Synthesis and electrochemical behaviour of titanium niobates: A step toward stable anode materials

Previous studies have demonstrated the potential long-term cyclability and stability of TNOs as electrodes in LIBs. However, the wide variety of stoichiometries of TNOs has complicated the study of the physicochemical properties of this material, which can change greatly between different phases, compositions and structures. In this study, two TNO compositions (TiNb 2 O 7 and Ti 2 Nb 10 O 29 ) have been synthesized via solid-state and hydrothermal synthesis. A detailed electrochemical characterization as electrodes for LIBs has been performed. A capacity of 257.3 mA h g −1 has been obtained with losses <6 % after 300 cycles at 1C for the hydrothermal route of the Ti 2 Nb 10 O 29 composition. Additionally, a complete recovery of capacity was observed after cycling at higher velocities (5C, 10C). • TiNb 2 O 7 and Ti 2 Nb 10 O 29 have been successfully obtained via solid-state and hydrothermal synthesis. • Hydrothermal niobium precursor is niobium oxalate, ensuring precise stoichiometric control. • Hydrothermal samples show the best electrochemical performance, related to morphology, homogeneity and defect structure. • Ti 2 Nb 10 O 29 obtained via hydrothermal synthesis demonstrates the best performance when cycled between 1 V and 3 V. • High stability and recovery have been demonstrated, even under low and high temperatures and during long-term cycling.