Investigation of transient behaviors in PEMFC from a perspective of the extended irreversible thermodynamics

• Published in: Energy conversion and management 2025-02, Vol.325, Article 119391
• Main Authors: Shen, Yaorui, He, Tingpu, Fu, Jianqin, Wei, Changhe, Sun, Xilei
• Format: Article
• Language: English
• Subjects: Entropy generation rate; Proton exchange membrane fuel cell; Transient performance; Voltage undershoot
• ISSN: 0196-8904
• DOI: 10.1016/j.enconman.2024.119391

[Display omitted] •A novel way is introduced to study the transient behaviors of fuel cell.•Mechanisms underlying voltage and multi-physical transient behaviors are revealed.•Relaxation processes occupy a remarkable share of total entropy generation rate.•Relaxation time is reduced by 98.44% at optimal operation region. For vehicle fuel cell, its transient behaviors not only directly determine the actual performance of vehicle, but also affect the operation stability and durability of fuel cell. Due to the lack of effective method to detect the transient performance, it is difficult to optimize and control the transient behaviors of automotive fuel cell. To address this issue, a one-dimensional, two phase and non-isothermal proton exchange membrane fuel cell (PEMFC) model considering physical parameters’ delay effect was established based on Cattaneo theory. According to the model, the transient behaviors of voltage and key physical quantities were investigated under various temperatures, relative humidity and current loads. Furthermore, based on the extended irreversible thermodynamic (EIT), a new parameter was introduced to evaluate the voltage and multi-physical transient behaviors within the same framework. Results showed that the trade-off between voltage and multi-physical transient behaviors can be effectively balanced by controlling the total entropy generation rate. Besides, it was also emphasized that PEMFC can achieve excellent overall transient behavior at membrane thickness of 10 μm and gas diffusion layers (GDL) porosity of 0.6. All these not only provide a new way for describing transient behaviors of PEMFC, but also contribute to PEMFC online fault diagnosis.