Supercapacitor based on the CuCo 2 S 4 @NiCoAl hydrotalcite array on Ni foam with high-performance

A simple hydrothermal method was implemented to controllably prepare the mesoporous network “sand rose” NiCoAl hydrotalcite (LDH) on Ni foam (NF). The effect of the Ni/Co/Al molar ratio on crystalline structure, morphology and electrochemical performance was explored systematically, where the LDH2.0 with a Ni/Co/Al molar ratio of 2.0/1.0/1.0 had the maximum specific capacitance due to the highest crystallinity and uniform configuration with 3D mesoporous network “sand rose” structure. To enhance supercapacitor performance, the LDH2.0 was covered on the CuCo2S4 nanotube array on NF to assemble CuCo2S4@LDH electrode material. The as-prepared CuCo2S4@LDH demonstrated an improved specific capacity with 938 C g−1 (1876 F g−1) at 1.0 A g−1 and super cycling stability (retention of 95.74% after 1000 cycles at 5 A g−1). The enhanced performance was attributed to the unique 3D hierarchically core-shell structure of the CuCo2S4@LDH and the synergistic effect of the core CuCo2S4 nanotube array on NF and the shell LDH. © 2020 Elsevier Ltd