Electrochemical properties of Ni0.4Zn0.6 Fe2O4 and the heterostructure composites (Ni-Zn ferrite-SDC) for low temperature solid oxide fuel cell (LT-SOFC)

• In solid oxide fuel cell, the redox reactions (HOR and ORR) demand good catalyst functions at the anode and cathode. Triple phase boundary (TPB) is an important mechanism to determine HOR and ORR as key factors to improve the reaction rate, charge transfer and ion diffusion processes. In the present work, Ni0.4Zn0.6Fe2O4 (Ni-Zn ferrite) and its heterostructures with Sm0.2Ce0.8O2 (SDC) are prepared and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to analyze the phase structure and morphology of the material. X-ray photoelectron spectroscopy (XPS) confirms the phase of Ni-Zn ferrite nanoparticles (NPs) and chemical states on the heterostructure surface. The electrical and conductive behaviors of synthesized samples are investigated through electrochemical impedance spectroscopy (EIS) and fuel cell measurements. Unlike to conventional way, the as-prepared samples promote redox reactions from two aspects: a) as an electrolyte for ion transport; b) as a mixed conductor to extend the ionic transport on TPB region. The ionic transfer mechanism of Ni-Zn ferrite/SDC composite leads the improved fuel cell performance up to 760 mW/cm(2) at 550 degrees C. Further investigations verify the appreciable proton conduction in the prepared devices in a range of 0.012-0.048 Scm(-1).

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Nyckelord

Low temperature SOFC

Ni-Zn ferrites

Heterostructure materials

Electro-catalytic function

Triple phase boundary

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