Hierarchical Columnar Cactus-like Co-MOF@NiCo-LDH Core–Shell Nanowrinkled Pillar Arrays for Supercapacitors with Ultrahigh Areal Capacitance
Fangqi Ye, Jiao–Jiao Zhou, Xinyue Jiang, Linping Wang, Yizhao Su, Bo Zhu, Luyang Chen
Abstract
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).