Electrolyte Formulations For Electrochemical Cells Containing A Silicon Electrode

Patent metadata

Field	Value
Publication number	US-2016240889-A1
Application number	US-201615045902-A
Country	US
Kind code	A1
Filing date	Feb 17, 2016
Priority date	Feb 17, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

Additives to electrolytes that enable the formation of comparatively more robust SEI films on silicon anodes. The SEI films in these embodiments are seen to be more robust in part because the batteries containing these materials have higher coulombic efficiency and longer cycle life than comparable batteries without such additives.

First claim

1 . An electrochemical cell comprising:
a silicon based anode; and a liquid electrolyte solution comprising a soluble additive wherein the additive is represented by the chemical structural formula:

where n≧1, R 2 is a substituted or unsubstituted alkyl group or a hydrogen and R 1 is a substituted or unsubstituted acrylate.

2 . The electrochemical cell of claim 1 wherein R 1 is represented by the chemical structural formula:

where R 3 is a substituted or unsubstituted alkyl group or a hydrogen.

3 . The electrochemical cell of claim 1 wherein the additive comprises poly(ethylene glycol) methyl ether acrylate.

4 . The electrochemical cell of claim 1 wherein the additive comprises ethylene glycol methyl ether acrylate

5 . The electrochemical cell of claim 1 wherein the additive comprises di(ethylene glycol) ethyl ether acrylate.

6 . The electrochemical cell of claim 1 wherein the electrolyte solution further comprises a blend of a high dielectric solvent and a low viscosity solvent.

7 . The electrochemical cell of claim 6 , wherein the blend comprises propylene carbonate.

8 . The electrochemical cell of claim 6 , wherein the blend comprises ethyl methyl carbonate.

9 . An electrochemical cell comprising:
a silicon based anode; and a liquid electrolyte solution comprising a soluble additive wherein the additive is represented by the chemical structural formula:

where m≦3 and n>1.

10 . The electrochemical cell of claim 9 wherein the additive comprises poly(ethylene) adipate.

11 . The electrochemical cell of claim 9 the additive comprises poly[di(ethylene glycol) adipate].

12 . The electrochemical cell of claim 9 wherein the electrolyte solution further comprises a blend of a high dielectric solvent and a low viscosity solvent.

13 . The electrochemical cell of claim 12 , wherein the blend comprises propylene carbonate.

14 . The electrochemical cell of claim 12 , wherein the blend comprises ethyl methyl carbonate.

15 . An electrochemical cell comprising:
a silicon based anode; and a liquid electrolyte solution comprising a soluble additive wherein the additive is represented by the chemical structural formula:

where n≧1 and R 4 is a substituted or unsubstituted alkyl chain.

16 . The electrochemical cell of claim 15 wherein the additive comprises a fluorine-substituted alkyl chain.

17 . The electrochemical cell of claim 15 wherein the additive comprises poly(2,2,2-trifluoroethyl acrylate).

18 . The electrochemical cell of claim 15 wherein the electrolyte solution further comprises a blend of a high dielectric solvent and a low viscosity solvent.

19 . The electrochemical cell of claim 18 , wherein the blend comprises propylene carbonate.

20 . The electrochemical cell of claim 18 , wherein the blend comprises ethyl methyl carbonate.

21 . An electrochemical cell comprising:
a silicon based anode; and a liquid electrolyte having one or more soluble additives included in a blend of solvents, wherein the additives are polymers with ethylene oxide functionality, and the blend comprises a high dielectric solvent and a low viscosity solvent.

22 . The electrochemical cell of claim 21 wherein the additive comprises a 2-carboxyethyl acrylate oligomer.

23 . The electrochemical cell of claim 21 wherein the additive comprises poly(1,4-butylene adipate).

24 . The electrochemical cell of claim 21 wherein the additive comprises poly(2,2,2-trifluoroethylacrylate).

25 . The electrochemical cell of claim 21 wherein the additive comprises poly(ethylene glycol) methyl ether acrylate.

26 . The electrochemical cell of claim 21 wherein the additive comprises poly(ethylene adipate).

27 . The electrochemical cell of claim 21 wherein the additive comprises poly(propylene glycol) acrylate.

28 . The electrochemical cell of claim 21 wherein the additive comprises and poly[di(ethylene glycol) adipate].

Assignees

• Wildcat discovery technologies inc

Inventors

• Cheng Gang
• Strand Deidre
• Zhu Ye
• Caldwell Marissa

Classifications

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0525

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

• H01M10/0567 Primary

  characterised by the additives · CPC title