Electrolyte solution for lithium ion secondary battery and lithium ion secondary battery using same

Patent metadata

Field	Value
Publication number	US-2020106134-A1
Application number	US-201816613871-A
Country	US
Kind code	A1
Filing date	May 9, 2018
Priority date	May 18, 2017
Publication date	Apr 2, 2020
Grant date	—

Abstract

An electrolyte solution capable of constituting a secondary battery in which a volume change due to charge and discharge is small and cycle characteristics are excellent is provided. The present example embodiment relates to an electrolyte solution for a lithium ion secondary battery comprising a fluorinated ether and a cyclic dicarboxylic acid ester.

First claim

1 . An electrolyte solution for a lithium ion secondary battery comprising a fluorinated ether and a cyclic dicarboxylic acid ester.

2 . The electrolyte solution for a lithium ion secondary battery according to claim 1 , further comprising LiPF 6 and/or LiN(FSO 2 ) 2 .

3 . The electrolyte solution for a lithium ion secondary battery according to claim 1 , wherein the content of the fluorinated ether in the electrolyte solution is 1 to 80 vol %.

4 . The electrolyte solution for a lithium ion secondary battery according to claim 1 , wherein the content of the cyclic dicarboxylic acid ester in the electrolyte solution is 0.1 mass % or more and 5 mass % or less.

5 . The electrolyte solution for a lithium ion secondary battery according to claim 1 , further comprising at least one compound selected from the group consisting of a cyclic carbonate, an open-chain carbonate and a fluoride thereof.

6 . The electrolyte solution for a lithium ion secondary battery according to claim 1 , wherein the fluorinated ether is represented by the following formula (1-1):
C n H 2n+1−l F l —O—C m H 2m+1−k F k   (1-1)
wherein n and m are each independently an integer of 1 to 6, l is an integer of 0 to 2n+1; k is an integer of 0 to 2m+1, and at least one of l and k is 1 or more.

7 . The electrolyte solution for a lithium ion secondary battery according to claim 1 , wherein the cyclic dicarboxylic acid ester is at least one compound selected from the group consisting of cyclic dicarboxylic acid esters represented by formula (2) and formula (3):

in formula (2), R 1 and R 2 each independently represent a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms which may be branched, with the proviso that both R 1 and R 2 do not represent single bonds at the same time;

in formula (3), R 3 and R 4 each independently represent a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms which may be branched, with the proviso that both R 3 and R 4 do not represent single bonds at the same time.

8 . A lithium ion secondary battery comprising the electrolyte solution for a lithium ion secondary battery according to claim 1 .

9 . The lithium ion secondary battery according to claim 8 , further comprising a negative electrode comprising a negative electrode active material comprising silicon as a constituent element.

10 . The lithium ion secondary battery according to claim 8 , further comprising a positive electrode comprising at least one compound selected from the group consisting of positive electrode active materials represented by the following formulae (A1), (A2) and (B):
Li(Li x M 1−x−z Mn z )O 2   (A1)
in formula (A1), 0.1≤x<0.3, 0.4≤z≤0.8, M is at least one element selected from the group consisting of Ni, Co, Fe, Ti, Al and Mg;
Li y Ni (1−x )M x O 2   (A2)

in formula (A2), 0≤x<1, 0<y≤1, and M is at least one element selected from the group consisting of Li, Co, Al, Mn, Fe, Ti, and B;
Li a (M x Mn 2−x−y Y y )(O 4−w Z w )   (B)

in formula (B), 0.4≤x≤1.2, 0≤y, x+y<2, 0≤a≤1.2, 0≤w≤1; M is a transition metal element and comprises at least one element selected from the group consisting of Co, Ni, Fe, Cr and Cu; Y is a metal element and comprises at least one element selected from the group consisting of Li, B, Na, Al, Mg, Ti, Si, K and Ca; and Z is at least one element selected from the group consisting of F and Cl.

11 . A method of producing a lithium ion secondary battery comprising:
stacking a positive electrode and a negative electrode via a separator to produce an electrode element, and enclosing the electrode element and an electrolyte solution in an outer package, wherein the electrolyte solution comprises a fluorinated ether and a cyclic dicarboxylic acid ester.

12 - 13 . (canceled)

Assignees

• Nec Corp

Inventors

• Hasegawa Takuya

Classifications

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/505

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

• H01M10/0525 Primary

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

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title