Hollocellulose lithium ion battery diaphragm and preparation method thereof

Abstract

The invention belongs to the crossing field of lithium ion battery diaphragms and biomass materials and specifically discloses a hollocellulose lithium ion battery diaphragm and a preparation method thereof. The preparation method comprises the steps: taking nano fibril cellulose, nano microcrystalline cellulose and cellulose derivative according to different mass fractions, dispersing into water and dispersing evenly by ultrasonic wave to obtain fiber suspension; preparing the fiber suspension into a wet diaphragm by a suction filtration method, hot pressing the wet diaphragm and performing vacuum drying on the wet diaphragm to obtain the hollocellulose lithium ion battery diaphragm. The prepared diaphragm is a hollocellulose completely-degradable diaphragm, the thickness of the diaphragm is 15 to 45mu m, the porosity is 45 to 80%, electrolyte absorptivity is larger than 400%, an ionic conduction rate is larger than 1.0mS cm<-1>, thermal stability is good, and a size change rate under condition of 200 DEG C for 3h is smaller 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.