Nanofiber-Architected Imidazole COF Enabling Ultrafast Desolvation-Dissociation Kinetics in Quasi-Solid-State Lithium Metal Batteries

Developing a novel gel polymer electrolyte (GPE) constitutes an effective strategy for addressing retarded Li⁺ transport and enabling ultrafast-charging quasi-solid-state lithium metal batteries (QSLMBs). Herein, a novel imidazolium cationic covalent organic framework (ICOF) incorporated into a nanofibrous skeleton GPE (ICOFNS-GPE) is reported, which accelerates desolvation-dissociation kinetics for rapid and uniform Li⁺ transport. In ICOF, imine/triazole bonds facilitate Li⁺ desolvation via lithiophilic coordination, whereas imidazolium cations promote anion anchoring to enhance dissociation, collectively optimizing desolvation-dissociation kinetics and stabilizing the Li anode. Furthermore, incorporating ICOF into polyacrylonitrile nanofiber networks forms hierarchical ion channels, enabling fast Li⁺ transport. As a result, ICOFNS-GPE exhibits both a high σ of 1.95 mS cm⁻¹ and a high (Formula presented.) of 0.74, which are attributed to the accelerated ionic migration kinetics. The assembled Li || NCM811 cells with ICOFNS-GPE can reach 133.0 mAh g⁻¹ at 5 C (capacity retention rate of 83.2% after 300 cycles). ICOFNS-GPE enables QSLMBs to achieve 73% capacity within 10 min and ensures stable operation under mechanical stresses (folding, pricking, cutting). This work presents a novel approach to engineering functional composite GPEs for ultrafast-charging QSLMBs.