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 V 2 O 5 @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 V 2 O 5 @CoV-LDH features V 2 O 5 as the first layer and CoV-LDH as the second layer, effectively merging the high capacitance and energy density of V 2 O 5 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 V 2 O 5 @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 V 2 O 5 @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.