Effects of TiO2 starting materials on the synthesis of Li2ZnTi3O8 for lithium ion battery anode

Abstract

Lithium zinc titanate (Li2ZnTi3O8) anode materials have been successfully synthesized using rutile-TiO2 with different particle sizes as titanium sources via a molten-salt method. Various physical and electrochemical methods are applied to characterize the effects of TiO2 particle sizes on the structures and physicochemical properties of the Li2ZnTi3O8 materials. When the particle size of TiO2 is too small (10nm), it is difficult to homogeneously mix TiO2 with the other raw materials. Thus, the final product Li2ZnTi3O8 has poor crystallinity, large particle size, small specific surface area, pore volume and average pore diameter, which are disadvantageous to its electrochemical performance. Using TiO2 with the proper particle size of 100nm as the titanium source, the Li2ZnTi3O8 (R-100-LZTO) with excellent electrochemical performance can be obtained. At 1Ag−1, 175.8 and 163.6mAhg−1 are delivered at the 1st and the 200th cycles, respectively. The largest capacities of 163, 133.3 and 122.5mAhg−1 are delivered at 2.5, 5 and 6Ag−1, respectively. The good high-rate performance of the R-100-LZTO originates from the good crystallinity, small particle size, large specific surface area and average pore diameter, low charge-transfer resistance and high Li+ diffusion coefficient.