Studies on electrochemical lithium insertion in isostructural titanium niobate and tantalate phases with shear ReO3 structure

•Electrochemical lithium insertion into ReO3 type phases TiNb2O7, TiTa2O7 is feasible.•TiNb2O7 exhibits good cycling behavior and high reversible capacity of 212 mAh g−1.•TiTa2O7 exhibits reversible capacity of 100 mAh g−1.

TiNb2O7 and TiTa2O7 phases are synthesized by solid-state reaction method and are investigated for electrochemical Li insertion/extraction. The electrochemical insertion of Li in these phases is characterized by both solid solution and two-phase regimes. The structure is stable toward Li insertion/extraction. The first cycle discharge capacity values are 307 mAh g−1 and 215 mAh g−1 in the voltage range of 3.0–1.0 V for TiNb2O7 and TiTa2O7 phases, respectively. The discharge capacities of TiNb2O7 and TiTa2O7 are 212 mAh g−1 and 100 mAh g−1, respectively, after 20 cycles.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide