Electrospun La0.5Sr0.5Mn0.875Zn0.125O3-δ nano-powders as a single-phase cathode for proton-conducting solid oxide fuel cells

Abstract

The electrospinning technique was employed to prepare the La 0.5 Sr 0.5 Mn 0.875 Zn 0.125 O 3-δ (LSMZn) cathode for proton-conducting solid oxide fuel cells (H–SOFCs). Although the fiber structure can be obtained with the electrospinning technique for the LSMZn precursor, the fiber structure disappeared after the calcination procedure, leading to the formation of fine LSMZn nano-powders. It was found that the electrospun LSMZn can reach a pure phase after firing at 1100 °C, whereas the traditional sol-gel prepared LSMZn required a calcination temperature of 1150 °C. Furthermore, the electrospun LSMZn had a smaller particle size and richer oxygen vacancy than the traditional sol-gel LSMZn. First-principles calculations indicated that the oxygen vacancy-rich surface promoted the cathode reaction. The H–SOFC using the single-phase electrospun LSMZn generated a power density of 1122 mW cm −2 at 700 °C. The performance was not only larger than the sol-gel LSMZn cell reported in this study but also larger than previous H–SOFCs using the single-phase Mn-based cathodes, suggesting the electrospinning technique was an effective method to produce high-performing cathodes for H–SOFCs.