Effect of Additive for Durable Anode on Reversal Potential Resulting from Fuel Starvation under Fuel Cell Operating Conditions

Abstract

A reversal potential (cell reversal) may occur under the fuel cell operating condition when there is a problem with the supply of hydrogen gas or when the electrode is locally isolated from hydrogen due to water, ice, or impurities. If fuel starvation is continuously left unattended under a current load, a reverse voltage of ~2 V or more may be observed at the anode of the fuel cell. The carbon-based catalyst support in the anode is thermodynamically very vulnerable under this condition, and corrosion occurs due to oxidation reactions. Therefore, in an application (or system) powered by fuel cells, the current load should be cut off when the fuel cell voltage reaches negative to prevent reversal potential. In spite of this system-level voltage monitoring, there will be local areas where the reverse voltage is very high locally at the electrode. Therefore, in order to prevent corrosion of the anode due to such a local abnormal voltage, it is intended to introduce a method of putting an additive in the electrode along with an active solution (voltage monitoring). This is significant in confirming the effect of electrode additives in fuel cell driving conditions, not evaluating whether only the electrode material itself is robust to high voltage using a potentiostat.