Electrolytes having improved low temperature performance
AssigneeValence Technology, Inc.
InventorsJeremy Barker, Feng Gao, Arnold Stux
Life of this patent
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Abstract
The present invention provides a novel electrolyte solvent which is usable with a variety of carbonaceous and metal oxide electrode active materials, providing improved performance over a broad temperature range, and which is stabilized to maintain cell capacity over a number of cycles.
Claims3
An electrochemical cell which comprises a first electrode, a counter electrode which forms an electrochemical couple with said electrode, and an electrolyte;
- said first electrode comprising particles of carbonaceous intercalation active material;
- and said electrolyte comprising a solvent mixture and a solute;
- said solvent mixture comprising ethylene carbonate (EC), propylene carbonate (PC), a compound represented by R′COOR″, and dimethyl carbonate (DMC), where R′ and R″ are each independently selected from the group consisting of ethyl and propyl;
- and wherein EC/DMC/R′COOR″ is in a weight ratio of about 25:40:35 and said PC is present in an amount less than said compound represented by R′COOR″.
An electrochemical cell which comprises a first electrode, a counter electrode which forms an electrochemical couple with said first electrode, and an electrolyte;
- said first electrode comprising particles of carbonaceous intercalation active material;
- and said electrolyte comprising a solvent mixture and a solute;
- said solvent mixture comprising ethylene carbonate (EC), propylene carbonate (PC), ethyl propionate (EP), and dimethyl carbonate (DMC), wherein said solvent said solvent mixture comprises EC/DMC/EP in a weight ratio of 23:40:35.
A lithium ion electrochemical cell which comprises a first electrode, a counter electrode which forms an electrochemical couple with said first electrode, and an electrolyte;
- each of said electrodes having an intercalation active material, with at least one said active material being a carbonaceous active material;
- and said electrolyte comprising a solvent mixture and a solute;
- and solvent mixture comprising ethylene carbonate (EC), propylene carbonate (PC), ethyl propionate (EP), and dimethyl carbonate (DMC), wherein said solvent mixture comprises EC/DMC/EP in a weight ratio of 25:40:35.
Dependencies are inferred from the claim text.