Lithium ion battery electrolytes and electrochemical cells including the same
AssigneeGM Global Technology Operations LLC
InventorsMeinan He, Mei Cai
Life of this patent
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Abstract
An electrolyte for a lithium ion battery includes a nonaqueous aprotic organic solvent and a lithium salt dissolved in the organic solvent. The organic solvent includes a cyclic carbonate, an acyclic carbonate, and an acyclic fluorinated ether for improved low temperature and high voltage performance as well as enhanced thermostability. The ether group has a general formula of R1—O—[R3—O]n—R2, where n=0 or 1, R1 and R2 are each straight-chain C1-C6 fluoroalkyl groups, and, when n=1, R3 is a methylene group or a polyethylene group.
Claims19
An electrolyte for a lithium ion battery, the electrolyte comprising:
- a nonaqueous aprotic organic solvent comprising a cyclic carbonate, an acyclic carbonate, and an acyclic fluorinated ether;
- and
- a lithium salt dissolved or ionized in the organic solvent,
- wherein the cyclic carbonate accounts for, by volume, 10-40% of the organic solvent, the acyclic carbonate accounts for, by volume, 60-80% of the organic solvent, and the acyclic fluorinated ether accounts for, by volume, 5-25% of the organic solvent,
- wherein the acyclic fluorinated ether is represented by the formula:
- where n=0 or 1,
- where R1 and R2 are each straight-chain C1-C6 fluoroalkyl groups, and
- where, when n=1, R3 is a methylene group or a polyethylene group, and
- wherein the organic solvent is substantially free of propylene carbonate.
An electrochemical cell comprising:
- a negative electrode made of a graphite-based material;
- a positive electrode spaced apart from the negative electrode, the positive electrode including at least one transition metal oxide that can undergo the reversible intercalation of lithium ions;
- and
- an electrolyte infiltrating pores of the negative and positive electrodes, the electrolyte including:
- a nonaqueous aprotic organic solvent comprising a cyclic carbonate, an acyclic carbonate, and an acyclic fluorinated ether;
- and
- a lithium salt dissolved or ionized in the organic solvent,
- wherein the acyclic fluorinated ether is represented by the formula:
- where n=0 or 1,
- where R1 and R2 are each straight-chain C1-C6 fluoroalkyl groups,
- where, when n=1, R3 is a methylene group or a polyethylene group, and
- where the total number of carbon atoms in the acyclic fluorinated ether is 2, 3, 4, 5, 6, or 7, and
- wherein the organic solvent is substantially free of propylene carbonate.
Dependencies are inferred from the claim text.