Synthesis of high performance carbon-coated lithium zinc titanate via an EDTA-assisted route

Abstract

Carbon-coated Li2ZnTi3O8 (Li2ZnTi3O8@C) anode materials have been firstly synthesized via an EDTA-assisted solid-state route using EDTA as the carbon source and chelating agent. The effects of sintering time on the structures and physicochemical properties of the Li2ZnTi3O8@C anodes are also systematically studied. The results show that the Li2ZnTi3O8 particles are nano-sized and coated with carbon layer. The conductive carbon greatly improves the electrochemical performance of Li2ZnTi3O8@C. Li2ZnTi3O8@C-700-3 with the sintering time of 3 h delivers large specific capacities and presents good cyclic performance at high current densities. The largest capacities of 171.1 and 154.1 mAh g−1 are obtained at 4 and 5 A g−1, respectively. At the 100th cycle, 143.3 and 133.2 mAh g−1 are still kept for the sample at 4 and 5 A g−1, respectively. The good electrochemical performance of Li2ZnTi3O8@C-700-3 originates from the large pore size, proper specific surface area and particle size, and low charge-transfer resistance.