Study of a highly durable low-humidification membrane electrode assembly using crosslinked polyvinyl alcohol for polymer electrolyte membrane fuel cells

Abstract

A low-humidification membrane electrode assembly (MEA) for polymer electrolyte membrane fuel cells (PEMFCs) is prepared by adding the hydrophilic polymer: polyvinyl alcohol (PVA) to the anode catalyst layer. Glutaraldehyde (GA) is employed as a crosslinking agent for PVA to prevent washing from the anode during cell operation. This is confirmed by an immersion test in deionized water for 2 h. A single cell test is conducted at 80 °C, ambient pressure, and 50 % relative humidity. Although MEA containing 1 wt% non-crosslinked PVA shows the best initial performance (788 mA cm−2 at 0.6 V), a considerable performance decrease of 41 % is observed following a 100-h durability test. However, MEA containing 5 wt% crosslinked PVA demonstrates enhanced durability, with little performance decline after 100 h of constant current operation. This strongly suggests that crosslinked PVA plays a crucial role in a low-humidification MEA at low humidity levels.