NiCo-MOF derived nanostructured NiCo-LDH@Ni(OH)2 heterogeneous composite as electrode material for hybrid supercapacitors

Abstract

Regulating the composition and microstructure of multiphase nanocomposites can be used to significantly improve the charge storage capacity of the materials. Herein, the thermometal NiCo-MOF was used as precursor, which was placed in the designed alkaline oxidation environment for alkalization treatment, and NiCo-LDH and Ni(OH)2 heterogeneous composite (NiCo-LDH@Ni(OH)2) was prepared. The ratio of Ni/Co in MOF precursor was further regulated to optimize the composition and structure. Finally, NiCo-LDH and Ni(OH)2 with two-dimensional nanosheet structure were obtained when the Ni/Co ratio was 2:1. Benefiting from the nanostructure of electroactive material and the synergistic effect of multicomponent heterogeneous composite, the electrochemical reactivity is effectively improved, which the NiCo-LDH@Ni(OH)2 electrode has a specific capacity of 754.8C g−1 at 1 A g−1. Further, hybrid supercapacitor (HSC) is assembled to explore practical applications device, which the NiCo-LDH@Ni(OH)2//AC HSC device can output energy density of 30.6 Wh kg−1, power density of 799.9 W kg−1, and maintain 89.0 % of the initial performance after 5000 cycles.