Conductive polymer binder for a novel silicon/graphene anode in lithium ion batteries

1. A composite electrode for use in a lithium-ion battery, the composite electrode comprising:

a silicon-graphene active material with a specific capacity between 500 and 3500 mAh/g; and

a conductive polymer binder, wherein the conductive polymer binder has a polymeric composition with repeating units of the formula:

wherein n+m is between 10 and up to 10 million; and n/m ratio is 9/1 to 1/9.

2. The composite electrode of claim 1 , wherein the n/m ratio is 7/3.

3. The composite electrode of claim 1 , wherein the conductive polymer binder is a copolymer of 1-pyrenebutyl methacrylate and methacrylic acid.

4. The composite electrode of claim 3 , wherein the methacrylic acid present in the copolymer is in an amount from about 30 to 78 mol % and the 1-pyrenebutyl methacrylate present in the copolymer is in an amount from about 22 to 70 mol %.

5. The composite electrode of claim 3 , wherein the methacrylic acid present in the copolymer is in an amount from about 10 to 51 wt % and the 1-pyrenebutyl methacrylate present in the copolymer is in an amount from about 49 to 90 wt %.

6. The composite electrode of claim 1 , wherein the electrode is comprised of about 1 to 20 wt % of polymer binder and about 80 to 99 wt % of silicon-graphene active material.

7. The composite electrode of claim 1 , wherein the silicon-graphene active material contains about 10 to 99 wt % of Si and about 1 to 90 wt % of C.

8. The composite electrode of claim 1 , wherein the electrode further comprises a graphene additive.

9. The composite electrode of claim 8 , wherein the electrode is comprised of about 5 to 20 wt % of polymer binder, about 65 to 94 wt % of silicon-graphene active material and about 1 to 15 wt % of graphene additive.

10. A composite electrode for use in a lithium-ion battery, the composite electrode comprising:

a silicon-graphene active material with a specific capacity between 500 and 3500 mAh/g; and

a conductive polymer binder, wherein the conductive polymer binder is poly (1-pyrenebutyl methacrylate) having the following formula:

wherein n is between 10 and up to 10 million.

11. The composite electrode of claim 10 , wherein the electrode is comprised of about 1 to 20 wt % of polymer binder and about 80 to 99 wt % of silicon-graphene active material.

12. The composite electrode of claim 10 , wherein the electrode further comprises a graphene additive.

13. A method for making a composite electrode for use in a lithium ion battery, the method comprising the steps of:

forming a solution of a solvent and a conductive polymer binder;

adding a silicon-graphene active material to the solution to form a slurry;

mixing the slurry to form a homogeneous mixture;

depositing a thin film of said thus obtained mixture over top of a substrate; and

drying the resulting composite to form said electrode,

wherein the conductive polymer binder has a polymeric composition with repeating units of the formula:

wherein n+m is between 10 and up to 10 million; n/m ratio is 9/1 to 1/9.

14. The method of claim 13 , wherein the n/m ratio is 7/3.

15. The method of claim 13 , wherein the conductive polymer binder is a copolymer of 1-pyrenebutyl methacrylate and methacrylic acid.

16. The method of claim 15 , wherein the 1-pyrenebutyl methacrylate present in the copolymer is in an amount from about 22 to 70 mol % and the methacrylic acid present in the copolymer is in an amount from about 30 to 78 mol %.

17. The method of claim 13 , wherein the electrode is comprised of about 1 to 20 wt % of polymer binder and about 80 to 99 wt % of silicon-graphene active material.

18. The method of claim 13 , wherein the electrode further comprises a graphene additive.

19. The method of claim 18 , wherein the electrode is comprised of about 5 to 20 wt % of polymer binder, about 65 to 94 wt % of silicon-graphene active material and about 1 to 15 wt % of graphene additive.

20. A method for making a composite electrode for use in a lithium ion battery, the method comprising the steps of:

forming a solution of a solvent and a conductive polymer binder;

adding a silicon-graphene active material to the solution to form a slurry;

mixing the slurry to form a homogeneous mixture;

depositing a thin film of said thus obtained mixture over top of a substrate; and

drying the resulting composite to form said electrode,

wherein the conductive polymer binder is poly (1-pyrenebutyl methacrylate) having the following formula:

wherein n is between 10 and up to 10 million.