Electrolyte solution, lithium sulfur secondary battery and module

Patent metadata

Field	Value
Publication number	US-2025253408-A1
Application number	US-202519188091-A
Country	US
Kind code	A1
Filing date	Apr 24, 2025
Priority date	Nov 4, 2022
Publication date	Aug 7, 2025
Grant date	—

Abstract

Provided is an electrolyte solution capable of providing a lithium-sulfur secondary battery that has excellent cycle characteristics and that is less likely to generate gas. The electrolyte solution is intended to be used in a lithium-sulfur secondary battery that includes: a positive electrode containing a sulfur-containing electrode active material that includes at least one selected from the group consisting of simple sulfur, lithium polysulfide (Li2Sn: 1<n<8), an organic sulfur compound, and an inorganic sulfur compound; and a negative electrode containing a material that occludes and releases a lithium ion. The electrolyte solution contains a non-aqueous electrolyte and a solvent. The solvent contains an acyclic diether having a Σ{σ×P(σ)} value, where σ≥0.01 (e/Å2), falling within a range indicated by the formula (1) (i.e., 0<Σ{σ×P(σ)}<0.24; where σ represents a screening charge density and P(σ) represents an σ-profile).

First claim

1 . An electrolyte solution for use in a lithium-sulfur secondary battery that includes: a positive electrode containing a sulfur-containing electrode active material that includes at least one selected from the group consisting of simple sulfur, lithium polysulfide (Li 2 S n : 1<n<8), an organic sulfur compound, and an inorganic sulfur compound; and a negative electrode containing a material that occludes and releases a lithium ion, the electrolyte solution comprising:
a non-aqueous electrolyte; and a solvent, the solvent containing an acyclic diether having a Σ{σ×P(σ)} value, where σ≥0.01 (e/Å 2 ), falling within a range indicated by the following formula (1):

0
<

∑

{

σ

×

P
⁢

(
σ
)

}

<
0.24

(
1
)

wherein σ represents a screening charge density and P(σ) represents an σ-profile.

2 . The electrolyte solution according to claim 1 , wherein the acyclic diether is a fluorinated acyclic diether.

3 . The electrolyte solution according to claim 1 , wherein the acyclic diether includes at least one selected from the group consisting of a compound represented by the following formula (A) or a compound represented by the following formula (B),
the formula (A) being:

wherein R 1a to R 10a are each independently a halogen atom, a hydrogen atom, an alkyl group having a carbon number of 2 or smaller, or a fluorinated alkyl group having a carbon number of 2 or smaller, and at least one of R 1a to R 10a is a halogen atom or a fluorinated alkyl group having a carbon number of 2 or smaller,
the formula (B) being:

wherein R 1b to R 8b are each independently a halogen atom, a hydrogen atom, an alkyl group having a carbon number of 2 or smaller, or a fluorinated alkyl group having a carbon number of 2 or smaller.

4 . The electrolyte solution according to claim 1 , wherein the acyclic diether includes at least one selected from the group consisting of compounds represented by the following formulas:

5 . The electrolyte solution according to claim 1 , wherein the acyclic diether is contained in an amount of 3 to 90% by mass of a whole amount of the electrolyte solution.

6 . A lithium-sulfur secondary battery comprising:
a positive electrode containing a sulfur-containing electrode active material that includes at least one selected from the group consisting of simple sulfur, lithium polysulfide (Li 2 S n : 1<n<8), an organic sulfur compound, and an inorganic sulfur compound; and a negative electrode containing a material that occludes and releases a lithium ion, wherein the electrolyte solution according to claim 1 is used.

7 . A module comprising the lithium-sulfur secondary battery according to claim 6 .

Assignees

• The School Corporation Kansai Univ
• Daikin Ind Ltd

Inventors

• Ishikawa Masashi
• Okuda Daisuke
• Murata Chihiro
• Hidaka Tomoya
• Yamazaki Shigeaki
• Mari Daichi

Classifications

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M2300/004

  Three solvents · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M4/5815

  Sulfides · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title