Non-aqueous electrolyte and power storage device using same

Patent metadata

Field	Value
Publication number	US-9966632-B2
Application number	US-201314417670-A
Country	US
Kind code	B2
Filing date	Jul 29, 2013
Priority date	Jul 31, 2012
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

Provided are a nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolytic solution containing from 0.001 to 5% by mass of 1,3-dioxane and further containing from 0.001 to 5% by mass of at least one selected from a specified phosphoric acid ester compound, a specified cyclic sulfonic acid ester compound, and a cyclic acid anhydride containing a side chain having allyl hydrogen; and an energy storage device using the same. This nonaqueous electrolytic solution is capable of improving electrochemical characteristics at high temperatures and further capable of not only improving a capacity retention rate after a high-temperature cycle test but also decreasing a rate of increase of an electrode thickness.

First claim

The invention claimed is:

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.

Assignees

• Ube Industries

Inventors

• Abe Koji

Classifications

• H01M10/0568

  characterised by the solutes · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01M6/166

  by the solute · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title