Metal-organic framework modified quasi-solid electrolytes for all-solid lithium batteries

Quasi-solid electrolytes demonstrate advantageous properties such as high flexibility and safety, making them highly applicable in the advancement of solid-state batteries. Nonetheless, their development is hindered by inherent drawbacks such as low ionic conductivity and interfacial instability. In this study, a zirconium-based metal-organic framework (MOF, UiO-66-NH2) is incorporated into a dual-crosslinking organogel (MOF-DCGE) matrix developed through thiols-alkene click polymerization, serving as a fast ion channel (with an ionic conductivity of up to 3.1 x 10-3 S cm-1 at room temperature). Furthermore, the inclusion of a flame-retardant UiO-66-NH2 enhances the electrolyte's flame resistance. In the organogel matrix, a C-S-C covalent network is established via click polymerization between polyester monomers and thiols, and an ionic network is formed through the interaction of polyimidazole ionic liquid and polycarboxylic acid monomers. These networks provide a robust mechanical infrastructure for the electrolyte while also ensuring solubility/lithiophilicity (with a stable cycle of up to 600 h for lithium symmetric batteries). Applying into cells, the modified electrolytes display impressive electrochemical performance, characterized by high capacity, favorable rate behavior, and long-term stability.