Solid oxide fuel cell system

A fuel cell system comprising:

• (a) a fuel cell stack comprising a plurality of tubular solid oxide fuel cells and a stack support structure attached to each of the fuel cells, the fuel cells each comprising an anode, a cathode, and an electrolyte sandwiched between the anode and cathode;
• (b) a fuel reformer thermally coupled to the stack, and including a reformer chamber having a reformer fuel inlet capable of fluidly coupling to a fuel source and a reformer fuel outlet fluidly coupled to the anode of at least one fuel cell;
• (c) external circuit electrical leads capable of electrically coupling to the anode and cathode of at least one fuel cell and capable of electrically coupling to an external electrical circuit;
• and
• (d) a thermal enclosure assembly enclosing the stack and reformer and including a fuel inlet fluidly coupled to the reformer fuel inlet, a fuel outlet fluidly coupled to the anode of at least one fuel cell, and an oxidant inlet and an oxidant outlet fluidly coupled to the cathode of at least one fuel cell.

A fuel cell stack comprising:

• at least one tubular solid oxide fuel cell, the fuel cell comprising an inner electrode layer, an outer electrode layer, an electrolyte layer sandwiched between the electrode layers, and a tab opening in the surface of the electrode outer layer and through the underlying electrolyte layer;
• an electrically conductive tab for electrically coupling to an external circuit, the tab comprising an electrically conductive material coating the portion of the inner layer in the tab opening;
• and
• a stack support structure attached to each of the fuel cells, wherein the stack support structure is a porous support matrix embedding the fuel cells therein, the porous matrix being made of an electronic or mixed (electronic and ionic) conductive, porous solid state material and being electrically coupled to the cathode of at least some of the fuel cells and being electrically coupled to the electrical leads.

A fuel cell stack comprising:

• at least one tubular solid oxide fuel cell, the fuel cell comprising an inner electrode layer, an outer electrode layer, an electrolyte layer sandwiched between the electrode layers, and a tab opening in the surface of the electrode outer layer and through the underlying electrolyte layer;
• an electrically conductive tab for electrically coupling to an external circuit, the tab comprising an electrically conductive material coating the portion of the inner layer in the tab opening;
• and
• a stack support structure attached to each of the fuel cells, wherein the stack support structure includes at least one anode current collector plate having openings for receiving the at least one fuel cell, and being electrically coupled to at least some of the anodes of the fuel cells and being electrically coupled to the electrical leads.

A fuel cell stack comprising:

• at least one tubular solid oxide fuel cell, the fuel cell comprising an inner electrode layer, an outer electrode layer, an electrolyte layer sandwiched between the electrode layers, and a tab opening in the surface of the electrode outer layer and through the underlying electrolyte layer;
• an electrically conductive tab for electrically coupling to an external circuit, the tab comprising an electrically conductive material coating the portion of the inner layer in the tab opening;
• and
• a stack support structure attached to each of the fuel cells, wherein the stack support structure includes at least one cathode current collector plate having openings for receiving the at least one fuel cell, and being electrically coupled to at least some of the cathodes of the fuel cells and electrically couplable to the external circuit.

A fuel cell stack comprising:

• at least one tubular solid oxide fuel cell, the fuel cell comprising an inner electrode layer, an outer electrode layer, an electrolyte layer sandwiched between the electrode layers, and a tab opening in the surface of the electrode outer layer and through the underlying electrolyte layer;
• an electrically conductive tab for electrically coupling to an external circuit, the tab comprising an electrically conductive material coating the portion of the inner layer in the tab opening;
• and
• a stack support structure attached to each of the fuel cells, wherein the stack support structure is a metal mesh wrapped around each of the fuel cells, the mesh having a porosity sufficient to allow the flow through of reactant to the outer electrode layer of at least one of the fuel cells.

A fuel cell stack comprising:

• at least one tubular solid oxide fuel cell, the fuel cell comprising an inner electrode layer, an outer electrode layer, an electrolyte layer sandwiched between the electrode layers, and a tab opening in the surface of the electrode outer layer and through the underlying electrolyte layer;
• an electrically conductive tab for electrically coupling to an external circuit, the tab comprising an electrically conductive material coating the portion of the inner layer in the tab opening;
• and
• a stack support structure attached to each of the fuel cells, wherein the support structure is a metal wire wrapped around each of the fuel cells, the wire being wrapped such that space is provided for reactant to flow past the wire to the outer electrode layer of at least one of the fuel cells.

A fuel cell stack comprising:

• (a) at least one tubular solid oxide fuel cell, the fuel cell comprising:
• an inner electrode layer;
• an outer electrode layer;
• an electrolyte layer sandwiched between the electrode layers;
• and a porous, electrically conductive inner core having a porosity sufficient to allow the flow through of reactant to the inner electrode layer, the inner core being inside the fuel cell and electrically coupled to the inner electrode layer;
• and
• (b) a stack support structure attached to the at least one fuel cell.

A fuel cell system comprising:

• (a) a fuel cell stack comprising a plurality of tubular solid oxide fuel cells and a stack support structure attached to each of the fuel cells, the fuel cells each comprising an anode, a cathode, and an electrolyte sandwiched between the anode and cathode;
• (b) a fuel reformer thermally coupled to the stack, and including a reformer tube coiled around the stack, the reformer tube having a reformer fuel inlet fluidly couplable to a fuel source and a reformer fuel outlet fluidly coupled to the anode of at least one of the fuel cells;
• (c) external circuit electrical leads electrically coupled to the anode and cathode of at least one of the fuel cells and capable of electrically coupling to an external electrical circuit;
• and
• (d) a thermal enclosure assembly enclosing the stack and reformer and include a fuel inlet fluidly coupled to the reformer fuel inlet, a fuel outlet fluidly coupled to the anode of at least one fuel cell, and an oxidant inlet and an oxidant outlet fluidly coupled to the cathode of at least one of the fuel cells.