A multi-layer-structured nickel-based electrode for high-performance binder-free asymmetric quasi-solid-state hybrid supercapacitors

A novel multi-layer-structured Ni-Mn LDH/rGO/Ni(OH)(2)@Ni foam (LRN@NF) is synthesized by a method combining hydrothermal and dip-coating processes, acting as an excellent electrode material for supercapacitors. The specific multi-layer structure and synergism of all the components boosts the electrochemical performance. Microstructural characterization illustrates the successful formation of the multi-layer structure and also demonstrates the important role of the incorporated graphene layers for the growth of Ni-Mn LDH. The Ni-Mn LDH/rGO/Ni(OH)(2)@Ni foam shows a high specific capacity of 7.49C center dot cm(-2) (specific capacitance of 14.40 F center dot cm(-2)) at 1 mA center dot cm(-2). Furthermore, the asymmetric quasi-solid-state hybrid supercapacitor (LRN@NF//AC; AC represents activated carbon) exhibits a high specific energy density of 0.23 mWh center dot cm(-2) at a specific power density of 0.91 mW center dot cm(-2) with a voltage window of 1.6 V, and 0.12 mWh center dot cm(-2) of energy density can be maintained even at 64.04 mW center dot cm(-2). Therefore, the LRN@NF electrode is suggested to be a promising candidate for high-performance supercapacitors, and our research also demonstrates the feasibility and universality of the construction idea for excellent multi-layer-structured supercapacitor electrodes.

Automated summary

A novel multi-layer-structured Ni-Mn LDH/rGO/Ni(OH)(2)@Ni foam electrode is synthesized, exhibiting excellent electrochemical performance with high specific capacity and energy density. The construction idea of this electrode shows promise for high-performance supercapacitors.