Unique hollow fries-like NiCo-LDH material derived from NiCo-MOF with significant advantages of high-performance supercapacitors

Regulation of the composition and microstructure of nanoelectrode materials is an effective way to improve the electrochemical property of supercapacitor electrode materials. In this paper, NiCo-MOF nanorods prepared by simple solution immersion method were used as precursors, which were subjected to alkalization, and hollow fries-like NiCo-LDH layered double hydroxide consisting of two-dimensional nanosheets was fabricated when the molar ratio of Ni²⁺/Co²⁺ was 1:1. This unique hollow fries structure of NiCo-LDH electrode material can provide more electrochemical reaction sites and improve its electrochemical performance. The analysis revealed the NiCo-LDH material derived from MOF has a specific capacity of 1491 F g⁻¹ at 1 A g⁻¹ and still has a capacity retention rate of 88% after 4000 cycles at 20 A g⁻¹. The mechanisms of charge storage were discussed by kinetic analysis. The assembled NiCo-LDH//AC ASC device has a high energy density of 30.3 Wh kg⁻¹ (power density of 806.7 W kg⁻¹), and a capacitance retention of 78% after 2000 cycles at 5 A g⁻¹. In this research, the hollow fries-like NiCo-LDH electrode materials derived from NiCo-MOF have the characteristics of a fast electron/ion transfer rate and a high utilization rate of active materials, which provides a new idea for MOF-derived nanoelectrode materials.