Science Daily October 10, 2019
Lithium-ion battery electrolytes currently contain a solvent mixture, with a dissolved lithium salt and often more than three organic additives. Researchers at Argonne National Laboratory have developed a unique electrolyte with a small amount of a second salt containing any one of several doubly or triply charged metal cations (Mg2+, Ca2+, Zn2+, or Al3+) they call MESA (mixed-salt electrolytes for silicon anodes). MESA gives silicon anodes increased surface and bulk stabilities, improving long-term cycling and calendar life. During charging, the metal cation additions in electrolyte solution migrate into the silicon-based anode along with the lithium ions to form lithium-metal-silicon phases, which are more stable than lithium-silicon. This new cell chemistry greatly reduces the detrimental side reactions between the silicon anode and electrolyte. Of the four metal salts tested, the added electrolyte salts with either magnesium (Mg2+) or calcium (Ca2+) cations proved to work the best over hundreds of charge-discharge cycles with the energy densities surpassing by up to 50%. The new chemistry is simple, scalable and fully compatible with existing battery technology…read more. Open Access TECHNICAL ARTICLE
Abstract. Credit: ACS Appl. Mater. Interfaces, 2019, 113329780-29790, July 18, 2019Â