Current recycling techniques often rely on harsh acids, while eco-friendly alternatives like deep eutectic solvents (DESs) have struggled with efficiency and economic feasibility, typically recovering less than 5% of lithium due to contamination and energy-intensive processes.
“The recovery rate is low because lithium is usually precipitated last after other metals,” explained Salma Alhashim, a lead author and Rice doctoral alumna.
“Our goal was to specifically target lithium using a DES mixture of choline chloride and ethylene glycol, which surrounds lithium with chloride ions and leaches it into the solution,” she said.
The team found that choline chloride, a component of the DES, effectively absorbs ‘microwaves’. By submerging battery waste in the solvent and applying microwave radiation, they could selectively leach lithium over other metals.
“This process is similar to how a kitchen microwave heats food…
