Enhancing supercapacitor performance through cobalt compounds doping in nickel-vanadium hydrotalcite

The primary constraint that hinders the progress of supercapacitors lies in the ionic and electronic conductivity of pseudo-capacitor materials. In this study, cobalt compounds were doped into nickel-vanadium hydrotalcite materials using the hydrothermal method. This resulted in the adhesion of cobalt hydroxide nanosheets onto the surface of hydrotalcite, indicating successful synthesis of Co-NiV-LDHs materials. The successful integration of cobalt hydroxide nanosheets onto the surface of NiV-LDHs leads to an impressive specific capacity of 946.3 F g⁻¹ for the Co-NiV-LDHs electrode material, achieved at a current density of 1 A g⁻¹. Furthermore, having endured a rigorous charging/discharging test of 5500 cycles at a current density of 10 A g⁻¹, the Co-NiV-LDHs material maintained an impressive rate of retention in capacitance (95.7%), significantly outperforming the NiV-LDHs material. Additionally, the meticulously crafted asymmetric supercapacitor which features a soft-packed Co-NiV-LDHs//AC ASC design, exhibited an impressive energy density of 33.3 Wh kg⁻¹ at a power density of 1535.1 W kg⁻¹. This study highlights the potential of our Co-NiV-LDHs samples as promising electrode materials, which exhibit pseudocapacitive properties that are ideal for polymerized asymmetric supercapacitors.