Electrolytic solution, electrochemical device, lithium-ion secondary cell and module

Patent metadata

Field	Value
Publication number	US-11929461-B2
Application number	US-201716092634-A
Country	US
Kind code	B2
Filing date	Apr 5, 2017
Priority date	Apr 12, 2016
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

The present invention provides an electrolytic solution capable of providing an electrochemical device, such as a lithium ion secondary battery, or a module that has excellent high-temperature storage performance. The electrolytic solution contains: a homocyclic compound other than aromatic compounds; and a cyclic dicarbonyl compound. The homocyclic compound contains at least one group selected from the group consisting of a nitrile group and an isocyanate group.

First claim

The invention claimed is:

1. An electrolytic solution comprising:
a homocyclic compound other than aromatic compounds, the homocyclic compound containing at least one group selected from the group consisting of a nitrile group and an isocyanate group; and
a cyclic dicarbonyl compound; and
a solvent,
wherein the homocyclic compound is at least one selected from the group consisting of the following compounds

the amount of the homocyclic compound relative to the electrolytic solution is 0.001 to 5 mass %,
the cyclic dicarbonyl compound is at least one selected from the group consisting of lithium difluorooxalatoborate, trifluoromethylmaleic anhydride and maleic anhydride,
the amount of the cyclic dicarbonyl compound relative to the electrolytic solution is 0.001 to 5 mass %,
the solvent containing a fluorinated carbonate (2) containing at least one group selected from the group consisting of —CF 3 and —CF 2 H, and a fluorinated saturated cyclic carbonate other than the fluorinated carbonate (2),
wherein a ratio by volume between the fluorinated carbonate (2) and the fluorinated saturated cyclic carbonate is (50 to 99)/(50 to 1), and
wherein the fluorinated carbonate (2) is at least one selected from the group consisting of:
a fluorinated carbonate represented by the following formula (2-1):
CF 3 —R 21 —OCOO—R 22

(wherein R 21 is a C1-C10 non-fluorinated or fluorinated alkylene group; and R 22 is a C1-C10 non-fluorinated alkyl group);
a fluorinated carbonate represented by the following formula (2-2):
CF 2 H—R 23 —OCOO—R 24

(wherein R 23 is a C1-C10 non-fluorinated or fluorinated alkylene group; and R 24 is a C1-C10 non-fluorinated alkyl group);
a fluorinated carbonate represented by the following formula (3-1):

(wherein R 31 is a single bond or a C1-C8 non-fluorinated or fluorinated alkylene group; and R 32 is H or a C1-C3 non-fluorinated or fluorinated alkyl group); and
a fluorinated carbonate represented by the following formula (3-2):

(wherein R 33 is a single bond or a C1-C8 non-fluorinated or fluorinated alkylene group; and R 34 is H or a C1-C3 non-fluorinated or fluorinated alkyl group).

2. An electrochemical device comprising the electrolytic solution according to claim 1 .

3. A lithium ion secondary battery comprising:
the electrolytic solution according to claim 1 .

4. A lithium ion secondary battery comprising:
a positive electrode;
a negative electrode; and
the electrolytic solution according to claim 1 ,
the positive electrode comprising a positive electrode current collector and a positive electrode active material layer containing a positive electrode active material,
the positive electrode active material containing Mn.

5. The lithium ion secondary battery according to claim 4 ,
wherein the positive electrode current collector and a portion in contact with the electrolytic solution among portions electrically coupled with the positive electrode current collector are formed from a valve metal or an alloy thereof.

6. A module comprising
the electrochemical device according to claim 2 .

7. A module comprising the lithium ion secondary battery according to claim 3 .

8. The electrolytic solution according to claim 1 , wherein the ratio by volume between the fluorinated carbonate (2) and the fluorinated saturated cyclic carbonate is (50 to 70)/(50 to 30).

Assignees

• Daikin Ind Ltd

Inventors

• Takahashi Kenzou
• Kinoshita Shinichi
• Sakata Hideo
• Yamazaki Shigeaki
• Arima Hiroyuki

Classifications

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01G11/60

  characterised by the solvent · CPC title

• H01G11/62

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

• H01G11/64

  characterised by additives · CPC title

• H01M4/505

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