Cylindrical lithium ion power battery with high energy ratio and long service lifetime

Abstract

The invention discloses a cylindrical lithium ion power battery with high energy ratio and long service lifetime. The height-diameter ratio of the cylindrical lithium ion power battery is 3.8-4.2. A battery core of the cylindrical lithium ion power battery comprises a positive coating, a positive tab, a negative coating, a negative tab and a diaphragm, wherein the diaphragm is arranged between a positive electrode and a negative electrode, the negative coating is wider than the positive coating and asymmetrically coats the positive coating, the distance, exceeding the front end of the positive coating, of the negative coating at a positive end is smaller than the distance, exceeding the front end of the positive coating, of the negative coating at a negative end, the battery core is accommodated in a closed space formed by an aluminum shell and a cover plate, the cover plate is sealed by dual rivets, the cover plate is provided with a groove at a position where pole posts are riveted, the groove is used for filling an insulation material at a riveting position, and a bevel angle is formed on the end surface of the aluminum shell. The invention provides the cylindrical lithium ion power battery with high energy ratio and long service lifetime, the capacity of a single battery is improved, meanwhile, the safety of the battery is considered; and the riveting mode of the cover plate and the end surface processing technique of the aluminum shell are optimized, the processing difficulty of the battery is reduced, and the production efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, in particular to a cylindrical lithium-ion power battery with high energy ratio and long service life. Background technique [0002] With the country's support and promotion of the new energy vehicle industry, the market's demand for lithium batteries is also increasing, and higher requirements are placed on the capacity and life of lithium-ion batteries. Cylindrical lithium-ion batteries have a higher filling rate than square lithium-ion batteries, so they have the characteristics of high energy ratio. However, the traditional 18650 batteries, due to their low capacity, require a large number of batteries for bicycles, and the production capacity is far from meeting the market demand. , and the BMS control system is complex and has great potential safety hazards. On the other hand, traditional cylindrical lithium-ion batteries mostly use ultrasonic spot welding to weld the tabs. The n...

AI Technical Summary

Problems solved by technology

Cylindrical lithium-ion batteries have a higher filling rate than square lithium-ion batteries, so they have the characteristics of high energy ratio, while traditional 18650 batteries, due to their low capacity, require a large number of batteries for bicycles, and their production capacity is far from meeting market demand. , and the BMS control system is complex, causing great potential safety hazards

On the other hand, traditional cylindrical lithium-ion batteries mostly use ultrasonic spot welding to weld the tabs. The number of tabs is small, and the battery flow area is limited, resulting in a large internal resistance of the battery and affecting the cycle life of the battery.

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