Electrolyte composition comprising a fluorinated acyclic ester and a fluorinated cyclic carbonate

Abstract

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

Claims

1. 1. An electrochemical cell comprising an anode, a cathode, and an electrolyte composition, wherein the anode comprises a combination of at least a carbon material and a silicon material as an anode active material, and the electrolyte composition comprises: a solvent, - based on the total weight of the electrolyte composition, R １ -COO-R ２ (In the formula, R １ is a C1-C4 alkyl group, and R ２ is a C1-C4 fluoroalkyl group), and - 0.5% to 10% by weight of a fluorinated cyclic carbonate compound, based on the total weight of the electrolyte composition; - Electrolyte salt and an electrochemical cell comprising:

2. The anode is made of Si / C, SiO ａ / C and Si / SiO ａ 2. The electrochemical cell of claim 1, wherein the composite material is selected from the group consisting of: ZnO / C (where 0<a<2).

3. 3. The electrochemical cell of claim 1 or claim 2, wherein the 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. 4. The electrochemical cell of claim 3, wherein the fluorinated acyclic carboxylic acid ester is 2,2-difluoroethyl acetate.

5. 4. The electrochemical cell of claim 3, wherein the fluorinated acyclic carboxylic acid ester is 2,2-difluoroethyl propionate.

6. 4. The electrochemical cell of claim 3, wherein the fluorinated acyclic carboxylic acid ester is 2,2,2-trifluoroethyl acetate.

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

8. 8. The electrochemical cell of any one of claims 1 to 7, wherein the 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. 9. The electrochemical cell according to claim 1, wherein the content of the fluorinated cyclic carbonate compound is 1% by weight to 9% by weight.

10. 10. The electrochemical cell of any one of claims 1 to 9, wherein the solvent of the electrolyte composition comprises a non-fluorinated cyclic carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, and mixtures thereof.

11. 11. The electrochemical cell of any one of claims 1 to 10, wherein the solvent of the electrolyte composition comprises a non-fluorinated acyclic carbonate selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and mixtures thereof.

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

13. An electronic, transport or telecommunications device comprising an electrochemical cell according to any one of claims 1 to 12.

14. To improve the high temperature cycling performance of an electrochemical cell containing a combination of at least a carbon material and a silicon material as an anode active material, - based on the total weight of the electrolyte composition, R １ -COO-R ２ (In the formula, R １ is a C1-C4 alkyl group, and R ２ is a C1-C4 fluoroalkyl group), and 0.5% to 10% by weight of a fluorinated cyclic carbonate compound, based on the total weight of the electrolyte composition; 10. Use of a combination of the above as an additive in an electrolyte composition.

15. 1. An electrolyte composition for improving high temperature cycling performance of an electrochemical cell, the electrochemical cell comprising a combination of at least a carbon material and a silicon material as an anode active material, the electrolyte composition comprising: - based on the total weight of the electrolyte composition, R １ -COO-R ２ (In the formula, R １ is a C1-C4 alkyl group, and R ２ is a C1-C4 fluoroalkyl group), and - 0.5% to 10% by weight of a fluorinated cyclic carbonate compound, based on the total weight of the electrolyte composition; 1. An electrolyte composition comprising:

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