NiFe layered double hydroxide electrodeposited on Ni foam coated with reduced graphene oxide for high-performance supercapacitors

High-performance electrode materials consisting of intertwined caterpillar-like NiFe layered double hydroxide bridges coated on reduced graphene oxide modified Ni foam (NiFe LDHs/rGO/NF) were prepared via a facile two-step electrodeposition method. First, rGO was electrochemically coated onto NF at a constant potential of -1.2 V vs. SCE for 600 s. Then NiFe LDHs of different Ni to Fe ratios were electrodeposited onto the formed rGO/NF electrodes at -1.2 V vs. SCE for 10 s. Under optimized conditions, NiFe LDHs/rGO/NF composites displayed a high specific capacitance of 1462.5 F g(-1) at a current density of 5 A g(-1) and retained about 64.7% of the original capacitance after 2000 cycles. Furthermore, a flexible asymmetric supercapacitor was prepared using NiFe LDHs/rGO/NF as the cathode and mesoporous carbon (MC) coated on NF as the anode. The supercapacitor exhibited an energy density of 17.71 Wh kg(-1) at a power density of 348.49 W kg(-1). All of these findings suggest that the new electrodes developed in this work hold a potential application prospect in flexible energy storage devices. (C) 2019 Elsevier Ltd. All rights reserved.