Soft Matter and Complex Systems Seminar

Conventional methods for lithium extraction via evaporation pools or hard rock mining are environmentally consequential both locally and globally. To meet the demand for mineral components for lithium batteries while lessening the environmental impact, new technologies for 'direct' lithium extraction aim to selectively capture lithium from aqueous solution among a mélange of competing ionic species. In this work, we present a new concept for direct lithium extraction based on far-from-equilibrium transport of lithium through self-assembled percolating colloidal graphene oxide (GO) driven by AC Electric fields. We report that these self-assembled GO networks enhance ionic conductivity, actively transporting and selecting lithium without requiring extensive pre-treatment. We demonstrate that lithium transport far-from-equilibrium can be enhanced relative to competing cations due to its weaker specific interactions with the percolating GO network, resulting in high mobility. This runs counter to many conventional approaches to lithium extraction, which rely on high lithium selectivity but are implicitly limited by low binding/exchange turnover rates. We propose that enhancing lithium transport, rather than binding selectivity, may be key to high-rate direct lithium extraction from brine sources.