Development of solid polymer electrolytes based on dioxazaborocane vitrimers

Details

Supervisors

Fustin, Charles-André

Faculty

Faculté des sciences

Degree label

Master [120] en sciences chimiques, à finalité approfondie

Abstract

The increasing demand for safer, more sustainable, and higher-performance energy storage systems has driven the development of solid-state batteries. In this context, solid polymer electrolytes represent a promising alternative to conventional liquid electrolytes, particularly for lithium metal batteries. However, achieving a suitable balance between ionic conductivity, mechanical properties and safety remains a major challenge. Vitrimers, a class of covalent adaptable networks capable of undergoing bond-exchange reactions while maintaining their crosslinked structure, offer an attractive strategy for overcoming these limitations. This work investigates the development of vitrimer-based solid polymer electrolytes using dioxazaborocane dynamic boronic ester chemistry. PEGMA-based networks containing dynamic crosslinkers, with or without dioxazaborocane dangling groups, were synthesized by UV-initiated free-radical photopolymerization. The materials were characterized through rheological and electrochemical measurements to evaluate their suitability as solid vitrimer electrolytes. The synthesized networks exhibited typical vitrimer characteristics, including stress relaxation, temperature-dependent network rearrangement, and self-healing behavior. The influence of network composition and lithium salt incorporation on both the dynamic properties and ionic transport was investigated. Promising ionic conductivities were obtained, with 8.1*10-5 S.cm-1 at 60 °C, placing these materials within the upper range commonly reported for vitrimer electrolytes. Overall, the developed dioxazaborocane-based vitrimer electrolytes showed promising properties, combining vitrimer behavior, thermal stability, self-healing capability, and competitive ionic conductivity. These results highlight their potential as solid polymer electrolytes for lithium batteries.