Solid oxide fuel cell with transitioned cross-section for improved anode gas management at the open end

1. A hybrid solid oxide fuel cell having a tubular, elongated, hollow, triangular active cross-section comprising an interconnection, air electrode, fuel electrode, and solid oxide electrolyte between the electrodes, which active triangular cross-section integrally transitions into at least one inactive flat cross-section with flattened parallel sides; each cross-section having channels therein which morph into and communicate with each other, for gas guidance within the same channel, at an interface section, without separate pieces, each communicating channel containing at least one open end, wherein, within the fuel cell, air feed tubes can pass from within the inactive cross-section to the active cross-section, wherein the active interior and exterior cross-section and channels are triangular and the inactive flat cross-section channels are selected from the group consisting of circular, triangular or oblong, and wherein the exterior cross sections also morph into each other.

2. The hybrid solid oxide fuel cell of claim 1 , having one open inactive and one closed active end, where at the interface section there is a continuous shape transition.

3. The hybrid solid oxide fuel cell of claim 1 , having two open fuel cell ends.

4. The hybrid solid oxide fuel cell of claim 1 , wherein the active cross-section at the interface section, integrally forms, merges and morphs into the inactive cross-section, without separate pieces, forming a structurally strong total fuel cell body.

5. The hybrid solid oxide fuel cell of claim 1 , wherein the active cross-section of the interface section is not a separate section physically attached, as by sintering, to the inactive cross-section.

6. The hybrid solid oxide fuel cell of claim 1 , having an open face at an inactive end providing a large surface area for a face seal.

7. The hybrid solid oxide fuel cell of claim 1 , wherein the inactive cross-section has a flattened cross-section at the inactive section top and bottom providing a large surface area for separating other adjacent cells at the inactive end through a gasket.

8. A solid oxide fuel cell stack comprising at least two parallel, adjacent, electrically interconnected, hybrid solid oxide fuel cells having a porous, ceramic non-electrically conducting, compliant gasket strip at any open fuel cell end, providing a separation between the parallel adjacent, fuel cells, each fuel cell containing:

(1) an active cross-section of an interconnection, interior air electrode, and exterior fuel electrode with solid oxide electrolyte between the electrodes, the active cross-section having a tubular, elongated, hollow sided cross-section selected from the group consisting of triangular, corrugated, and stepped triangle; and

(2) at least one inactive flat cross-section with a flattened parallel sides; each cross-section being integral and having interior channels therein which morph into and communicate with each other without separate pieces, for gas guidance within the same channel, at a cross-section interface, each communicating channel containing at least one open end; where air can be fed into the open end, while contacting an air electrode material on the inside of the active part of the channel, and a fuel can pass through integral fuel channels adjacent to the fuel electrode, to the gasket strip at an open cell end, which gasket strip at an open end will allow a predetermined amount of spent fuel to pass through it, and a predetermined amount of spent fuel to pass out of the stack transverse to the gasket, said fuel contacting a fuel electrode on the outside of the active cross-section;

wherein the fuel cell stack has one open fuel cell end and one closed fuel cell end and at least one air/oxidant feed tube, where air/oxidant can be fed into the feed tube at the open end, pass to the closed end and reverse flow at the closed end and redirected to the open end while contacting air electrode material, wherein the inactive flat cross-section channels are selected from the group consisting of circular, triangular or oblong, and wherein the exterior cross sections also morph into each other.

9. The solid oxide fuel cell stack of claim 8 , wherein the active tubular, elongated hollow side portion is a triangular side portion and the gasket strip is about 20 vol. % to 85 vol. % porous.

10. The solid oxide fuel cell stack of claim 8 , having two open fuel cell ends.

11. The solid oxide fuel cell stack of claim 8 , each fuel cell having two open fuel cell ends, where the compliant gasket strip is at least 98% theoretical density, providing flow impedance and the fuel cell is a once through design, where at the interface section there is a continuous shape transition.

12. The solid oxide fuel cell stack of claim 8 , each fuel cell having one open end and one closed end, where the fuel cell stack is a seamless design, and wherein the active cross-section at the interface section, integrally forms, merges and morphs into the inactive cross-section, without separate pieces, forming a structurally strong total fuel cell body.