Electrolyte composition with fluorinated acyclic ester and fluorinated cyclic carbonate

Patent metadata

Field	Value
Publication number	US-2023006255-A1
Application number	US-202017781705-A
Country	US
Kind code	A1
Filing date	Nov 13, 2020
Priority date	Dec 3, 2019
Publication date	Jan 5, 2023
Grant date	—

Abstract

An electrochemical cell comprises an anode, a cathode and an electrolyte composition, wherein the anode comprises as anode active material a combination of at least a carbon material and a silicon material; and the electrolyte composition comprises a solvent, from 0.5 wt. % to 70 wt. %, based on the total weight of the electrolyte, of a fluorinated acyclic carboxylic acid ester compound, from 0.5 wt. % 10 wt. %, based on the total weight of the electrolyte, of a fluorinated cyclic carbonate compound; and an electrolyte salt.

First claim

1 . An electrochemical cell comprising an anode, a cathode and an electrolyte composition, wherein said anode comprises as an anode active material a combination of at least a carbon material and a silicon material; and said electrolyte composition comprises:
a solvent; from 0.5 wt. % to 70 wt. %, based on the total weight of the electrolyte, of a fluorinated acyclic carboxylic acid ester compound of general formula
R1-COO—R2

wherein R1 is a C1-C4 alkyl group, and R2 is C1-C4 fluoroalkyl group,
from 0.5 wt. % to 10 wt. %, based on the total weight of the electrolyte, of a fluorinated cyclic carbonate compound; and
an electrolyte salt.

2 . The electrochemical cell according to claim 1 , wherein the anode is a composite material selected from Si/C, SiOa/C and Si/SiOa/C, with 0<a<2.

3 . The electrochemical cell according to claim 1 , wherein said fluorinated acyclic carboxylic acid ester is selected from the group consisting of 2,2-difluoroethyl acetate, 2,2,2-trifluoroethyl acetate, 2,2-difluoroethyl propionate, 3,3-difluoropropyl acetate, 3,3-difluoropropyl propionate, and mixtures thereof.

4 . The electrochemical cell according to claim 3 , wherein said fluorinated acyclic carboxylic acid ester is 2,2-difluoroethyl acetate.

5 . The electrochemical cell according to claim 3 , wherein said fluorinated acyclic carboxylic acid ester is 2,2-difluoroethyl propionate.

6 . The electrochemical cell according to claim 4 , wherein said fluorinated acyclic carboxylic acid ester is 2,2,2-trifluoroethyl acetate.

7 . The electrochemical cell according to claim 1 , wherein the content of the fluorinated acyclic carboxylic acid ester compound is from 0.5 wt. % to 10 wt. %, based on the total weight of the electrolyte.

8 . The electrochemical cell according to claim 1 , wherein said fluorinated cyclic carbonate is selected from the group consisting of 4-fluoroethylene carbonate, 4,5-difluoro-1,3-dioxolan-2-one, 4,5-difluoro-4-methyl-1,3-dioxolan-2-one, 4,5-difluoro-4,5-dimethyl-1,3-dioxolan-2-one, 4,4-difluoro-1,3-dioxolan-2-one, 4,4,5-trifluoro-1,3-dioxolan-2-one, tetrafluoroethylene carbonate, and mixtures thereof.

9 . The electrochemical cell according to claim 1 , wherein the content of the fluorinated cyclic carbonate compound is from 1 wt. % to 9 wt. %.

10 . The electrochemical cell according to claim 1 , wherein the solvent of the electrolyte composition comprises a non-fluorinated cyclic carbonate.

11 . The electrochemical cell according to claim 1 , wherein the solvent of the electrolyte composition comprises a non-fluorinated acyclic carbonate.

12 . The electrochemical cell according to claim 1 , wherein the electrolyte composition further comprises an additive selected from a lithium boron compound, a cyclic sultone, a cyclic sulfate, a cyclic carboxylic acid anhydride, or a combination thereof.

13 . An electronic device, transportation device, or telecommunications device, comprising an electrochemical cell according to claim 1 .

14 . A method of improving cycling performance at high temperature of an electrochemical cell comprising an anode and an electrolyte composition, wherein said anode comprises, as an anode active material, a combination of at least a carbon material and a silicon material, the method comprising:
adding an additive to the electrolyte composition, the additive comprising:
from 0.5 wt. % to 70 wt. %, based on the total weight of the electrolyte, of a fluorinated acyclic carboxylic acid ester compound of general formula
R 1 —COO—R 2

wherein R 1 is a C1-C4 alkyl group, and R 2 is C1-C4 fluoroalkyl group, and
from 0.5 wt. % to 10 wt. %, based on the total weight of the electrolyte, of a fluorinated cyclic carbonate compound.

15 . The electrochemical cell according to claim 10 , wherein the non-fluorinated cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, and mixtures thereof.

16 . The electrochemical cell according to claim 11 , wherein the non-fluorinated acyclic carbonate is selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate; and mixtures thereof.

17 . The electrochemical cell according to claim 6 , wherein the content of the fluorinated acyclic carboxylic acid ester compound is from 2 wt. % to 5 wt. %, based on the total weight of the electrolyte.

18 . The electrochemical cell according to claim 8 , wherein said fluorinated cyclic carbonate is selected from the group consisting of 4-fluoroethylene carbonate, 4,5-difluoro-1,3-dioxolan-2-one, and mixtures thereof.

19 . The electrochemical cell according to claim 9 , wherein the content of the fluorinated cyclic carbonate compound is from 2 wt. % to 5 wt. %.

Assignees

• Solvay

Inventors

• Lee Hyun-Cheol
• Hwang Hyung-Kwon
• Moon Eun-Ji
• Hough Lawrence Alan
• Won Du-Hyun
• Lee Jong-Hyun

Classifications

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M10/0525

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

• H01M10/052

  Li-accumulators · CPC title

• H01M4/364

  as mixtures · CPC title