Electrochemical cells
View Patent ↗Electrochemical cells and methods of making cells are disclosed. In some embodiments, an electrochemical cell includes a housing, a negative electrode in the housing, a positive electrode in the housing, the positive electrode including a wax, and a separator between the negative and positive electrodes.
1. An electrochemical cell, comprising:
a housing;
a negative electrode in the housing;
a positive electrode in the housing; and
a separator between the negative and positive electrodes,
wherein the positive electrode has a first portion comprising a catalyst and a first concentration of wax, and a second portion comprising a catalyst and a second concentration of wax, the second concentration being different than the first concentration.
2. The cell of claim 1 , wherein second concentration is less than the first concentration.
3. The cell of claim 2 , wherein the second portion is between the first portion and the negative electrode.
4. The cell of claim 1 , wherein the second portion is substantially free of the wax.
5. The cell of claim 4 , wherein the second portion is between the first portion and the negative electrode.
6. The cell of claim 1 , wherein the first portion is less than about 0.1 mm thick.
7. The cell of claim 1 , wherein the first portion has a thickness less than about 20% of the thickness of the positive electrode.
8. The cell of claim 1 , wherein second portion is outwardly disposed relative to the first portion, the first portion having a lower concentration of wax than the second portion.
9. The cell of claim 1 , wherein the positive electrode has an interior surface substantially free of the wax.
10. The cell of claim 1 , wherein the positive electrode has a first layer comprising the wax and a second layer substantially free of the wax, the second layer being between the first layer and the negative electrode.
11. The cell of claim 1 , wherein the positive electrode includes a first layer having a first concentration of the wax, and a second layer having a second concentration less than the first concentration of the wax, the second layer being between the first layer and the negative electrode.
12. The cell of claim 1 , wherein the wax is distributed substantially throughout the positive electrode.
13. The cell of claim 1 , wherein the positive electrode comprises less than about 20% of the wax by weight.
14. The cell of claim 1 , wherein the positive electrode comprises less than about 10% of the wax by weight.
15. The cell of claim 1 , wherein the positive electrode comprises less than about 5% of the wax by weight.
16. The cell of claim 1 , wherein the wax comprises a material selected from the group consisting of hexatriacontane, octacosane, carnauba wax, beeswax, China wax, and montan wax.
17. The cell of claim 1 , wherein the positive electrode further comprises a binder.
18. The cell of claim 17 , wherein the catalyst comprises manganese oxide, and the binder comprises polytetrafluoroethylene.
19. The cell of claim 17 , wherein the binder is selected from the group consisting of polyethyelene, polyacrylamide, fluorocarbons, and mixtures thereof.
20. The cell of claim 1 , wherein the cell is a metal-air cell.
21. The cell of claim 1 , wherein the cell is an air-assist cell.
22. The cell of claim 1 , wherein the cell is an alkaline cell.
23. The cell of claim 1 , wherein the catalyst comprises manganese oxide.
24. The cell of claim 1 , wherein the second concentration of wax is 0% wax by weight.
25. A method of making an electrochemical cell, comprising:
incorporating a wax into a positive electrode such that the positive electrode has a first portion comprising a catalyst and a first concentration of wax, and a second portion comprising a catalyst and a second concentration of wax, the second concentration being different from the first concentration; and
incorporating the positive electrode into the cell.
26. The method of claim 25 , further comprising melting the wax.
27. The method of claim 25 , further comprising applying solid wax on a surface of the positive electrode.
28. The method of claim 25 , further comprising contacting a substrate comprising the wax with the positive electrode.
29. The method of claim 25 , further comprising laminating the wax to the positive electrode.