Cathode for air assisted battery
View Patent ↗A cathode for an air recovery alkaline battery is disclosed. The cathode contains at least about 60% by weight MnO 2 and at least about 2% by weight of a hydrophobic polymer; the MnO 2 consists essentially of electrochemically synthesized MnO 2 .
1. A method of making a cathode for a rechargeable air assisted battery, the cathode comprising (1) a catalyst comprising manganese dioxide, (2) carbon particles, and (3) a hydrophobic polymer,
the method comprising
(a) combining the catalyst comprising manganese dioxide, the carbon particles, and a solvent to form a mixture that does not include the hydrophobic polymer;
(b) combining the mixture with the hydrophobic polymer and stirring the combination at a temperature below about 10°C. to provide a slurry without fibrillation of the hydrophobic polymer;
(c) warming the slurry to at least about 20°C. and mixing the slurry at this temperature to fibrillate the hydrophobic polymer;
(d) loading the slurry onto a cathode current collector; and
(e) drying the slurry by removing the solvent to provide the cathode, wherein the cathode comprises at least 70% of manganese dioxide by weight.
2. The method of claim 1 , wherein step (b) comprises stirring the slurry under vacuum.
3. The method of claim 1 , wherein step (b) comprises stirring the slurry at a speed of about 15 rpm.
4. The method of claim 1 , wherein step (c) comprises stirring the slurry at a speed of about 15 rpm.
5. The method of claim 1 , wherein the hydrophobic polymer is polytetrafluoroethylene.
6. The method of claim 1 , wherein the cathode current collector comprises nickel.
7. The method of claim 1 , wherein the cathode current collector comprises a nickel foam.
8. The method of claim 1 , wherein the cathode comprises at least 85% by weight of manganese dioxide.
9. The method of claim 1 , wherein step (b) comprises stirring the slurry at a temperature of about 0°C.
10. The method of claim 1 , wherein the solvent is water.
11. The method of claim 1 , wherein step (a) further comprises stirring the mixture at a speed of about 65 rpm.