Building Na-ion full cells using homologous Prussian blue and its phosphide derivative

Abstract

Due to their low production cost and rich resource availability, Na-ion batteries have emerged as the best option for grid-scale energy storage systems. Nonetheless, the commercialization of Na-ion batteries has been hampered by a shortage of acceptable anode and cathode materials. In this work, we report a superior Na-ion full cell constructed using a homologous Prussian blue (PB) cathode and its derived core–shell FeP@C anode. The PB cathode delivers a discharge capacity of 111 mAh/g and a prominent lifetime of 2000 loops with 99.7% capacity retention. Additionally, the FeP@C anode manifests a reversible capacity of 368.4 mAh/g and an outstanding rate capability of 111.1 mAh/g at 20 A/g. When assembled into a Na-ion full cell, a remarkable discharge capacity of 108.3 mAh/g with steady-state cyclic behavior is achieved. This homologous design strategy is expected to provide an alternative possibility for constructing high-performance Na-ion full cells.