A method for improving arch amount of lithium ion cell

Abstract

The invention discloses a method for improving the arch magnitude of a lithium ion battery septum, which comprises the steps that an already-produced large lithium ion battery septum is rolled into amother roll which is then divided and cut into a plurality of sections of divided and cut rolls, then, unrolling to the lithium ion battery septum on the divided and cut roll is carried out by utilizing a front set of compression rollers, next, the unrolled strip septum is treated with heating and micro stretching by utilizing a front set of the compression rollers and a back set of the compression rollers and a heating device, afterwards, the septum after the heating and the micro stretching is treated with rolling again by utilizing the back set of the compression rollers. As the measurementthat the edge of the bent and transformative septum which generates a bias line is straightened is adopted, the arch magnitude of the lithium ion battery septum is improved; in addition, the wrinkling phenomenon of the surface of the lithium ion battery septum can be reduced by the heating and the micro stretching, and the planeness of the surface is also improved.

Description

technical field [0001] The invention relates to a production method of a lithium-ion battery diaphragm. Background technique [0002] The diaphragm used in lithium-ion batteries is a polyolefin microporous diaphragm. It is used in lithium-ion batteries to allow lithium ions to pass through the micropores on the diaphragm smoothly under the drive of charging and discharging voltage to realize battery life. Charging and discharging, and at the same time, the electrical insulation of the polyolefin material can be used to separate the positive and negative poles of the battery to avoid short circuits. [0003] As we all know, one process for manufacturers to produce lithium-ion battery separators is to first roll a large sheet of lithium-ion battery separators into a parent roll, and then cut it into multiple slitting rolls before leaving the factory. When using, the user unrolls the strip-shaped lithium-ion battery separator rolled on the slitting roll, cuts the lithium-ion b...

AI Technical Summary

Problems solved by technology

Obviously, the smaller the bow of the diaphragm, the better, otherwise, it will not be able to isolate the positive and negative poles of the battery well, and it will easily cause a short circuit in the battery.

[0004] The above-mentioned processing method of directly rolling a large lithium-ion battery separator produced into a parent roll, and then cutting it into a roll of slitting rolls, due to the internal stress of the separator that has been rolled into a parent roll , which will cause a large amount of bowing of the diaphragm on the cut slitting roll, resulting in a lower yield of the processed diaphragm