Metal–organic frameworks and their composites: Design, synthesis, properties, and energy storage applications

Abstract

Porous crystalline metal–organic frameworks (MOFs) are promising materials for supercapacitors (SCs) owing to their excellent pore structures, large surface areas, adjustable topological types, and multivalent active metal nodes, which endow them with ideal energy-storage performance. However, despite their successful application in many fields such as catalysis, gas adsorption and separation, and sensors, various intrinsic defects have hindered their practical application in SCs. In recent years, MOFs have demonstrated significant advancements in their electrochemical performance, and their applications in SCs have been gaining momentum. This review summarizes the design, classification, synthesis strategies, and properties of MOFs. The formation conditions and mechanisms of MOFs are discussed and the effects of the different types and synthesis strategies of MOFs on their properties are compared to improve their design and preparation. The research progress on pristine MOFs and their composites in SCs is reviewed, highlighting the solutions for the intrinsic defects in pristine MOFs in SC applications. The challenges of utilizing MOF-based materials in SC applications are summarized and potential solutions for their future development are suggested.