Research Progress of Covalent Organic Framework (COF) Based Anode Materials in Metal Ion Batteries

Covalent organic frameworks (COFs), characterized by structural designability, ordered porosity, and tunable redox activity, have emerged as promising electrode materials for metal-ion batteries (LIBs, SIBs, and ZIBs). This review summarizes the progress and challenges of COFs in lithium-, sodium-, and zinc-ion batteries. In LIBs, COFs like TRO-BT-COF offer high capacity via redox-active sites (e.g., C=O, C=N), but suffer from low conductivity, structural rigidity, and complex synthesis. For SIBs, materials such as BCOF-1 exhibit pseudocapacitive behavior and ordered pores, yet face sodium-ion induced swelling and redox site complexity. In ZIBs, COFs like HqTp-COF enable Zn²⁺ storage through coordination with functional groups, but hydrolytic instability in aqueous electrolytes and inefficient ion desolvation limit performance. Key challenges across systems include poor electrical conductivity, electrolyte compatibility issues, and scalability of synthesis. Potential solutions involve integrating conductive additives, engineering flexible/hierarchical structures, and developing hydrophobic or dynamic covalent frameworks. By addressing these limitations, COFs could unlock high-performance, sustainable metal-ion batteries for next-generation energy storage.