Enabling wide temperature battery operation with hybrid lithium electrolytes

We demonstrate that an ionic liquid 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide combined with propylene carbonate and lithium bis(trifluoromethanesulfonyl)imide yields a hybrid electrolyte that enables a wide operational temperature window (-20 degrees C to 60 degrees C). When integrated into a lithium titanate & Vert;lithium cobalt oxide full-cell configuration, high-rate capability is achieved at -20 degrees C with >40% retention at a C/2 cycling rate, and negligible capacity fade is observed during rate capability tests and long-term cycling at 60 degrees C.