“…However, as the mass transport is not the major potential loss for OER, weaker ambient mass transport does not show significant influences on the electrode performance in the EC mode. Noted that the air velocities in the surrounding environment of the oxygen electrode derived here from the quiescent case models are at the same magnitude or lower than the typical indoor air velocity in a ventilated room [43,44], which indicates that the air currents typical in indoor spaces might significantly alter the mass transport characteristics of the air-breathing RMFC. It is worthwhile to further investigate the performance of RMFC subject to the indoor air motion, which, however, is currently out of the scope of the present study.…”