Nitridated mesoporous Li4Ti5O12 spheres for high-rate lithium-ion batteries anode material

Nitridated mesoporous Li4Ti5O12 spheres were synthesized by a simple ammonia treatment of Li4Ti5O12 derived from mesoporous TiO2 particles and lithium acetate dihydrate via a solid state reaction in the presence of polyethylene glycol 20000. The carbonization of polyethylene glycol could effectively restrict the growth of primary particles, which was favorable for lithium ions diffusing into the nanosized TiO2 lattice during the solid state reaction to form a pure phase Li4Ti5O12. After a subsequent thermal nitridation treatment, a high conductive thin TiOxNy layer was in situ constructed on the surface of the primary nanoparticles. As a result, the nitridated mesoporous Li4Ti5O12 structure, possessing shorter lithium-ion diffusion path and better electrical conductivity, displays significantly improved rate capability. The discharge capacity reaches 138 mAh g−1 at 10 C rate and 120 mAh g−1 at 20 C rate in the voltage range of 1–3 V.