Boosting Performance of a Protonic Ceramic Fuel Cell by the Incorporation of Active Nano-Structured Layers

A powerful strategy to expandthe triple-phase boundaryand enhance the PCFC performance with the nano-structured active layer Protonic ceramic fuel cells (PCFCs) are a promising optionforefficient energy-conversion devices, which are hindered by sluggishcathodic kinetics. Here, a Ba0.95La0.05Fe0.8Zn0.2O3-& delta; (BLFZ)-infiltratedBaCe(0.7)Zr(0.1)Y(0.1)Yb(0.1)O(3-& delta;) (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 NH3 and H-2 fuel. BLFZ nanoparticles are homogeneouslydistributed in a porous BCZYYb scaffold, as confirmed by SEM imagesand EDS mappings. The reduction of & SIM;59% in polarization resistancefor symmetrical cells at 600 & DEG;C is achieved. The electrochemicalreaction processes are revealed by the electrochemical impedance spectraand the distribution of relaxation time analysis. Compared to theBLFZ-BCZYYb composite cathode, the single cell with the NAL showsan over 1.3-fold and 1.5-fold increase in peak power density, 601and 486 mW cm(-2) at 650 & DEG;C with H-2 and NH3 fuel, respectively. The enhancement of cell performanceis attributed to the coupling of proton conduction and electrocatalyticactivity of the NAL, which expand the proton-accessible cathode areaat the cathode/electrolyte interface. No obvious degradation is achievedfor the PCFC measured at 600 & DEG;C with H-2 and NH3 fuel.