Facile construction of single-crystalline sodium niobate anode materials: insight into the relationship of the morphology and excellent performance for lithium-ion batteries

Electrode materials structures hold the key to enhance the performance. Based on the time-dependent growth process of niobium precursor, single-crystal Na₂Nb₂O₆·nH₂O nanowires and NaNbO₃ nanocubes were successfully synthesized through a facile and friendly hydrothermal route at 180 °C under different reaction times. NaNbO₃ nanowires were derived by calcination treatment of Na₂Nb₂O₆·nH₂O nanowires which was employed as self-sacrificing templates. By comparing the electrochemical behavior of these niobium-based anodes, NaNbO₃ nanocubes show a discharge capacity of about 115 mA h g⁻¹ over 1000 cycles at 1000 mA g⁻¹, exhibiting higher reversible capacity and superior rate performance than NaNbO₃ nanowires. The superior cell performance could be interpreted in terms of the different morphologies of NaNbO₃, which results in the better Li-ion diffusion abilities and higher pseudo-capacitance of the as-fabricated NaNbO₃ nanocubes electrode. This work provides fundamental insights into the morphology–property relationship of both NaNbO₃ nanowires and NaNbO₃ nanocubes, providing a solid guide for developing anode materials for Li-ion battery.