Cathodes for lithium-air battery cells with acid electrolytes

1. A layered metal-air cathode for a metal-air battery, said cathode comprising three layers laminated together, the three layers comprising:

an active catalyst layer;

a transition layer laminated to the active catalyst layer, the transition layer comprises carbon nanofibers; and

a backing layer laminated to the transition layer such that the transition layer is disposed between the active catalyst layer and the backing layer.

2. The metal-air cathode of claim 1 , wherein the layered metal-air cathode is structured to have a total thickness of between 4-400 μm.

3. The metal-air cathode of claim 1 , wherein the active catalyst layer comprises electrocatalyst particles loaded onto one of nanosize carbon materials and metal oxide materials.

4. The metal-air cathode of claim 3 , wherein the electrocatalyst comprises one of a single electrocatalyst and a bifunctional electrocatalyst.

5. The metal-air cathode of claim 1 , wherein the active catalyst layer is fabricated to have a thickness of between 1-100 μm.

6. The metal-air cathode of claim 1 , wherein the transition layer is fabricated to have a thickness of between 5-100 μm.

7. The metal-air cathode of claim 1 , wherein the transition layer comprises a hydrophobic polymer.

8. The metal-air cathode of claim 1 , wherein the backing layer comprises one of a carbon fiber and a metal mesh having a plurality of open channels of a variety of sizes structured and operable facilitate air diffusion into the layered metal-air cathode.

9. The metal-air cathode of claim 1 , wherein the backing layer is fabricated to have a thickness of between 10-300 μm.