Comprehensive review of current trends and future directions of metal-supported solid oxide fuel cell: From materials to applications

Abstract

This review provides a systematic analysis of metal-supported solid oxide fuel cells (MS-SOFCs) as next-generation energy conversion devices. By integrating multiscale simulations with experimental validation, we establish performance benchmarks for key components, including thin electrolytes, mixed ionic–electronic conductors (MIECs) used as cathodes, and corrosion-resistant metal substrates. The paper elucidates critical degradation pathways, such as chromium poisoning and interfacial instability, and proposes mitigation strategies based on advanced manufacturing techniques, including plasma spraying and in situ sintering. System-level challenges related to thermal management, gas transport optimization, and scalable production are identified, ultimately delineating research priorities for achieving sub-600°C operation and commercial deployment.

1. Introduction

Global decarbonization agendas and national hydrogen roadmaps are reshaping the electricity and fuel markets. As reported recently by the International Energy Agency (IEA), China has announced dual carbon goals—emissions before 2030 and achieve carbon neutrality before 2060—and has made remarkable progress in adding renewable capacity [1]. A range of innovative energy technologies, including lithium-ion batteries [2–6], all-solid-state batteries [7–12], lithium–sulfur batteries [13–15], and sodium-ion batteries [16–20], among others [21–26], have been developed and implemented. At the forefront of new energy innovation, solid oxide fuel cells (SOFCs) directly convert chemical energy into electrical energy through electrochemical reactions and are well-positioned to support these objectives [27]. As an advanced energy conversion technology, SOFCs play a crucial role in modern energy systems owing to their high efficiency, environmental benefits, fuel diversity, and operational versatility. They not only drive innovation in energy technologies but also contribute to sustainable development and carbon emission mitigation [28–30].

As shown in Table 1 [31–33], from a historical perspective, SOFC development has progressed from electrolyte-supported cells with thick yttria-stabilized zirconia (YSZ) electrolytes operating at 800–1000°C (Gen-I), to anode-supported intermediate-temperature SOFCs at 600–800°C (Gen-II), and now to metal-supported SOFCs (MS-SOFCs, Gen-III) that target lower operating windows around 500–700°C. Fig. 1(a) shows an obvious increase in current and power density due to systematic processing and microstructure optimization [34]. The architecture of a typical repeating unit (RU) is illustrated in Fig. 1(b), comprising a metal support, a porous anode and cathode, and a thin dense electrolyte [35]. Owing to the electrical conductivity of the metallic substrate and the engineered current-collection schemes, lateral charge transport can be facilitated at the cell level without sacrificing gas transport in the porous layers.

Compared to ceramic-supported architectures, metallic supports provide higher fracture toughness and thermal conductivity, enabling faster thermal transients, improved tolerance to thermal gradients, and simplified lower-cost manufacturing pathways compatible with larger active areas [31–32,36–37]. When paired with metal-compatible electrode formulations and appropriate barrier layers, MS-SOFCs can operate at reduced temperatures while maintaining durability during cycling and redox perturbations. It is worthwhile to conduct comprehensive research toward the recent developments of MS-SOFC because of their several intrinsic advantages, which will give hope to the rapidly growing expansion of commercial MS-SOFC applications. By introducing the MS, which combines well with the interconnector (IC), into the cell, high thermal conductivity and outstanding mechanical stability can be achieved. Meanwhile, choosing metal-compatible electrode materials also enhances the thermal cycling resistance, which leads to low-temperature operation and enables application as a mobile power source [38]. Most importantly, the metal-based design can support monolithic fabrication, thereby improving alignment by minimizing stacking and lowering manufacturing costs through reduced material usage and process steps. Therefore, MS-SOFC can be applied in several domains that require mobile power, such as auxiliary power units (APUs) and full power sources in fuel cell vehicles (FCVs), and even in military domains. This review presents a comprehensive overview of MS-SOFCs as integrated systems connecting materials, electrochemical reactions, thermal management, and manufacturing processes. We summarize and compare recent experimental results and simulation studies to clarify how the structure and process affect the performance and durability. This review also outlines the progress.