Issue 36, 2023

Improving the durability of cobaltite cathode of solid oxide fuel cells – a review

Abstract

Solid oxide fuel cells (SOFCs) are highly efficient, low-emission, and fuel-flexible energy conversion devices. However, their commercialization has lagged due to the lack of long-term durability. Among several performance degradation mechanisms, cathode degradation and elemental inter-diffusion of the electrolyte and cathode has been identified as the predominant factors. In the most common SOFC systems, a cobalt-based perovskite material is used, for example LSC or LSCF. These cobalt-based materials offer mixed conductivity and higher concentration of oxygen vacancies as compared to LSM at lower operating temperature leading to favorable reduction kinetics. However, the presence of cobalt results in higher cost, higher thermal expansion co-efficient (TEC) mismatch and most importantly leads to rapid degradation. Various elements like strontium, cobalt, cerium, chromium, or zirconium accumulate or deposit at the electrode–electrolyte interface, which results in sluggish reaction kinetics of the oxygen reduction reaction (ORR). These elements react to form secondary phases that have lower ionic and electronic conductivity, cover active reaction sites, and eventually lead to cell and system deterioration. Over the past decade, several studies have focused on preventative and protective measures to prolong SOFC lifetime which includes novel fabrication techniques, introduction of new layers, addition of thin films to block the cation transport. Such efforts to prevent the formation of insulating phases and decomposition of the cathode have resulted in a remarkable improvement in long-term stability. In this review paper, current research on leading mechanisms responsible for the degradation of cobaltite cathode of solid oxide fuel cell has been summarized and durability improvement strategies of cobalt-based SOFC cathodes have been discussed.

Graphical abstract: Improving the durability of cobaltite cathode of solid oxide fuel cells – a review

Article information

Article type
Review Article
Submitted
18 apr 2023
Accepted
15 aug 2023
First published
22 aug 2023
This article is Open Access
Creative Commons BY license

RSC Adv., 2023,13, 25029-25053

Improving the durability of cobaltite cathode of solid oxide fuel cells – a review

A. M. Mehdi, A. Hussain, R. H. Song, T. Lim, W. W. Kazmi, H. A. Ishfaq, M. Z. Khan, S. Qamar, M. W. Syed and M. T. Mehran, RSC Adv., 2023, 13, 25029 DOI: 10.1039/D3RA02571C

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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