A cell interaction phenomenon in a multi-cell stack under one cell suffering fuel starvation

Cell interaction is the main factor resulting in a shorter lifespan for multi-cell stacks than for a single fuel cell stack. To explain this mechanism, we propose a cell interaction phenomenon in which one cell experiences fuel starvation. A specific voltage distribution along the straight channel direction has been observed with an innovative multipoint monitoring method. This phenomenon also can be used for fuel starvation diagnosis. This study proposes an ingenious simplified two-chamber model to analyze the current and voltage redistribution mechanism under fuel starvation. The reliability of this model has been validated in this paper. The model shows that current convergence resulted by fuel starvation in one cell can lead to a concomitant local current convergence in nearby normal cells. Based on our calculation, >85% of reaction current concentrates in the anode inlet region of the fuel-starved cell, resulting in a 70% current convergence in the two adjacent normal cells. A serious corrosion of the fuel-starved cell is observed in the post-mortem study. The faulty cell presents a 5° contact angle decrease and a 28% ECSA loss. Scanning electron microscopy and Transmission electron microscopy results show that the decline of anode outlet regions' cathode catalyst layers are more serious. Some optimal strategies have been proposed to solve this problem.