Two-dimensional covalent triazine frameworks for advanced electrochemical energy storage applications

Two-dimensional covalent triazine frameworks (2D CTFs) are novel conjugated porous polymers created through the covalent bonding of organic monomers with triazine structural units. Owing to their distinctive physicochemical characteristics, such as elevated specific surface area, adjustable pore architecture, superior electrochemical stability, low weight, and recyclability, they have emerged as a focal point of research in electrochemical energy storage. The utilization of 2D CTFs in diverse electrochemical energy storage systems, including lithium-, sodium-, potassium- and zinc-ion batteries, as well as supercapacitors, not only demonstrates the enhancement of the energy and power densities of these devices, but also promotes their cycling stability and rate performance. This review offers a comprehensive examination of the correlation between the distinctive 2D morphology of 2D CTFs and their electrochemical performance, specifically how their elevated specific surface area and plentiful active sites promote ion transport and electrochemical reactions, consequently improving the energy density, power density, and cycling stability of energy storage devices. In addition, we outline the benefits of 2D CTFs in electrochemical energy storage while highlighting existing obstacles, including material conductivity constraints and large-scale production issues. Finally, it also suggests future research avenues, including the enhancement of conductivity by functionalization design and the optimization of synthesis procedures for large-scale production.