Rapid Lithiation and Delithiation Property of V-Doped Li₂ZnTi₃O₈ as Anode Material for Lithium-Ion Battery

Abstract

Li2–xVxZnTi3O8 (x = 0, 0.05, 0.1 and 0.15) anode (negative electrode) materials were successfully synthesized by a facile solid-state reaction method, and the structure, morphology, and electrochemical properties of the Li2–xVxZnTi3O8 materials were investigated. Li2–xVxZnTi3O8 (x = 0 and 0.05) samples show the pure phase structure with P4332 space group, but several rutile TiO2 peaks are founded in Li2–xVxZnTi3O8 (x ≥ 0.1). V-doping does not change the electrochemical reaction mechanism and destroy the structure of Li2ZnTi3O8. All samples show a size distribution under 1 μm, but the V-doped powders show a narrower particle size distribution and less agglomeration than those of pristine Li2ZnTi3O8. Electrochemical kinetics results reveal that the V-doped Li2ZnTi3O8 samples display higher reversibility, larger lithium diffusion coefficients and lower charge-transfer resistances than those of pristine Li2ZnTi3O8. Galvanostatic electrochemical tests show that the Li1.95V0.05ZnTi3O8/Li half cell delivers the highest lithiation capacities at various rates (213.3, 171.2, 132.5, and 84.7 mA h g–1 at 0.2, 1, 2, and 5 C rates, respectively), whereas the Li2ZnTi3O8/Li half cell delivers much less lithiation capacities at all rates (184.5, 129.5, 107.3, and 24 mA h g–1 at 0.2, 1, 2, and 5 C rates, respectively). The simple preparation process, low preparation cost, excellent cycling stability, and wide voltage range give the Li1.95V0.05ZnTi3O8 potential for commercial application in the future.