Semiconductor ionic Cu doped CeO2 membrane fuel cells

Abstract

Operation of low-temperature solid oxide fuel cells (LT-SOFCs) in the range of 300–500 °C has emerged as a promising technology and desired operational temperature for clean and efficient energy conversion. However, the lack of suitable electrolyte materials for these temperatures presents a significant challenge. In this article, a novel approach is proposed to address the hurdle of operational temperature by tailoring copper-doped cerium oxide, Cu0.1Ce0.9O2 as a semiconductor ionic membrane (SIM) to act as an electrolyte in a cell. The Cu0.1Ce0.9O2 formed a single-phase cubic fluorite structure. As a SIM, it shows enhanced ionic conductivity and reduced electrolyte/electrode polarizations, therefore achieved good fuel cell performance and electro-kinetics, reaching a power density of 515 mW/cm2 at 500 °C, with an ionic conductivity exceeding 0.1 S/cm. The detailed investigation shows dominant protonic conduction (H+) behavior in the Cu0.1Ce0.9O2 membrane. Interesting phenomenon of coupling effect elaborated through the distribution of relaxation time (DRT) analysis depicted to understand the romance of protons and electrons conduction mechanism. These advancements lead to Cu0.1Ce0.9O2 as a new type of SIM in LT-SOFCs, emphasizing the need for further research and development in this promising field to unlock the SIM and fuel cell potential.