Recent Development in Reversible Solid Oxide Fuel Cells: Theory, Integration and Prospective

Abstract

Reversible solid oxide fuel cell (RSOC) has gained widespread attention due to their potential for high efficiency in implementing multi‐energy distributed systems. When high power demand is required, RSOC can operate in the solid oxide fuel cell (SOFC) mode, directly converting the chemical energy from hydrogen or other renewable fuels into electricity. When excess electricity is available, RSOC can operate in the solid oxide electrolysis cell (SOEC) mode, producing fuels through the electrolysis of water or co‐electrolysis of water and carbon dioxide. The reversible operation of RSOC enables the direct conversion between chemical energy and electricity, offering a promising solution for clean and sustainable energy with low cost and high round‐trip efficiency. This paper introduces the research background and working principles of RSOC, provides a detailed overview of the current research status of electrolyte, fuel electrode, and oxygen electrode materials, discusses the optimization design of RSOC stacks and energy utilization strategies in the system. In addition, the future development directions of RSOC were also explored, which is of significant importance for the commercialization of RSOC.

Development of Nanostructured Lanthanum Strontium Cobalt Ferrite/Gadolinian-Doped Ceria Composite Electrodes of Solid Oxide Cells Formed by In Situ Polarization

“…The solid oxide cell (SOC) is the most efficient electrochemical energy conversion and storage device, and it can be operated reversibly under solid oxide electrolyzer cell (SOEC) mode to store renewable electricity from solar and wind energy in the form of hydrogen fuel and under solid oxide fuel cell (SOFC) mode to generate electricity by consuming the generated hydrogen. − Conventional SOCs consisting of oxide-ion-conducting electrolytes such as yttria-stabilized zirconia (YSZ) sandwiched between Ni/YSZ cermet fuel electrodes and oxygen electrodes such as lanthanum strontium manganite (LSM) usually require operating temperatures in the range of 800–1000 °C. , Such high operation temperatures are not favorable for long-term stability due to interface delamination and considerable microstructure degradation. ,, The most effective strategy to increase the durability of SOCs is to lower the operating temperature to intermediate levels of 600–800 °C. ,, With the reduction in SOC operation temperatures, conventional electrode materials, in particular oxygen electrodes such as LSM, are no longer applicable due to the increasingly dominant polarization loss for the oxygen reduction and oxygen evolution reactions (ORR and OER) because of the high activation energy and low ionic conductivity of the materials. − This led to the significant development of mixed ionic–electronic conducting (MIEC) materials such as lanthanum strontium cobalt ferrite (LSCF) and barium strontium cobalt ferrite (BSCF) , as oxygen electrodes to substantially reduce the polarization resistance due to the extended three-phase boundaries (TPBs) . However, cobaltite-based perovskites react readily with YSZ electrolytes, which limits the wide application of LSCF- and BSCF-based electrode materials in YSZ electrolyte-based SOCs.…”