Covalent organic frameworks enabled solid/quasi-solid state electrolytes for rechargeable batteries: Synthesis, progress, challenges and perspectives

Solid-state electrolytes (SSEs) are recognized as highly competitive candidates for next-generation rechargeable batteries and have attracted considerable interest for applications in portable electronics and electric vehicles owing to their outstanding safety, high energy density, excellent flexibility, ecological sustainability, as well as economic feasibility. Nevertheless, their practical applications are severely restricted by unstable electrode/electrolyte interfacial compatibility and insufficient ionic conductivity. Covalent organic frameworks (COFs), a class of crystalline porous materials, have emerged as functional components for SSEs due to their unique structural merits, including tunable frameworks, high crystallinity, ordered pore channels, and excellent thermal stability. Additionally, COFs offer innovative strategies to regulate ion transport, suppress dendrite growth, and achieve performance improvements in SSEs. This review summarizes the synthesis strategies of COFs, including solvothermal, ionothermal, microwave-assisted, mechanochemical, interfacial polymerization, electropolymerization, and room-temperature synthesis. The application progress of COF-based materials in SSEs for lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), zinc-ion batteries (ZIBs), and other energy storage devices is systematically reviewed. Furthermore, it summarizes the existing problems and challenges of the application of COFs for SSEs and proposes future optimization directions. It aims to offer fundamental insights into the design and application of advanced COFs for SSEs.