Advanced electrochemical properties of Ce-modified Li2ZnTi3O8 anode material for lithium-ion batteries

摘要

A series of Li2ZnTi3-xCexO8 (x= 0, 0.05, 0.1, 0.15) anode materials have been synthesized via a facile solidstate method. XRD shows that the dopant Ce ions cannot completely enter the Li2ZnTi3O8 lattice and an impurity phase CeO2 appears in the three doped materials. The Li2ZnTi3-xCexO8 (x= 0.05) sample exhibits the best rate capability among all the as-prepared samples, indicating its appropriate amount of Ce ions modification. The initial discharge specific capacities delivered by Li2ZnTi3-xCexO8 (x =0.05) are 317.6, 227.8, 210.4, 197.3, 187.7 and 181.1 mAhg-1 at 0.5, 2, 5, 10, 15 and 20C, respectively, and a reversible capacity of 132.7 mAhg(-1) can be retained after 500 cycles at 10C with a capacity retention of 68.9%. The doping of Ce4+ can increase the intrinsic Li+ diffusion coefficient and CeO2 scattering on the surface of Li2ZnTi3O8 is beneficial to improve the extrinsic electronic conductivity. The synergistic effect is probably responsible for the excellent electrochemical performance of Li2ZnTi3-xCexO8 (x=0.05). (C) 2017 Elsevier Ltd. All rights reserved.