Hierarchical Columnar Cactus-like Co-MOF@NiCo-LDH Core-Shell Nanowrinkled Pillar Arrays for Supercapacitors with Ultrahigh Areal Capacitance

The design of metal-organic framework/layered double hydroxide (MOF/LDH) heterogeneous hybrids is crucial to the enhancement of areal capacitance for supercapacitor electrodes. Herein, the NiCo-LDH nanowrinkles are evenly epitaxially grown on the surface of self-supported Co-MOF nanoneedles to form aligned nanopillar arrays by a facile electrodeposition. Thanks to the high porosity of the Co-MOF, excellent redox activity of NiCo-LDH, and interfacial synergy of the core-shell multicomponent heterostructure, the Co-MOF@NiCo-LDH composite has an extraordinary areal capacitance (44.1 F cm-2 at 5 mA cm-2), which is 7.6 and 2.6 times higher than that of the bare NiCo-LDH and Co-MOF, respectively. Furthermore, the constructed asymmetric supercapacitor with activated carbon demonstrates a satisfactory energy density of 0.89 mWh cm-2 at the power density of 7.5 mW cm-2 and superior cycling stability (97.6% capacitance retention after 10,000 cycles).