Progress and prospects of Ni–Co layered double hydroxides for advanced energy storage in rechargeable supercapacitors and batteries

Nickel–cobalt layered double hydroxides (Ni-Co LDHs) have garnered significant attention as promising materials for next-generation energy storage systems due to their unique layered architecture, high redox activity, and compositional tunability. Their intrinsic features, such as high surface area, variable metal ratios, and the ability to host diverse intercalated species, make them highly suitable for use in rechargeable supercapacitors and batteries. Present review provides a comprehensive overview of recent advancements in the design, synthesis, and functionalization of Ni-Co LDH-based materials tailored for energy storage applications. Key synthesis routes, including hydrothermal, solvothermal, electrodeposition, co-precipitation, and emerging techniques like microwave and solvent-deficient methods are critically examined. The review also highlights exfoliation strategies (both solvent-based and solvent-free), intercalation tuning, and structural modifications that enhance electrochemical performance. Special attention is given to the transformation of Ni-Co LDHs into their derived chalcogenides and the development of Ni-Co LDH-based hybrid composites for energy storage applications. Finally, future perspectives are outlined, focusing on overcoming current limitations through mechanistic insights, electrolyte engineering, and advanced material architectures to push the performance boundaries of Ni-Co LDH-based electrodes for sustainable and high-performance energy storage devices.