Enhanced electrocatalytic activity and stability of high performance symmetrical solid oxide fuel cells with praseodymium-doped SrCo0.2Fe0.8O3−δ electrodes

Abstract

Symmetrical solid oxide fuel cells (SSOFCs) represent a promising path towards energy conversion and storage solutions characterized by reduced material costs, simplified manufacturing, and improved operational stability. The development of high-performance symmetrical electrodes with superior catalytic activity and durability remains a critical challenge. In this study, a series of praseodymium-doped SrCo_0.2Fe_0.8O_3−δ perovskites, Pr_xSr_1−xCo_0.2Fe_0.8O_3−δ (x = 0, 0.1, 0.2, 0.4, 0.6, 0.8, 1) are systematically explored, to evaluate their potential as efficient symmetrical electrodes for SSOFCs. Among the compositions studied, Pr_0.2Sr_0.8Co_0.2Fe_0.8O_3−δ (P_0.2SCF) stands out, with an excellent crystal structure and microstructural stability demonstrated by XRD, XPS and SEM test results, and low polarization resistance values at 850 °C of 0.029 Ω cm² for the cathode and 0.054 Ω cm² for the anode. In particular, a single cell containing P_0.2SCF achieved an impressive maximum power density of 719.08 mW cm⁻² at 850 °C as well as good stability. The results of the DRT analysis show that the main rate-limiting steps of the cell are the gas diffusion and catalytic dissociation processes. These results underscore the potential of P_0.2SCF as a highly effective perovskite electrode material for SSOFCs and highlight the key role of Pr doping in enhancing perovskite electrode performance and advancing sustainable energy technologies.