Interweaved Nanofiber Anode Coating Based on Covalent Organic Frameworks for High‐Performance Lithium‐Metal Batteries

Abstract

AbstractHigh‐rate lithium‐metal batteries call for unique interfacial structures of anode with interfacial compatibility, facilitated lithium insertion/extraction and dendrite suppression properties to meet the growing high‐rate demand. Here, we develop an interweaved porous coating based on a kind of covalent organic framework (ODH─Cu3─COF) based helical nanofibers through the assembly of non‐linear oxalyldihydrazide unit and rigid Cu3 unit. The interweaved helical nanofibers network with well‐arranged polar groups (i.e., C═N, ─CO─NH─, and pyrazole groups) could serve as nuclei sites to achieve fast Li+ insertion/extraction and dendrite suppression in high‐rate conditions. Benefiting from the advantages of interface design, the resultant ODH─Cu3─COF modified anode improves the Coulombic efficiency (97.5%, 120 cycles at 5 mA cm−2) and showcases a stable lifespan (1000 h at 2 mA cm−2 and 2 mAh cm−2) in symmetric cell. Moreover, the high‐rate property of ODH─Cu3─COF@Li||LFP full cell presents an excellent cycling stability (900 cycles at 5 C) in commercial carbonate electrolyte. Theoretical calculations reveal that lithiophilic ODH─Cu3─COF has high Li affinity to reduce the nucleation barrier and achieve fast desolvation process in an interface to promote the lifespan of high‐rate lithium‐metal batteries.