Lithium ion battery ceramic diaphragm coated with polyvinylidene fluoride, and preparation method therefor

Abstract

The invention discloses a lithium ion battery ceramic diaphragm coated with polyvinylidene fluoride. The lithium ion battery ceramic diaphragm comprises a base material diaphragm, wherein at least one surface of the base material diaphragm is coated with ceramic slurry; the ceramic diaphragm is prepared by the following steps of mixing and dispersing polyvinylidene fluoride and a dispersing agent at a weight ratio of 1 to 0.1-50 to obtain a dispersion glue solution; mixing and dispersing the dispersion glue solution and ceramic granules at a weight ratio of 1 to 0.1-10 to obtain ceramic slurry; and uniformly coating the surface of the base material diaphragm with the ceramic slurry, and drying the base material diaphragm to obtain the lithium ion battery ceramic diaphragm coated with polyvinylidene fluoride. The surface of the base material diaphragm of the lithium ion battery is coated with the ceramic diaphragm of polyvinylidene fluoride and ceramic granules, wherein the ceramic diaphragm is 0.1-10um in thickness; the ceramic diaphragm is compact in surface and uniform in thickness; polyvinylidene fluoride has a relatively high decomposition temperature, so that the diaphragm can be protected when the surface of the base material diaphragm is coated with the polyvinylidene fluoride; and therefore, the thermal resistance of the diaphragm is improved, so that the safety performance of the lithium ion battery is further improved.

Description

[0001] technical field

[0002] The invention belongs to the field of lithium ion batteries, in particular to a lithium ion battery ceramic diaphragm coated with polyvinylidene fluoride and a preparation method thereof. Background technique

[0003] Lithium-ion batteries have a series of advantages: high specific energy, long cycle life, no memory effect, no pollution to the environment, high safety, fast charging and discharging, etc., so they have become the characteristics of new power supply technology research in recent years. China's new energy vehicles are developing rapidly and have become the world's largest producer of new energy vehicles. In 2015, the sales volume of new energy vehicles in my country exceeded 300,000. In a pure electric vehicle, the cost of the power battery accounts for the entire vehicle cost. Nearly half, and recently there have been endless safety issues about the "heart" power battery of new energy vehicles, which puts forward more stringent r...

Images