Enhancing anode functional layer performance in solid oxide fuel cells: The role of reduced graphene oxide

This study explores the enhancement of solid oxide fuel cell (SOFC) performance through the incorporation of reduced graphene oxide (rGO) into NiO-YSZ (yttria stabilized zirconia) anode functional layers (AFLs). By systematically varying the rGO content (1–5 wt %), AFL thickness, and sintering temperature , the effects on cell performance are thoroughly evaluated. Pellet cells operated at 800 °C demonstrate that a 1 wt % rGO addition maximizes the peak power density at 0.542 W/cm 2 , which is ∼17 % higher than that of the rGO-free reference cell, attributed to improved electrical conductivity and the formation of additional active reaction zones. In contrast, higher rGO loadings result in compromised performance due to increased charge transfer and gas diffusion resistances, besides mechanical issues such as delamination observed at excessive loadings. Optimization results reveal that a ∼20 μm AFL thickness and a sintering temperature of 1250 °C provide the best balance between porosity and phase contiguity. These optimized conditions are also successfully scaled up to a commercial-size cell (81 cm 2 active area), achieving a ∼30 % performance enhancement over the large-scale reference cell. Impedance spectroscopy and FESEM analyses corroborate the observed improvements in electrode microstructure and polarization characteristics. In conjunction with structural and thermal stability evaluations, the findings highlight the potential of rGO as a scalable additive for high-performance SOFCs. • 1 wt % rGO addition into AFL boosts SOFC power by ∼17 %. • Excess rGO (>1 wt%) raises cell resistance, causing delamination and cracks. • Optimal AFL thickness (∼20 μm) maximizes power, thicker layers hinder diffusion. • AFL sintering at 1250 °C balances porosity and TPBs, improving charge transfer. • Scaling to 81 cm 2 cells gives 30 % gain, but current collection needs optimization.