Flexible asymmetric supercapacitor based on structure-optimized Mn₃O₄/reduced graphene oxide nanohybrid paper with high energy and power density

A highly flexible Mn₃O₄/reduced graphene oxide (rGO) nanohybrid paper with high electrical conductivity and high mass loading of Mn₃O₄ nanofibers (0.71 g cm^-3) is developed via a facile gel formation and electrochemical reduction process, which is low-cost, environmental friendly, and easy to scale up. Confined Mn₃O₄ nanofibers are well dispersed within the rGO sheets, which demonstrate to be a promising cathode material for flexible asymmetric supercapacitors (ASCs). When coupled with an electrochemically reduced rGO paper as the anode, a flexible ASC device, based on the Mn₃O₄/rGO nanohybrid paper as the cathode, is assembled; and it demonstrates remarkable electrochemical performance: a high volumetric capacitance of 54.6 F cm^-3 (546.05 mF cm^-2), and remarkable volumetric energy and power density (0.0055 Wh cm^-3 and 10.95 W cm^-3) being achieved with excellent cycling ability. The nanohybrid paper shows great improvement for flexible energy devices in terms of electrochemical properties. A highly flexible Mn₃O₄/reduced graphene oxide (rGO) nanohybrid paper with high electrical conductivity and high mass loading of Mn₃O₄ nanofiber (0.71 g cm^-3) is successfully developed via a facile gel formation and electrochemical reduction process. Through this novel design and processing control, the energy and power density of the flexible Mn₃O₄/rGO-based asymmetric supercapacitor are greatly improved.