Interfacial Modification to Nanoflower-Like NiV-Layered Double Hydroxide for Enhancing Supercapacitor Performance

Vanadium-based hydrotalcite materials have attracted much attention in supercapacitor electrodes due to their polyvalent properties. Nevertheless, the weak electrical conductivity of hydrotalcite limits its further development. In order to overcome this problem, nanoflowers P-NiV-LDHs-8 and Se-NiV-LDHs-1 were obtained by ingenious modification on the surface of nanoflower microlamellae of NiV-LDHs. Compared with Se-NiV-LDHs-x (x = 0.5, 2), P-NiV-LDHs-x (x = 4, 12), NiV-LDHs, Ni₂P, and NiSe₂, nanoflowers P-NiV-LDHs-8 and Se-NiV-LDHs-1 have better mass-specific capacity and corresponding rate performances. The self-assembled P-NiV-LDHs-8//AC and Se-NiV-LDHs-1//AC (AC = activated carbon) soft package devices have relatively superior energy density and power density. Moreover, the specific capacitance retention also maintains a relatively impressive level. It is proven that the interfacial modification has a positive effect on the energy storage performance of NiV-LDHs from the perspectives of phosphating and selenizing.