A new insight into the in-plane heterogeneity of commercial-sized fuel cells via a novel probability distribution-based method

The equipotential assumption in fuel cells is extensively utilized to investigate in-plane heterogeneity, serving both numerical modeling and the deployment of cell voltage monitors (CVMs). Nonetheless, the evaluation of cell state is notably affected by the placement of CVM systems, as the presence of in-plane heterogeneity in fuel cells can introduce significant variations. Currently, there is a lack of established criteria for identifying the optimal deployment strategy for CVM systems, which poses potential risks to the precise assessment of the cell’s state. Consequently, an innovative approach employing probability statistics, termed voltage fluctuation analysis method, is introduced to ascertain the optimal configuration of the CVM system for fuel cells and reveal the distribution characteristics of fuel cell in-plane heterogeneity. This novel technique is applied to a specially designed 5-cell stack comprising graphite bipolar plates equipped with multiple voltage-measuring tap points. The results indicate that voltage losses in the bipolar plates, attributed to fluctuations in in-plane currents, are pervasive under various operational conditions. The anode outlet region exhibits the most significant voltage fluctuations, with levels approximately 51.3% higher compared to other regions. Conversely, the central region of the bipolar plate displays unusual voltage stability. A multi-point impedance technique is utilized to elucidate the underlying mechanisms of current and voltage redistribution. The effectiveness of the voltage fluctuation analysis method in determining the optimal configuration of the CVM system is substantiated through extensive experimental investigation. Finally, the potential application of this technique in various settings is explored.