Flexible cathodes
View Patent ↗A cathode for a lithium battery is described. The cathode includes: (a) a current collector including aluminum foil; and (b) an active cathode material including: (i) manganese dioxide; (ii) conductive materials; and (iii) a binder selected from the group consisting of linear di- and tri-block polymers, linear tri-block polymers cross-linked with melamine resin, ethylene-propylene copolymers, ethylene-propylene-diene terpolymers, tri-block fluorinated thermoplastics, hydrogenated nitrile rubbers, fluoro-ethylene-vinyl ether copolymers, thermoplastic polyurethanes, thermoplastic olefins, and polyvinylidine fluoride homopolymers.
1. A cathode for a lithium battery, the cathode comprising:
(a) a current collector including aluminum foil; and
(b) active cathode material including:
(i) manganese dioxide;
(ii) conductive materials; and
(iii) a binder selected from the group consisting of styrene-ethylene-butylene-styrene polymers, linear tri-block polymers cross-linked with melamine resin, ethylene-propylene-diene terpolymers, hydrogenated nitrile rubbers, thermoplastic polyurethanes, and thermoplastic olefins.
2. The cathode of claim 1 , wherein the binder is styrene-ethylene-butylene-styrene polymer.
3. The cathode of claim 1 , wherein the binder is a linear tri-block polymer cross-linked with a melamine resin.
4. The cathode of claim 3 , wherein the binder is styrene-ethylene-butylene-styrene cross-linked with a melamine resin.
5. The cathode of claim 1 , wherein one side of the current collector is coated with active cathode material.
6. The cathode of claim 1 , wherein both sides of the current collector are coated with active cathode material.
7. The cathode of claim 1 , wherein the current collector consists essentially of aluminum.
8. A method for making a cathode for a lithium battery, the method comprising:
(a) combining an active cathode material, conductive materials, a solvent, and a binder to form a mixture;
(b) dispersing the mixture to form a slurry containing from 25% by weight to 40% by weight of the solvent;
(c) applying the slurry to a substrate using a solution extrusion process to form a coated substrate; and
(d) drying the coated substrate.
9. The method of claim 8 wherein the method further includes calendering the cathode after step (d).
10. The method of claim 8 , wherein the substrate is an aluminum foil.
11. The method of claim 10 , wherein the foil is flame treated prior to step (c).
12. The method of claim 11 , wherein the foil is coated with a primer prior to step (c).
13. The method of claim 8 , wherein the solvent is a hydrocarbon solvent.
14. The method of claim 13 , wherein the solvent is a paraffinic solvent.
15. The method of claim 13 , wherein the solvent is an aromatic hydrocarbon solvent.
16. The method of claim 8 , wherein the slurry contains from 30% by weight to 35% by weight of the solvent.
17. A method for making a cathode for a lithium battery, the method comprising:
(a) combining an active cathode material, conductive materials, a hydrocarbon solvent, and a binder to form a mixture;
(b) dispersing the mixture to form a slurry;
(c) applying the slurry to a substrate using a solution extrusion process to form a coated substrate; and
(d) drying the coated substrate.
18. The method of claim 17 , wherein the solvent is a paraffinic solvent.
19. The method of claim 17 , wherein the solvent is an aromatic hydrocarbon solvent.