Robust Operation of Fuel Cell Systems in Subfreezing Conditions: A Material-Based Solution to Achieve Better Anode Durability

Automotive fuel cells can suffer from cell voltage reversals because of hydrogen fuel starvation at the anode, which can be exacerbated by subfreezing temperatures because of extensive ice formation and its blockage of the hydrogen supply channels. Here we report on low-temperature (−15 to 45 °C) reversal degradation due to hydrogen starvation and evaluate the use of a reversal-tolerant anode (RTA) with an oxygen evolution reaction (OER) catalyst (e.g., iridium oxide). During subfreezing cell reversal, we observed a water electrolysis cell voltage plateau, but the typically subsequent voltage plateau for carbon corrosion usually seen at high temperatures was not found. Repeated cell-reversal tests at subfreezing temperature shows a much slower degradation rate compared with that of high-temperature reversals. A series of isothermal reversal tests at different temperatures indicate that the degradation rate related with carbon corrosion is temperature dependent. As for the effect of RTA on the cell-reversa...