Cylindrical lithium battery cap device with built-in BMS (Battery Management System) board

Abstract

The utility model relates to the technical field of cylindrical lithium batteries, in particular to a cylindrical lithium battery cap device with a built-in BMS (Battery Management System) board, which comprises a cap mechanism, a cathode ring is arranged in the cap mechanism, and the cathode ring is electrically connected with a steel shell of the cylindrical lithium battery. The negative electrode ring and the steel shell can be subjected to laser welding, and rapid and large-scale production is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of cylindrical lithium batteries, in particular to a cylindrical lithium battery cap device with a built-in BMS board. Background Art

[0002] Cylindrical lithium battery is a common secondary battery, also called lithium-ion battery. It consists of a cylindrical container, which contains components such as positive electrode, negative electrode and electrolyte. The battery cap is the component structure of the cylindrical lithium battery, which performs the sealing process on the top.

[0003] At present, there are cylindrical lithium batteries without BMS system and with BMS system on the market. Battery Management System (BMS) is an important part of modern battery technology, especially in electric vehicles and renewable energy storage systems. The main function of BMS is to ensure the safety and stability of battery packs and improve energy efficiency.

[0004] Since the dimensions of lithium batteries are standardized, such as No. 5 and No. 7 batteries, if a cylindrical lithium battery needs to be equipped with a BMS system, the lithium battery cell needs to be reduced in size. After the independently sealed battery cell and independent BMS system are completed, the two need to be installed in the battery housing and electrically connected. For this type of cylindrical lithium battery with a BMS system, the BMS system is installed separately from the battery cell, resulting in a greatly reduced battery cell, reduced battery capacity, increased overall battery weight, high manufacturing costs, and complex installation during production and processing, which limits the scope of battery application and performance.

[0005] Therefore, how to make a miniaturized rechargeable cylindrical lithium battery with a built-in BMS board has become a technical challenge in this field.

[0006] The applicant has applied for an invention patent with application number CN202310996046.2 and the name of "A cylindrical lithium battery cap with built-in BMS board", which includes: a steel shell; a cap with a BMS board connected to the inner side of the steel shell; a plastic explosion-proof bracket, the lower end of which is connected to the inside of the cap with the BMS board; a positive conductive metal cover, the lower end of which is connected to the inside of the plastic explosion-proof bracket; a PCBA board, connected to the upper outer edge of the positive conductive metal cover; the middle of the lower end of the PCBA board It extends into the middle of the positive conductive metal cover, and the PCBA board includes a BMS chip, a power management chip, a battery control chip, a display chip, and a multi-way protector; the outer edge of the upper end of the PCBA board is connected to a negative electrode hardware ring; the opening of the steel shell is rolled inward in a whole circle and contacts the negative electrode hardware ring to conduct the negative electrode; the inner wall of the negative electrode hardware ring is connected to the positive electrode plastic cover, there is damping between the two, and the middle part of the positive electrode plastic cover is an open hole structure, and it fits with the external positive electrode hardware column. The present invention solves the cap structure of the existing cylindrical lithium battery. In order to meet the use requirements, the BMS used for monitoring is built-in to simplify the installation steps.

[0007] In the above scheme, the negative electrode hardware ring is welded to the opening of the steel shell by soldering. However, since the opening of the steel shell is in an inwardly rolled state, it is difficult to perform manual welding. In addition, sufficient time is required during the welding process to ensure that the solder is fully melted and wets the object to be welded. Therefore, it takes a lot of time and is not conducive to large-scale production. Utility Model Content

[0008] In order to solve the problems in the above-mentioned background technology, the utility model provides a cylindrical lithium battery capping device with a built-in BMS board, which can save production time and facilitate large-scale production.

[0009] The utility model solves the technical problem by adopting the following scheme: a cylindrical lithium battery capping device with a built-in BMS board, comprising a capping mechanism, wherein a negative electrode ring is arranged inside the capping mechanism;

[0010] The capping mechanism is composed of a capping shell, a positive conductive metal cover, a BMS mainboard, and a plastic explosion-proof bracket for protecting the electronic components at the bottom of the BMS mainboard;

[0011] The cap housing is used to be connected to the inner side of the steel shell of the cylindrical lithium battery;

[0012] The positive electrode conductive metal cover is located in the cap housing and is used to be electrically connected to the positive electrode of the lithium battery;

[0013] The plastic explosion-proof bracket is located inside the positive conductive metal cover;

[0014] The BMS mainboard is located at the top of the plastic explosion-proof bracket;

[0015] The negative electrode ring is located at the top of the BMS main board, the negative electrode ring is tightly connected to the cap shell, and the negative electrode ring is electrically connected to the steel shell;

[0016] The steel shell is bent inward at the top and gradually extends toward the bottom until its end abuts against the top surface of the negative electrode ring.

[0017] In summary, the beneficial effects of the utility model are: the negative electrode ring and the steel shell can be laser welded to achieve rapid and large-scale production.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of this embodiment;

[0020] Figure 2 It is a structural schematic diagram of this embodiment.

[0021] In the figure: 1. capping mechanism; 11. capping shell; 12. positive electrode conductive metal cover; 13. BMS main board; 14. plastic explosion-proof bracket; 2. steel shell; 3. negative electrode ring. DETAILED DESCRIPTION

[0022] In order to make the content of the utility model more clearly understood, the utility model is further described below based on specific embodiments in combination with the accompanying drawings.

[0023] It should be noted that the terms "center", "upper", "lower", "front", "back", "left", "right", "inner", "outer" and the like used herein to indicate directions or positional relationships are based on directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. Unless otherwise specified, "plurality" means two or more.

[0024] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood by specific circumstances.

[0025] like Figure 1 to Figure 2 As shown, the cylindrical lithium battery capping device with built-in BMS board in this embodiment includes a capping mechanism 1, and a negative electrode ring 3 is arranged inside the capping mechanism.

[0026] like Figure 2 As shown, the capping mechanism 1 is composed of a capping shell 11 , a positive conductive metal cover 12 , a BMS mainboard 13 , and a plastic explosion-proof bracket 14 for protecting electronic components at the bottom of the BMS mainboard 13 .

[0027] Specifically, Figure 1 As shown, the cap housing 11 of this embodiment is used to connect to the inner side of the steel shell 2 of the cylindrical lithium battery; the positive conductive metal cover 12 is located in the cap housing 11 and is used to be electrically connected to the positive electrode of the lithium battery. The BMS mainboard 13 is located at the top of the plastic explosion-proof bracket 14; the BMS mainboard 13 includes a BMS mainboard, and a positive insulating cover provided on the BMS mainboard, and several electronic components forming a management system. The electronic components are arranged at the bottom of the BMS mainboard and located in the positive conductive metal cover 12, and the plastic explosion-proof bracket 14 is surrounded by the outer periphery of the electronic components and fixed in the positive conductive metal cover 12; the positive insulating cover is arranged toward the positive side of the cylindrical lithium battery and forms a sealed connection with the cap housing 11 and the steel shell 2 of the cylindrical lithium battery, and the BMS mainboard 13 and the positive insulating cover are integrally formed or separately arranged; the negative ring 3 is located at the top of the BMS mainboard 13, the negative ring 3 is tightly connected to the cap housing 11, and the negative ring 3 is electrically connected to the steel shell 2.

[0028] like Figure 1 As shown, the steel shell 2 of this embodiment is bent inward at the top and gradually extends to the bottom until its end abuts against the top surface of the negative electrode ring 3. The steel shell 2 and the negative electrode ring 3 can be laser welded. Laser welding is a non-contact process that does not require physical contact with the welding workpiece. Mechanical wear and deformation can be reduced by laser welding. In addition, laser welding can produce smooth and uniform welds to form high-quality welds, and laser welding is fast, which can reduce production time and facilitate large-scale production.

[0029] The embodiments described above are only preferred implementation modes of the present utility model and cannot be used to limit the protection scope of the present utility model. Any non-substantial changes and modifications made by technicians in this field on the basis of the utility model shall fall within the protection scope of the present utility model.

Claims

1. A cylindrical lithium battery capping device with a built-in BMS board, comprising a capping mechanism (1), characterized in that: A negative electrode ring (3) is provided in the capping mechanism; The capping mechanism (1) is composed of a capping shell (11), a positive conductive metal cover (12), a BMS mainboard (13), and a plastic explosion-proof bracket (14) for protecting electronic components at the bottom of the BMS mainboard (13); The cap housing (11) is used to be connected to the inner side of the steel shell (2) of the cylindrical lithium battery; The positive electrode conductive metal cover (12) is located inside the cap housing (11) and is used for being electrically connected to the positive electrode of the lithium battery; The plastic explosion-proof bracket (14) is located inside the positive electrode conductive metal cover (12); The BMS mainboard (13) is located at the top of the plastic explosion-proof bracket (14); The negative electrode ring (3) is located at the top of the BMS main board (13), the negative electrode ring (3) is tightly connected to the cap shell (11), and the negative electrode ring (3) is electrically connected to the steel shell (2); The steel shell (2) is bent inward at the top and gradually extends toward the bottom until its end abuts against the top surface of the negative electrode ring (3).

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