Alkanol-enabled instantaneous precipitation of lithium carbonate and phosphate at low temperature

This study shows that ethanol addition to supersaturated Li⁺–CO₃²⁻ solutions dramatically accelerates the lithium carbonate (Li₂CO₃) precipitation from brine. With an addition of ≥5 vol% ethanol, precipitation becomes instantaneous, completing within ∼30 min at room temperature versus >1 day without ethanol, and is even faster at higher temperatures, in some cases reaching equilibrium within seconds. Ethanol addition produces much finer Li₂CO₃ particles than those without ethanol. The observed behavior seems to be specific to lithium salts: lithium phosphate (Li₃PO₄) showed similar acceleration, whereas CaCO₃ and MgCO₃ did not. Pre-mixing ethanol with Li⁺ before carbonate addition did not show this effect, indicating the importance of timing. The mechanism of the demonstrated method involves ethanol collapsing nucleation barrier rather than changing the equilibrium solubility. This approach potentially enables energy-efficient Li recovery at lower temperatures for shorter durations.