Considering the tendency of people to buy a new phone every couple of years, it’s no wonder there are so many leftover batteries from old cellphones. These batteries are toxic when they end up in landfills, and typically require harsh processes to recycle. Scientists at Rice University have been searching for new ways to deal with the glut of used lithium-ion batteries from old electronics for the past few years, and now it seems they’ve finally found a good solution. Basically, the researchers have come up with a solvent that can extract more than 90 percent of cobalt from powdered compounds, and a small but still significant amount from used batteries. Cobalt and other strategic metals are limited in supply and crucial for energy-storage devices, which is why this new solvent is such a big deal; it presents a way of dealing with old batteries sustainably while providing precious metals for new batteries.