Dimensional engineering of Ni-Mn MOF composites: Unveiling the electrochemical influence of 1D MWCNT and 2D rGO for high-performance supercapacitors

Abstract

High-performance, energy-dense supercapacitors are crucial in advancing electric vehicle (EV) technology and supporting clean energy initiatives, necessitating electrode materials with superior electrochemical activity, stability, and energy density. Metal organic frameworks have garnered significant interest as possible futuristic supercapacitor electrode materials because of their numerous redox active sites, tunable porosity, and vast surface area. In order to boost the energy storage performance, nickel-manganese MOF composites were incorporated with reduced graphene oxide and multi-walled carbon nanotubes (1D). Compositing Ni-Mn MOF with 1D and 2D carbonaceous materials induced structural modification that enhanced porosity, ion diffusion, and surface accessibility, thereby significantly boosting electrochemical performance. The improved specific capacitance (1153.9 F/g) of Ni-Mn MOF/MWCNT than the Ni-Mn MOF/rGO composite (826.8 F/g) is mainly due to the conductive pathways provided by MWCNT, promoting faster electron transport. and ion kinetics. The Ni-Mn MOF/MWCNT //AC device exhibited a broadened operating window of 1.4 V and maintains an excellent retention rate 85 % for 5000 cycles. This study demonstrates that the electrochemical performance varied with the dimensional tailoring as the 1D MWCNT composite outperformed the 2D rGO counterpart by providing ion mobility pathways and superior utilization of active sites.