A fast and stable sodium-based dual-ion battery achieved by Cu3P@P-doped carbon matrix anode

Abstract Sodium-based dual-ion batteries (SDIBs) are of great interest as promising candidates for large-scale energy storage due to the advantages of low cost, high cell voltage, and eco-friendliness. However, their practical applications are restricted by the unsatisfactory rate and cycling performance resulted from the sluggish Na+ reaction kinetics of anode materials. Herein, a novel SDIB is developed by using Cu3P particles confined in conductive P-doped carbon layers (Cu3P@PC) as the anode for the first time. The rational designed architecture of Cu3P@PC accelerates Na+ diffusion kinetics and alleviates volume variation effects, which endows the as-assembled Cu3P@PC//expanded graphite (EG) SDIB outstanding performance. The device delivers good rate performance up to 30 C at an upper cutoff voltage of 5.0 V, excellent cycling stability with a capacity retention of 94% over 900 cycles at 10 C, among the best results of the reported SDIBs.