Al3+ doped CeO2 for proton-conducting fuel cells

Developing high ionic conducting electrolytes is crucial for applying proton-conducting fuel cell (PCFCs) practically. The current study investigates the effect of alumina on the structural, morphological, electrical and electrochemical properties of CeO2. Lattice oxygen vacancies are induced in CeO2 by a general doping concept that enables fast ionic conduction at low-temperature ranges (300-500 ℃)  for PCFCs. Rietveld refinement of the XRD patterns established the pure cubic fluorite structure of Al-doped CeO2 (ADC) samples and confirmed Al ions integration in the CeO2 lattice. The electronic structure of the alumina-doped ceria of the materials (10ADC, 20ADC, and 30ADC) has been investigated. As a result, it was found that the best composition of 30ADC-based electrolytes induced maximum lattice oxygen vacancies. The corresponding PCFC exhibited a maximum power output of 923 mW/cm2 at 500 ℃. Moreover, the investigation proves the proton-conducting ability of alumina-doped ceria-based fuel cells by using an oxide ion-blocking layer.