Semiconductor technology reduces power battery fire risk

When a lithium-ion battery is charged, lithium ions are transported to the negative electrode and deposited on the surface of the battery in the form of lithium metal, thereby forming dendritic protrusions. These lithium dendrites can cause uncontrollable volume fluctuations and lead to reactions between solid electrodes and liquid electrolytes, which can cause fires and severely affect battery performance. To effectively solve this problem, a research team led by Dr. Joong Kee Lee of the Energy Storage Research Center of the Korea Institute of Science and Technology (KIST) successfully suppressed dendrite growth by forming a protective semiconductor passivation layer on the surface of the lithium electrode. The crystals have multiple branches and can cause fires in batteries in electric vehicles. It is understood that in order to prevent dendrite formation, the research team exposed the plasma to fullerene (C60). Fullerene is a highly electronically conductive semiconductor material that enables the formation of a semiconducting passivating carbonaceous layer between the lithium electrode and the electrolyte. The semiconducting passivation carbonaceous layer allows lithium ions to pass through, while blocking electrons through the resulting Schottky barrier, and preventing electrons and ions from interacting on and inside the electrode surface, avoiding the formation of lithium crystals and dendrite growth. Dr. Joong Kee Lee said:“The dendrite growth on the lithium electrode is effectively inhibited, which helps to improve the safety of the battery. The research proposes techniques for developing highly safe lithium metal electrodes, providing a blueprint for developing next-generation batteries without fire risks.”The next goal of the research team is to improve the commercial viability of the technology:“Replacing fullerenes with cheaper materials to make semiconducting passivating carbonaceous layers makes them more cost-effective.”