Bifunctionalized CoFe-LDH Nanosheets via Iron Oxide and Nickel Hydroxide Nanostructures as an Efficient Electrode for Aqueous Hybrid Supercapacitors

The development of battery-type electrode materials is very crucial for hybrid supercapacitors due to structural degradation, mismatched electrochemical properties, and complex hybrid charge storage mechanisms. Layered double hydroxides (LDHs) especially CoFe-LDHs are widely chosen in view of their fascinating electrochemical performance. However, they face some challenges including the limited conductivity, structural degradation, and layer stacking fault, which result in fading energy density as well as cycle stability. To address these limitations, functionalization of nanostructures has emerged as an effective strategy. These modifications enhance the electrical conductivity and structural integrity of CoFe-LDHs, facilitating efficient charge transport. In this study, Ni(OH)2 nanoflakes and Fe16O20 nanoparticles decorated on CoFe-LDH nanosheets were prepared using a single-step hydrothermal method in two different Co/Fe/Ni molar ratios, namely, 3:1:1 (CFN311) and 3:1:2 (CFN312). The electrochemical study exhibits specific capacities of 55 mA h g–1 (CFN311) and 25 mA h g–1 (CFN312) at 0.5 A g–1. Furthermore, the fabricated aqueous hybrid supercapacitor device demonstrates a specific capacitance of 71 F g–1 at 1 A g–1 along with a maximum specific energy density of 25 W h kg–1 and power density of 7600 W kg–1. This work highlights the potential of CNF311 as an efficient electrode for high-performance aqueous hybrid supercapacitors.