Alkaline battery including lambda-manganese dioxide
View Patent ↗An alkaline battery includes a cathode including lambda-manganese dioxide and gamma-manganese dioxide, an anode including zinc, a separator between the cathode and the anode, and an alkaline electrolyte contacting the anode and the cathode.
1. An alkaline battery comprising:
a cathode comprising a binder, carbon particles that are different from the binder, and an active cathode material including a lambda-manganese dioxide and a gamma-manganese dioxide;
an anode comprising zinc;
a separator between the anode and the cathode; and
an alkaline electrolyte contacting the anode and the cathode,
wherein the weight ratio of lambda-manganese dioxide to gamma-manganese dioxide ranges from 1:19 to 3:1.
2. The battery of claim 1 , wherein the fraction of lambda-manganese dioxide is substantially less than the fraction of gamma-manganese dioxide.
3. The battery of claim 1 , wherein the weight ratio of lambda-manganese dioxide to gamma-manganese dioxide ranges from 1:9 to 1:1.
4. The battery of claim 1 , wherein the weight ratio of lambda-manganese dioxide to gamma-manganese dioxide ranges from 1:3 to 1:1.
5. The battery of claim 1 , wherein the cathode includes between 2 wt % and 10 wt % of carbon particles.
6. The battery of claim 1 , wherein the carbon particles include expanded graphite, natural graphite, or a blend thereof.
7. The battery of claim 1 , wherein the carbon particles include from 10 to 90% by weight natural graphite.
8. The battery of claim 1 , wherein the gamma-manganese dioxide is an electrochemically-produced manganese dioxide.
9. The battery of claim 1 , wherein the binder comprises a polymer selected from the group consisting of polyethylene, polyacrylamide, polyvinylidenefluoride, and polytetrafluoroethylene.
10. The battery of claim 1 , wherein the binder comprises polyethylene.
11. The battery of claim 1 , wherein the cathode includes between 0.05 wt % and 5 wt % of the binder.
12. An alkaline battery comprising:
a cathode comprising a binder, carbon particles that are different from the binder, and an active cathode material including a lambda-manganese dioxide and a gamma-manganese dioxide in a weight ratio of at least 1:9, a natural graphite and an expanded graphite;
an anode including zinc;
a separator between the anode and the cathode; and
an electrolyte contacting the cathode, the anode and the separator.
13. The battery of claim 12 , wherein the weight ratio of lambda-manganese dioxide to gamma-manganese dioxide ranges from 1:3 to 1:1.
14. The battery of claim 12 , wherein the cathode includes between 2 wt % and 10 wt % of carbon particles.
15. The battery of claim 12 , wherein the carbon particles include from 10 to 90% by weight natural graphite.
16. The battery of claim 12 , wherein the binder comprises a polymer selected from the group consisting of polyethylene, polyacrylamide, polyvinylidenefluoride, and polytetrafluoroethylene.
17. The battery of claim 12 , wherein the binder comprises polyethylene.
18. The battery of claim 12 , wherein the cathode includes between 0.05 wt % and 5 wt % of the binder.
19. A method of manufacturing an alkaline battery, the method comprising:
providing a positive electrode including a binder, carbon particles that are different from the binder, and an active cathode material including a lambda-manganese dioxide and a gamma-manganese dioxide; and
forming a battery including the positive electrode and a zinc electrode,
wherein the weight ratio of lambda-manganese dioxide to gamma-manganese dioxide ranges from 1:19 to 3:1.
20. The method of claim 19 , wherein providing the electrode includes preparing lambda-manganese dioxide by a method comprising:
contacting water with a lithium manganese oxide;
adding an acid to the water and compound until the water has a pH of 1 or less;
separating a solid from the water and acid; and
drying the solid at a temperature of 150° C. or below to obtain the lambda-manganese dioxide.
21. The method of claim 20 , wherein the lithium manganese oxide is a compound of the formula Li 1+x Mn 2−x O 4 , wherein x is from −0.02 to +0.02 and the compound has a B.E.T. specific surface area of between 1 and 10 m 2 /g.
22. The method of claim 20 , wherein the solid is dried at a temperature of less than about 120° C.
23. The method of claim 19 , wherein providing a positive electrode includes combining between 2 wt % and 10 wt % carbon particles with the active cathode material.
24. The method of claim 23 , wherein the carbon particles include expanded graphite, natural graphite, or a blend thereof.
25. The method of claim 19 , wherein the gamma-manganese dioxide is an electrochemically-produced manganese dioxide.
26. The method of claim 19 , wherein the binder comprises a polymer selected from the group consisting of polyethylene, polyacrylamide, polyvinylidenefluoride, and polytetrafluoroethylene.
27. The method of claim 19 , wherein the binder comprises polyethylene.
28. The method of claim 19 , wherein the positive electrode includes between 0.05 wt % and 5 wt % of the binder.
29. A method of manufacturing an alkaline battery, the method comprising:
providing a positive electrode including a binder, carbon particles that are different from the binder, and an active cathode material including a lambda-manganese dioxide and a gamma-manganese dioxide in a weight ratio of at least 1:9, a natural graphite and an expanded graphite; and
forming a battery including the positive electrode and a zinc electrode.
30. The method of claim 29 , wherein the binder comprises a polymer selected from the group consisting of polyethylene, polyacrylamide, polyvinylidenefluoride, and polytetrafluoroethylene.
31. The method of claim 29 , wherein the binder comprises polyethylene.
32. The method of claim 29 , wherein the positive electrode includes between 0.05 wt % and 5 wt % of the binder.