Conventional lithium-ion batteries power our lives in most things, from wireless earbuds to electric cars. However, researchers are still trying to resolve the catch that lithium-ion liquid electrolytes can catch fire. University of Missouri scientists believe they could resolve this issue, with ultra thin-film coatings in solid state batteries.
Thin-Film Coatings Could Make Solid Batteries Competitive
Solid-state batteries could resolve the lithium-ion flammability issue, if consumers adopted them on a wide scale. But there’s another catch here, and that’s because these batteries do not last as long as lithium-ion ones do.
You see, solid state batteries start out looking good, until something happens early in their operating lives. That something occurs when part of their solid electrolyte breaks down, and forms a solid electrolyte interphase layer (SEI) on the surface of their cathode electrode.
How the Solid Electrolyte Interphase Forms on the Cathode
“When the solid electrolyte touches the cathode,” explains project leader Matthias Young. “It reacts and forms an interphase layer that’s about 100 nanometers thick” (that’s 1,000 times smaller than the width of a single human hair.
“This layer blocks the lithium ions and electrons from moving easily, increasing resistance, and hurting battery performance.” This problem has stumped scientists for over ten years, that was until Matthias Young came up with his elegantly simple proposal.
Applying Ultra-Thin Coatings to Solid Battery Cathodes
Matthias Young’s University of Missouri laboratory, specializes in developing thin-films formed by vapor-phase oxidative molecular layer deposition. He has now decided to see whether one of his films could prevent solid electrolytes and cathodes interacting.
“The thin-film coatings on solid state batteries need to be thin enough to prevent reactions,” Young explains on the university website that we link to below. “But not so thick that they block lithium-ion flow.
“We aim to maintain the high-performance characteristics of the solid electrolyte and cathode materials,” he continues. “Our goal is to use these materials together, without sacrificing their performance for the sake of compatibility.”
More Information
Anode-Free Solid-State Batteries At Princeton
Solid Electrolyte Interface Trips Lithium-Metal
