Exploring low-temperature behaviour of battery electrolyte solvent blends via spectroscopic neutron imaging

Li-ion batteries (LIBs) are the most widespread form of energy storage, in applications from consumer electronics to grid storage. However, LIB operation at low temperatures is subject to heighten safety risks due to increased internal resistance and cell shorting via Li metal dendrite formation. The introduction of methyl acetate (MA) in commercial LIB electrolytes has been successfully explored to enhance low-temperature (~ -35 ºC) performance by reducing viscosity, increasing ionic conductivity, and lowering the freezing point of the electrolyte. To better understand the effects of adding MA into electrolytes, and the mechanisms that contribute to better low temperature performance, we propose a systematic study of electrolytes with blends of ethylene carbonate, diethylene carbonate, and methyl acetate. To study these hydrocarbon-based electrolytes in a non-destructive way within the environment they operate, ‘spectroscopic neutron imaging’ (SNI) will be utilized, to monitor the effects of MA on solidification and component separation behaviour of electrolytes.