EurekAlert July 14, 2021
A team of researchers in the US (Sandia National Laboratory, University of Oregon, industry, Lawrence Berkeley National Laboratory) repeatedly charged and discharged lithium coin cells with the same high-intensity electric current that electric vehicles need to charge. Using cryogenic femtosecond laser cross sectioning and subsequent scanning electron microscopy, they observed the electroplated Li-metal morphology and the accompanying solid electrolyte interphase (SEI) into and through the intact coin cell battery’s separator, gradually opening pathways for soft-short circuits that cause failure. They found that separator penetration by the SEI guided the growth of Li dendrites through the cell. A short-circuit mechanism via SEI growth at high current density within the separator is provided. These results will help future efforts for separator and electrolyte design for Li-metal anodes making future high-performance batteries, such as for electric vehicles, safer, more powerful, and longer lasting…read more. Open Access TECHNICAL ARTICLE
Abstract. Credit: ACS Energy Lett. 2021, 6, 6, 2138–2144, May 14, 2021Â