Advancing HT-PEM fuel cell technology: durability and performance under start–stop conditions

Abstract

High-temperature proton exchange membrane (HT-PEM) fuel cells represent a promising avenue for efficient and low-emission energy conversion, especially in automotive and distributed power applications. However, one of the critical challenges limiting their widespread deployment is performance degradation under dynamic operating conditions, particularly during frequent start–stop cycles. This review provides a comprehensive overview of recent advances in understanding and improving the durability and performance of HT-PEM fuel cells under these conditions. Key degradation mechanisms—such as catalyst layer degradation, membrane instability, and interfacial delamination—are examined alongside mitigation strategies, including novel material development, system design optimization, and operational control techniques. In addition, the review analyzes the coupling among these mechanisms, for instance, how membrane dehydration accelerates catalyst corrosion through acid redistribution, and how delamination locally distorts current density and mass transfer pathways, thus providing a more integrated degradation picture. The review highlights recent experimental and modeling studies that shed light on transient behavior and long-term reliability. Special emphasis is placed on recent disruptive technologies, such as hybrid inorganic–organic membranes, multifunctional catalysts, and digital-twin-based lifetime prediction models. By identifying current gaps and emerging solutions, this work aims to guide future research efforts and support the development of robust, high-performance HT-PEM systems suitable for real-world applications.