Single chamber fuel electrolyte materials

In conventional fuel cell designs, the electrolyte not only mediates the electrochemical reactions taking place at the anode and cathode, but also separates the fuel from the oxidant to prevent direct combustion. It was already recognized by Gool [235] that (i) many fuels do not directly react with oxygen at typical fuel cell temperatures and (ii) the catalytic activity of anode and cathode materials are quite selective to certain type of reactions. This renders possible single chamber fuel cells, that is, fuel cells without separation of anode and cathode compartment (sometimes called mixed gas fuel cells). Anode and cathode may then be placed either on the two sides of the electrolyte like in... 

Interestingly, research has started on single chamber SOFC (SC-SOFC) concepts. However, the SC-SOFC exhibits inherently low power density and is therefore primarily of academic interest. It has the potential to relax cell component requirements and probably to ease manufacture. The principle of SC-SOFC is that it is fed by an air fuel mixture which flows onto the PEN contained in a single compartment, avoiding the use of gas separator plates and high temperature sealants. The fluid may flow simultaneously or sequentially along the electrodes. Both electrodes are either built onto the same side of the electrolyte some distance apart or on opposite sides. Low temperature operation would apparently suppress direct combustion of the air fuel mixture provided the electrode materials chosen are highly selective towards their respective catalytic reactions. SC-SOFC stacks may hold prospects in specific applications where the reaction products are the prime focus. 

The electrode and electrolyte materials used in SC-SOFCs are similar to the ones being used in conventional SOFCs operated with separate fuel and air compartments. However, selectivity and catalytic activity requirements and overheating impose different constraints on the cell component materials under single-chamber operating conditions. 

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