Method for preparing lithium-sulfur battery cathode material by using bacterial cellulose hydrogel

Abstract

The invention discloses a method for preparing a lithium-sulfur battery cathode material by using bacterial cellulose hydrogel, comprising the following steps of S1, preparing a lithium sulfate/glucose/bacterial cellulose aerogel composite material; and S2, converting the lithium sulfate in the lithium sulfate/glucose/bacterial cellulose aerogel composite material into lithium sulfide, convertingthe glucose into porous carbon, and converting the bacterial cellulose into carbon nanofibers. The method can construct a carbon nanofiber meshed structure, and the lithium sulfide nanoparticles in the structure are coated with the porous carbon, thereby improving the electron transmission efficiency in an electrode, suppressing a shuttling effect, and solving the problem of electrode collapse during lithium-sulfur battery charging and discharging so as to improve the performance of the lithium-sulfur battery.

Description

technical field [0001] The invention belongs to the technical field of lithium-sulfur batteries, and in particular relates to a method for preparing positive electrode materials of lithium-sulfur batteries by using bacterial cellulose hydrogel. Background technique [0002] With the development of science and technology, people's demand for energy storage systems continues to expand, and higher requirements are also placed on chemical power sources. Chemical power sources are now developing in the direction of miniaturization, light weight, and high specific capacity. At present, lithium-ion batteries are widely used in the market due to their high working voltage, small size, low cycle life, and no pollution. However, with the rapid development of electric vehicles, smart grids, and portable electronic devices, the energy density of lithium-ion batteries such as lithium cobalt oxide and lithium iron phosphate, which are currently commercialized, obviously cannot meet marke...

AI Technical Summary

Problems solved by technology

First, the electronic conductivity of sulfur and its corresponding sulfides at room temperature is very low, resulting in serious attenuation of battery cycle capacity; second, the intermediate product of lithium polysulfide (Li 2 S x , 4≤x≤8) are easily dissolved in the organic electrolyte and cause the "shuttle effect", resulting in the loss of active materials, the reduction of Coulombic efficiency and the deterioration of cycle stability; Changes (about 80%) will cause electrode structure collapse, capacity fading and even battery damage

In addition, the sulfur content and sulfur loading of current lithium-sulfur batteries are too low

Images