K-doped Li₂ZnTi₃O₈/C as an efficient anode material with high performance for Li-ion batteries

Li₂ZnTi₃O₈/C and Li_1.9K_0.1ZnTi₃O₈/C were successfully synthesized using the sol-gel method. Doping K apparently yielded a wider tunnel, helpful for increasing the rate of transport of lithium ions, and furthermore yielded excellent electrochemical properties. The first discharge capacity for Li_1.9K_0.1ZnTi₃O₈/C was 352.9 mA h g^-1 at a current density of 200 mA g^-1. Li_1.9K_0.1ZnTi₃O₈/C also performed stably, retaining a capacity of 323.7 mA h g^-1 at the 100th cycle, indicative of its excellent cycling properties. In the rate performance test, Li_1.9K_0.1ZnTi₃O₈/C showed at the first cycle a high discharge capacity of 379.5 mA h g^-1 for a current density of 50 mA g^-1 and a capacity of 258.9 mA h g^-1 at 1000 mA g^-1. The results indicated that K-doping should be considered a useful method for improving electrochemical performances.