A kind of all-cellulose lithium-ion battery separator and preparation method thereof

Abstract

The invention belongs to the intersection field of lithium-ion battery separators and biomass materials, and specifically discloses an all-cellulose lithium-ion battery separator and a preparation method thereof. The preparation method is as follows: taking nano-fibril cellulose, nano-microcrystalline cellulose and cellulose derivatives and dispersing them in water according to different mass fractions, and ultrasonically dispersing evenly to obtain a fiber suspension; preparing the fiber suspension by suction filtration A wet separator is formed, and the wet separator is subjected to hot-pressing treatment and then vacuum-dried to obtain the all-cellulose lithium-ion battery separator. The prepared diaphragm is a fully degradable diaphragm made of cellulose, with a thickness of 15-45 μm, a porosity of 45-80%, an electrolyte absorption rate greater than 400%, and an ion conductivity greater than 1.0 mS cm ‑1 , Good thermal stability, 3h dimensional change rate at 200°C is less than 0.1%.

Description

technical field [0001] The invention belongs to the intersection field of lithium-ion battery separators and biomass materials, and in particular relates to an all-cellulose lithium-ion battery separator and a preparation method thereof. Background technique [0002] With the rapid development of portable electronic devices, wearable devices, electric vehicles, and energy storage devices, the performance requirements of batteries are getting higher and higher. Lithium-ion batteries are widely used because of their high energy density, high operating voltage, 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 i...

AI Technical Summary

Problems solved by technology

[0003] Although traditional commercial polyolefin separators, such as polypropylene film and polyethylene film, have some good properties, 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 performance. Battery further needs

From a practical point of view, the two biggest disadvantages of polyolefin separators are surface hydrophobicity and thermal instability, which seriously affect the safety and performance of lithium-ion batteries.

In terms of development trends, traditional polyolefin separators are derived from petroleum-based raw materials, are non-renewable and non-degradable, and do not conform to the general trend of environmental friendliness and sustainable development.