Nonaqueous electrolyte solution, and lithium ion secondary battery having the same

A nonaqueous electrolyte solution, comprising:

• a lithium salt;
• at least one oxo-acid ester derivative of phosphorus selected from compounds represented by formulae (2) and (3) present in an amount of 20% by mass or more and 60% by mass or less;
• at least one disulfonate ester represented by formula (4);
• and
• 0.5% by mass or more and 20% by mass or less of a cyclic carbonate ester containing a halogen:
• in formula (2), R21 and R22 each independently represent any group selected from an alkyl group, an aryl group, an alkenyl group, a cyano group, a phenyl group, an amino group, a nitro group, an alkoxy group and a cycloalkyl group, and a halogen-substituted group thereof;
• R21 and R22 may be bonded to form a cyclic structure;
• and X21 represents a halogen atom,
• in formula (3), R31 represents any group selected from an alkyl group, an aryl group, an alkenyl group, a cyano group, a phenyl group, an amino group, a nitro group, an alkoxy group and a cycloalkyl group, and a halogen-substituted group thereof;
• and X31 and X32 each independently represent a halogen atom,
• in formula (4), Q represents an oxygen atom, a methylene group or a single bond;
• A1 represents a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms which may be branched, a carbonyl group, a sulfinyl group, a substituted or unsubstituted perfluoroalkylene group having 1 to 5 carbon atoms which may be branched, a substituted or unsubstituted fluoroalkylene group having 2 to 6 carbon atoms which may be branched, a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms which contains an ether bond and may be branched, a substituted or unsubstituted perfluoroalkylene group having 1 to 6 carbon atoms which contains an ether bond and may be branched, or a substituted or unsubstituted fluoroalkylene group having 2 to 6 carbon atoms which contains an ether bond and may be branched;
• and A2 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted fluoroalkylene group, or an oxygen atom.

A nonaqueous electrolyte solution, comprising:

• a lithium salt;
• tri(trifluoroethyl) phosphate present in an amount of 20% by mass or more and 60% by mass or less;
• at least one disulfonate ester represented by formula (4) in an amount of 0.05% by mass or more and 10% by mass or less;
• and
• at least one aprotic solvent selected from cyclic carbonates and linear carbonates in a remaining amount:
• in the formula (4), Q represents an oxygen atom, a methylene group or a single bond;
• A1 represents a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms which may be branched, a carbonyl group, a sulfinyl group, a substituted or unsubstituted perfluoroalkylene group having 1 to 5 carbon atoms which may be branched, a substituted or unsubstituted fluoroalkylene group having 2 to 6 carbon atoms which may be branched, a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms which contains an ether bond and may be branched, a substituted or unsubstituted perfluoroalkylene group having 1 to 6 carbon atoms which contains an ether bond and may be branched, or a substituted or unsubstituted fluoroalkylene group having 2 to 6 carbon atoms which contains an ether bond and may be branched;
• and A2 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted fluoroalkylene group, or an oxygen atom.