Preparation Of Jute Based Carbon And SnO₂ Composites And Their Electrochemical Performance

Lithium-ion batteries have a wide range of applications and great demand in many fields,such as electronic networks,electric vehicles and industrial production.It has also been widely studied and researched by scholars for its complete charge/discharge response,long cycle time and low discharge rate.The performance of the anode material is of great significance to the overall performance of the battery,so we pay attention to the anode battery widely.Due to the low theoretical capacity of traditional graphite anode materials(372 m Ah g-1),the majority of researchers and scholars continue to explore and find promising anode alternative materials,SnO₂ has been widely recognized due to its high theoretical capacity(782 m Ah g-1).However,its huge volume expansion(>300%)during charge/discharge cycles has led to its susceptibility to pulverisation and aggregation,as well as problems with cycle stability and poor electrical conductivity.In order to improve the above problems,SnO₂materials are often modified.In this paper,jute is used as the raw material to extract jute cellulose substrate by hydrothermal method as well as chemical activation method to prepare jute porous carbon substrate,and SnO₂ nanoparticles are embedded in the carbon substrate.The above experimental method not only reduces the experimental cost,but also reduces environmental pollution,and better accomplishes the synergistic effect between the two.In this paper,the physical characterisation and electrochemical properties of the corresponding materials were tested,and the main research contents and conclusions are as follows.(1)Jute were treated with alkali boiling and acid treatment to extract cellulose from jute fibres as a precursor,SnCl₄.5H₂O was used as the tin source and mixed with urea,and SnO₂ nanoparticles were prepared by hydrothermal method using ethanol mixed with deionised water 1:1 as the solvent,and the prepared jute cellulose was compounded with SnO₂ nanoparticles to obtain SnO₂@JFCC composites.The effects of hydrothermal time and calcination temperature on the material properties were investigated.The results showed that when the hydrothermal carbonisation temperature was 200°C,the hydrothermal time was 24 h and the calcination temperature was 500°C,the specific surface area was the largest,the structure was stable,the composite effect was the best and its electrochemical properties were the best.The discharge specific capacity was stable at 1298.5 m Ah g^-1 for 100 turns at 0.2 C.(2)Jute were treated by solid-phase activation,and SnO₂@JFPC composites were obtained by using zinc chloride as the activator to prepare porous carbon of jute fibres compounded with SnO₂ nanoparticles.The effect of the amount of activator and the hydrothermal carbonization time on the material properties was investigated.The test results showed that the composite material with well-developed pores and excellent electrochemical properties could be obtained with a hydrothermal time of 24 h when the mass ratio of jute and Zn Cl₂was 1:4.The discharge specific capacity was stabilised at 899.2 m Ah g^-1 at 0.2 C for 100 cycles.