with low energy at low voltage, reaching 4.2V when fully charged. The solder joint is electrically connected to the steel case 21, and the positive electrode conductive metal cap 12 is electrically connected to the positive electrode of the cell 22, thereby forming an internal circuit circuit that can be used to output the 3.6V of the cell 22 as different voltages such as 1.2V, 1.5V, and 9V. [Example]

[0024] Example 4 A cylindrical lithium battery includes a battery insulating case, a steel case 21 installed inside the battery insulating case, and a cell 22 installed inside the steel case 21, wherein the negative electrode 222 of the cell is electrically connected to the steel case 21, and the steel case 21 is fitted with a cylindrical lithium battery cap incorporating the BMS substrate described in Example 2, and the positive electrode 221 of the cell is electrically connected to the positive electrode conductive metal cap 12. [Example]

[0025] Example 5 A cylindrical lithium battery manufacturing process used in manufacturing the cylindrical lithium battery described in Example 3 or Example 4, comprising the following steps: A cap manufacturing process, including: Step 1: Install multiple electronic components on the BMS motherboard, and then complete the installation process on the BMS motherboard. Step 2: After applying waterproof paint to the plastic bracket, spray the sealant on it. After the sealant has dried, soften the plastic bracket. Step 3: Insert the positive electrode conductive metal cap into the plastic bracket with the sealant dried, and then install the BMS component to complete the manufacturing of the lithium battery cap with the built-in BMS component. A battery core manufacturing process, including: Step 1, mix ingredients, Step 2, application, Step 3, create a sheet, Step 4, winding, Finished product assembly process, including: Step 1: Place the cell in the steel case, and laser weld the negative electrode of the cell to the bottom of the inside of the steel case. Step 2: Roll the grooves in the steel case to fix the cells inside and prevent them from falling. Step 3: Laser weld the positive electrode of the cell to the back edge of the positive electrode conductive metal cap. Step 4: Dry the components with the caps welded to remove moisture, then inject the electrolyte. Step 5: Roll the entire opening of the steel case inward, press it against the solder part of the positive electrode insulating cap, and seal it so that the negative electrode is conductive. Step 6: Cover the packaging with the corresponding printing sleeve according to the customer's requirements, and print the code. Step 7: Put it in the cabinet and perform chemical conversion treatment and aging treatment. Step 8: Fully charge the rechargeable lithium batteries after aging treatment, and separate batteries of different capacities and voltages. Step 9: Pack the battery in a special packaging box for rechargeable lithium batteries to ensure safe storage and transportation. The above manufacturing process is simple and convenient, and suitable for mass production of the lithium battery according to the present invention at low cost.

[0026] The above embodiments are merely preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Any insubstantial modifications and substitutions made by those skilled in the art based on the present invention also fall within the scope of protection claimed by the present invention. [Explanation of symbols]

[0027] 1: cap mechanism, 11: cap case, 12: positive electrode conductive metal cap, 121: main body, 122: flange, 1221: embossed portion, 123: explosion-proof relief portion, 13: BMS component, 131: BMS motherboard portion, 132: positive electrode insulating cap portion, 1321: solder portion, 133: electronic component, 134: slot, 14: plastic bracket, 21: steel case, 22: cell, 221: positive electrode of cell, 222: negative electrode of cell

Claims

1. A cylindrical lithium battery cap incorporating a BMS substrate, comprising a cap mechanism (1), the cap mechanism (1) comprising a cap case (11), a positive electrode conductive metal cap (12), a BMS component (13), and a plastic bracket (14) or a metal conductive ring (15) used to protect the BMS component (13); The cap case (11) is used to connect to the inside of the steel case (21) of a cylindrical lithium battery; The positive electrode conductive metal cap (12) is located inside the cap case (11) and is used for electrical connection with the positive electrode of the lithium battery cell (22); The BMS component (13) comprises a BMS motherboard part (131), a positive electrode insulating cap part (132), and a plurality of electronic components (133) installed on the BMS motherboard part (131) and forming a BMS management system, the positive electrode insulating cap part (132) is installed facing the positive electrode side of the cylindrical lithium battery and is hermetically connected to the cap case (11) and the steel case (21) of the cylindrical lithium battery, the BMS motherboard (131) and the positive electrode insulating cap part (132) are integrally formed or installed separately, The positive electrode insulating cap portion (132) is located above the positive electrode conductive metal cap (12) and faces the positive electrode side of the battery, the positive electrode insulating cap portion (132) is hermetically fitted with the cap case (11), and the BMS component (13) is electrically connected to the steel case; The positive electrode conductive metal cap (12) includes a grooved body portion (121) and a flange portion (122) integrally molded with the body portion (121), and electronic components (133) on the BMS motherboard portion (131) are installed facing the groove; When the plastic bracket (14) is used, the BMS motherboard part (131) and the plastic bracket (14) are located between the positive electrode conductive metal cap (12) and the positive electrode insulating cap part (132), and the positive electrode insulating cap part (132) abuts and connects to the flange part (122); When a metal conductive ring (15) is used, the BMS motherboard (131) and the metal conductive ring (15) are located between the positive electrode conductive metal cap (12) and the positive electrode insulating cap part (132), and the metal conductive ring (15) is located between the flange part (122) and the BMS motherboard part (131).

2. The cylindrical lithium battery cap with a built-in BMS substrate according to claim 1, characterized in that an embossed portion (1221) is provided on the side of the flange portion (122) facing the positive electrode insulating cap portion (132).

3. The cylindrical lithium battery cap with a built-in BMS substrate according to claim 1, wherein the positive electrode conductive metal cap (12) is hermetically connected to the positive electrode insulating cap part (132) and the cap case (11).

4. The cylindrical lithium battery cap with a built-in BMS substrate according to claim 1, characterized in that the positive electrode conductive metal cap (12) is hermetically connected to a plastic bracket (14) and a cap case (11).

5. 2. The cylindrical lithium battery cap with a built-in BMS substrate according to claim 1, wherein an explosion-proof relief part (123) is provided in the center of the positive electrode conductive metal cap (12) on the side facing the positive electrode of the cell, the thickness of the explosion-proof relief part (123) is thinner than the thickness of other positions of the positive electrode conductive metal cap (12), and when the internal pressure of the cell (22) exceeds a threshold value, the explosion-proof relief part (123) can prevent an explosion caused by excessive pressure inside the battery.

6. 2. The cylindrical lithium battery cap with a built-in BMS board according to claim 1, wherein the BMS motherboard part (131) and the positive electrode insulating cap part (132) are provided with an air-to-air slot that communicates with the outside air, and after the explosion-proof relief part explodes, the explosion-proof relief part is conductive with the slot.

7. a cylindrical lithium battery comprising: a battery insulating case; a steel case (21) placed inside the battery insulating case; and a cell (22) placed inside the steel case (21), wherein a negative electrode (222) of the cell is electrically connected to the steel case (21); a cylindrical lithium battery cap incorporating the BMS substrate according to any one of claims 1 to 6 is provided inside the steel case (21); a positive electrode (221) of the cell is electrically connected to a positive electrode conductive metal cap (12); a solder portion is provided around the positive electrode insulating cap portion (132) on a side of the positive electrode conductive column facing the battery, the solder portion being electrically connected to the steel case (21); and a solder portion is provided around the positive electrode insulating cap portion (132) on a side facing the positive electrode conductive column of the battery, the solder portion being electrically connected to the steel case (21).

8. 9. The cylindrical lithium battery according to claim 8, wherein the motherboard part and the positive electrode insulating cap part (132) are provided with a chemical formation hole that is used for charging and discharging the lithium battery to activate the lithium battery and is used during a chemical formation treatment of the lithium battery.

9. A process for producing a cylindrical lithium battery according to claim 8, comprising the following steps: The manufacturing process of the cap includes: Step 1: Mounting a plurality of electronic components (133) on the BMS motherboard unit (131) to complete the mounting process of the BMS motherboard unit (131); Step 2: After applying waterproof coating to the plastic bracket (14), spray the sealant on it. After the sealant has dried, soften the plastic bracket. Step 3: Insert the positive electrode conductive metal cap (12) into the plastic bracket (14) on which the sealant has dried, and then attach the BMS component (13) to complete the manufacture of the lithium battery cap incorporating the BMS component (13); The manufacturing process of the battery winding core includes: Step 1: Mix ingredients Step 2: Apply Step 3: Create a sheet. Step 4, winding, The final product assembly process includes: Step 1: Insert the cell (22) into the steel case (21) and laser weld the negative electrode (222) of the cell to the inside bottom of the steel case (21); Step 2: Roll the grooves in the steel case (21) so that the cell (22) is fixed inside the steel case (21) and does not fall off. Step 3: Laser welding the positive electrode (221) of the cell to the rear edge of the positive electrode conductive metal cap (12); Step 4: Dry the components with the caps welded to remove moisture, then inject the electrolyte. Step 5: The entire opening of the steel case (21) is rolled inward and pressed against the solder part of the positive electrode insulating cap part (132), sealing the negative electrode so that it is conductive. Step 6: Cover the packaging with the corresponding printing sleeve according to your requirements, and print the code. Step 7: Put it in a cabinet and perform chemical conversion treatment and aging treatment. Step 8: Fully charge the rechargeable lithium batteries after aging treatment, and separate the batteries with different capacities and voltages. Step 9: Pack the battery in a special packaging box for rechargeable lithium batteries to ensure safe storage and transportation.

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