It was invented by a team of Columbia Engineering led by Yuan Yang, assistant professor of materials science and engineering, with collaboration of the Brookhaven National Lab and the City University of New York. They have developed a new method for safely prolonging battery life by inserting a nano-coating of boron nitride (BN) to stabilize solid electrolytes in lithium metal batteries. In actual batteries, during lithium plating, dendrites often form and if they penetrate the membrane separator in the middle of the battery, they can create short-circuits, raising concerns about battery safety. “We decided to focus on solid, ceramic electrolytes. They show great promise in improving both safety and energy density, as compared with conventional, flammable electrolytes in Li-ion batteries,” says Yang.
The researchers selected BN as a protective layer because it is chemically and mechanically stable with lithium metal, providing a high degree of electronic insulation. It can be readily prepared by chemical vapor deposition to form large-scale (~dm level), atomically thin scale (~nm level), and continuous films. The inventors expect to fabricate solid-state batteries with high performance and long-cycle lifetimes. Their findings are outlined in a new study published by Joule.