Integrated fuel cell and combustion system

1. A topping cycle fuel cell unit, the fuel cell unit comprising:

a support plate comprising an inlet region, an active region downstream of the inlet region, and a termination region downstream of the active region, the support plate having internal flow passages that extend from the inlet region through the active region and the termination region; and

a combustion region downstream of the termination region,

wherein the active region comprises:

a first electrode layer coupled with the support plate;

an electrolyte layer coupled with the first electrode layer such that the first electrode layer is between the support plate and the electrolyte layer; and

a second electrode layer coupled with the electrolyte layer such that the electrolyte layer is between the first electrode layer and the second electrode layer, wherein the second electrode layer is configured to be coupled to another support plate of another fuel cell unit,

wherein the internal flow passages are configured to receive and direct air input to the inlet region across the first electrode layer or the second electrode layer, and to receive and direct fuel input to the inlet region across the other of the first electrode layer or the second electrode layer such that the first electrode layer, the electrolyte layer, and the second electrode layer create electric current, and

wherein the internal flow passages are further configured to direct at least some of the air and at least some of the fuel from the active region through the termination region to the combustion region, where the at least some air and the at least some fuel is combusted and output via combustion outlets in the combustion region to generate propulsive force by the combustion outlets.

2. The fuel cell unit of claim 1 , wherein the first electrode layer is an anode layer and the second electrode layer is a cathode layer, and

the internal flow passages are configured to receive and direct fuel across the first electrode layer and to receive and direct air across the second electrode layer.

3. The fuel cell unit of claim 1 , wherein the first electrode layer is a cathode layer and the second electrode layer is an anode layer, and

the internal flow passages are configured to receive and direct air across the first electrode layer and to receive and direct fuel across the second electrode layer.

4. The fuel cell unit of claim 1 , wherein the support plate is a planar plate.

5. The fuel cell unit of claim 1 , wherein the support plate is a non-planar plate.

6. The fuel cell unit of claim 1 , wherein the support plate is conductive.

7. The fuel cell unit of claim 1 , wherein the support plate, the first electrode layer, the electrolyte layer, and the second electrode layer are shaped to be positioned onboard an aircraft with the support plate conductively coupled to one or more electronic loads of the aircraft such that at least some of the electric current created by the first electrode layer, the electrolyte layer, and the second electrode layer powers the one or more electronic loads, and wherein the combustion outlets are oriented on the aircraft to propel the aircraft.

8. The fuel cell unit of claim 1 , wherein the first support plate includes a structure disposed between different groups of the passages.

9. The fuel cell unit of claim 8 , wherein a first group of the passages that direct flow of the air is located on one side of the support plate and a different, second group of the passages that direct flow of the fuel is located on a side of support plate opposite the one side of the support plate.

10. The fuel cell unit of claim 1 , further comprising a porous layer disposed between the support plate and the first electrode layer.