Solvothermal ion exchange synthesis of ternary cubic phase Zn2Ti3O8 solid spheres as superior anodes for lithium ion batteries

A rational strategy for the synthesis of ternary cubic phase Zn2Ti3O8 solid spheres has been developed for application in lithium ion batteries. In this process, titanium glycolate solid spheres are used as nanostructure template and titanium source, whose functional groups are replaced by zinc ions through a solvothermal ion exchange method in accordance with the Zn/Ti atomic ratio of 2:3. When adjusting the Zn/Ti atomic ratios to 0:3, 1:3, the anatase TiO2 solid spheres and multiphase complex of TiO2/ZnTiO3 solid spheres can be obtained. However, with the increasing of Zn/Ti atomic ratio to 3:3, in addition of cubic phase Zn2Ti3O8 solid spheres, a lot of hexagonal ZnO nanoparticles are synthesized. As anodes for lithium ion batteries, the delivered capacities of Zn2Ti3O8 solid spheres are higher than those of TiO2 and TiO2/ZnTiO3 solid spheres at 300 mA g(-1). Notably, the high purity cubic phase Zn2Ti3O8 solid spheres can still release a reversible capacity of 146.7 mAh g(-1) even at 2000 mA g(-1) over 1000 cycles. Also, the Zn2Ti3O8 solid spheres show a good electrochemical performance in the full cells. The superior electrochemical properties are ascribed to the favorable crystal structure and highly developed porous structure of Zn2Ti3O8 solid spheres. (C) 2019 Elsevier Ltd. All rights reserved.