Electrochemical performance enhancement of electrospun nanofiber cathode through impregnation method

Abstract

Intermediate-temperature proton-conducting solid oxide fuel cells often require impregnation techniques to improve the sluggish cathode reaction rate. Nevertheless, the limited impregnation efficiency poses a significant challenge. To tackle this issue, an innovative approach involving the synthesis of La0.6Sr0.4Co0.2Fe0.8O3+δ (LSCF) nanofibers (LSCF-NF) through electrospinning and their use as an impregnation substrate was employed. Through meticulous optimization of the skeleton microstructure, Bi0.75Ba0.25FeO3-δ (BBF) was successfully impregnated in the LSCF substrate, leading to a remarkable enhancement of cell performance. Specifically, the cell performance improved from 680 mWcm−2 to an impressive 1350 mW cm−2 at 700 °C, underscoring the efficacy of this novel technique. The density functional theory (DFT) simulation confirms that BBF is beneficial for proton migration. The distribution of relaxation time method (DRT) analysis coupled with electrochemical impedance spectroscopy has revealed a noteworthy increase in oxygen adsorption and reduction rates following the implementation of impregnation combined with microstructure optimization. These results establish impregnation combined with microstructure optimization as a highly effective strategy for boosting the performance of fuel cells, paving the way for further advancements in this exciting field.