LAUSR

Abstract Electrolyte decomposition in Li-ion batteries (LIB) and its entailing gas evolution significantly impacts cell performance. CO2 is one of the most abundantly evolved gases from common LIB electrolytes and could potentially affect Li+ solution transport during LIB operation. To this end, a comparative analysis of the Li+ diffusion coefficient ( D Li + ) which governs mass transport is required. Herein a methodology is established to saturate common battery electrolytes with a soluble gas without introducing other contaminants, so as to determine D Li + in saturated and unsaturated samples. As a proof of concept, the values of D Li + are determined in 1M LiPF6 and 1M LiClO4 in ethylene carbonate (EC):dimethyl carbonate (DMC) with and without dissolved CO2, confirmed by gas chromatography–mass spectrometry (GC-MS). The results obtained by pulse field gradient nuclear magnetic resonance (PFG-NMR) diffusion measurements agree for both electrolytes; saturating the electrolyte with CO2 has no measurable effect on D Li + and therefore does not hinder Li+ mass transport.