Facile Sulfuration Route to Enhance the Supercapacitor Performance of 3D Petal-like NiV-Layered Double Hydroxide

The charge conductivity properties and ionic delivery of pseudocapacitive materials are important factors for the charge storage process. Herein, the new petal-like S-NiV-layered double hydroxide (LDH) materials are successfully synthesized by a presynthetic solvothermal reaction and a sulfidation modification procedure. The specific capacitance of the new petal-like S-NiV-LDHs electrode reaches 1403 F g −1 when the current density is 1 A g −1 , and this is attributed to Ni 3 S 2 formed on the surface of NiV-LDHs. When the current density is up to 20 A g −1 , the rate performance of the new petal-like S-NiV-LDHs electrode is 65.04%. It can be seen that the comprehensive electrochemical performance of the new petal-like S-NiV-LDHs is better than the petal-like NiV-LDHs before modification. When the power density of the S-NiV-LDHs//activated carbon asymmetric supercapacitor cell is 2278.48 W kg −1 , its energy density is 20 Wh kg −1 . The innovation of this work lies in that, based on the microstructure of petal-like NiV-LDHs with rich mesoporous structure, the surface of petal-like NiV-LDHs is slightly sulfurized, which makes the new petal-like S-NiV-LDHs electrode material have smaller electrochemical impedance, richer oxidation states, richer chemical active sites, better energy storage, and cycle stability.