Compositions and methods for parallel processing of electrode film mixtures
Materials and methods for preparing electrode film mixtures and electrode films including reduced damage bulk active materials are provided. In a first aspect, a method for preparing an electrode film mixture for an energy storage device is provided, comprising providing an initial binder mixture comprising a first binder and a first active material, processing the initial binder mixture under high shear to form a secondary binder mixture, and nondestructively mixing the secondary binder mixture with a second portion of active materials to form an electrode film mixture.
1. A parallel processing method for preparing an electrode film comprising:
providing a bulk active material;
forming an electrode film mixture by mixing the bulk active material with an initial binder mixture by a first nondestructive mixing process; and
forming an electrode film from the electrode film mixture, wherein the electrode film is a free-standing film,
wherein the electrode film comprises a total binder loading of about 1.5% to about 4% by mass.
2. The method of claim 1 , wherein the first nondestructive mixing process comprises mixing at least one of a lower pressure, lower velocity, and faster feed rate than processing under high shear.
3. The method of claim 1 , further comprising processing the bulk active material prior to forming an electrode film mixture.
4. The method of claim 3 , wherein processing the bulk active material comprises a nondestructive mixing process.
5. The method of claim 1 , wherein providing the bulk active material comprises providing a bulk active material mixture comprising the bulk active material and a bulk binder.
6. The method of claim 5 , further comprising processing the bulk active material mixture by a nondestructive mixing process.
7. The method of claim 5 , wherein the bulk binder is selected from the group consisting of PVDF, CMC and combinations thereof.
8. The method of claim 1 , wherein the initial binder mixture comprises a first binder and a first active material.
9. The method of claim 8 , wherein the first binder and the first active material are mixed by a second nondestructive mixing process to form the initial binder mixture prior to forming the electrode film mixture.
10. The method of claim 9 , wherein at least one of the first and the second nondestructive mixing processes is an acoustic mixing process.
11. The method of claim 8 , wherein the initial binder mixture is processed by a high shear mixing process prior to forming the electrode film mixture.
12. The method of claim 8 , wherein the mass ratio of the first active material to the first binder is between about 1:1 to about 4:1 by weight.
13. The method of claim 8 , wherein the combined D 50 particle size distribution of a total active material, including the bulk active material and the first active material, in the electrode film mixture is at least about 6 μm.
14. The method of claim 8 , wherein the first binder comprises a fibrillizable binder.
15. The method of claim 14 , wherein the first binder comprises PTFE.
16. The method of claim 1 , wherein the bulk active material comprises a treated surface.
17. The method of claim 1 , wherein the bulk active material comprises graphite.
18. The method of claim 1 , wherein the bulk active material in the electrode film comprises active material particle surfaces that are pristine.
19. The method of claim 1 , wherein the electrode film mixture is not exposed to a high shear process before being formed into the electrode film.
20. The method of claim 1 , wherein the method is a dry fabrication process in which substantially no solvents are used.
21. The method of claim 1 , wherein the electrode film has a tensile strength of greater than about 0.25 MPa.
22. The method of claim 21 , wherein the electrode film has a tensile strength of about 0.3 MPa to about 0.7 MPa.
23. The method of claim 1 , further comprising attaching the electrode film to a current collector to form an electrode.
24. The method of claim 23 , further comprising inserting the electrode within a housing to form an energy storage device.
25. The method of claim 24 , wherein the energy storage device is a battery.