Large Scale One-Pot Synthesis of Monodispersed Na ₃ (VOPO ₄ ) ₂ F Cathode for Na-Ion Batteries

Abstract

Na-ion batteries (NIBs) have received significant interest as potential candidates for large-scale energy storage owing to the widespread distribution of sodium and superior low-temperature performance. However, their commercial application is usually hindered by the high production cost and inadequate performance for electrode materials, particularly for cathodes. Na 3 (VOPO 4 ) 2 F (NVOPF) has been recognized as one of the most promising cathodes for high-energy NIBs owing to the high working voltage and energy density. Here, we report a facile highly efficient room-temperature solution protocol for large-scale synthesis of NVOPF cathode for NIBs. By simply regulating pH, NVOPF can be obtained, which delivered a discharge capacity of 120.2 mAh g -1 at 0.1 C and 72% capacity retention over 8000 cycles at 25 C. Besides, the kilogram-level NVOPF products have been synthesized, and 26650 cylindrical cells were fabricated, which exhibit excellent cycling stabilities, remarkable low-temperature performance with comparable safety features. We hope our findings could provide insights on the industrial application of NVOPF in NIBs.