Electrolyte formulations for electrochemical cells containing a silicon electrode
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.
1. A lithium ion battery capable of multiple charge and discharge cycles 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, the structure is linear, R 2 is a substituted or unsubstituted alkyl group or a hydrogen and R 1 is a substituted or unsubstituted acrylate.
2. The lithium ion battery 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 lithium ion battery of claim 1 wherein the additive comprises poly(ethylene glycol) methyl ether acrylate.
4. The lithium ion battery of claim 1 wherein the additive comprises ethylene glycol methyl ether acrylate.
5. The lithium ion battery of claim 1 wherein the additive comprises di(ethylene glycol) ethyl ether acrylate.
6. The lithium ion battery of claim 1 wherein the electrolyte solution further comprises a blend of a high dielectric solvent and a low viscosity solvent.
7. The lithium ion battery of claim 6 , wherein the blend comprises propylene carbonate.
8. The lithium ion battery of claim 6 , wherein the blend comprises ethyl methyl carbonate.
9. A lithium ion battery capable of multiple charge and discharge cycles 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, the structure is linear, and R 4 is a substituted or unsubstituted alkyl chain.
10. The lithium ion battery of claim 9 wherein the additive comprises a fluorine-substituted alkyl chain.
11. The lithium ion battery of claim 9 wherein the additive comprises poly(2,2,2-trifluoroethyl acrylate).
12. The lithium ion battery of claim 9 wherein the electrolyte solution further comprises a blend of a high dielectric solvent and a low viscosity solvent.
13. The lithium ion battery of claim 12 , wherein the blend comprises propylene carbonate.
14. The lithium ion battery of claim 12 , wherein the blend comprises ethyl methyl carbonate.
15. A lithium ion battery capable of multiple charge and discharge cycles 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 linear polymers with ethylene oxide functionality, and the blend comprises a high dielectric solvent and a low viscosity solvent.
16. The lithium ion battery of claim 15 wherein the additive comprises a 2-carboxyethyl acrylate oligomer.
17. The lithium ion battery of claim 15 wherein the additive comprises poly(1,4-butylene adipate).
18. The lithium ion battery of claim 15 wherein the additive comprises poly(2,2,2-trifluoroethylacrylate).
19. The lithium ion battery of claim 15 wherein the additive comprises poly(ethylene glycol) methyl ether acrylate.
20. The lithium ion battery of claim 15 wherein the additive comprises poly(propylene glycol) acrylate.