Solid oxide fuel cell

A solid oxide fuel cell (or SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel. Fuel cells are characterized by their electrolyte material; the SOFC has a solid oxide or ceramic electrolyte.

Advantages of this class of fuel cells include high combined heat and power efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. The largest disadvantage is the high operating temperature, which results in longer start-up times and mechanical and chemical compatibility issues.

Introduction

Solid oxide fuel cells are a class of fuel cells characterized by using a solid oxide material as the electrolyte. SOFCs use a solid oxide electrolyte to conduct negative oxygen ions from the cathode to the anode. The electrochemical oxidation of the hydrogen, carbon monoxide or other organic intermediates by oxygen ions thus occurs on the anode side. More recently, proton-conducting SOFCs (PC-SOFC) have been developed to transport protons instead of oxygen ions through the electrolyte with the advantage of running at lower temperatures than traditional SOFCs.

They operate at very high temperatures, typically between 600 and 1,000 °C. At these temperatures, SOFCs do not require expensive platinum group metals catalysts, as is currently necessary for lower temperature fuel cells such as PEMFCs, and are not vulnerable to carbon monoxide catalyst poisoning. However, vulnerability to sulfur poisoning has been widely observed, and the sulfur must be removed before entering the cell.