Superior rate capability of crystalline nickel-cobalt layered double hydroxide@amorphous nickel cobalt phosphate core-shell heterostructure for aqueous supercapacitors and Zn-based batteries

Crystalline/amorphous NiCo-LDH@NCP core-shell heterostructure hollow nanospheres were synthesized through a solvothermal-template strategy to enhance the electrochemical stability and rate performance of nickel cobalt phosphate-based materials. The engineered heterostructure mitigates structure collapse, shortens ion diffusion paths, and promotes charge transfer via a Mott-Schottky heterointerface. DFT simulations confirm built-in electric field formation and interfacial charge redistribution. The optimized NiCo-LDH@NCP-2h electrode exhibits 1615.6 F g⁻¹ at 1 A g⁻¹ and 81.7% capacitance retention after 3000 cycles. The assembled NiCo-LDH@NCP-2h//AC asymmetric supercapacitor achieves 27.56 Wh kg⁻¹ at 399.42 W kg⁻¹, while the NiCo-LDH@NCP-2h//Zn battery delivers 158.7 mAh g⁻¹ at 1 A g⁻¹ with excellent rate capability.