Lithium ion battery and cell thereof

Abstract

The invention discloses a cell of a lithium ion battery, which comprises a negative pole piece and a positive pole piece which are mutually overlaid and wound into a cylinder shape, and an isolation membrane between the negative pole piece and the positive pole piece, wherein the negative pole piece comprises a copper foil serving as a negative pole collector, and negative pole membranes coated on two surfaces of the copper foil; and the negative pole piece is also provided with a negative pole lead-out end which is fixed on the copper foil at the tail ends of the negative pole membranes and is pasted with a tape. By changing the position of the negative pole lead-out end to reduce the strain of an easily broken part of the copper foil, the grain boundary of the copper foil cannot be damaged in the charging process, lithium cannot insert into the grain boundary of the copper foil, and the copper foil cannot be broken neither; therefore, the internal resistance of the battery is greatly reduced when the battery is discharged, and the output of the voltage and current is ensured. The invention also discloses a lithium ion battery, which comprises the cell of the lithium ion battery, a steel shell covering the cell and electrolyte rushing into the steel shell.

Description

technical field [0001] The invention relates to a lithium ion battery and its battery core, in particular to a cylindrical lithium ion battery and its battery core which are not prone to breakage of pole pieces during charging. Background technique [0002] With the development of modern society, various mobile devices, such as video cameras, notebook computers, portable DVDs, digital cameras, etc., have become more and more widely used, thus forming an increasing demand for high-energy batteries. Since cylindrical batteries have the highest energy density, and lithium-ion batteries have many outstanding advantages such as light weight, large energy storage, high power, no pollution, long life, small self-discharge coefficient, and wide temperature range, the cylindrical lithium-ion Batteries are gradually gaining popularity as the best power source for mobile devices. [0003] see figure 1 with figure 2 , is a schematic diagram of the design structure of the positive an...

AI Technical Summary

Problems solved by technology

Due to the breakage of the pole piece, the battery cell of the lithium-ion battery will have no voltage output, cannot be discharged, and even a safety accident will occur.

Images