Toilless selenylation route to enhance the supercapacitor conductive performance of nanoflower-like NiAl-layered double hydroxide

The poor ionic and electronic conductivities of pseudocapacitive materials are important constraints for the further development of supercapacitors . In this work, a new Se-NiAl-LDHs electrode material was successfully synthesized by a pre-synthetic solvothermal reaction and selenization modification procedure. On the basis of the NiAl-LDHs microstructure, partially new crystalline NiSe 2 selenides are surface-generated, and the resulting Se-NiAl-LDHs electrode material exhibits an impressive specific capacitance of 1098 F g −1 at a current density of 1 A g −1 . Furthermore, this newly synthesized Se-NiAl-LDHs electrode exhibits a good capacity retention of 60.47% at 20 A g −1 , which is superior to the outdated NiAl-LDHs electrode. Moreover, when the power density reaches 1593.17 W kg −1 , the energy density of the as-prepared soft-encapsulated Se-NiAl-LDHs//AC ASC is 29 Wh kg −1 . The focus of this work is to selenize the NiAl-LDHs microstructure so that the energy storage performance has been improvement due to the better energy storage, smaller electrochemical impedance, multiple oxidation states and more abundant chemical active sites after selenide treatment.