A scaled-up proton exchange membrane fuel cell with enhanced performance and durability

Abstract A proton exchange membrane fuel cell with enhanced performance and durability has been developed by using graphene for the microporous layer on the cathode side, and short-side-chain ionomer in the catalyst layers and electrolyte membrane layer. The cell components are analyzed for their detailed morphological, microstructural, physical, and electrochemical characteristics, and the performance and durability are investigated following the established protocol of accelerated stress tests for a scaled-up cell with an active area of 45 cm2 at 75 °C and 35 kPag, and a range of reactant flow rate and relative humidity conditions. The results indicate that the graphene flakes are arranged in the in-plane direction of the cell, and coupled with the improved proton conductivity and water retention of the short-side chain ionomer and membrane, the cell exhibits excellent performance and durability, and is highly tolerant to the variations in the operating conditions. Before and after 30,000 cycles of the accelerated stress tests, the maximum power densities are around 1.13 W/cm2 and 0.75 W/cm2 for the high-flow fully humidified reactants, and about 0.77 W/cm2 and 0.50 W/cm2 for the low-flow and low-humidity conditions, respectively. The excellent performance and durability at low relative humidity operation are significantly important for practical applications.