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 lithium battery, comprising:
a housing;
an anode comprising lithium in the housing;
an electrolyte comprising a non-aqueous solvent and a lithium salt; and
a cathode in the housing,
wherein the cathode comprises a cathode active material comprising iron disulfide and a binder selected from the group consisting of linear tri-block copolymers cross-linked with melamine resin, ethylene-propylene-diene terpolymers, hydrogenated nitrile rubbers, and thermoplastic polyurethanes.
2. The battery of claim 1 , wherein the cathode further comprises a current collector comprising aluminum.
3. The battery of claim 1 , wherein the cathode further comprises a current collector comprising an aluminum alloy.
4. The battery of claim 1 , wherein the cathode further comprises a current collector comprising an aluminum foil.
5. The battery of claim 1 , wherein the cathode has a thickness of from 16 mil to 22 mil.
6. The battery of claim 1 , wherein the cathode further comprises a conductive material selected from the group consisting of carbon black and graphite.
7. The battery of claim 1 , wherein the cathode has a porosity of from 30% to 35%.
8. The battery of claim 1 , wherein the battery is a prismatic battery.
9. A method of making a lithium battery, the method comprising:
combining a binder and a cathode active material comprising iron disulfide to form a cathode; and
adding the cathode, an anode comprising lithium, and an electrolyte comprising a non-aqueous solvent and a lithium salt into a housing to form the battery,
wherein the binder is selected from the group consisting of linear tri-block copolymers cross-linked with melamine resin, ethylene-propylene-diene terpolymers, hydrogenated nitrile rubbers, and thermoplastic polyurethanes.
10. The method of claim 9 , wherein the cathode also comprises a current collector comprising aluminum or an aluminum alloy.
11. A method of making a lithium battery, the method comprising
(a) coating a slurry comprising iron disulfide and a binder selected from the group consisting of polyvinylidiene fluoride homopolymers, linear tri-block copolymers cross-linked with melamine resin, ethylene-propylene-diene terpolymers, tn-block fluorinated thermoplastics, hydrogenated nitrile rubbers, fluoro-ethylene-vinyl ether copolymers, thermoplastic polyurethanes, and thermoplastic olefins onto a cathode current collector;
(b) drying the coated current collector from step (a) in a first heating zone having a temperature of 45° C. to 80° C. and subsequently in a second heating zone having a temperature of 75° C. to 130° C. to provide a cathode; and
(c) incorporating the cathode, an anode comprising lithium, and an electrolyte comprising a non-aqueous solvent and a lithium salt into a housing to form the battery.
12. The method of claim 11 , wherein the binder comprises a polyvinylidene fluoride homopolymer.
13. The method of claim 12 , wherein the polyvinylidene fluoride homopolymer comprises polyvinylidene difluoride.
14. The method of claim 11 , wherein the cathode current collector comprises aluminum or an aluminum alloy.
15. The method of claim 11 , wherein the slurry comprises a solvent including a hydrocarbon.
16. The method of claim 15 , wherein the hydrocarbon comprises a paraffinic solvent.
17. The method of claim 15 , wherein the hydrocarbon comprises an aromatic hydrocarbon.
18. A method of making a lithium battery, the method comprising:
(a) coating a slurry comprising iron disulfide, a hydrocarbon solvent, and a binder selected from the group consisting of polyvinylidene fluoride homopolymers, linear tri-block copolymers cross-linked with melamine resin, ethylene-propylene-diene terpolymers, tri-block fluorinated thermoplastics, hydrogenated nitrile rubbers, fluoro-ethylene-vinyl ether copolymers, thermoplastic polyurethanes, and thermoplastic olefins onto a cathode current collector;
(b) drying the coated current collector from step (a) to provide a cathode; and
(c) incorporating the cathode, an anode comprising lithium, and an electrolyte comprising a non-aqueous solvent and a lithium salt into a housing to form the battery.
19. The method of claim 18 , wherein the binder comprises a polyvinylidene fluoride homopolymer.
20. The method of claim 18 , wherein the cathode also comprises a current collector comprising aluminum or an aluminum alloy.
21. The method of claim 18 , wherein the hydrocarbon solvent comprises a paraffinic solvent.
22. The method of claim 18 , wherein the hydrocarbon solvent comprises an aromatic hydrocarbon.