Rational design of nanorod-supported Ni3S2 nanosheet array for advanced asymmetric pseudocapacitor with a great energy density

We report a template method by rationally designing a self-supported Ni 3 S 2 nanosheet-wrapped ZnO nanorod (Ni 3 S 2 @ZnO) standing vertically on Ni foam surface. In this work, an organic molecule of 2-methylimidazole (2-MI) using as a structural director, which is commonly used in metal–organic frameworks(MOFs), has been adopted to link those Ni 3 S 2 nanosheets forming a shear-wall structure. This special morphology with multi-dimension (2D with 1D) exhibits advantages on the high capacitance of about 3546 F g −1 at a current density of 0.5 A g −1 . Besides this, Ni 3 S 2 @ZnO can deliver an extraordinarily capacitance of 1872 F g −1 even at a high current density of 25 A·g −1 , which in the meantime displayed a good capacity retention of 70.3% after 10,000 cycles. An asymmetric supercapacitor was then constructed, performing a quite stable capacitance of about 197 F g −1 at a high current density of 15 A g −1 for 5000 cycles and a sufficient energy density of 140 Wh kg −1 , which proves its potential on lighting up six red LEDs in practical usage.