Hydrogen Fuel Cells for Transportation – Current Challenges and Future Prospects

In the present scenario of a global initiative to secure global net-zero by mid-century and keep the global temperature increase within 2C, hydrogen and fuel cells are considered to play an important role in the energy transition, particularly for the decarbonization of transit buses, trucks, rail transport, ships, ferries, and the residential heating sector [1, 2]. Even though fuel cells were invented more than hundred eighty years ago and then went through a rapid development for the space program in the 1960s - followed by even more intensive development in automotive applications since the 1990s, there are only two major fuel cell car models available in the international market, with a third coming in 2024. This is due to several technical barriers that still require continual improvement, including their high cost, which stems from the need to balance durability, performance, and materials [3, 4]. Thus, the question is: Is there a future for fuel cells for transportation

Battery Management in Electric Vehicles - Current Status and Future Trends

Rechargeable batteries, particularly lithium-ion batteries (LiBs), have emerged as the cornerstone of modern energy storage technology, revolutionizing industries ranging from consumer electronics to transportation [1,2]. Their high energy density, long cycle life, and rapid charging capabilities make them indispensable for powering a wide array of applications, with electric vehicles (EVs) standing out as one of the most transformative domains. The rise of EVs represents a pivotal shift in the automotive industry, driven by the urgent need to mitigate climate change and reduce greenhouse gas emissions

On the optimal cathode catalyst layer for polymer electrolyte fuel cells: bimodal pore size distributions with functionalized microstructures

A high advancement has been achieved in the design of proton exchange membrane fuel cells (PEMFCs) since the development of thin-film catalyst layers (CLs). However, the progress has slowed down in the last decade due to the difficulty in reducing Pt loading, especially at the cathode side, while preserving high stack performance. This situation poses a barrier to the widespread commercialization of fuel cell vehicles, where high performance and durability are needed at a reduced cost. Exploring the technology limits is necessary to adopt successful strategies that can allow the development of improved PEMFCs for the automotive industry. In this work, a numerical model of an optimized cathode CL is presented, which combines a multiscale formulation of mass and charge transport at the nanoscale (∼10nm) and at the layer scale (∼1μm). The effect of exterior oxygen and ohmic transport resistances are incorporated through mixed boundary conditions. The optimized CL features a vertically aligned geometry of equally spaced ionomer pillars, which are covered by a thin nanoporous electron-conductive shell. The interior surface of cylindrical nanopores is catalyzed with a Pt skin (atomic thickness), so that triple phase points are provided by liquid water. The results show the need to develop thin CLs with bimodal pore size distributions and functionalized microstructures to maximize the utilization of water-filled nanopores in which oxygen transport is facilitated compared with ionomer thin films. Proton transport across the CL must be assisted by low-tortuosity ionomer regions, which provide highways for proton transport. Large secondary pores are beneficial to facilitate oxygen distribution and water removal. Ultimate targets set by the U.S. Department of Energy and other governments can be achieved by an optimization of the CL microstructure with a high electrochemical surface area, a reduction of the oxygen transport resistance from the channel to the CL, and an increase of the catalyst activity (or maintaining a similar activity with Pt alloys). Carbon-free supports (e.g., polymer or metal) are preferred to avoid corrosion and enlarge durability.This work was supported by projects PID2019-106740RBI00 and EIN 2020-112247 of the Spanish Research Council

Convective Flow Optimization inside a Lid-Driven Chamber with a Rotating Porous Cylinder Using Darcy-Brinkman-Forchheimer Model

The active flow optimization and the entropy generation of a spinning porous cylinder on laminar mixed convective flow in a lid-driven differentially heated square chamber have been explored numerically in this study. The cold top surface of the chamber is sliding in the right direction at a fixed velocity, while the cylinder is rotating at a fixed angular velocity, either assisting or opposing the main flow. Navier–Stokes and thermal energy equations define the transport phenomena, while an averaging approach via the Darcy–Brinkman–Forchheimer model is implemented for the porous medium. Three different mixed convection cases based on Reynolds number (31.62 ≤ Re ≤ 316.23), Grashof number (103 ≤ Gr ≤ 105), and Richardson number (0.1 ≤ Ri ≤ 10) are considered in the flow optimization along with the alteration of rotational Reynolds number (Rec = 10, 0, − 10), size (λ = 0.3, 04, 0.5), and position (1–5) of the cylinder. Quantitative evaluations of thermal performance are done in terms of mean Nusselt number, Bejan number, performance evaluation criterion, and thermal performance criterion. The optimization study primarily supports clockwise rotation at the central position of the porous cylinder with specific sizes (diameters) based on the ranges of governing parameters in each simulation case. It is found that the porous cylinder’s rotation primarily determines fluid flow across the porous area