Poly(ionic liquid)/expanded pore NH2-UiO-66 composite solid-state electrolyte for high-performance solid-state lithium-ion batteries

Abstract

The development of high-performance solid electrolytes is essential for advancing ion batteries. This research introduces a novel approach for the simultaneous construction of poly(ionic liquid) and ionic conductors, creating a synergistic system that integrates a new polycationic ionic liquid matrix with ionic liquid-modified ionic conductors (Li-IL@PA-UiO-66-NH₂). This method markedly improves the interfacial compatibility between the polymer substrate and the functional filler. The filler enhances the composite electrolyte, achieving a higher transference number and ionic conductivity documented in recent studies, alongside improved voltage stability. We engineer and manufacture poly(1-vinyl-3-dodecylimidazole) bis(trifluoromethanesulfonimide) ([P(VIM-R)]TFSI) ionic liquids, which are subsequently utilized as the primary polymer, resulting in the formation of a poly(ionic liquid) solid-state electrolyte (P-GPE). Subsequently, we integrate it with the Li-IL@PA-UiO-66-NH₂ ionic conductor to formulate a poly(ionic liquid) composite solid-state electrolyte (P-CPE). The findings indicate that the ionic conductivity of P-CPE at 30 °C is 2.35 × 10⁻⁴ S cm⁻¹, with a transference number of 0.77. This value is 1.85 and 1.33 times higher than that of P-GPE, and the material can function safely up to 5 V. This study emphasizes the role of solid-state electrolytes in advancing the development of next-generation solid-state batteries.