Cylindrical battery negative electrode end cover and cylindrical battery thereof

Abstract

The present invention provides a cylindrical battery negative electrode end cover and a cylindrical battery thereof. The cylindrical battery negative electrode end cover comprises a top cover sheet, ariveting block located above the top cover sheet and isolated from the top cover sheet, and a negative electrode column fixedly connected with the riveting block, wherein the top cover sheet is provided with a first negative electrode installation hole and a second negative electrode installation hole; the negative electrode columns comprise a first negative electrode column and a second negativeelectrode column which are respectively installed in the first negative electrode installation hole and the second negative electrode installation hole in an insulating manner, and the top cover sheet is provided with an overturning sheet located between the first negative electrode column and the second negative electrode column. When the internal air pressure of the battery exceeds a preset value, the overturning sheet is driven by air pressure to overturn towards the riveting block and is in contact with the riveting block so as to be electrically connected with the top cover sheet and thenegative pole. Due to the arrangement of the multi-negative-pole structure, the overcurrent capacity can be improved, the anti-rotation effect can be achieved, the riveting block can serve as an external output component and can also be combined with the overturning piece to form a safety device, the structure is good in compactness, the extra height size is not increased, the volume energy density is high, and the requirements of an existing high-energy-density battery can be met.

Description

technical field [0001] The invention relates to the field of energy storage devices, in particular to a negative terminal cover of a cylindrical battery and a cylindrical battery thereof. Background technique [0002] With the country's support and promotion of the new energy automobile industry, the market's demand for secondary batteries is also increasing, and higher requirements are placed on the capacity and life of secondary batteries. Cylindrical batteries have a higher filling rate than prismatic batteries, so they have the characteristics of high energy ratio. At present, some battery manufacturers use cylindrical batteries to replace prismatic batteries and apply them to automotive batteries. [0003] However, traditional cylindrical batteries, such as 18650 batteries, have a limited battery flow area, resulting in a relatively large internal resistance of the battery, which affects the cycle life of the battery. At the same time, if the ternary battery system wit...

AI Technical Summary

Problems solved by technology

The top cover of a cylindrical battery is usually circular, and its utilization rate is much lower than that of a square battery during installation. It is impossible to increase the current capacity by increasing the size of the pole, and the round top cover is integrated with a conductive A lot of volume will be wasted when components such as sheets and insulators are used, so it is difficult for cylindrical batteries to balance energy density and safety issues at the same time

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