Gel electrolyte for lithium ion secondary battery, and lithium ion secondary battery

1. A gel electrolyte for a lithium ion secondary battery, comprising:

a lithium salt;

a copolymer of at least one first monomer selected from compounds represented by chemical formulae (1) and (2) and a second monomer represented by chemical formula (4);

at least one oxo-acid ester derivative of phosphorus selected from compounds represented by chemical formulae (5) to (7); and

at least one disulfonate ester selected from a cyclic-chain-type disulfonate ester represented by chemical formula (8) and a linear-chain-type disulfonate ester represented by chemical formula (9):

wherein in formula (1), R 1 represents H or CH 3 ; and in formulae (1) and (2), R 2 represents one of substituents represented by the following formula (3),

wherein in formula (3), R 3 represents an alkyl group having 1 to 6 carbon atoms,

wherein in formula (4), R 4 represents H or CH 3 ; R 5 represents —COOCH 3 , —COOC 2 H 5 , —COOC 3 H 7 , —COOC 4 H 9 , —COOCH 2 CH(CH 3 ) 2 , —COO(CH 2 CH 2 O) n CH 3 , —COO(CH 2 CH 2 O) n C 4 H 9 , —COO(CH 2 CH 2 CH 2 O) n CH 3 , —COO(CH 2 CH(CH 3 )O) n CH 3 , —COO(CH 2 CH(CH 3 )O) n C 2 H 5 , —OCOCH 3 , —OCOC 2 H 5 , or —CH 2 OC 2 H 5 ; and n represents an integer of 1 to 3,

wherein in formula (5), R 11 , R 12 and R 13 each independently represent any group selected from an alkyl group, an aryl group, an alkenyl group, cyano group, phenyl group, an amino group, nitro group, an alkoxy group, a cycloalkyl group and a halogen-substituted group thereof; and two of or all of R 11 , R 12 and R 13 may be bonded to form a ring structure,

wherein in formula (6), R 21 and R 22 each independently represent any group selected from an alkyl group, an aryl group, an alkenyl group, cyano group, phenyl group, an amino group, nitro group, an alkoxy group, a cycloalkyl group and a halogen-substituted group thereof; R 21 and R 22 may be bonded to form a ring structure; and X 21 represents a halogen atom,

wherein in formula (7), R 31 represents any group selected from an alkyl group, an aryl group, an alkenyl group, cyano group, phenyl group, an amino group, nitro group, an alkoxy group, a cycloalkyl group and a halogen-substituted group thereof; and X 31 and X 32 each independently represent a halogen atom,

wherein in formula (8), Q represents an oxygen atom, a methylene group or a single bond; A l represents a substituted or unsubstituted alkylene group which may be branched and has 1 to 5 carbon atoms, a carbonyl group, a sulfinyl group, a substituted or unsubstituted perfluoroalkylene group which may be branched and has 1 to 5 carbon atoms, a substituted or unsubstituted fluoroalkylene group which may be branched and has 2 to 6 carbon atoms, a substituted or unsubstituted alkylene group which contains an ether bond and may be branched and has 1 to 6 carbon atoms, a substituted or unsubstituted perfluoroalkylene group which contains an ether bond and may be branched and has 1 to 6 carbon atoms, or a substituted or unsubstituted fluoroalkylene group which contains an ether bond and may be branched and has 2 to 6 carbon atoms; and A 2 represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted fluoroalkylene group or an oxygen atom, and

wherein in formula (9), R 6 and R 9 each independently represent an atom or a group selected from hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted fluoroalkyl group having 1 to 5 carbon atoms, a polyfluoroalkyl group having 1 to 5 carbon atoms, —SO 2 X 3 (X 3 is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms), —SY 1 (Y 1 is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms), —COZ (Z is hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms), and a halogen atom; and R 7 and R 8 each independently represent an atom or a group selected from a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted phenoxy group, a substituted or unsubstituted fluoroalkyl group having 1 to 5 carbon atoms, a polyfluoroalkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 5 carbon atoms, a polyfluoroalkoxy group having 1 to 5 carbon atoms, hydroxyl group, a halogen atom, —NX 4 X 5 (X 4 and X 5 are each independently hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms), and —NY 2 CONY 3 Y 4 (Y 2 to Y 4 are each independently hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms).

2. The gel electrolyte for a lithium ion secondary battery according to claim 1 , wherein the gel electrolyte comprises 5 to 60% by mass of the oxo-acid ester derivative of phosphorus.

3. The gel electrolyte for a lithium ion secondary battery according to claim 1 , wherein the gel electrolyte comprises 0.05 to 10% by mass of the disulfonate ester.

4. The gel electrolyte for a lithium ion secondary battery according to claim 1 , further comprising 0.5 to 20% by mass of a halogen-containing cyclic-chain type carbonate ester.

5. A lithium ion secondary battery, comprising the gel electrolyte for a lithium ion secondary battery according to claim 1 .

6. The gel electrolyte for a lithium ion secondary battery according to claim 2 , wherein the gel electrolyte comprises 0.05 to 10% by mass of the disulfonate ester.

7. The gel electrolyte for a lithium ion secondary battery according to claim 2 , further comprising 0.5 to 20% by mass of a halogen-containing cyclic-chain type carbonate ester.

8. The gel electrolyte for a lithium ion secondary battery according to claim 3 , further comprising 0.5 to 20% by mass of a halogen-containing cyclic-chain type carbonate ester.

9. A lithium ion secondary battery, comprising the gel electrolyte for a lithium ion secondary battery according to claim 2 .

10. A lithium ion secondary battery, comprising the gel electrolyte for a lithium ion secondary battery according to claim 3 .

11. A lithium ion secondary battery, comprising the gel electrolyte for a lithium ion secondary battery according to claim 4 .