Cu-doped Li2ZnTi3O8 anode material with improved electrochemical performance for lithium-ion batteries

In this paper, Cu-doped Li2Zn1_,CuxTi308 (x = 0, 0.05, 0.1, 0.15) were successfully prepared using titanate nanowires as a precursor. The effects of Cu-doping on the physicochemical properties of Li2ZnTi308 were extensively investigated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), galvanostatic charge discharge testing, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that the Li2Zn1_,CuxTi308 (x= 0, 0.05, 0.1, 0.15) compounds are pure well-crystallized spinet phase. In addition, the Cu-doping does not change the morphology and the electrochemical reaction process of Li2ZnTi308. Galvanostatic charge discharge testing denotes that the L12Zn0.9Cu01Ti308 exhibits highest discharge capacity among all the samples and show higher cyclic stability and better rate capability compared with pristine Li2ZnTi308. When charge discharge current density increases up to 1000 mA g-1, the Li2Zn0.9Cu01Ti308 sample still maintains a capacity of 165.4 mA h g-1, while the pristine Li2ZnTi308 sample shows severe capacity decline at same current density. CV result reveals that the L12Zn0.9Cu01Ti308 has the lowest polarization. It is shown by EIS that the Li2Zn0.9Cu01Ti308 exhibits higher diffusion coefficient of Lit. The superior cycling performance and good rate capability, as well as simple synthesis route of the Cu-doped Li2ZnTi308 are expected to show a potential commercial application.