Minnesota Student Turns Corn Stalks into Lithium Recovery Material
Lithium is crucial for rechargeable batteries, but recovering it from dilute sources can be difficult and energy-intensive. John Liu, a high school student from St. Paul, Minnesota, tackled this problem by exploring materials that are usually left behind after harvest: corn stalks and wheat straw.
Liu's project used the abundant agricultural waste to create scaffolds for a passive capillary-evaporative lithium pre-concentration process. This approach combines plant-based structures' ability to move liquid through tiny spaces with evaporation to increase lithium concentration in dilute solutions. The corn stalk pith and wheat straw were functionalised for this purpose, turning naturally occurring agricultural material into engineered structures for lithium recovery.
Liu's work has been recognised at both the state and international levels. He earned a Gold Award at the 2026 Minnesota State Science and Engineering Fair and was named one of Minnesota’s finalists for the Regeneron International Science and Engineering Fair. At ISEF, Liu received $2,400 as a second-award winner in the environmental engineering category.