Nonaqueous electrolyte secondary battery
A nonaqueous electrolyte secondary battery is provided with: a positive electrode; a negative electrode that contains lithium titanate; a separator that is interposed between the positive electrode and the negative electrode; and a nonaqueous electrolyte that contains an electrolyte salt and a nonaqueous solvent. The nonaqueous solvent contains propylene carbonate, a chain carbonate A represented by general formula R 1 OCOOR 2 (wherein each of R 1 and R 2 represents an alkyl group having 2 or more carbon atoms), and a chain carbonate B represented by general formula R 3 OCOOR 4 (wherein R 3 represents a methyl group and R 4 represents an alkyl group). The volume fraction of the propylene carbonate in the nonaqueous solvent is within the range of 25-33% by volume; the volume fraction of the chain carbonate A in the nonaqueous solvent is within the range of 65-74% by volume; and the volume fraction of the chain carbonate B in the nonaqueous solvent is within the range of 1-10% by volume.
1. A nonaqueous electrolyte secondary battery, comprising:
a positive electrode;
a negative electrode comprising lithium titanate;
a separator interposed between the positive electrode and the negative electrode; and
a nonaqueous electrolyte comprising an electrolyte salt and a nonaqueous solvent,
wherein the nonaqueous solvent comprises:
propylene carbonate;
a chain carbonate A represented by a general formula R 1 OCOOR 2 (where R 1 and R 2 represent an alkyl group having 2 or more carbon atoms); and
a chain carbonate B represented by a general formula R 3 OCOOR 4 (where R 3 represents a methyl group, and R 4 represents an alkyl group),
a volume fraction of the propylene carbonate in the nonaqueous solvent is in the range of 25 to 33 volume %,
a volume fraction of the chain carbonate A in the nonaqueous solvent is in the range of 65 to 74 volume %, and
a volume fraction of the chain carbonate B in the nonaqueous solvent is in the range of 1 to 10 volume %.
2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the chain carbonate B is selected from dimethyl carbonate, ethyl methyl carbonate, and a mixture thereof.
3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the chain carbonate A is diethyl carbonate.