Polyphosphazene-derived carbon modified nanowires for high-performance electrochemical energy storage

Two one-dimensional nanowires, Fe3O4 and MnO2 nanowires, were modified with polyphosphazene-derived carbon (PZSC) using in situ polymerization and high-temperature calcination methods. PZSC coated with MnO2 nanowire (MnO2/PZSCNW) was designed as the positive electrode, while PZSC coated with Fe3O4 nanowire (Fe3O4/PZSCNW) was designed as the negative electrode. Both MnO2/PZSCNW (+) and Fe3O4/PZSCNW (-) exhibit much larger specific capacities than the corresponding MnO2 and Fe3O4 nanowires, reaching 75.5 mAh g-1 and 75.9 mAh g-1, respectively. The maximum specific capacity, power and energy density of MnO2/PZSCNW (+)//Fe3O4/PZSCNW (-) in alkaline electrolyte are up to 63.2 mAh g-1, 429.6 W kg-1 and 53.7 Wh kg-1, respectively. After 10 000 cycles, the cell maintains 100% capacity. The experimental results indicate that the polyphosphazene-derived carbon coating can significantly improve the electrochemical performance, providing a feasible solution for constructing high-performance supercapacitors.