Organic Electrolytes for Re-Usable, High Performance Thermal Batteries

"Electrochemically, thermally and chemically stable lithium bis[a,a-dialkyl malonato] borate salts that melt between 100 oC and 150 oC (lower than the melting point of Li-metal), have high boiling point (above 200 oC) and have high decomposition point(above 300 oC) are proposed as candidates for lithium-metal batteries. When molten, these salts are expected to have high ionic conductivities (between 1 and 10 S m-1 c.a. 0.5 S m-1 typical of Li-ion electrolytes) sans organic solvents and largeelectrochemical stability windows beyond 0-5 V. The preclusion of organic solvents will improve battery safety, lower capacity loss and increase shelf life. The proposed electrolytes are expected to be thermodynamically stable with lithium metal therebyeliminating the use of excess lithium in the battery normally incorporated to compensate for the lithium consumption during discharge. Thus, the use of this class of electrolytes in lithium-metal batteries will increase the energy density, the operationallife, and reduce cost. Thinner separators can be used with these electrolytes to give higher power. They will be used as pristine electrolytes and the preclusion of volatile organic solvents that are flammable will make lithium-metal batteries safer."