US scientists turn bourbon waste into high-performance electrodes

Researchers at the University of Kentucky have developed a sustainable method to convert bourbon whiskey stillage—a large-volume, moisture-rich waste grain byproduct from Kentucky’s booming bourbon industry—into high-performance electrode materials for energy storage devices. Using hydrothermal carbonization, a process akin to high-pressure cooking, the soggy stillage is transformed into carbon powders without the need for drying. These powders are then further processed into two types of carbon materials: hard carbon for lithium-ion storage and activated carbon with a highly porous structure for electrical charge storage. The team successfully fabricated coin-sized supercapacitors using these stillage-derived carbons, achieving energy densities comparable to or exceeding commercial standards. Notably, their hybrid lithium-ion supercapacitor, combining hard-carbon and activated-carbon electrodes, demonstrated up to 25 times greater energy storage per kilogram than conventional devices. This innovation not only offers a valuable use for a difficult-to-manage distillery waste but also represents a significant advancement in materials science by producing both electrode types from a