Preparation Of SnO₂/carbon Cloth Composites And Their Electrochemical Properties For Lithium Ion Batteries

In recent years,with the development of science and technology and the diversification of the demand for electronic products,electronic products and intelligent equipment become more and more miniature and lightweight,so the flexible electrode material began to attract people's attention.Among the numerous possible alternative anode materials,SnO₂ has a high theoretical capacity?781mAh/g?and low potential of lithium ion intercalation.Therefore,it is considered to be one of the most promising candidates in the future.However,the severe volume change issue in the process of charging and discharging results in pulverization of active material and loss of electrical contact at the anode,then,the cycle performance of the lithium-ion battery began to deteriorate.Based on these questions,the SnO₂/carbon cloth flexible electrode material was successfully prepared by two-step method and their electrochemical properties were studied in this paper.The first step is preparing a layer of SnO₂ on the carbon cloth flexible substrate as the seed layer by RF magnetron sputtering method;and the second step is growing nano-sized flower-like SnO₂ by hydrothermal method.Firstly,the effects of working pressure,sputtering power and substrate temperature on the growth of tin dioxide films were studied by single factor method.The crystal structure,microstructure and electrochemical properties of the samples were tested.The mechanism of growth and the mechanism of lithium were studied.According to the test results,the best progress parameters were obtained.In addition,the effect of SnO₂ film thickness on the electrochemical performance of the electrode was studied.Then,the mechanism of lithium storage of SnO₂/carbon cloth composites prepared by magnetron sputtering was investigated.Secondly,the main process parameters of SnO₂/carbon cloth composites prepared by hydrothermal method were optimized by single factor method,the effects of[OH-]/[Sn4+]concentration ratio and reaction temperature on the microstructure and electrochemical properties of SnO₂/carbon cloth composites were systematically studied.According to the test results,the best progress parameters were obtained,and the growth mechanism of SnO₂/carbon cloth composites was investigated.Finally,the modified SnO₂/carbon cloth composites were studied,the first step is preparing a layer of SnO₂ on the carbon cloth flexible substrate as the seed layer by RF magnetron sputtering method;and the second step is growing nano-sized flower-like SnO₂ by hydrothermal method.Compared with SnO₂/carbon cloth composites without seed layer prepared directly by hydrothermal method,the coating and uniformity of SnO₂ on the carbon cloth were improved significantly after modification.The cycling performance of SnO₂/carbon cloth electrodes were investigated by galvanostatic charge and discharge between 0 and 3.0 V at the constant current of 200 ?A,The primary discharge capacity is 3.62 mAh/cm2,and the discharge capacity of SnO₂/carbon cloth composites is 1.82 mAh/cm2?668 mAh/g?after 100 cycles.In addition,the electrochemical properties of SnO₂/carbon cloth composites were compared with the tin-based anode materials prepared by other different methods.It was concluded that the SnO₂/carbon cloth composites exhibit excellent electrochemical performance,The results of this work proposed a method for preparing flexible electrode material.