Self-sacrificed synthesis of three-dimensional Na3V2(PO4)3nanofiber network for high-rate sodium–ion full batteries

The morphological optimization of Na3V2(PO4)3(NVP) material has a great significance for improving the electrochemical performance since NVP suffers from intrinsic low electronic conductivity. For this purpose, a novel 3D NVP nanofiber network is controllably constructed viaa facile self-sacrificed template method. Based on time-dependent experiments, an outside-in morphological evolution mechanism from microsphere to 3D nanofiber network is proposed. The as-synthesized material exhibits excellent cyclability (95.9% capacity retention over 1000 cycles at 10C) and enhanced high-rate performance (94mAhg−1at 100C) for sodium half cell. Notably, when evaluated as full battery (NaTi2(PO4)3as anode) cathode, it also shows outstanding cycling stability (96.9% capacity retention over 300 cycles at 5C) and superior rate capability (80mAhg−1at 50C). Such remarkable performance is attributed to the 3D nanofiber network structure, which provides multi-channel ionic diffusion pathway, continuous electronic conduction, and improved structural integrity. This self-sacrificed template strategy presented here can inspire new thought in constructing novel nanofiber/nanowire structures and accelerate the development of high-power sodium–ion batteries.