Battery cathodes
View Patent ↗Batteries and related compositions and methods are disclosed. In some embodiments, a method of making a battery can include heating at least one cathode including a cathode material in an atmosphere including oxygen, heating the cathode in a vacuum, adding the cathode into a housing, adding a separator into the housing, and adding an anode into the housing.
1. A method of making a battery, the method comprising:
(a) heating at least one cathode comprising a current collector, a cathode active material that is reduced during operation of the battery, and a polymeric binder at a temperature of between 160° C. and 240° C. in an atmosphere in step (a) comprising oxygen at a partial pressure of from 0.1 inch Hg to 4 inches Hg to oxidize residual aromatic compounds or hydrocarbons in the cathode without substantially oxidizing the binder;
(b) after step (a), heating the at least one cathode in a vacuum to remove water from the cathode;
(c) adding the at least one cathode into a housing;
(d) adding a separator into the housing; and
(e) adding an anode comprising an anode active material that is oxidized during operation of the battery into the housing.
2. The method of claim 1 , wherein the atmosphere comprises oxygen at a partial pressure of from 0.1 inch Hg to 2 inches Hg.
3. The method of claim 1 , wherein step (b) comprises heating the at least one cathode at a temperature of at least 160° C.
4. The method of claim 1 , wherein step (b) comprises heating the at least one cathode at a temperature of from 160° C. to 240° C.
5. The method of claim 1 , wherein the cathode active material comprises iron disulfide.
6. The method of claim 1 , wherein the cathode active material comprises manganese dioxide.
7. The method of claim 1 , wherein the binder comprises a styrenic block copolymer.
8. The method of claim 7 , wherein the binder comprises styrene-ethylene/butylene-styrene.
9. The method of claim 1 , wherein step (b) comprises heating the at least one cathode in a vacuum until the cathode material includes 600 ppm of water or less.
10. The method of claim 1 , wherein step (b) comprises heating the at least one cathode in a vacuum until the cathode material includes from 400 ppm to 600 ppm of water.
11. The method of claim 1 , wherein step (b) comprises heating the at least one cathode in a vacuum for at least four hours.
12. The method of claim 1 , wherein step (a) comprises heating the at least one cathode until the cathode material has a differential scanning calorimetry peak at from 290° C. to 300° C. with a height of 30 Joules/gram or less.
13. The method of claim 12 , wherein after step (b), the cathode material comprises less than 0.1 percent by weight Mn 3 O 4 .
14. The method of claim 13 , wherein the peak has a height of from 5 Joules/gram to 30 Joules/gram.
15. The method of claim 1 , wherein the battery is a primary battery.
16. The method of claim 1 , wherein the anode active material comprises lithium.
17. The method of claim 1 , wherein in step (a) the atmosphere further comprises an inert gas in a mixture with the oxygen.
18. The method of claim 1 , wherein in step (a) the atmosphere further comprises nitrogen in a mixture with the oxygen.