Solid polymer electrolyte electrochemical storage cell containing a redox shuttle additive for overcharge protection

摘要

A class of organic redox shuttle additives is described, preferably comprising nitrogen-containing aromatics compounds, which can be used in a high temperature (85 C. or higher) electrochemical storage cell comprising a positive electrode, a negative electrode, and a solid polymer electrolyte to provide overcharge protection to the cell. The organic redox additives or shuttles are characterized by a high diffusion coefficient of at least 2.110.sup.-8 cm.sup.2 /second and a high onset potential of 2.5 volts or higher. Examples of such organic redox shuttle additives include an alkali metal salt of 1,2,4- triazole, an alkali metal salt of imidazole, 2,3,5,6-tetramethylpyrazine, 1,3,5- tricyanobenzene, and a dialkali metal salt of 3-4-dihydroxy-3- cyclobutene-1,2-dione.