A novel sp3Al-based porous single-ion polymer electrolyte for lithium ion batteries

Abstract

We report synthesis of an Al-based porous gel single-ion polymer electrolyte, lithium poly (glutaric acid aluminate) (LiPGAA), using glutaric acid and lithium tetramethanolatoaluminate as the precursors. The three-dimensional network compound provides short lithium-ion transport pathways and allows organic solvents to be accommodated in the composite for rapid ion transport. The tetraalkoxyaluminate units in the material enable Li-ions to be weakly associated with the polymeric framework, leading to a high ionic conductivity of 1.47 × 10⁻⁴ S cm⁻¹ at room temperature and a high Li-ion transference number of 0.8. A membrane of the polymer was prepared via a solution cast method with PVDF-HFP poly(vinylidene-fluoride-co-hexafluoropropene) followed by soaking in a solution of ethylene carbonate (EC) and propylene carbonate (PC) (v/v, 1 : 1). A Li-ion battery assembled with the composite membrane displays remarkable cyclability with nearly 100% coulombic efficiency over a wide temperature range.