NONAQUEOUS ELECTROLYTE SOLUTION AND ELECTRICITY STORAGE DEVICE USING SAME

• US 20190312310A1
• Filed: 12/11/2017
• Published: 10/10/2019
• Est. Priority Date: 12/22/2016
• Status: Active Grant

• Current Assignee: MU Ionic Solutions Corporation
• Original Assignee: UBE Industries Limited (UBE Corporation)
• Inventors: ABE, Koji
• Granted Patent: US 11,462,771 B2
• Time in Patent Office: Days
• CPC Class Codes: H01G 11/60 characterised by the solvent
• CPC Class Codes: H01G 11/64 characterised by additives
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 2300/0028 characterised by the solvent
• CPC Class Codes: H01M 6/16 with organic electrolyte H01M6/18 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention relates to a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution containing 0.1 to 5% by mass of a compound represented by the following general formula (I) and an energy storage device including the foregoing nonaqueous electrolytic solution. This nonaqueous electrolytic solution is able to improve charging storage properties and discharging storage properties of an energy storage device when used in the high-temperature and high-voltage environment.

In the formula, R¹ and R² each independently represent an alkyl group having 1 to 4 carbon atoms.

Claims

1. :

A nonaqueous electrolytic solution for an energy storage device, which has an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution comprising 0.1 to 5% by mass of a compound represented by the following general formula (I);

2. :

The nonaqueous electrolytic solution according to claim 1, wherein the compound represented by the general formula (I) is one or more selected from the group consisting of 5,5-dimethyl-1,3-dioxane, 5-ethyl-5-methyl-1,3-dioxane, 5-methyl-5-propyl-1,3-dioxane, 5,5-diethyl-1,3-dixoane, 5-ethyl-5-propyl-1,3-dioxane, and 5-butyl-5-ethyl-1,3-dioxane.

3. :

The nonaqueous electrolytic solution according to claim 1, wherein the compound represented by the general formula (I) is an asymmetric compound in which R¹ and R² in the general formula (I) are different from each other.

4. :

The nonaqueous electrolytic solution according to claim 1, wherein the nonaqueous solvent comprises a linear ester having a molecular weight of 70 or more and 120 or less in an amount ranging from 60 to 80% by volume relative to the total volume of the nonaqueous solvent.

5. :

The nonaqueous electrolytic solution according to claim 4, wherein the linear ester having a molecular weight of 70 or more and 120 or less comprises one or more linear carboxylic acid esters selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, and methyl pivalate, and a proportion of the linear carboxylic acid ester is 1 to 100% by volume relative to the total volume of the linear ester.

6. :

The nonaqueous electrolytic solution according to claim 1, further comprising at least one of a cyclic carbonate having an unsaturated bond of a carbon-carbon double bond or a carbon-carbon triple bond and a cyclic carbonate having a fluorine atom.

7. :

The nonaqueous electrolytic solution according to claim 1, further comprising a nitrile compound.

8. :

The nonaqueous electrolytic solution according to claim 7, wherein the nitrile compound is one or more polyvalent nitriles having two or more intermediate carbon chains between the CN group and the CN group and selected from the group consisting of succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, sebaconitrile, 1,3,5-hexanetricarbonitrile, 1,3,6-hexanetricarbonitrile, 1,2,3-propanetricarbonitrile, and 1,3,5-pentanetricarbonitrile.

9. :

The nonaqueous electrolytic solution according to claim 8, wherein the nitrile compound is a polyvalent nitrile having 5 or more and 8 or less intermediate carbon chains between the CN group and the CN group and selected from the group consisting of pimelonitrile, suberonitrile, and sebaconitrile.

10. :

The nonaqueous electrolytic solution according to claim 7, wherein a total amount (Cd+Cn) of a content of the compound of the general formula (I), Cd, and a content of the nitrile compound, Cn, is 0.6% by mass or more and 7% by mass or less in the nonaqueous electrolytic solution.

11. :

The nonaqueous electrolytic solution according to claim 7, wherein a relation between a content of the compound of the general formula (I), Cd, and a content of the nitrile compound, Cn, is (Cd<

Cn).

12. :

The nonaqueous electrolytic solution according to claim 6, further comprising one or more selected from the group consisting of an aromatic compound, an S(═

O) group-containing compound, a phosphorus-containing compound, and a cyclic acid anhydride.

13. :

An energy storage device comprising a positive electrode, a negative electrode, and a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution being a nonaqueous electrolytic solution comprising 0.1 to 5% by mass of a compound represented by the following general formula (I);

14. :

The energy storage device according to claim 13, wherein the positive electrode comprises, as a positive electrode active material, a complex metal oxide of lithium containing one or more selected from the group consisting of cobalt, manganese, and nickel, or a lithium-containing olivine-type phosphate containing one or more selected from the group consisting of iron, cobalt, nickel, and manganese.

15. :

The energy storage device according to claim 13, wherein the negative electrode comprises, as a negative electrode active material, one or more selected from the group consisting of metal lithium, a lithium alloy, a carbon material capable of absorbing and releasing a lithium ion, tin, a tin compound, silicon, a silicon compound, and a lithium titanate compound.