High mass-loading α-Fe2O3 nanoparticles anchored on nitrogen-doped wood carbon for high-energy-density supercapacitor

The trade-off between mass-loading and cycling stability is always a big challenge for iron oxide-based electrodes. Herein, α-Fe2O3 nanoparticles uniformly anchored on nitrogen-doped wood carbons with high mass-loading have been synthesized via a facile electrodeposition method accompanied by post-heating treatment. The resultant composite delivers a high specific capacitance of 603 F/g at 0.1 A/g and superior capacitance retention of 85.5% after 10000 cycles at 10 A/g, indicating excellent long-term cycling stability. Such excellent electrochemical performance can be attributed to the synergistic effects of α-Fe2O3 nanoparticles and the conductive matrix as well as the formation of interfacial Fe-O-C bonding, which enables the composite electrode to provide plenty of accessible redox active sites, sufficient electron transport and electrolyte ions diffusion and robust interfacial interaction. Consequently, the asymmetrical supercapacitor exhibits a high energy density of 30.3 Wh/kg at 125 W/kg, suggesting its great potential for practical applications.