Preparation method of cellulose coated lithium ion battery diaphragm

Abstract

The invention relates to a cellulose coated lithium ion battery diaphragm and a preparation method thereof. The preparation method comprises the steps that pulp is taken and subjected to beating and papermaking to form a matrix, after dissolving, the surface of a matrix is coated with dissolved pulp as a coating, a coated diaphragm is taken out after soaking in a coagulation bath for a period of time, then after most of water is removed through hot pressing treatment, vacuum drying is carried out until the water is completely removed, and the cellulose coated lithium ion battery diaphragm is prepared. According to the preparation method, a toxic organic solvent is not used in the preparation process, environmental protection is achieved, the prepared diaphragm is a fully degradable diaphragm with a thickness of 25-65 [mu]m, porosity of 65-85%, the electrolyte absorption rate greater than 400% and the ionic conductivity rate greater than 1.5mS cm<-1>, thermal stability is good, and thedimensional change rate is less than 0.1% for 3h under a condition of 200 DEG C.

Description

technical field [0001] The invention relates to a preparation method of a cellulose-coated lithium-ion battery diaphragm, which belongs to the intersection field of lithium-ion battery diaphragms and biomass materials. Background technique [0002] With the rapid development of portable electronic devices, electric vehicles, and energy storage devices, the performance requirements for batteries are getting higher and higher. Lithium-ion batteries are widely used because of their high energy density, long cycle life, small self-discharge, and no memory effect. As a key component of lithium-ion batteries, separator largely determines the performance of lithium-ion batteries. [0003] Although traditional commercial polyolefin separators, such as polypropylene film and polyethylene film, have some good characteristics, such as good chemical stability and closed-cell property, their shortcomings are also obvious, and it is difficult to meet the current society's demand for high...

AI Technical Summary

Problems solved by technology

Although the traditional paper-based materials have many good properties of cellulose, the paper-based materials made of ordinary fibers have problems such as too large pores and poor uniformity, making it difficult to use them as lithium-ion battery separators.