Voltage behavior improvement for proton exchange membrane fuel cell stack suffering fuel starvation

Fuel starvation severely affects the performance and durability of proton exchange membrane fuel cell stack. In this paper, the individual voltage characteristics of a 40-cell proton exchange membrane fuel cell stack under different load currents were studied in detail. The cell voltage oscillation, plunge and polarity reversal were observed. To alleviate the hydrogen concentration loss, an effective and simple hydrogen supply method, dual-path hydrogen provision (DHP), was proposed. In the proposed method, high-pressure hydrogen could be fed to the stack from the anode outlet in addition to the anode inlet. An experiment with identical conditions was carried out. It was found that the proposed mitigation measure could significantly alleviate voltage degradation and delay the polarity reversal. The overall output performance of the PEMFC stack was improved by 13.7%, and the maximum improvement of the individual cell was 664%. This paper contributes to a better understanding of the voltage behavior of fuel cells under fuel starvation and provides an effective, practical and low-cost migration measure for most of the commercial PEMFC stack.