Constructing Co(OH)F Nanorods@NiCo-LDH Nanocages Derived from ZIF-67 for High-Performance Supercapacitors

Nanostructured multicomponent hydroxide has recently drawn wide attention as positive material for high-performance supercapacitors. Herein, a multi-dimensional Co(OH)F@NiCo-LDH (LDH = layered double hydroxide) composite with layered nanocages has uniformly grown on nickel foam (NF) by a solvent-assisted process, which involves the in situ growth of ZIF-67 on the surface of Co(OH)F nanorods, followed by chemical etching of the hybrids. Benefiting from its subtle structural design, the Co(OH)F@NiCo-LDH exhibits high specific capacitance of 4070 mC cm(-2) at 1 mA cm(-2) (1313.3 C g(-1) at 1 A g(-1)), desirable rate performance (3104 mC cm(-2) at 20 mA cm(-2)), and outstanding cycling stability (92.7% retention after 7000 cycles). Moreover, a two-electrode system assembled by Co(OH)F@NiCo-LDH and reduced graphene oxide exhibits a peak energy density of 49.34 Wh kg(-1) at the corresponding power density of 865 W kg(-1). These results demonstrate that the Co(OH)F@NiCo-LDH is an advanced positive material for the electrochemical device.