Electrolyte solvent formulation
AssigneeNew Dominion Enterprises, Inc.
InventorMason K. Harrup
Life of this patent
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Abstract
An all-inorganic electrolyte formulation for use in a lithium-ion battery system comprising at least one of each a phosphoranimine, a phosphazene, a monomeric organophosphate and a supporting lithium salt. The electrolyte preferably has a melting point below 0° C., and a vapor pressure of combustible components at 60.6° C. sufficiently low to not produce a combustible mixture in air, e.g., less than 40 mmHg at 30° C. The phosphoranimine, phosphazene, and monomeric phosphorus compound preferably do not have any direct halogen-phosphorus bonds. A solid electrolyte interface layer formed by the electrolyte with an electrode is preferably thermally stable ≥80° C.
Claims20
A battery, comprising:
- a metal anode;
- an electrolyte consisting essentially of:
- a cyclic phosphazene having at least one fluorinated substituent, in an amount of 10-50% by volume,
- an optional phosphoranimine compound,
- an optional monophosphorus compound, and
- an organic carbonate-based solvent,
- the electrolyte being substantially without:
- a phosphoranimine compound comprising an organosilyl or tert-butyl ligand of the phosphoranimine nitrogen,
- a compound having a direct halogen-phosphorus bond, and
- a compound having a hydroxyl group;
- a cathode;
- a metal salt;
- and
- a dynamic solid electrolyte interface layer on the metal anode comprising breakdown products of the cyclic phosphazene and the organic carbonate-based solvent, wherein the solid electrolyte interface layer is adapted to break down and reform on the metal anode from battery cycling,
- wherein the cyclic phosphazene acts at least as a free radical sponge to slow thermal degradation of the organic carbonate-based solvent.
A battery, comprising:
- a lithium metal anode;
- an electrolyte comprising 2,2,2-trifluoroethoxy-2,2,2-ethoxy cyclotriphosphazene (FM2), in an amount of at least 10% and up to 20% by volume, and an organic carbonate-based solvent, substantially without a phosphoranimine compound comprising an organosilyl or tert-butyl ligand of the phosphoranimine nitrogen, wherein the electrolyte lacks compounds having direct halogen-phosphorus bonds and compounds having hydroxyl groups;
- and
- a solid electrolyte interface layer dynamically formed and reformed on the lithium metal anode from at least the FM2 and the organic carbonate-based solvent during cycling of the battery comprising breakdown products of the FM2.
A battery, comprising:
- a metal anode;
- an electrolyte consisting essentially of a 2,2,2-trifluoroethoxy substituted cyclic phosphazene, an organic solvent, and non-phosphoranimine additives;
- a cathode;
- a supporting salt;
- a solid electrolyte interface layer on the metal anode comprising breakdown products of the 2,2,2-trifluoroethoxy substituted cyclic phosphazene, the organic solvent, and the non-phosphoranimine additives, wherein the solid electrolyte interface layer breaks adown and reforms on the metal anode during discharge and recharge of the battery, acts as an efficient free radical quencher, and provides an effective barrier that protects the bulk electrolyte from continuous degradation,
- wherein the electrolyte lacks compounds having direct halogen-phosphorus bonds and compounds having hydroxyl groups.
Dependencies are inferred from the claim text.