![Lithium String](https://paw.princeton.edu/sites/default/files/styles/portrait_feature/public/images/content/RESEARCH_Lithium%20String%201.jpg?itok=5KAXOvUR)
Photo: Bumper DeJesus / Princeton University
A team of researchers led by civil and environmental engineering professor Z. Jason Ren has developed a faster and greener technique to extract lithium — an essential component of batteries used in electric vehicles and energy storage for the grid. The extraction method involves dipping porous fibers twisted into strings into salty waters. The water absorbs and travels up the strings (like a tree drawing water from its roots) and eventually evaporates. What’s left behind are salt ions such as sodium and lithium, as pictured here, which can ultimately be harvested.