Covalent organic frameworks for solid-state electrolytes of lithium metal batteries

Covalent organic frameworks (COFs) with a periodic network and open crystalline porous characteristic have received considerable attention due to their customizable structures and properties. Benefiting from the well-defined 1D nanochannels and ease of functionalization, they show great potential for the construction of ionic conductors and have attracted tremendous research interest. Over the past few years, COF-based solid-state electrolytes (SSEs) have made rapid progress and obtained substantial achievements. However, the research on COF-based SSEs is still in its infancy stage, and designing high-performance COF-based SSEs remains a challenge. Therefore, a timely and systematic summary of research progress in COF-based SSEs is requisite to clarify the design strategy and identify the development direction. We hope this review will provide fundamental insights and enlightening perspectives for the design of advanced COF-based SSEs.