One-Step Electrodeposition of MnO2@NiAl Layered Double Hydroxide Nanostructures on the Nickel Foam for High-Performance Supercapacitors

The composites of manganese dioxide (MnO2) and NiAl layered double hydroxides (NiAl-LDHs) were directly grown on the nickel foam by one-step electrodeposition. The as-prepared MnO2@ NiAl-LDH porous flower-like nanostructures on nickel foam as binder-free electrodes for supercapacitors exhibit a specific capacitance as high as 1554 F/g at a current density of 1 A g(-1), far higher than that of individual MnO2 (439 F g(-1)) and NiAl-LDHs (742 F g(-1)). In addition, they also display a good rate capability over a wide range of current densities from 1 to 10 A g(-1) and a satisfactory cycling performance with similar to 71% capacity retention at 5 A g(-1) up to 1000 cycles. The good performance may be attributed to the synergistic effects between MnO2 and NiAl-LDH including the good dispersion of MnO2 on the layer of NiAl-LDHs and the enhanced rate of electron transfer due to their intimate contact. Considering the main merits such as low cost, easy preparation, binder-free property and high performance, the MnO2@ NiAl-LDH nanostructures on nickel foam are promising as an efficient supercapacitive electrode. (C) 2016 The Electrochemical Society. All rights reserved.