ZIF-67 derived hollow OCS/NiCo-LDH nanocages as binder-free electrodes for high performance supercapacitors

Abstract

Layered double hydroxides (LDHs) are under the current research focus because of their uniqueness in low cost, highly tunable composition and properties. However, rational design the nanostructure of LDH is highly desirable to optimize their performance. Herein, a novel binder-free organic domestic wastes-derived carbons (OCS) decorated NiCo-LDH nanocages was designed and fabricated using a ZIF-67-derived strategy on Ni foam, and the resultant integrated OCS/NiCo-LDH@Ni foam electrode could directly acted as promising electrode for supercapacitor. The integrated electrode could deliver a high specific capacitance of 1784 F g−1 at a current density of 1 A g−1, and 732 F g−1 at 10 A g−1. The maximum specific capacitance 611.46 F g−1 was delivered at 3 A g−1 by the assembled symmetric supercapacitor. 83.2% capacitance retention and about 100% coulombic efficiency were retained after 6000 GCD cycles at current density of 8 A g−1. OCS/NiCo-LDH@Ni foam electrode was also demonstrated to possess high energy density of 108.7 W h Kg−1 at 2400 W Kg−1. This work opens a promising avenue for the new and rational design of high performance supercapacitor and the recycling utilization of solid waste.