Donald Sadoway is an emeritus professor of materials chemistry at MIT and the chief science advisor at Ambri Incorporated, a molten-metal battery company based in Cambridge, Massachusetts. In this episode, Sadoway explains why lithium-ion batteries are so dangerous, why we need to develop batteries with super-cheap ingredients, Ambri’s decade-long road to commercialization, the origin of the neodymium-iron-boron magnet, coercivity, and why iridium is his favorite element.