Effect of Conductive Nitride-Modified Tungsten Oxide Catalyst on Electrochemical Performance of Lithium-Sulfur Batteries
During the preparation of carbon nanotube films(CNTs),the precursor WCl6 alcohol solution was sprayed by floating catalyst CVD,and then a film was formed by natural drying;subsequently the film was hydrothermal treated and calcined;finally a WO2.9-W2N/CNTs composite film was obtained.The W2N can improve the poor conductivity of WO3.In addition,the oxygen vacancies of WO2.9 can provide more active sites for the deposition of Li2S than those of WO3.WO2.9-W2N can form Li-O bond and Li-N bond with polysulfides(LiPSs);as a result,the chemical adsorption and anchoring of LiPSs onto the matrix is strengthened.The prepared lithium-sulfur battery with the composite film as anode possesses excellent electrochemical performances;after 500 cycles at a rate of 0.2 C,its discharge specific capacity remains above 850 mAh·g-1.It is demonstrated excellent electrochemical reaction kinetics and its catalytic effect to the electrochemical reactions.The shuttling inhibition of WO2.9-W2N/CNTs mainly occurs by trapping-anchoring-catalytic conversion.
carbon nanotube,lithium-sulfur,catalytic conversion,adsorption anchoringactive site
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