Metal-Organic Framework-Based Electrodes for Asymmetric Supercapacitors

Supercapacitors (SCs) are a promising electrochemical device in the field of electrochemical energy storage, but their wide range applications are limited by relatively low energy density. Asymmetric supercapacitors (ASCs) based on different positive and negative electrodes offer the possibility to increase the energy density by extending the voltage window. It is essential to explore novel electrode materials to boost the electrochemical properties of ASCs. Metal-organic frameworks (MOFs) have emerged as ideal electrode materials for SCs, due to their high porosity, tunable structure and highly dispersed active sites. MOFs can also be used as templates or precursors for the preparation of versatile electrode materials, such as carbon materials and metal compounds. In this minireview, SCs and MOF-based electrode materials are first introduced, followed by an overview of recent advances in the synthesis of MOF-based electrode materials including pristine MOFs, MOF derivatives and their composites, and their applications in ASCs acted as negative electrode, positive electrode or both. Finally, the challenges and prospects of MOF-based ASCs are discussed.