Solvent-free lithium and sodium containing electrolytes based on pseudo-delocalized anions

Abstract

Mixing the standard battery salt LiTFSI with various Li-salts of novel pseudo-delocalized organic anions [N(CH₃)₂((CH₂)_nSO₃)((CH₂)_mSO₃)]⁻ (MM_nm11), results in super-cooled solvent-free liquid electrolytes with glass transition temperatures of ca. 50 °C. Synthesis routes and full chemical characterisation of the new pseudo-delocalized anions are presented, as well as phase and thermal stabilities. The ion conductivities and electrochemical stabilities are evaluated towards lithium and sodium battery application.