Rechargeable cylindrical lithium battery

Abstract

The utility model relates to the technical field of cylindrical lithium batteries, in particular to a rechargeable cylindrical lithium battery which comprises a battery cell and a conductive shell wrapped outside the battery cell, a positive terminal is arranged at one end of the battery cell, a negative terminal is arranged at the other end of the battery cell, and a negative cap is arranged at one end, close to the negative terminal, of the conductive shell. The negative electrode cap comprises a plastic support and a negative electrode conductive part electrically connected with the negative electrode terminal, an installation containing cavity is formed in the plastic support, a BMS assembly is installed in the installation containing cavity, and the positive electrode terminal and the BMS assembly are both electrically connected with the conductive shell. The utility model aims to reduce the risk that the BMS component in the cylindrical lithium battery is damaged by external force, slow down the aging process of the BMS component due to high temperature, and improve the overall durability and reliability of the battery.

Description

Technical Field

[0001] The utility model relates to the technical field of cylindrical lithium batteries, in particular to a rechargeable cylindrical lithium battery. Background Art

[0002] Rechargeable cylindrical lithium battery refers to a rechargeable and rechargeable battery with a cylindrical shape that uses lithium-ion technology as an energy storage mechanism. In order to ensure battery safety, extend battery life, and optimize battery performance, cylindrical lithium batteries equipped with BMS (Battery Management System) systems are now available on the market. The BMS system can monitor the voltage, current, temperature and other key parameters of each battery cell in real time to ensure that the battery operates within a safe operating range. Real-time monitoring of key parameters such as voltage, current, and temperature of each battery cell to ensure that the battery operates within a safe operating range. The charging state of the battery cells can also be adjusted to avoid overcharging or over-discharging of the battery cells, thereby extending the battery life.

[0003] The applicant has applied for an invention patent with application number CN202310996046.2 and the name is "A cylindrical lithium battery cap with built-in BMS component", which includes: a steel shell; a cap with a BMS board connected to the inner side of the steel shell; a plastic 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 bracket; a PCBA board, connected to the upper outer edge of the positive conductive metal cover; the middle part of the lower end of the PCBA board extends To 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 hardware ring; the opening of the steel shell is rolled inward in a whole circle and contacts the negative hardware ring to conduct the negative electrode; the inner wall of the negative hardware ring is connected to the positive plastic cover, and there is damping between the two, and the middle of the positive plastic cover is an open hole structure, and it fits with the external positive hardware column. The utility model solves the existing cap structure of cylindrical lithium batteries. In order to meet the use requirements, the BMS used for monitoring is built-in to simplify the installation steps.

[0004] However, the above solution integrates structures including the BMS board inside the top cap of the lithium battery. It is now found that the presence of the positive conductive column outside the cap makes the top geometric contour more prominent; during transportation, the top is more likely to contact foreign objects or the ground, increasing the risk of collision and easily causing damage to the BMS inside the top cap. During charging, lithium ions move from the positive electrode to the negative electrode, and during discharge, they move from the negative electrode to the positive electrode. Therefore, the positive electrode usually undergoes higher electrochemical reactions and energy conversions, thereby generating more heat, causing the BMS components close to the positive electrode to experience performance degradation or aging problems caused by high temperature. Utility Model Content

[0005] In order to solve the problems in the above background technology, the utility model provides a rechargeable cylindrical lithium battery.

[0006] The utility model solves the technical problem by adopting the following scheme: a rechargeable cylindrical lithium battery, comprising a battery cell and a conductive shell wrapped around the battery cell, wherein one end of the battery cell is provided with a positive terminal, and the other end is provided with a negative terminal, and one end of the conductive shell close to the negative terminal is provided with a negative electrode cap, and the negative electrode cap comprises a plastic bracket and a negative electrode conductive member electrically connected to the negative terminal, an installation cavity is provided in the plastic bracket, a BMS component is installed in the installation cavity, and the positive terminal and the BMS component are both electrically connected to the conductive shell.

[0007] By adopting the above technical solution, the BMS component is moved from the top cap to the installation cavity inside the negative electrode cap close to the negative terminal, which can effectively reduce the risk of impact caused by the top protruding structure during transportation and use, protect sensitive BMS components from external damage, and avoid aging due to high temperature in the positive electrode area, thereby improving the overall durability and reliability of the battery.

[0008] Furthermore, the BMS component includes a mainboard installed in the installation cavity and a plurality of patch components arranged on the mainboard, and the plurality of patch components constitute a BMS battery management system.

[0009] By adopting the above technical solution, the BMS system is constructed by directly mounting the chip components on the mainboard and integrated into the mounting cavity of the plastic bracket, so that the interior of the battery is compact to avoid reducing the battery capacity.

[0010] Furthermore, a negative conductive cover electrically connected to the negative terminal is provided in the installation cavity, and a fixed embedding groove is provided around the installation cavity. The negative conductive cover and the edge of the mainboard are both embedded in the fixed embedding groove to form a sealing structure.

[0011] By adopting the above technical solution, the battery can be prevented from being loosened due to external vibration and impact.

[0012] Furthermore, the negative electrode conductive cover is provided with a groove for accommodating each patch element on the side facing the BMS component, and a plastic explosion-proof bracket for protecting each patch element is also provided in the groove, and a protective groove adapted for each patch element is provided on the plastic explosion-proof bracket.

[0013] By adopting the above technical solution, the patch component can be prevented from shifting when the battery is in use.

[0014] Furthermore, the negative electrode conductive cover is provided with an anti-skid pattern on one edge facing the BMS component, and the anti-skid pattern abuts against the main board.

[0015] By adopting the above technical solution, the anti-skid pattern abuts against the mainboard to prevent the mainboard from shifting when the battery is in use.

[0016] Furthermore, a pressure relief portion is provided at the center of the negative conductive cover, the thickness of the pressure relief portion is smaller than the cover wall of the negative conductive cover, and the end surface of the pressure relief portion is provided with a cross indentation for automatically opening when the internal pressure of the battery abnormally rises to a preset threshold.

[0017] By adopting the above technical solution, when there is an abnormality inside the battery, the cross indentation as a weak point will rupture first to release the internal pressure, effectively preventing the battery from exploding or severely deforming.

[0018] In summary, the beneficial effects of the utility model are as follows: the utility model can significantly reduce the risk of the top being hit during transportation and use due to the top cap and the positive conductive column causing the top to protrude too much, by moving the top cap to the bottom and moving the BMS component from the top cap to the installation cavity inside the negative electrode cap near the negative terminal, thereby protecting the sensitive BMS component from damage by external forces, and moving the BMS component to the negative end with a lower temperature can avoid being too close to the positive end and causing excessive aging, thereby improving the overall durability and reliability of the battery.

[0019] 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

[0020] Figure 1 It is a schematic diagram of the structural decomposition of this embodiment;

[0021] Figure 2 is a cross-sectional view of this embodiment;

[0022] Figure 3 is a schematic diagram of the plastic explosion-proof bracket of this embodiment;

[0023] Figure 4 Schematic diagram of the negative electrode cap of this embodiment.

[0024] In the figure: 1. battery cell; 11. positive terminal; 12. negative terminal; 2. conductive shell; 3. negative electrode cap; 31. plastic bracket; 311. installation cavity; 312. fixed groove; 32. negative electrode conductive part; 4. BMS component; 41. main board; 42. patch component; 5. negative electrode conductive cover; 51. groove; 52. anti-slip pattern; 53. pressure relief part; 531. cross indentation; 6. plastic explosion-proof bracket; 61. protection groove. DETAILED DESCRIPTION

[0025] 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.

[0026] 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.

[0027] 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.

[0028] like Figures 1 to 4 As shown, a rechargeable cylindrical lithium battery comprises a battery cell 1 and a conductive shell 2 wrapped around the battery cell 1, a positive terminal 11 is provided at one end of the battery cell 1, and a negative terminal 12 is provided at the other end, wherein the conductive shell 2 of this embodiment is provided with a negative electrode cap 3 at one end close to the negative terminal 12, the negative electrode cap 3 comprises a plastic bracket 31 and a negative electrode conductive member 32 electrically connected to the negative terminal 12, a through structure is formed between the plastic bracket 31 and the negative electrode conductive member 32, an installation cavity 311 is provided in the plastic bracket 31, a BMS component 4 is installed in the installation cavity 311, and the positive terminal 11 and the BMS component 4 are both electrically connected to the conductive shell 2.

[0029] In this embodiment, the cap structure is set at the bottom of the positive conductive column facing away from the top, and the BMS component 4 is moved from the top cap to the installation cavity 311 inside the negative cap 3 near the negative terminal 12, which can effectively reduce the risk of impact caused by the top protruding structure during transportation and use, protect the sensitive BMS component 4 from external force damage, and thus improve the overall durability and reliability of the battery. And because the conductive shell 2 is connected to the positive terminal 11 of the internal battery cell 1, the entire conductive shell 2 can be positive and electrically connected to the BMS component 4, and the negative terminal 12 is directly connected to the BMS component 4, which is convenient for detecting the internal battery cell 1.

[0030] like Figure 1 As shown, the BMS assembly 4 of this embodiment includes a mainboard 41 installed in the installation cavity 311 and a plurality of patch components 42 arranged on the mainboard 41, and the plurality of patch components 42 constitute a BMS battery management system. The mainboard 41 of the BMS and the patch components 42 are integrated into the installation cavity 311 of the plastic bracket 31, which greatly improves the utilization rate of the internal space of the battery, makes the battery design more compact, and avoids taking up too much battery size and reducing the battery capacity. The patch components 42 are directly mounted on the mainboard 41 to improve the stability of the BMS system.

[0031] like Figure 1 and Figure 2 As shown, a negative electrode conductive cover 5 electrically connected to the negative electrode terminal 12 is also provided in the installation cavity 311 of this embodiment, and a fixed embedding groove 312 is also provided on the periphery of the installation cavity 311, and the negative electrode conductive cover 5 and the edge of the main board 41 are both embedded in the fixed embedding groove 312 to form a sealing structure. The negative electrode conductive cover 5 can establish an electrical connection between the negative electrode terminal 12 and the BMS main board 41, and the sealing design of the negative electrode conductive cover 5 and the edge of the main board 41 embedded in the fixed embedding groove 312 enhances the connection stability between the components, and even when the battery is subjected to external mechanical effects such as vibration and impact, the internal structure can be kept stable.

[0032] like Figure 3 As shown, the negative electrode conductive cover 5 of this embodiment is provided with a groove 51 for accommodating each patch element 42 on the side facing the BMS component 4, and a plastic explosion-proof bracket 6 for protecting each patch element 42 is also provided in the groove 51, and a protective groove 61 adapted to each patch element 42 is provided on the plastic explosion-proof bracket 6. The plastic explosion-proof bracket 6 is made of plastic material, and a protective groove 61 adapted to the patch element 42 is provided at one end facing the BMS mainboard 41 to prevent the patch element 42 from shifting when the battery is used. In addition, an anti-slip pattern 52 is provided on the edge of the negative electrode conductive cover 5 facing the BMS component 4, and the anti-slip pattern 52 abuts against the mainboard 41, which can increase the friction coefficient between the negative electrode conductive cover 5 and the mainboard 41. When the battery is subjected to vibration or external force, the relative sliding between the two can be effectively prevented, and the position of the BMS component 4 can be kept stable.

[0033] like Figure 1 and Figure 4 As shown, a pressure relief portion 53 is provided at the center of the negative electrode conductive cover 5 of this embodiment, and the thickness of the pressure relief portion 53 is smaller than the cover wall of the negative electrode conductive cover 5, and a cross indentation 531 is provided on the end face of the pressure relief portion 53 for automatically opening when the internal pressure of the battery abnormally rises to a preset threshold. The design of the pressure relief portion 53 provides a safe pressure release channel for the battery. When gas accumulates inside the battery due to abnormal conditions and the pressure exceeds the preset threshold, the cross indentation 531 will rupture first as a weak point to release the internal pressure, effectively preventing the battery from exploding or severely deforming, and protecting the safety of users.

[0034] The beneficial effects of this embodiment are as follows: this embodiment effectively reduces the threat of external impact to sensitive electronic components by moving the BMS component 4 into the negative electrode cap 3 and equipping it with a pressure relief portion 53, while providing a pressure overload protection mechanism that can automatically release internal pressure in extreme cases, thereby significantly improving the safety of the battery during use.

[0035] 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 rechargeable cylindrical lithium battery, comprising a battery cell and a conductive shell wrapped around the battery cell, wherein one end of the battery cell is provided with a positive terminal and the other end is provided with a negative terminal, characterized in that: A negative electrode cap is provided at one end of the conductive shell close to the negative terminal. The negative electrode cap includes a plastic bracket and a negative electrode conductive member electrically connected to the negative terminal. An installation cavity is provided in the plastic bracket. A BMS component is installed in the installation cavity. The positive terminal and the BMS component are both electrically connected to the conductive shell.

2. A rechargeable cylindrical lithium battery according to claim 1, characterized in that: The BMS assembly includes a mainboard installed in the installation cavity and a plurality of patch components arranged on the mainboard, and the plurality of patch components constitute a BMS battery management system.

3. A rechargeable cylindrical lithium battery according to claim 2, characterized in that: A negative conductive cover electrically connected to the negative terminal is also provided in the installation cavity, and a fixed embedding groove is also provided on the periphery of the installation cavity. The negative conductive cover and the edge of the main board are both embedded in the fixed embedding groove to form a sealing structure.

4. A rechargeable cylindrical lithium battery according to claim 3, characterized in that: The negative electrode conductive cover is provided with a groove for accommodating each patch element on the side facing the BMS component, and a plastic explosion-proof bracket for protecting each patch element is also provided in the groove, and a protective groove adapted for each patch element is provided on the plastic explosion-proof bracket.

5. A rechargeable cylindrical lithium battery according to claim 4, characterized in that: The negative electrode conductive cover is provided with an anti-skid pattern on one edge facing the BMS component, and the anti-skid pattern abuts against the main board.

6. A rechargeable cylindrical lithium battery according to claim 5, characterized in that: A pressure relief portion is provided at the center of the negative conductive cover. The thickness of the pressure relief portion is smaller than the cover wall of the negative conductive cover. The end surface of the pressure relief portion is provided with a cross indentation for automatically opening when the internal pressure of the battery abnormally rises to a preset threshold.

Images