Solid polymer electrolyte electrochemical storage cell containing a redox shuttle additive for overcharge protection
First Claim
1. A solid polymer electrolyte rechargeable electrochemical cell having a positive electrode, a negative electrode, a solid polymer electrolyte comprising a polyether polymer, and an organic redox shuttle additive selected from the group consisting of 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, to protect the cell against overcharging.
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Abstract
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 2.1×10-8 cm2 /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.
99 Citations
14 Claims
- 1. A solid polymer electrolyte rechargeable electrochemical cell having a positive electrode, a negative electrode, a solid polymer electrolyte comprising a polyether polymer, and an organic redox shuttle additive selected from the group consisting of 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, to protect the cell against overcharging.
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8. An electrochemical cell capable of functioning at a temperature of at least about 85°
- C. comprising a positive electrode, a negative electrode, a solid polymer electrolyte, and an organic redox shuttle additive selected from the group consisting of an alkali metal salt of 1,2,4-triazole, an alkali metal salt of imidazole, and 1,3,5-tricyanobenzene to protect the cell against overcharging and further characterized by a diffusion coefficient of at least about 1.4×
10-7 cm2 and an onset voltage of at least about 2.5 volts. - View Dependent Claims (9, 10, 11)
- C. comprising a positive electrode, a negative electrode, a solid polymer electrolyte, and an organic redox shuttle additive selected from the group consisting of an alkali metal salt of 1,2,4-triazole, an alkali metal salt of imidazole, and 1,3,5-tricyanobenzene to protect the cell against overcharging and further characterized by a diffusion coefficient of at least about 1.4×
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12. An electrochemical cell capable of functioning at a temperature of at least about 85°
- C. comprising a lithium-containing negative electrode, a positive electrode, a solid polymer electrolyte comprising a solid polymer and a lithium compound, and an organic redox shuttle additive selected from the group consisting of an alkali metal salt of 1,2,4-triazole and an alkali metal salt of imidazole to protect the cell against overcharging comprising an aromatic compound containing a plurality of nitrogen atoms and further characterized by a diffusion coefficient of at least about 2.1×
10-7 cm2 and an onset voltage of at least about 2.5 volts, said redox shuttle additive present in said cell in a concentration which is sufficient to permit said redox shuttle additive to carry all of the charging current. - View Dependent Claims (13, 14)
- C. comprising a lithium-containing negative electrode, a positive electrode, a solid polymer electrolyte comprising a solid polymer and a lithium compound, and an organic redox shuttle additive selected from the group consisting of an alkali metal salt of 1,2,4-triazole and an alkali metal salt of imidazole to protect the cell against overcharging comprising an aromatic compound containing a plurality of nitrogen atoms and further characterized by a diffusion coefficient of at least about 2.1×
Specification