Non-aqueous electrolyte and power storage device using same

1. A nonaqueous electrolytic solution, comprising:

(i) an electrolyte salt dissolved in a nonaqueous solvent comprising a cyclic carbonate and a linear ester; and

(ii) additives comprising:

from 0.001 to 5% by mass of 1,3-dioxane; and

from 0.001 to 5% by mass of a phosphoric acid ester compound represented by formula (I):

wherein:

each of R 1 and R 2 independently represents an alkyl group having from 1 to 6 carbon atoms or a halogenated alkyl group having from 1 to 6 carbon atoms, in which at least one hydrogen atom is substituted with a halogen atom;

R 3 represents an alkynyl group having from 3 to 6 carbon atoms; and

each of R 4 and R 5 independently represents a hydrogen atom, a halogen atom, or an alkyl group having from 1 to 4 carbon atoms.

2. The nonaqueous electrolytic solution according to claim 1 , comprising the phosphoric acid ester compound represented by formula (I), wherein the phosphoric acid ester compound represented by formula (I) is at least one selected from the group consisting of methyl 2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(dimethoxyphosphoryl)acetate, 2-propynyl 2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(diethoxyphosphoryl)propanoate, 2-proynyl 2-(dimethoxyphosphoryl)propanoate, methyl 2-(diethoxyphosphoryl)-2-fluoroacetate, ethyl 2-(diethoxyphosphoryl)-2-fluoroacete, 2-propenyl 2-(diethoxyphosphoryl)-2-fluoroacetate, 2-propynyl 2-(diethoxyphosphoryl)-2-fluoroacetate, methyl 2(diethoxyphosphoryl)-2,2-difluoroncetate, ethyl 2-(diethoxyphosphoryl)-2,2-difluoroacetate, 2-propenyl 2-diethoxyphosphoryl-2,2-difluoroacetate, and 2-propynyl 2-(diethoxyphosphoryl)-2,2-difluoroacetate.

3. The nonaqueous electrolytic solution according to claim 1 , wherein the cyclic carbonate is one or more selected from the group consisting of ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 4-fluoro-1,3-dioxolan-2-one, trans- or cis-4,5-difluoro-1,3-dioxolan-2-one, vinylene carbonate, vinyl ethylene carbonate, and 4-ethynyl-1,3-dioxolan-2-one.

4. The nonaqueous electrolytic solution according to claim 1 , wherein the linear ester is one or more selected from the group consisting of methyl ethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, methyl butyl carbonate, ethyl propyl carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, and a linear carboxylic acid ester.

5. The nonaqueous electrolytic solution accord to claim 1 , wherein the electrolyte salt comprises at least one lithium salt selected from the group consisting of LiPF 6 , LiBF 4 , LiPO 2 F 2 , Li 2 PO 3 F, LiN(SO 3 F) 2 , LiN(SO 2 CF 3 ) 2 , Lin(SO 2 C 2 F 5 ) 2 , lithium bis[oxalate-O,O′]borate, difluorobis[oxalate-O,O′]phosphate, and lithium tetrafluoro[oxalate-O,O′]phosphate.

6. The nonaqueous electrolytic solution according to claim 5 , wherein a concentration of the lithium salt is from 0.3 to 2.5 M relative to the nonaqueous solvent.

7. An energy storage device, comprising:

a positive electrode;

a negative electrode: and

the nonaqueous electrolytic solution according to claim 1 .

8. The energy storage device according to claim 7 , comprising a positive electrode active material which is a complex metal oxide of lithium comprising one or more selected from the group consisting of cobalt, manganese, and nickel, or a lithium-containing olivine-type phosphate comprising one or more selected from the group consisting of iron, cobalt, nickel, and manganese.

9. The energy storage device according to claim 8 , comprising a negative electrode active material comprising one or more selected from the group consisting of a lithium metal, a lithium alloy, a carbon material capable of absorbing and releasing lithium, a tin compound, silicon, a silicon compound, and a lithium titanate compound.

10. The energy storage device according to claim 7 , comprising a negative electrode active material comprising one or more selected from the group consisting of a lithium metal, a lithium alloy, a carbon material capable of absorbing and releasing lithium, tin, a tin compound, silicon, a silicon compound, and a lithium titanate compound.