Layered double hydroxide-based nanomaterials for supercapacitors and batteries: Strategies and mechanisms

Supercapacitors and batteries play crucial roles in sustainable energy storage devices. Layered double hydroxide (LDH) exhibits outstanding adaptability to various electrochemical environments. However, poor electrical conductivity, limited electrochemical activity, and insufficient stability limits the application of LDH. Overcoming these obstacles is essential to fully exploit its potential in large-scale applications. This review extensively examines the crystal structure, properties, preparation, and modification techniques of LDH, as well as its application in different energy storage devices and various in situ characterization methods. The evolution of LDH from 1842 to 2024 is systematically reviewed, with a detailed analysis of recent advancements in characterization and modification methods, including the template method, high entropy alloy, superlattice, vacancy regulation, and defect engineering. Additionally, the review discusses the utilization of LDH in various energy storage devices such as supercapacitors, lithium-ion batteries, air batteries, and halogen ion batteries. Future research directions for LDH are also outlined, such as AI assistance and in-situ characterization. In conclusion, this review provides a comprehensive analysis of the structure, properties, and challenges of LDH in supercapacitors and batteries, aiming to address the current gaps in existing reviews and serve as a valuable reference for researchers and industry professionals.