Energy storage performance of hydrogen fuel cells operating in a marine salt spray environment using experimental evaluation

In a marine salt spray environment, sodium chloride poisoning will significantly deteriorate the performance of the hydrogen fuel cells; for example, proton exchange membrane fuel cells (PEMFCs). Currently, the degradation mechanisms of the PEMFC caused by the sodium chloride poisoning are often evaluated by the pollution of the F ions; however, the pollution of the sodium chloride in the membrane electrodes is seldomly inspected. In this avail, this work experimentally explores the influence of the sodium chloride pollution on the PEMFC performance in the marine salt spray environment by analyzing the concentration diffusion characteristics of the sodium chloride in the PEMFC membrane electrodes. Firstly, a set of experiments were carried out to determine the distribution of the sodium chloride components in the membrane electrodes, where five different salt spray environments (i.e., 100 mg/L, 200 mg/L, 300 mg/L, 400 mg/L, and 500 mg/L of the salt component, respectively) were used/employed to analyze the concentration diffusion characteristics of the sodium chloride. Then, the obtained samples were microscopically characterized and elementally analyzed by the field emission scanning electron microscopy (FESEM) and the energy spectrometry. Subsequently, a least squares-based model was proposed to predict the diffusion rate of the contaminating ions in the membrane electrodes. Lastly, the pollution of the sodium chloride was evaluated/assessed to reveal the performance degradation of the PEMFCs. The experimental results demonstrated that (1) the sodium chloride fraction existed as crystals or ions in the membrane electrodes in the marine salt spray environment; (2) the sodium chloride poisoning was founded in the proton exchange membrane in the form of sodium ions; (3) and the sodium-to-chloride ratio was proportional to the contamination time and the salt spray in the proton exchange membrane.