PNb₉O₂₅ nanofiber as a high-voltage anode material for advanced lithium ions batteries

If the operating voltage of anode materials is below 1.0 V versus Li⁺/Li, the side reaction between electrolyte and anode materials will occur extensively. Thus, high-voltage anode materials have aroused interest recently. In this work, we report the preparation of PNb₉O₂₅ nanofiber via a facile electrospinning method. The PNb₉O₂₅ nanofiber shows the high rate performance and excellent cycling performance when it is used as anode in lithium ions batteries. For instance, the PNb₉O₂₅ nanofiber can deliver a capacity of 233, 212.1, 193.8, and 181.4 mA h g⁻¹ at 0.2, 1, 3, and 6C, respectively. After 1000 cycles, it can reach at 134.3 mA h g⁻¹ with capacity retention of 70.9%. Meanwhile, the ex situ X-ray photoelectron spectroscopy technique has been adopted to investigate the evolution in valence state of each element for PNb₉O₂₅ nanofiber. In addition, the PNb₉O₂₅ nanofiber is chosen as the anode material in lithium ion full cell in this work, demonstrating the potential for practical application.