Co2P/Sn4P3 particle encapsulated in N, P codoped carbon nanocubes for efficient sodium storage

Abstract Phosphorus-based materials as the anode for sodium-ion batteries have drawn extensive attention because of their high theoretical capacity and low insertion potential. Nevertheless, the severe volume variation and low electric conductivity hindered their further practical applications. Herein, a novel Co2P/Sn4P3 hybrid encapsulated in carbon nanocubes was fabricated by a coprecipitation method followed by phosphating progress. Accompanying with the N, P codoping and abundant grain boundaries, which facilitates electric transport and provides rich active sites, the as-synthesized Co2P/Sn4P3@C anode delivered a high charge specific capacity of 185.6 mA h g−1 after 400 cycles at the current density of 1000 mA g−1 and outstanding cycling stability with a high capacity retention of 86.9%. Kinetics exploration indicated that the capacity was governed by the surface pseudo-capacitive controlled process due to the abundant defects originated from heteroatom doping and grain boundaries.