An electrochemical method for high accuracy measurements of water transfer in fuel cells

A novel method for the high accuracy measurement of water transfer in differential polymer electrolyte fuel cells (PEFCs) is proposed. This method is based on the potential difference forming in a H2/H2 concentration cell in the presence of humidity differences between the electrodes. In the present work, the relation between the partial pressures of hydrogen and water vapor and the potential difference over the concentration cell are verified. Furthermore, a validation experiment allowed to confirm that the targeted accuracy of 0.25% for the differential humidity can be obtained with our method, making it suitable for the measurement of water transfer in small‐scale differential cells.

► A water transfer measurement method using a H2/H2 concentration cell is proposed.
► The open cell voltage versus H2 and H2O partial pressures agrees well with theory.
► The setup is self-calibrated based on the voltage response to pressure variations.
► An accuracy of +/− 0.25% on the differential humidity can be reached.