A Review and Perspective on Advancement in Metal-Organic Framework-Based Composites for Supercapacitors: From Dimensionalities to Functionalities

The need for efficient energy storage devices driven by the continuous increase in global energy demand has led to the development of advanced electrodes. Exploring advanced electrode materials with tailored nanostructures for high-performance supercapacitors is a promising approach to address current energy issues. Metal-organic frameworks (MOFs) are porous crystalline substances having a periodic structure constructed from metal centers coordinating with organic linkers and well-flourished with exceptional qualities such as high surface area, crystalline and designable structures, greater porosity, and synthetic versatility. However, the low conductivity and poor cyclic performance associated with MOFs hinder their efficient usage in the energy storage sector. To overcome these challenges, MOFs can be integrated with different functional materials to construct hierarchical heterostructures possessing spatial dimensionalities, which ultimately gives rise to ranged functionalities, unleashing their full potential. Leveraging the synergy between MOFs and functional materials to achieve exceptional electrochemical outputs is currently thriving in materials science. MOF materials can be coupled with zero-, one-, two-, and three-dimensional functional materials to construct hierarchical morphologies. Controllable integration of these functional materials into MOFs surprisingly introduces some unique functionalities that enhance stability and electronic conductivity. In addition, density functional theory (DFT) is explored to obtain insights into the mechanisms of the charge storage phenomena and electrical behavior of electrodes. This review presents context on the recent advancement of MOF composites ranging from their dimensionalities to functionalities for future directions in supercapacitor application.