Achieving high-performance Li2ZnTi3O8 anode for advanced Li-ion batteries by molybdenum doping

Abstract

The Li2ZnTi3-xMoxO8 (x = 0, 0.05, 0.1 and 0.15) anode materials are successfully synthesized through a simple solid-state method, and few Li2MoO4 phase can be found in Li2ZnTi3-xMoxO8 (x = 0.1 and 0.15). All samples are composed of nanocrystalline particles and irregular micron-sized particles with a relatively uniform particle size of 100–200 nm Li2ZnTi2.9Mo0.1O8 shows the best electrochemical properties among all samples. The Li2ZnTi2.9Mo0.1O8 delivers a charge/discharge capacity of 188.1/188.2 mA h/g at 1 A/g after 400 cycles, but the corresponding capacity of pristine Li2ZnTi3O8 is only 104.5 (102.2) mA h/g. The Mo6+ doping enhances the reversible capacity, rate performance, and cycling stability of Li2ZnTi3O8, especially at large current densities. The improved electrochemical performance of Li2ZnTi3-xMoxO8 can be ascribed to the enhanced electrical conductivity, improved intercalation/de-intercalation reversibility of Li ions, increased lithium-ion diffusion coefficients, and reduced charge-transfer resistance. This work provides an effective strategy to construct high-performance anode materials for advanced lithium-ion battery; this effective design strategy may be used to enhance the reversible specific capacity, and rate the performance and cycle stability of other insertion-host anode materials.