One-Step Calcination Process for the Construction of Oxygen Deficient Fe2O3/N, P Co-doped Carbon Composites for High-Performance Supercapacitors

To explore the high performance of supercapacitors, oxygen deficient Fe 2 O 3 /N, P co-doped carbon (N-Fe 2 O 3 /NPC) composites were successfully fabricated by the one-step calcination of a precursor of FeOOH/polyaniline composites via a simple strategy of introducing oxygen vacancy (denoted as oxygen defects). The influences of carbonization temperature and carbonization time on the electrochemical properties of the N-Fe 2 O 3 /NPC composites were investigated. The results show that N-Fe 2 O 3 /NPC-450-2h exhibits high capacitance (605 mF cm −2 at a current density of 5 mA cm −2 ) and cycle life (100% after 2000 cycles). The assembled N-Fe 2 O 3 /NPC-450-2h-based symmetrical supercapacitor possesses a capacity retention rate of 100% after 5500 cycles at a current density of 10 mA cm −2 . In addition, the symmetrical supercapacitor shows a maximum energy density of 0.0148 mWh cm −2 (0.255 mWh cm −3 ) when the power density is 0.8 mW cm −2 (13.8 mW cm −3 ). N-Fe 2 O 3 /NPC-450-2h has broad application prospects as an electrode material for long-life symmetrical supercapacitors.