Electrolytes for stable cycling of high capacity lithium based batteries

Abstract

Electrolytes are described with additives that provide good shelf life with improved cycling stability properties. The electrolytes can provide appropriate high voltage stability for high capacity positive electrode active materials. The core electrolyte generally can comprise from about 1.1M to about 2.5M lithium electrolyte salt and a solvent that consists essentially of fluoroethylene carbonate and/or ethylene carbonate, dimethyl carbonate and optionally no more than about 40 volume percent methyl ethyl carbonate, and wherein the lithium electrolyte salt is selected from the group consisting of LiPF6, LiBF4 and combinations thereof. Desirable stabilizing additives include, for example, dimethyl methylphosphonate, thiophene or thiophene derivatives, and/or LiF with an anion complexing agent.

Dependencies are inferred from the claim text.