Electrolyte solution for secondary battery and secondary battery using same

Patent metadata

Field	Value
Publication number	US-10587008-B2
Application number	US-201415039585-A
Country	US
Kind code	B2
Filing date	Nov 25, 2014
Priority date	Nov 28, 2013
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

The present invention provides a lithium ion secondary battery having excellent high temperature cycle characteristics. The present invention relates to an electrolyte solution containing a non-aqueous electrolyte solvent containing two or more open chain sulfone compounds represented by a specific formula and one or more carbonate ester compounds represented by a specific formula; and to a secondary battery comprising these.

First claim

The invention claimed is:

1. An electrolyte solution for a secondary battery comprising a non-aqueous electrolyte solvent comprising:
at least one open chain sulfone compound having 4 or more carbon atoms selected from the group consisting of ethyl isopropyl sulfone, diethyl sulfone, isopropyl methyl sulfone, isopropyl isobutyl sulfone and dipropyl sulfone;
at least one open chain sulfone compound having 3 or less carbon atoms selected from the group consisting of dimethyl sulfone and ethyl methyl sulfone;
one or more carbonate ester compounds selected from the group consisting of ethylene carbonate, propylene carbonate, 4-fluorinated ethylene carbonate and dimethyl carbonate, wherein the carbonate ester compound comprises at least ethylene carbonate; and
at least one fluorinated ether compound selected from the group consisting of H(CF 2 ) 2 CH 2 O(CF 2 ) 2 H, CH 3 CH 2 O(CF 2 ) 4 F, F(CF 2 ) 4 CH 2 O(CF 2 ) 2 H, CF 3 CHFCF 2 OCH 2 (CF 2 ) 2 F, H(CHF) 2 CH 2 O(CF 2 ) 2 H, (CF 3 )(CF 2 )CH 2 O(CF 2 ) 2 H, H(CF 2 ) 3 CH 2 O(CF 2 ) 2 H, CF 3 (CF 2 )CH 2 O(CF 2 )CF 3 , F(CF 2 ) 4 OC 2 H 5 , H(CF 2 ) 2 CH 2 OCF 2 CHFCF 3 , F(CF 2 ) 2 CH 2 OCF 2 CHFCF 3 , H(CF 2 ) 4 CH 2 O(CF 2 )H, CF 3 OCH 2 (CF 2 ) 2 F, CF 3 CHFCF 2 OCH 2 (CF 2 ) 3 F, CH 3 CF 2 OCH 2 (CF 2 ) 2 F, CH 3 CF 2 OCH 2 (CF 2 ) 3 F, CH 3 O(CF 2 ) 5 F, F(CF 2 ) 3 CH 2 OCH 2 (CF 2 ) 3 F, F(CF 2 ) 2 CH 2 OCH 2 (CF 2 ) 2 F, H(CF 2 ) 2 CH 2 OCH 2 (CF 2 ) 2 H and CH 3 CF 2 OCH 2 (CF 2 ) 2 H,
wherein the content of the fluorinated ether compound in the non-aqueous electrolyte solvent is from 40 to 50 vol %;
the total content of the open-chain sulfone compounds in the non-aqueous electrolyte solvent is from 20 to 30 vol %;
the content of the carbonate ester compound in the non-aqueous electrolyte solvent is from 20 to 30 vol %; and
the content of the open chain sulfone compound having 4 or more carbon atoms is larger than the content of the open chain sulfone compound having 3 or less carbon atoms; and
the content of the open-chain sulfone compound having 4 or more carbon atoms in the non-aqueous electrolyte solvent is from 3 to 25 vol % and the content of the open-chain sulfone compound having 3 or less carbon atoms in the non-aqueous electrolyte solvent is from 2 to 10 vol %.

2. The electrolyte solution for a secondary battery according to claim 1 , wherein the non-aqueous electrolyte solvent comprises ethylene carbonate and at least one carbonate ester compounds selected from the group consisting of propylene carbonate, 4-fluorinated ethylene carbonate and dimethyl carbonate.

3. The electrolyte solution for a secondary battery according to claim 1 , wherein the non-aqueous electrolyte solvent further comprises at least one fluorinated phosphate ester selected from the group consisting of tris (trifluoromethyl) phosphate, tris (pentafluoroethyl) phosphate, tris (2,2,2-trifluoroethyl) phosphate, tris (2,2,3,3-tetrafluoropropyl) phosphate, tris (3,3,3-trifluoropropyl) phosphate, and tris (2,2,3,3,3-pentafluoropropyl) phosphate.

4. A secondary battery comprising the electrolyte solution for a secondary battery according to claim 1 .

5. The secondary battery according to claim 4 , comprising a positive electrode comprising a positive electrode active material which operates at 4.5 V or higher versus lithium.

6. The secondary battery according to claim 5 , wherein the positive electrode active material is a lithium manganese composite oxide represented by any of the following Formulas (4), (5), and (6):
Li a (M x Mn 2-x-y Y y )(O 4-w Z w )  (4)

wherein in Formula (4), 0.4≤x≤1.2, 0≤y, x+y<2, 0≤a≤1.2 and 0≤w≤1 are satisfied; M includes at least one selected from the group consisting of Co, Ni, Fe, Cr, and Cu; Y is at least one selected from the group consisting of Li, B, Na, Mg, Al, Ti, Si, K, and Ca, Z is at least one of F and Cl;
LiMPO 4   (5)

wherein in Formula (5), M is at least one of Co and Ni; and
Li(Li x M 1-x-z Mn z )O 2   (6)

wherein in Formula (6), 0≤x<0.3 and 0.3≤z≤0.7 are satisfied, and M is at least one selected from Co, Ni, and Fe.

7. The secondary battery according to claim 5 , wherein the positive electrode active material is a lithium manganese composite oxide represented by the following Formula (7):
LiNi x Mn 2-x-y A y O 4   (7)

wherein, in Formula (7), 0.4<x<0.6 and 0≤y<0.3 are satisfied, and A is at least one selected from Li, B, Na, Mg, Al, Ti, and Si.

8. A method for producing a secondary battery comprising an electrode element, an electrolyte solution, and an outer package, the method comprising the steps of:
producing the electrode element by placing a positive electrode and a negative electrode so as to be faced with each other; and
encapsulating the electrode element, and the electrolyte solution which comprises the electrolyte solution for a secondary battery according to claim 1 into the outer package.

9. The electrolyte solution for a secondary battery according to claim 1 , wherein the volume content of the open chain sulfone compound having 4 or more carbon atoms is 2-fold or more of the volume content of the open chain sulfone compound having 3 or less carbon atoms.

10. The electrolyte solution for a secondary battery according to claim 9 , wherein the carbonate ester compound consists of ethylene carbonate and propylene carbonate.

11. The electrolyte solution for a secondary battery according to claim 10 , wherein the open chain sulfone compound having 4 or more carbon atoms consists of ethyl isopropyl sulfone.

12. The electrolyte solution for a secondary battery according to claim 1 , wherein the non-aqueous electrolyte solvent further comprises tris (2,2,2,-trifluoroethyl) phosphate.

Assignees

• Nec Corp

Inventors

• Takahashi Makiko
• Noguchi Takehiro

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/052

  Li-accumulators · CPC title