Electrolyte, electrochemical device, secondary cell, and module

Patent metadata

Field	Value
Publication number	US-2017077552-A1
Application number	US-201515122812-A
Country	US
Kind code	A1
Filing date	Mar 16, 2015
Priority date	Mar 28, 2014
Publication date	Mar 16, 2017
Grant date	—

Abstract

Provided is an electrolyte solution for secondary batteries that are less likely to generate gas and excellent in high-temperature storage characteristics; an electrochemical device using the electrolyte solution; and a module using the electrochemical device. The electrolyte solution contains a solvent and an electrolyte salt, the solvent containing a fluorine-containing acyclic carbonate represented by the formula (1) and a fluorine-containing succinic anhydride represented by the formula (2). The electrolyte solution contains not less than 0.001 mass % but less than 90 vol % of the fluorine-containing acyclic carbonate, and the electrolyte solution contains 0.001 to 20 mass % of the fluorine-containing succinic anhydride.

First claim

1 . An electrolyte solution comprising a solvent and an electrolyte salt,
the solvent comprising a fluorine-containing acyclic carbonate represented by the formula (1) and a fluorine-containing succinic anhydride represented by the formula (2), the electrolyte solution containing not less than 0.001 mass % but less than 90 vol % of the fluorine-containing acyclic carbonate, the electrolyte solution containing 0.001 to 20 mass % of the fluorine-containing succinic anhydride, the formula (1) being:
Rf 1 OCOORf 2   (1)

wherein Rf 1 and Rf 2 are the same as or different from each other and individually represent a C1-C4 alkyl group or a C1-C4 fluorine-containing alkyl group, but at least one of Rf 1 and Rf 2 is C1-C4 fluorine-containing alkyl group, the formula (2) being:

wherein Rf 3 to Rf 6 are the same as or different from one another and individually represent a hydrogen atom, a fluorine atom, or a C1-C10 fluorine-containing alkyl group, but not all of Rf 3 to Rf 6 are hydrogen atoms.

2 . The electrolyte solution according to claim 1 ,
wherein the fluorine-containing acyclic carbonate is at least one selected from the group consisting of CF 3 CH 2 OCOOCH 2 CF 3 , CF 3 CH 2 OCOOCH 3 , and CF 3 CF 2 CH 2 OCOOCH 2 CF 2 CF 3 .

3 . The electrolyte solution according to claim 1 ,
wherein the fluorine-containing succinic anhydride is at least one selected from the group consisting of compounds represented by the following formulas (3) to (5):

4 . The electrolyte solution according to claim 1 ,
wherein the solvent further comprises at least one selected from the group consisting of a non-fluorinated saturated cyclic carbonate, a fluorinated saturated cyclic carbonate, and a non-fluorinated acyclic carbonate.

5 . The electrolyte solution according to claim 1 ,
wherein the electrolyte salt is at least one lithium salt selected from the group consisting of LiPF 6 , LiBF 4 , LiSO 3 CF 3 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, and a salt represented by LiPF a (C n F 2n+1 ) 6-a wherein a represents an integer of 0 to 5 and n represents an integer of 1 to 6.

6 . An electrochemical device comprising the electrolyte solution according to claim 1 .

7 . A secondary battery comprising the electrolyte solution according to claim 1 .

8 . A module comprising the electrochemical device according to claim 6 .

Assignees

• Daikin Ind Ltd

Inventors

• Taeda Mayuko
• Yamazaki Shigeaki
• Arima Hiroyuki
• Kuwajima Yoshiko
• Miura Toshirou
• Kinoshita Shinichi
• SHIMADA Tomo

Classifications

• H01G11/62

  characterised by the solute, e.g. salts, anions or cations therein · CPC title

• H01G11/60

  characterised by the solvent · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/0525

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

• H01M2300/0034

  Fluorinated solvents · CPC title