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 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;
forming an electrode film mixture by mixing the secondary binder mixture with a second active material 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.
2. The method of claim 1 , wherein mixing the secondary binder mixture with the second active material by the first nondestructive mixing process comprises mixing at least one of a lower pressure, lower velocity, and faster feed rate than the processing under high shear step.
3. The method of claim 1 , 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 providing the initial binder mixture.
4. The method of claim 3 , wherein at least one of the first and the second nondestructive mixing processes is an acoustic mixing process.
5. The method of claim 1 , wherein mixing comprises mixing the binder mixture with an active material mixture, the active material mixture comprising the second active material.
6. The method of claim 5 , wherein the active material mixture further comprises a second binder.
7. The method of claim 1 , wherein the mass ratio of the first active material to the first binder is between about 1:1 to about 4:1 by weight.
8. The method of claim 1 , wherein the second active material comprises a treated surface.
9. The method of claim 1 , wherein the second active material within the electrode film comprises active material particle surfaces that are pristine.
10. The method of claim 1 , wherein the combined D 50 particle size distribution of a total active material, including the first and second active materials, in the electrode film mixture is at least about 6 μm.
11. 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.
12. The method of claim 1 , wherein the method is a dry fabrication process in which substantially no solvents are used.
13. The method of claim 1 , wherein the first binder comprises a fibrillizable binder.
14. The method of claim 13 , wherein the first binder comprises PTFE.
15. The method of claim 1 , wherein the electrode film has a tensile strength of greater than about 0.25 MPa.
16. The method of claim 15 , wherein the electrode film has a tensile strength of about 0.3 MPa to about 0.7 MPa.
17. The method of claim 1 , wherein the electrode film comprises a total binder loading of about 1.5% to about 4% by mass.
18. The method of claim 1 , further comprising attaching the electrode film to a current collector to form an electrode.
19. The method of claim 18 , further comprising inserting the electrode within a housing to form an energy storage device.
20. The method of claim 19 , wherein the energy storage device is a battery.