Layered double hydroxide based composites for energy storage applications: Insights into supercapacitors and batteries

Layered Double Hydroxides (LDHs), a class of hydrotalcite-like compounds, have emerged as promising electrode materials in energy storage systems (ESSs), viz. batteries and supercapacitors, owing to their exceptional properties. These include tuneable interlayer spacing, multiple oxidation states, facile synthesis, and dual charge storage faradaic and non-faradaic mechanisms. Despite their potential, LDHs face inherent limitations, such as low electrical conductivity and limited surface area, which hinder their application as electrodes. To address these challenges, the development of LDH-based composites has proven transformative. By engineering nanomorphologies, optimizing material composition, expanding ion transport pathways, and enhancing redox activity, LDH-based composites significantly improve the electrochemical performance of supercapacitors. In batteries, these composites are critical in suppressing dendrite growth, serving as precursors for anode materials, and establishing electrically conductive networks. This comprehensive review explores the recent advancements in synthesizing LDH-based composites, their impact on electrochemical performance, and the challenges to address. It also provides future perspectives for designing next-generation energy storage systems that are more efficient, durable, and capable of meeting the growing demand for green energy solutions.