Nanoarchitectonics of high-performance supercapacitors based on mesoporous carbon and MnO2 electrodes using Aquivion electrolyte membrane

Abstract

Mesoporous carbons can contribute to the development of high energy and high-power density energy storage devices due to their tunable pore structures, high surface area and excellent electrical conductivity. The well-known mesoporous carbon CMK-3 with a hierarchical nanoporous structure can be promising candidate as electrode materials for supercapacitors to achieve high performance. Herein, we have produced a series of well-ordered mesoporous carbon materials with nano-sized structural units adopting two methods of synthesis: i) standard method and ii) ultrasonication assisted synthesis. Mesoporous carbons with hierarchical porous features and high surface area were obtained by both methods, and symmetrical supercapacitors containing these carbons and using an Aquivion membrane as polymer electrolyte were subsequently fabricated. Specific capacitance values of 66 and 78 F g−1 at 0.2 A g−1 were found for sonication assisted synthesised carbon (USC) and standard method derived carbon (SMC), respectively. Furthermore, the fabricated SMC//MnO2 supercapacitor with asymmetric configuration delivers a capacitance performance of 95 F g−1 and presents a low self-discharge rate if charged for 3 h at 1.6 V. This asymmetric supercapacitor device, as-assembled, also demonstrates a long-term durability of more than 10,000 galvanostatic charge and discharge cycles and 150 h under floating conditions at 1.6 V, which is among the best asymmetric supercapacitors developed.