There are still many challenges in the transformation of supercapacitors from laboratory research to industrial application, especially the low-mass load electrodes used in laboratories cannot meet the needs of commercial applications. Herein, we present a highly loaded nickel-cobalt double hydroxide-based (NiCo-LDH) supercapacitor. Three-dimensional ZnO@C nanorod scaffolds with high conductivity were introduced, and ZnO@C@NiCo-LDH heterostructure materials on carbon cloth were prepared by solvothermal, high-temperature annealing, electrochemical deposition and other methods, achieving loading up to 11.0 mg•cm⁻². The typical synthesis process is as follows. Firstly, the neatly arranged ZnO nanorods were grown on the carbon cloth fiber by seed growth method. Then, ZIF-8 nanoparticle coatings were grown in situ on zinc oxide nanorods through etching and recombination in a solution containing 2-methylimidazole. Subsequently, we obtained ZIF-8-derived carbon-coated ZnO nanorods by carbonizing ZnO@ZIF-8 heteronanostructures in nitrogen. During the carbonization process, the ZIF-8 shell is transformed into a carbon layer containing zinc oxide nanoparticles. Finally, NiCo-LDH nanosheets were deposited on the ZnO@C framework by electrochemical cyclic voltammetry. The conductive ZnO@C nanorods can avoid the agglomeration of NiCo-LDH nanosheets and promote the transport of electrons. The outer NiCo-LDH nanosheets with high capacity can continue to improve the electrolyte ion contact points on the electrode surface, further improving the specific capacity of the material. This heterostructure electrode utilizes the synergistic effect of the two to greatly improve the charge storage capacity and exhibits excellent electrochemical performance. The results show that the assembled asymmetric supercapacitor ZnO@C@NiCo-LDH//AC achieves a high energy density of 0.93 mWh•cm⁻² at a power density of 15 mW•cm⁻². After 5000 cycles at a current density of 10 mA•cm⁻², the capacity retention rate is still 93.6%, demonstrating excellent stability. This work provides a new idea for developing new high-mass load electrodes.

Key words: heterostructure materials, supercapacitor, ZnO nanorods, nickel-cobalt double hydroxide, high loading electrode