High-temperature resistant lithium ion battery and preparation method thereof

Abstract

The invention belongs to the technical field of a lithium ion battery, and particularly relates to a high-temperature resistant lithium ion battery and a preparation method thereof. The method comprises the following steps of tearing off a protection film on a surface of a battery cell subjected to capacity grading test; cleaning the surface of the battery cell so that no impurity on the surface of the battery cell is ensured; die-cutting a composite film to the composite film with same size as the battery cell; and pasting the composite film onto the surface of the battery cell, and pressingthe battery cell with a soft silica gel roller. The invention also provides the high-temperature resistant lithium ion battery. The lithium ion battery is prepared by the preparation method and comprises the battery cell and the composite film, wherein the composite film is pasted onto the surface of the battery cell and comprises a heat isolation film and a heat dissipation film. With the high-temperature resistant lithium ion battery and the preparation method thereof, provided by the invention, the high-temperature resistant performance of the lithium ion battery can be improved on the premise that an electrolyte structure is not changed, the service lifetime of the lithium ion battery is prolonged, and the application range of the battery is wider.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a high temperature resistant lithium ion battery and a preparation method thereof. Background technique [0002] Lithium-ion battery is a secondary battery with high energy density, high reliability, good processability and excellent environmental performance, and has been widely used in various portable electronic devices. Existing lithium-ion batteries include positive pole pieces, separators, negative pole pieces and electrolyte that are wound on top of each other, and the diaphragm is spaced between adjacent positive and negative pole pieces to insulate the positive and negative pole pieces, and is used to keep the electrolyte, The outer layer is packed with aluminum-plastic film. In the preparation process, the positive and negative electrodes are first prepared into slurry, and then coated on aluminum foil and copper foil respectively to make pole...

AI Technical Summary

Problems solved by technology

[0003] As the application fields of batteries become more and more extensive, the requirements for the use environment of batteries are becoming more and more stringent. Due to the influence of electrolyte, existing lithium-ion batteries cannot be used for a long time in a high temperature environment exceeding 80°C. Once the storage time is too long, the electrolyte will decompose in the high temperature environment, which will eventually cause the battery to be unusable; then this will not be able to meet the needs of some places where the battery needs to be used under high temperature conditions.

[0004] At present, the way to solve the high temperature resistance of lithium-ion batteries in the market is to change the electrolyte structure inside the battery, so that the battery can withstand high temperature environment, but the performance of lithium-ion batteries is greatly reduced due to the change of electrolyte structure, which seriously affects the use of batteries life