Solid oxide cells with porous layers, and methods for fabrication thereof

A solid oxide cell comprising:

• a nonporous oxide layer constructed to conduct oxygen ions and to operate as a solid electrolyte;
• a porous functional layer disposed over a first side of the nonporous oxide layer;
• one or more first porous layers disposed over a side of the porous functional layer opposite the nonporous oxide layer;
• and
• one or more second porous layers disposed over a second side of the nonporous oxide layer the opposite the first side,
• wherein the nonporous oxide layer has a density greater than that of the porous functional layer,
• an electronic conductivity of the nonporous oxide layer is less than 25% of an ionic conductivity of the nonporous oxide layer,
• the porous functional layer is effective to increase an ionic transference number of the nonporous oxide layer and the porous functional layer to at least 0.9 at a temperature less than or equal to 550° C.,
• at least one of the one or more first porous layers is constructed to operate as a first electrode, and
• at least one of the one or more second porous layers is constructed to operate as a second electrode.

A method of fabricating a solid oxide cell, the method comprising:

• (a) providing one or more first precursors for forming one or more second porous layers;
• (b) providing one or more second precursors for forming a nonporous oxide layer on the one or more first precursors;
• (c) sintering the first and second precursors at a temperature greater than or equal to a first threshold, so as to form the one or more second porous layers over a second side of the nonporous oxide layer;
• (d) providing one or more third precursors for forming one or more first porous layers over a first side of the nonporous oxide layer opposite the second side;
• and
• (e) sintering the one or more third precursors at a temperature less than the first threshold, so as to form the one or more first porous layers over the first side of the nonporous oxide layer,
• wherein the nonporous oxide layer has a density greater than that of the first and second porous layers,
• for each of the first and second porous layers, an electronic conductivity of the respective porous layer is greater than 25% of an ionic conductivity of the respective porous layer,
• at least one of the one or more first porous layers is constructed to operate as a first electrode, and
• at least one of the one or more second porous layers is constructed to operate as a second electrode.