Alkaline battery
View Patent ↗An alkaline battery includes a cathode including lambda-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. A method of manufacturing an alkaline battery comprising:
providing a positive electrode including an active cathode material including lambda-manganese oxide; and
forming a battery including the positive electrode and a zinc electrode,
wherein the active cathode material has a specific discharge capacity to a 0.8V cutoff of greater than 300 mAh/g at a discharge rate of 20 mA/g of active cathode material.
2. A method of manufacturing an alkaline battery, the method comprising:
providing a positive electrode including an active cathode material including lambda-manganese oxide, wherein providing the electrode includes preparing lambda-manganese dioxide by a method comprising:
contacting water with a compound of the formula Li 1+x Mn 2−x O 4 , wherein x is from −0.02 to +0.02;
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 120° C. or below to obtain the lambda-manganese dioxide; and
forming a battery including the positive electrode and a zinc electrode,
wherein the active cathode material has a specific discharge capacity to a 0.8V cutoff of greater than 300 mAh/g at a discharge rate of 20 mA/g of active cathode material.
3. The method of claim 2 , wherein the compound has a B.E.T. surface area of between 1 and 10 m 2 /g.
4. The method of claim 2 , wherein the compound has a total pore volume of between 0.05 and 0.15 cubic centimeters per gram.
5. The method of claim 2 , wherein the compound of the formula Li 1+x Mn 2−x O 4 has a spinel-type crystal structure.
6. The method of claim 2 , wherein the solid is dried at a temperature of less than about 100° C.
7. The method of claim 2 , wherein the solid is dried at a temperature between 50° C. and 70° C.
8. The method of claim 2 , wherein x is from −0.005 to +0.005.
9. The method of claim 2 , wherein contacting water and the compound includes forming a slurry.
10. The method of claim 9 , wherein the slurry is maintained at a temperature below 50° C.
11. The method of claim 9 , wherein the temperature of the slurry is maintained substantially constant during the addition of acid.
12. The method of claim 2 , wherein the acid concentration is between 1 and 8 molar.
13. The method of claim 2 , wherein the acid is sulfuric acid, nitric acid, perchloric acid, hydrochloric acid, toluene sulfonic acid, or trifluoromethyl sulfonic acid.
14. The method of claim 2 , wherein the pH is 1 or less.
15. The method of claim 2 , further comprising washing the solid separated from the water and acid with water until the washings have a pH greater than 6.