Impact of NaCl Spray on the Durability of PEMFC Single Cells and Stacks in Marine Environment

Abstract

The present work investigates the effects of a salt spray injected into the airflow of proton exchange membrane fuel cells (PEMFCs) at various time scales and contamination levels, with the long-term objective of identifying the appropriate protection of fuel cells for maritime applications. A dedicated experimental setup generates a sodium chloride (NaCl) mist in the cathode airflow to contaminate single cells and stacks. Constant current density tests led to lifetime shortening with partial recovery after cathode rinsing. Then, membrane electrode assemblies (MEAs) post-mortem characterizations revealed that NaCl was present in the cathode gas diffusion layer, and chlorine reached the catalyst layer for high concentrations. Furthermore, chlorides enhanced current collectors and bipolar plates (BPs) degradation, as corrosion products were identified in MEAs and stack effluents. Meanwhile, a sailboat propulsion stack operated 50 hours at sea was analyzed. As for the laboratory work, chlorine and stainless steel from BPs were found in MEAs, comforting the idea that the marine environment can damage fuel cells. Overall, this study evidences that NaCl effects on PEMFCs not only depend on the concentration but also on the MEA type, plate material, and startup/shutdown procedure.