Gradient porous electrode architectures for rechargeable metal-air batteries
A cathode for a metal air battery includes a cathode structure having pores. The cathode structure has a metal side and an air side. The porosity decreases from the air side to the metal side. A metal air battery and a method of making a cathode for a metal air battery are also disclosed.
1. A cathode for a metal air battery, comprising a cathode structure comprising pores, the cathode structure having a metal side and an air side, with the porosity decreasing as a continuous gradient from the air side to the metal side.
2. The cathode of claim 1 , wherein the porosity of the metal side is from 45% to 65%.
3. The cathode of claim 1 , wherein the porosity of the metal side is from 50% to 60%.
4. The cathode of claim 1 , wherein the porosity of the air side is from 75% to 90%.
5. The cathode of claim 1 , wherein the porosity of the air side is from 80% to 85%.
6. The cathode of claim 1 , wherein the average pore size is from 50 nm to 1000 nm.
7. The cathode of claim 1 , wherein the average pore size is from 100 nm to 500 nm.
8. The cathode of claim 1 , wherein the average pore size is from 100 to 200 nm.
9. The cathode of claim 1 , wherein the cathode comprises carbon foam.
10. The cathode of claim 1 , wherein the cathode comprises a ceramic.
11. The cathode of claim 1 , wherein the cathode is derived from mesoporous silica structures.
12. The cathode of claim 1 , further comprising a catalyst.
13. The cathode of claim 12 , wherein the catalyst is at least one selected from the group consisting of precious metals, metal oxides and metal-porphyrins.
14. The cathode of claim 12 , wherein the catalyst is a bimetallic catalyst.
15. The cathode of claim 14 , wherein the bimetallic catalyst comprises at least one d8 catalyst species selected from the group consisting of Fe, Co, Ni, and Pt and at least one d10 catalyst species selected from the group consisting of Cu, Ag, and Au.
16. The cathode of claim 1 , further comprising an anode, the anode comprising at least one selected from the group consisting of Li, Na, Mg, and Zn.
17. A metal air battery, comprising:
an anode;
a cathode material comprising pores, the cathode material having a metal side and an air inlet side, the porosity decreasing as a continuous gradient from the air side to the metal side; and,
an electrolyte between the anode and the cathode.
18. The metal air battery of claim 17 , wherein the porosity of the metal side is from 45% to 65%.
19. The metal air battery of claim 17 , wherein the porosity of the metal side is from 50% to 60%.
20. The metal air battery of claim 17 , wherein the porosity of the air side is from 75% to 90%.
21. The metal air battery of claim 17 , wherein the porosity of the air side is from 80% to 85%.
22. The metal air battery of claim 17 , wherein the average pore size is from 50 nm to 1000 nm.
23. The metal air battery of claim 17 , wherein the average pore size is from 100 nm to 500 nm.
24. The metal air battery of claim 17 , wherein the average pore size is from 100 to 200 nm.
25. The metal air battery of claim 17 , wherein the cathode material comprises carbon foam.
26. The metal air battery of claim 17 , wherein the cathode material comprises a ceramic.
27. The metal air battery of claim 17 , wherein the cathode material is derived from mesoporous silica structures.
28. The metal air battery of claim 1 , further comprising a catalyst.
29. The metal air battery of claim 28 , wherein the catalyst is at least one selected from the group consisting of precious metals, metal oxides and metal-porphyrins.
30. The metal air battery of claim 28 , wherein the catalyst is a bimetallic catalyst.
31. The metal air battery of claim 30 , wherein the bimetallic catalyst comprises at least one d8 catalyst species selected from the group consisting of Fe, Co, Ni, and Pt and at least one d10 catalyst species selected from the group consisting of Cu, Ag, and Au.
32. The metal air battery of claim 17 , wherein the anode comprises at least one metal selected from the group consisting of Li, Na, Mg, and Zn.
33. A method of making a cathode for a metal air battery, comprising the step of forming a cathode support from a cathode material comprising pores, the cathode support having a metal side and an air side, such that the porosity continuously decreases from the air side to the metal side.