When manufacturers slice high-purity silicon ingots to produce wafers for electronics, they can lose almost half of the material to a sludgy waste. Now, researchers have developed a method to reclaim silicon nanoparticles from that sludge and have incorporated the Si into the anodes of lithium-ion batteries (Sci. Rep. 2015, DOI: 10.1038/srep09431). Led by Jiaxing Huang of Northwestern University and Hee Dong Jang of the Korea Institute of Geoscience & Mineral Resources, in South Korea, the team dried wafer waste and rinsed it with hydrochloric acid to remove contaminants from the cutting process. This left a dust containing nanoscopic Si particles and microscopic chunks of silicon carbide—a common coating on silicon cutting tools. Researchers then dispersed the dust in water and poured it into an ultrasonic atomizer, which Huang says works like a household ultrasonic humidifier. Smaller Si particles inside water droplets get sprayed out by the machine, while larger SiC particles remain in the atomizer (shown). The recovered Si nanoparticles, used to create battery anodes, performed as well as traditional Si structures synthesized to store lithium ions.