Ternary NiMoCo-layered double hydroxides grown on chemically plated Ni[sbnd]P alloyed nickel foam for high-performance supercapacitors

Abstract

Ternary metal layered double hydroxide compounds are used as electrode materials to increase the specific capacitance of supercapacitors. Improvement of the substrate material also benefits the electrode material, which already displays excellent electrochemical properties. In this study, nickel foam (NF) was cleaned and then modified by chemical plating, which can significantly improve the corrosion resistance and retain the optimal electrical conductivity properties of the metallic material. This is because of the typically amorphous structure of the chemically plated NiP alloy. It also makes NF less susceptible to corrosion under strong alkaline conditions. Co-ZIF-67 was then prepared by a facile method, and NiMo-LDH was grown by controlling the duration of hydrothermal reaction during NF/Ni-P@Co-ZIF-67 treatment. Finally, NF/Ni-P@NMC-LDH composites with embroidered spherical nanosheets of NiMoCo-LDH (NMC-LDH) were synthesized on NF/Ni-P and used to encourage the non-binder direct growth of electrodes. The binder-free electrode, NF/Ni-P@NMC-LDH, exhibited outstanding electrochemical properties in 6 mol of KOH, including an ultra-high specific capacitance of 2980 F g−1 at 1 A g−1 and a capacitance retention of 82.95 % at 10 A g−1. The cycle performance was also much higher compared to NF@NMC-LDH, with good cycle stability (82.68 % at 10 A g−1 after 5000 cycles). The NF/Ni-P@NMC-LDH//AC ASC showed a high specific energy at 727.9 W·kg−1, generating 91.2 Wh·kg−1 with excellent capacity retention (86.97 % after 5000 cycles). Therefore, this work can provide new ideas for improving the specific capacitance of supercapacitors and preparing new electrode materials, which may have multiple application potentials in the whole energy storage industry.