Directly anchored vanadium-based flower-like composite on nickel foam: enhancing surface area and stability for improved supercapacitor performance

In this study, we successfully synthesized a novel flower-like composite V2O5@CoV-LDH, which was directly anchored onto nickel foam through a two-step hydrothermal method to enhance surface area and stability. The synthesized flower-like composite V2O5@CoV-LDH features V2O5 as the first layer and CoV-LDH as the second layer, effectively merging the high capacitance and energy density of V2O5 with the large surface area and multivalent states of CoV-LDH. Moreover, this unique bilayer composite structure, directly anchored onto nickel foam, significantly enhances the overall stability of the electrode material. This design demonstrates outstanding performancedue to a strong synergistic effect, which provides the composite with more reactive sites, shorter ion transport pathways, and enhanced cycling stability. The test results show that the V2O5@CoV-LDH electrode achieves a high specific capacitance of 1822 F g(-1) at 1 A g(-1) and retains 85.99% of its capacitance after 5000 charge-discharge cycles, demonstrating excellent stability. The asymmetric supercapacitor assembled with the V2O5@CoV-LDH electrode and activated carbon electrode delivers an energy density of 59.85 Wh kg(-1) at a power density of 900 W kg(-1). After 10,000 cycles at 5 A g(-1), the specific capacitance remains at 88%, indicating promising potential for practical applications.