Strategies to enhance electrochemical performance of isoreticular 2d conjugated metal correlated organic frameworks via transition metals intercalation for battery-supercapacitor hybrids

Abstract

Exploration of novel electrode materials for next generation energy storage devices is a trending topic at present times. Herein, first row transition metals based 2D conductive MOFs with distinct metal centers are investigated for their energy storage profiles. All the parameters affecting the structural, electrical, and electrochemical properties of 2D MOFs by replacing metal ions have been meticulously discussed. Cu and Ni based 2D conductive MOFs using a linker HHTP (2,3,6,7,10,11- hexahydroxytriphenylene) were synthesized through ultrasonication technique. The hybrid supercapacitors based on both MOFs have been fabricated. Encouragingly, the Ni based MOF have appeared to be a more proficient electrode material whereas, Cu-MOF based device was appeared to be more stable. Ni-MOF based hybrid supercapacitor has exhibited the 198C/g specific capacity with decent energy density (44 W h/kg), power density (3663 W/kg) and durability (84 % after 3000 cycles). In contrast, Cu-MOF based device has shown the satisfying durability (95 % capacity after 3000 cycles) with relatively low specific capacity (138C/g), energy density (39 W h/kg) and power density (3298 W/kg). The regression parameters of Dunn's model have also been calculated to scrutinize the underlying phenomenon of surface adsorption, surface, and bulk redox reactions. This work thus provides a viable path and guiding strategies to design next generation hybrid energy storage devices.