Electrochemical performance of nanocrystalline Li2CoTiO4 cathode materials for lithium ion batteries

• Li2CoTiO4 cathode materials with tunable nanostructures were synthesized.
• Small particle or grain size can increase the Li ion diffusion rate.
• Li2CoTiO4 with small particle size has good cycle stability and rate capability.

Cation disordered Li2CoTiO4 titanate with 3D lithium ion channels could be a promising new cathode material for lithium ion batteries due to its high theoretical capacity. Herein the Li2CoTiO4 materials with tunable nanostructures were synthesized by a sol–gel method and subsequent heat treatment at different temperatures. The microstructure and electrochemical properties of the nanocrystalline Li2CoTiO4 materials have been systematically investigated. The Li2CoTiO4 material synthesized at lower temperature possessed smaller particle size and grain size, and allowed a higher reversible extraction of lithium ions per formula unit. Furthermore, the small particle size enabled insertion of lithium along short diffusion paths, and thus an increase of the lithium ion diffusion coefficient.