Progress on application of covalent organic frameworks for advanced lithium metal batteries

Since Li metal batteries (LMBs) theoretically possess high energy density, they are the most concerned rechargeable batteries at present. Whereas, poor safety and short cycling lives of the LMBs originate from various problems of LMBs components including cathode/anode materials, electrolytes, and separators have impeded their practical application. Covalent organic frameworks (COFs), which feature diverse structures, flexible frameworks, and versatile functions, have been extensively investigated as potential alternatives for above mentioned key components of LMBs. With the rational design and pre-/postsynthesis functionalization, COFs can be precisely customized for targeted functionalities, which can tackle the issues of LMBs. The current status of the application of COFs in LMBs, which covers working principles and strategies for improving electrochemical performance, will be discussed in this review. What's more, the challenges and potential directions for further developments of COFs in LMBs are presented in the final section.