Intertwined Cu3V2O7(OH)2·2H2O nanowires/carbon fibers composite: A new anode with high rate capability for sodium-ion batteries

Abstract

Sodium-ion batteries (SIBs) have recently attracted intensive attentions as a potential alternative to LIBs for large-scale energy storage applications. However, one of the major challenges to the commercialization of SIBs is the limited choice of anode materials that can offer high rate capability. In this regard, we report intertwined Cu3V2O7(OH)2·2H2O nanowires/carbon fibers composite, fabricated by a facile hydrothermal method, as the anode material for SIBs. It shows s a highly reversible Na-ion storage capacity of 287.4 mAh g−1 after 50 cycles at a large current density of 0.5 A g−1, and excellent rate performance of delivering 206.5 and 127.7 mAh g−1 after 50 cycles at high current densities of 5 and 10 A g−1, respectively. The promising performance is ascribed to both the crystal structure of Cu3V2O7(OH)2·2H2O with a large interlayer spacing, and unique intertwined network morphology of CuVOH-NWs/CFs composite in which CuVOH-NWs and CFs synergistically functioned. This work will pave a way to develop more metal vanadates materials as anodes for high-performance SIBs.