Structure and electrochemical properties of Zn-doped Li₄ Ti ₅O₁₂ as anode materials in li-ion battery

Zinc-doped lithium titanates with the formula of Li4-xZn xTi5O12 (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+/Ti 3+. 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.