A low-temperature electrolyte for lithium and lithium-ion batteries

An electrolyte consisting of 1 M solution of lithium hexafluorophosphate in 1:1:1 ethylene carbonate(EC)–dimethyl carbonate(DMC)–ethyl methyl carbonate(EMC) is proposed for low temperature applications of lithium and lithium-ion cells. The new electrolyte has good conductivity and electrochemical stability. Lithium and lithium-ion cells using the new electrolyte were found to be operable at temperatures down to −40°C. The paper also reports on the electrochemical stability of aluminum metal, which is used as a substrate for the positive electrodes in lithium-ion cells, in the new electrolyte.