Covalent Organic Frameworks for Capacitive Energy Storage: Recent Progress and Technological Challenges

Abstract

Covalent-organic frameworks (COFs) are emerging organic crystalline materials with a porous framework that extends into two or three dimensions. Originating from their versatile and rigorous synthesis conditions, COFs have abundant and tunable pores, large and easily accessible surfaces, and plenty of redox-active sites, making them promising material candidates for various energy storage applications. One important area is to serve as capacitive electrode materials in supercapacitors. This review provides a timely and comprehensive summary of the recent progress in the design and synthesis of COF-based or COF-derived materials for capacitive energy storage applications. The review starts with a brief introduction to COFs’ structural features and synthesis methods. Next, recently reported literature is categorized and introduced following their different energy storage mechanisms and material assembly or treatment approaches. Finally, the existing challenges and future directions for realizing practical COF-based supercapacitors are discussed.