BaNb3.6O10 nanowires with superior electrochemical performance towards ultrafast and highly stable lithium storage

High-performance anode materials for development of long cycling life and environmental benignity lithium-ion batteries (LIBs) are greatly desired. Here, the nanostructure, electrochemical performance and structural evolution of barium niobates in LIBs are reported of the first time. One-dimensional barium niobium oxide (BaNb3.6O10) nanowires are prepared by electrospinning technique, displaying the "nanoparticle-in-nanowire" morphology. The BaNb3.6O10 nanowires show high structural stability, high reversible specific capacity (263.8 mAh g−1 at 100 mA g−1), superior rate performance and long-term cycling capability (keeping 60% of the initial reversible capacity at a high current density of 1000 mA g−1 after 5000 cycles). In addition, the mechanism for lithium storage in BaNb3.6O10 is also studied by using ex-situ transmission electron microscopy (TEM), in-situ X-ray diffraction (XRD), in-situ TEM and theory calculations. The results show that BaNb3.6O10 nanowires have reversibility and structural stability for the lithiation and delithiation process. The fabricated BaNb3.6O10/LiMn2O4 full cell demonstrates a practical energy density of 270 Wh Kg−1. This work perfectly confirms that the one-dimensional BaNb3.6O10 nanowires are an ideal material for LIBs.