Reversible Solid Oxide Cell

A reversible solid oxide cell, or rSOC, is a solid state electrochemical device that can be operated alternately as a solid oxide fuel cell and as a solid oxide electrolysis cell. It consists of a dense electrolyte, commonly yttria stabilized zirconia, sandwiched between a nickel and zirconia fuel electrode and an oxygen electrode such as lanthanum strontium cobalt ferrite, and it operates at temperatures between roughly 600 and 900 degrees Celsius. Run as a fuel cell it oxidizes a gaseous fuel to generate electricity and heat; run in reverse as an electrolysis cell it consumes electricity and heat to convert oxidation products back into fuel, which can be pressurized and stored, making the device attractive for seasonal energy storage. Roundtrip efficiency is estimated near 60 percent for hydrogen and steam systems and can exceed 70 percent for systems that exploit methane formation.