A New Strategy for Improving Durability of Electrodes in Cell Reversal during Fuel Starvation Cycles of PEMFC with Reversal Tolerant Anode

Due to the strengthening of environmental regulations of international societies, the introduction of eco-friendly technologies is being rapidly carried out in the marine and shipping sectors. Among them, fuel cells (especially PEMFC) are in the limelight as a propulsion system for small and medium-sized coastal ships due to fast starting characteristics and low operating temperature. However, ships require higher output than passenger cars, which require an FC capacity of about 100 kW. In the case of such a large-capacity FC, hydrogen may not be evenly diffused to the electrode when starting or when an electric load rapidly increases due to stoichiometry control. In some parts (or all) of the electrode where hydrogen supply is insufficient, fuel starvation will proceed, and cell reversal may occur. This cell reversal phenomenon causes severe degradation of the anode.<br/>Degradation by cell reversal can be mitigated by adding a material with OER activity such as iridium oxide to the anode. This anode is called a reversal tolerant anode (RTA). In addition, several studies have been conducted on RTA under various conditions. However, we observed that when RTA was added in fuel starvation cycles, the anode was well protected but the cathode rather degraded. Therefore, in this study, we sought the cause of cathode degradation during fuel starvation cycles and conducted experiments to prevent it.