Battery diaphragm, preparation method and application thereof, and battery

Abstract

The invention provides a battery diaphragm, a preparation method and application thereof, and a battery, and relates to the technical field of batteries. The battery diaphragm provided by the invention comprises a base membrane and a liquid absorption layer arranged in the central area of the base membrane, the liquid absorption layer is mainly composed of at least one of polyvinylidene fluoride, polyethylene or polypropylene; the ratio of the area of the liquid absorption layer to the area of the base film is 1: (4-16); the thickness of the liquid absorption layer is 5-8 microns; and the liquid absorption rate of the base film area covered with the liquid absorption layer on the surface is 113-145%. The battery diaphragm can promote the uniform distribution of the electrolyte, improve the overall infiltration of a battery cell and inhibit the occurrence of side reactions by regulating and controlling the gradient difference of the electrolyte in the battery circulation process, so that the cycle performance of the battery is improved, and the cycle life of the battery is prolonged.

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