Hierarchically crystalline copper borate nanosheets as a freestanding electrode for a hybrid supercapacitor.

In this study, we have suggested a straightforward approach to fabricating a binder-free electrode of hierarchically crystalline copper borate (Cu-B) nanosheets grown on nickel foam using the Successive Ionic Layer Adsorption Reaction (SILAR) method. The best-performing electrode shows a remarkable specific capacitance (Cs) of 2002 Fg at 1 Ag and Cs retention of 85 % for 10,000 GCD cycles. The assembled CB/NF-2//AC device exhibits high cycling stability and achieves a high energy of 52.