Elucidating d-π conjugated isoreticular 2,3,6,7,10,11-hexahydroxytriphenylene and hexahydroxybenzenebased metal organic frameworks for battery-supercapacitor hybrids

Abstract

Energy storage technology has witnessed a phenomenal expansion in developing electrode materials with the capability of providing high energy density and/or high power density. Metal organic frameworks (MOFs) family have become a strong competitor of already existed electrode materials in past few years. In this study, we synthesized two conductive copper based conductive MOFs (c-MOFs) with different linkers (HHTP: 2,3,6,7,10,11-hexahydroxytriphenylene, HHB: hexahydroxybenzene) named as Cu3(HHTP)2 and Cu3(HHB)2. Battery-supercapacitors were fabricated of both c-MOFs with activated carbon and evaluated for their energy storage profiles. The dynamics of variation in electrochemical properties of honeycomb-structured c-MOFs due to replacing linker have been discussed conscientiously. The Cu3(HHTP)2 was witnessed to appear more favorable material for energy storage applications as it possesses remarkable specific capacity (138C/g), energy density (33 W h/kg), and power density (3582 W/kg) with 95% capacity retention after 1000 cycles. Theoretical approach was employed further to open a new revenue to assess battery-supercapacitors by calculating regression parameters of Dunn's model to explain surface and bulk phenomenon occurring for charge storing. This study bridges the gap between batteries and supercapacitors and a guide toward the development of new generation energy storage device with enhanced properties.