Direct interfacial growth of MnO2 nanoparticles on carbon nanofiber surfaces for high-performance asymmetric supercapacitors

Abstract

Facile interfacial growth of MnO₂ nanoparticles on carbon nanofibers (MnO₂/CNF) and the application of this material as a high-performance positive electrode material in asymmetric supercapacitors are presented. Rational combination of MnO₂/CNF positive and CNF negative electrode materials enabled asymmetric devices with extended operating voltage windows of 1.8 V, and much higher power densities (4434 W kg⁻¹) and energy densities (36 W h kg⁻¹) compared with similar devices being reported. The assembled novel hybrid aqueous asymmetric capacitor shows excellent cycling stability with 90.9% capacity retention for 1000 cycles. The asymmetric supercapacitors were based on low cost and environmental friendly materials and have great potential for practical devices.