Xin Li joined the Harvard Paulson School of Engineering and Applied Sciences in 2015 and is now an associate professor of materials science. His research group designs new energy-related materials and devices through advanced characterization, synthesis, and simulation, currently focusing on Li and Na solid-state batteries. Xin received his BS degree in physics from Nanjing University in China, PhD degree in materials science and engineering from Pennsylvania State University, and performed postdoctoral research at CalTech and MIT. He can be reached by email at lixin@seas.harvard.edu.