TiNb2O7 nanoparticles assembled into hierarchical microspheres as high-rate capability and long-cycle-life anode materials for lithium ion batteries

Abstract

As a competitor for Li₄Ti₅O₁₂ with a higher capacity and extreme safety, monoclinic TiNb₂O₇ has been considered as a promising anode material for next-generation high power lithium ion batteries. However, TiNb₂O₇ suffers from low electronic conductivity and ionic conductivity, which restricts the electrochemical kinetics. Herein, a facile and advanced architecture design of hierarchical TiNb₂O₇ microspheres is successfully developed for large-scale preparation without any surfactant assistance. To the best of our knowledge, this is the first report on the one step solvothermal synthesis of TiNb₂O₇ microspheres with micro- and nano-scale composite structures. When evaluated as an anode material for lithium ion batteries, the electrode exhibits excellent high rate capacities and ultra-long cyclability, such as 258 mA h g⁻¹ at 1 C, 175 mA h g⁻¹ at 5 C, and 138 mA h g⁻¹ at 10 C, extending to more than 500 cycles.