The large-scale adoption of fuel cells system for sustainable power generation will require the combined use of both multidimensional models and of dedicated testing techniques, in order to evolve the current technology beyond its present status. This requires an unprecedented understanding of concurrent and interacting fluid dynamics, material and electrochemical processes. In this review article, Polymer Electrolyte Membrane Fuel Cells (PEMFC) are analysed. In the first part, the most common approaches for multi-phase/multi-physics modelling are presented in their governing equations, inherent limitations and accurate materials characterisation for diffusion layers, membrane and catalyst layers. This provides a thorough overview of key aspects to be included in multidimensional CFD models. In the second part, advanced diagnostic techniques are surveyed, indicating testing practices to accurately characterise the cell operation. These can be used to validate models, complementing the conventional observation of the current–voltage curve with key operating parameters, thus defining a joint modelling/testing environment. The two sections complement each other in portraying a unified framework of interrelated physical/chemical processes, laying the foundation of a robust and complete understanding of PEMFC. This is needed to advance the current technology and to consciously use the ever-growing availability of computational resources in the next future.

The energy shift towards carbon-free solutions is creating an ever-growing engineering interest in electrolytic cells, i.e., devices to produce hydrogen from water-splitting reactions. Among the available technologies, Proton Exchange Membrane (PEM) electrolysis is the most promising candidate for coping with the intermittency of renewable energy sources, thanks to the short transient period granted by the solid thin electrolyte. The well-known principle of PEM electrolysers is still unsupported by advanced engineering practices, such as the use of multidimensional simulations able to elucidate the interacting fluid dynamics, electrochemistry, and heat transport. A methodology for PEM electrolysis simulation is therefore needed. In this study, a model for the multidimensional simulation of PEM electrolysers is presented and validated against a recent literature case. The study analyses the impact of temperature and gas phase distribution on the cell performance, providing valuable insights into the understanding of the physical phenomena occurring inside the cell at the basis of the formation rate of hydrogen and oxygen. The simulations regard two temperature levels (333 K and 353 K) and the complete polarization curve is numerically predicted, allowing the analysis of the overpotentials break-up and the multi-phase flow in the PEM cell. An in-house developed model for macro-homogeneous catalyst layers is applied to PEM electrolysis, allowing independent analysis of overpotentials, investigation into their dependency on temperature and analysis of the cathodic gas–liquid stratification. The study validates a comprehensive multi-dimensional model for PEM electrolysis, relevantly proposing a methodology for the ever-growing urgency for engineering optimization of such devices.

Hydrogen is one of the most promising energy vectors for achieving the decarbonization of the propulsion systems market. Polymer Electrolyte Membrane Fuel Cell system (PEMFCs) stand out in this panorama, thanks to reduced activation times and low temperatures of use, easily adapting to the needs of the sector. In this paper, a multi-phase, multi-component and non-isothermal 3D-CFD model is proposed to simulate the effects of PEMFC ageing, limiting the system durability due to slow membrane corrosion and loss of material performance and properties degradation, resulting in a reduced current density under equal voltage. The model is applied both in 1D and 3D frameworks implementing a validated model from literature, allowing to estimate the useful life of the cell as a function of parameters such as the degradation rate and the crossover rate. Simulations are carried out at different membrane thicknesses and for different membrane conductivities, using a hydrogen-fuelled serpentine-type PEM fuel cell. The study relevance lies in the possibility to investigate the critical aspects limiting PEMFC system durability, as well as the optimal conditions of use, and it allows to identify corrective design actions.

As it is known the transport sector represents a major contributor to climate change. In particular, private transport contributes to the degradation of the air quality inside the cities or the residential areas. To address this issue, a progressive reduction of the use of fossil fuels as a primary energy source for these vehicles and the promotion of cleaner powertrain alternatives is in order. This study focuses on designing a fuel cell powertrain for a hydrogen-powered passenger car using numerical modeling. To this purpose, we initially modeled a base fuel cell and optimized its performance by using various materials for the bipolar plates and adjusting the platinum loading between the anode and cathode. Then, a preliminary design of the new powertrain has been proposed in order to achieve a nominal power of 100 kW and it has been tested on a WLTP 3b homologation cycle. Finally, we have been able to numerically estimate the behavior of the three main feeding line: hydrogen line, air line and cooling line. In conclusion, the obtained results demonstrate how numerical modelling can be successfully used in the design of complex systems such as those related to alternative energy. This work also provides a solid basis for the future development of increasingly efficient and environmentally friendly hydrogen vehicles.