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US 2024/0178452 A1Published application
Nonaqueous Electrolyte Solution and Nonaqueous Secondary Battery
AssigneeAsahi Kasei Kabushiki Kaisha
InventorsNaoki Matsuoka, Makoto Ito
Life of this patent
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Abstract
The present invention provides a nonaqueous electrolyte solution which contains a nonaqueous solvent and a lithium salt, wherein: the nonaqueous solvent contains acetonitrile in an amount of 3% by volume to 97% by volume relative to the total amount of the nonaqueous solvent; the lithium salt contains a cyclic anion-containing lithium salt that is represented by formula (1) (wherein Rf moieties may be the same as or different from each other, and each represents a fluorine atom or a perfluoro group having 4 or less carbon atoms); and the content of the cyclic anion-containing lithium salt that is represented by formula (1) is from 0.001 to 5 in terms of the molar ratio relative to the content of the acetonitrile.
Claims17
1:
- A non-aqueous electrolyte solution comprising a non-aqueous solvent and a lithium salt, wherein
- the non-aqueous solvent contains acetonitrile in an amount of 3% by volume or more and 97% by volume or less relative to the total amount of the non-aqueous solvent, and
- the lithium salt contains a cyclic anion-containing lithium salt represented by the following formula (1):
- wherein Rfs may be the same or different and Rf each represents a fluorine atom or a perfluoro group having 4 or less carbon atoms, and
- the content of the cyclic anion-containing lithium salt represented by the formula (1) is 0.001 or more and 5 or less, in terms of a molar ratio, relative to the content of the acetonitrile.
2 more elements
2:
- The non-aqueous electrolyte solution according to claim 1, wherein the cyclic anion-containing lithium salt represented by the formula (1) contains one or more of cyclic anion-containing lithium salts represented by the following formulas (1-1) to (1-5)
3:
- The non-aqueous electrolyte solution according to claim 1, wherein the content of the cyclic anion-containing lithium salt represented by the formula (1) is 0.08 or more and 0.79 or less, in terms of a molar ratio, relative to the content of the acetonitrile.
4:
- The non-aqueous electrolyte solution according to claim 1, wherein the content of the acetonitrile is 10% by volume or more and 66% by volume or less relative to the total amount of the non-aqueous solvent.
5:
- The non-aqueous electrolyte solution according to claim 1, wherein the lithium salt further contains LiPF6, and
- LiPF6 and the cyclic anion-containing lithium salt represented by the formula (1) are contained at a molar concentration satisfying the relationship:
- LiPF6≤cyclic anion-containing lithium salt.
6:
- The non-aqueous electrolyte solution according to claim 5, wherein the content of the cyclic anion-containing lithium salt represented by the formula (1) is more than 10, in terms of a molar ratio, relative to the content of LiPF6.
7:
- The non-aqueous electrolyte solution according to claim 5, wherein the content of LiPF6 is less than 0.01 mol as the amount per 1 L of the non-aqueous solvent.
8:
- The non-aqueous electrolyte solution according to claim 5, wherein the content of the cyclic anion-containing lithium salt represented by the formula (1) is 150 or less, in terms of a molar ratio, relative to the content of LiPF6.
9:
- The non-aqueous electrolyte solution according to claim 1, wherein the lithium salt does not contain LiPF6.
10:
- The non-aqueous electrolyte solution according to claim 1, wherein the non-aqueous electrolyte solution further comprises a nitrogen-containing cyclic compound represented by the following formula (2):
- wherein substituents represented by R1, R2 and R3 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a fluorine-substituted alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a fluorine-substituted alkoxy group having 1 to 4 carbon atoms, a phenyl group, a cyclohexyl group, a nitrile group, a nitro group, an amino group, an N,N′-dimethylamino group or an N,N′-diethylamino group, and two or more of these substituents are hydrogen atoms.
11-17. (canceled)
18:
- A non-aqueous secondary battery comprising a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and the non-aqueous electrolyte solution according to claim 1.
19:
- The non-aqueous secondary battery according to claim 18, wherein the positive electrode active material contains a lithium phosphorus metal oxide having an olivine crystal structure containing iron (Fe) atoms,
- regarding the non-aqueous electrolyte solution,
- the content of the cyclic anion-containing lithium salt represented by the formula (1) is 0.9 or more, in terms of a molar ratio, relative to the total content of the lithium salt,
- the lithium salt contains LiPF6,
- the content of the cyclic anion-containing lithium salt represented by the formula (1) is 20 or more and 150 or less, in terms of a molar ratio, relative to the content of LiPF6,
- the content of the cyclic anion-containing lithium salt represented by the formula (1) is 0.08 or more and 0.27 or less, in terms of a molar ratio, relative to the content of the acetonitrile, and
- the content of the acetonitrile is 30% by volume or more and 66% by volume or less relative to the total amount of the non-aqueous solvent.
4 more elements
20:
- The non-aqueous secondary battery according to claim 18, wherein the positive electrode active material contains a lithium-containing metal oxide represented by the following general formula (at):
- LipNiqCorMnsMtOu (at)
- wherein M is at least one metal selected from the group consisting of Al, Sn, In, Fe, V, Cu, Mg, Ti, Zn, Mo, Zr, Sr and Ba, and p, q, r, s, t and u are within the following ranges:
- 0<p<1.3, 0<q<1.2, 0<r<1.2, 0≤s<0.5, 0≤t<0.3, 0.7≤q+r+s+t≤1.2 and 1.8<u<2.2, and p is the value determined by the charging/discharging state of the battery,
- regarding the non-aqueous electrolyte solution,
- the lithium salt contains LiPF6,
- the content of the cyclic anion-containing lithium salt represented by the formula (1) is 3 or more and 150 or less, in terms of a molar ratio, relative to the content of LiPF6,
- the content of the cyclic anion-containing lithium salt represented by the formula (1) is 0.15 or more and 0.79 or less, in terms of a molar ratio, relative to the content of the acetonitrile, and
- the content of the acetonitrile is 10% by volume or more and 50% by volume or less relative to the total amount of the non-aqueous solvent.
6 more elements
21:
- The non-aqueous secondary battery according to claim 18, wherein the non-aqueous secondary battery comprises a battery exterior, and the battery exterior contains aluminum in at least a part of a liquid contact layer with the non-aqueous electrolyte solution on the positive electrode side.
22:
- The non-aqueous secondary battery according to claim 18, wherein at least a part of the contact portion with the non-aqueous electrolyte solution on the positive electrode side in the battery exterior body is made of iron or an iron alloy.
23-25. (canceled)