Additives for overcharge protection in electrochemical cells

摘要

The invention relates to an improvement in a cell which is normally susceptible to damage from overcharging comprised of a negative electrode, a positive electrode, and an electrolyte comprised of an overcharge protection salt carried in a carrier or solvent. Representative overcharge protection salts are embraced by the formula:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ M a Q
where M is an electrochemically stable cation selected from the group consisting of alkali metal, alkaline earth metal, tetraalkylammonium, or imidazolium groups, and Q is a borate or heteroborate cluster and a is the integer 1 or 2.