Redox Additive Electrolyte Study of Mn-MOF Electrode for Supercapacitor Applications

The selection of appropriate electrode materials and electrolytes in addition to optimization of their combinations is a key to improve the performance of supercapacitors. Among the new electrode materials, metal-organic frameworks (MOFs) based electrodes are attracting attention in energy storage devices, including supercapacitors and batteries. In recent years, the redox additive electrolytes have been projected as efficient options over simple aqueous electrolytes. The present work reports the synthesis of a layered MOF, i.e., manganese-1,4- benzene dicarboxylate (Mn-BDC) and explores its utility as a supercapacitor electrode in the presence of an optimized redox additive electrolyte (0.2 M K-3[Fe(CN)(6)] in 1 M Na2SO4 (0.2 M KFCN)). As demonstrated for the first time in this study, the combined use of the porous Mn-BDC electrode and KFCN electrolyte has provided a synergistic enhancement in the supercapacitor performance. The present Mn-BDC/KFCN combination has delivered a high specific capacitance of 1590 F/g at a current density of 3 A/g. Furthermore, the Mn-BDC electrode could retain around 82% of its initial specific capacitance even after 3000 continuous charge-discharge cycles. In view of its encouraging electrochemical performance parameters, the proposed system can be touted as an efficient supercapacitor assembly.