Enhanced ionic conductivity of yttria-stabilized ZrO2 with natural CuFe-oxide mineral heterogeneous composite for low temperature solid oxide fuel cells

We report for the first time that the commercial yttrium stabilized zirconia (YSZ) nanocomposite with a natural CuFe-oxide mineral (CF) exhibits a greatly enhanced ionic conductivity in the low temperature range (500-600 °C), e.g. 0.48 S/cm at 550 °C. The CF-YSZ composite was prepared via a nanocomposite approach. Fuel cells were fabricated by using a CF-YSZ electrolyte layer between the symmetric electrodes of the Ni0.8Co0.2Al0.5Li (NCAL) coated Ni foam. The maximum power output of 562 mW/cm2 has been achieved at 550 °C. Even the CF alone to replace the electrolyte the device reached the maximum power of 281 mW/cm2 at the same temperature. Different ion-conduction mechanisms for YSZ and CF-YSZ are proposed. This work provides a new approach to develop natural mineral composites for advanced low temperature solid oxide fuel cells with a great marketability.