Nanowerk October 29, 2022
The lithium-metal batteries cycling encounters a low Coulombic efficiency (CE) due to the unceasing electrolyte decomposition. Improving the stability of solid electrolyte interphase (SEI) suppresses the decomposition and increases CE. However, SEI morphology and chemistry alone cannot account for CE, and a full explanation is still lacking. Researchers in Japan found that in diverse electrolytes, the large shift in the Li electrode potential and its association with the Li+ coordination structure influences the CE. Machine learning regression analysis and vibrational spectroscopy revealed that the formation of ion pairs is essential for upshifting the Li electrode potential, that is, for weakening the reducing ability of Li, which would lead to a high CE with diminished electrolyte decomposition. The researchers designed various electrolytes with enhanced ion-pairing solution structure to enable a significantly improved CE (>99%)…read more. TECHNICAL ARTICLE
Electrolyte design concept. Credit: Nature Energy (2022)Â