Boosting Performance of a Protonic Ceramic Fuel Cell by the Incorporation of Active Nano-Structured Layers
Junmeng Jing, Ze Lei, Chaoyu Wang, Ziwei Zheng, Haoran Wang, Panpan Zhang, Zhibin Yang, Suping Peng
Abstract
Protonic ceramic fuel cells (PCFCs) are a promising option for efficient energy-conversion devices, which are hindered by sluggish cathodic kinetics. Here, a Ba 0.95 La 0.05 Fe 0.8 Zn 0.2 O 3−δ (BLFZ)-infiltrated BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3−δ (BCZYYb) nano-structured active layer (NAL) between the porous cathode and the dense electrolyte is designed, which can provide a powerful strategy to expand the triple-phase boundaries, allowing excellent electrochemical performance for PCFC with NH 3 and H 2 fuel. BLFZ nanoparticles are homogeneously distributed in a porous BCZYYb scaffold, as confirmed by SEM images and EDS mappings. The reduction of ∼59% in polarization resistance for symmetrical cells at 600 °C is achieved. The electrochemical reaction processes are revealed by the electrochemical impedance spectra and the distribution of relaxation time analysis. Compared to the BLFZ-BCZYYb composite cathode, the single cell with the NAL shows an over 1.3-fold and 1.5-fold increase in peak power density, 601 and 486 mW cm –2 at 650 °C with H 2 and NH 3 fuel, respectively. The enhancement of cell performance is attributed to the coupling of proton conduction and electrocatalytic activity of the NAL, which expand the proton-accessible cathode area at the cathode/electrolyte interface. No obvious degradation is achieved for the PCFC measured at 600 °C with H 2 and NH 3 fuel.