Structure and Electrochemical Properties of Zn-Doped Li4Ti5O12 as Anode Materials in Li-Ion Battery

Zinc-doped lithium titanates with the formula of Li4-xZnxTi5O12 (x = 0, 0.25, 0.5, 1) were synthesized as anode materials via a solid-state reaction. The phase composition does not change by Zn doping when x < 1 but results in the increase in the relative peak intensity ratio of I-(311)/I-(111) and I-(400)/I-(111) in X-ray diffraction. The conductivity is improved by Zn doping via the generation of mixing Ti4+/Ti3+. The specific capacity at 0.5C decreases by Zn doping, which is ascribed to the location of Zn2+ at the 8a site; however, the capacity retention is improved remarkably compared to that of the undoped one when discharged at a high rate. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3294846] All rights reserved.