Browse Topic: Fuel cells
We present atomistic molecular dynamics simulations of linear and branched fluorinated polymer chains, with and without imidazole functionalization, designed as a model for solvent-free proton-conducting membranes for high-temperature fuel cell applications. Simulations conducted over a temperature range of 300 to 550 K, and diffusion-based relaxation times reveal that glass transition temperatures depend on polymer architecture: the branched and functionalized systems exhibit transitions near 400 K compared to 500 K for the linear chain. Fluorine-fluorine radial distribution functions demonstrate that branching disrupts local packing order, while imidazole substitution creates specific intra-chain interactions. Radius-of-gyration distributions reveal that branching significantly increases chain extension and creates multiple conformational families, whereas imidazole groups stabilize compact conformations at low temperatures that transition to more diverse states upon heating. These findings provide molecular-scale insight into how polymer architecture controls thermal transitions and structural organization in model high-temperature polymer electrolyte membranes.
A dispatch from the automaker's “let's just try it” city finds hydrogen fuel cells, automated parking robots, and a robust spirit of innovation. For a planned high-tech community created by an automaker, Woven City is not laser-focused on automobiles and transportation. In fact, to get a glimpse of Toyota's priorities here, look to the pedestrian stoplights at intersections. They remain a constant green, until the connected city senses an approaching vehicle and turns them red. This focus on pedestrians over vehicles is one small part of Toyota's rebranding as a mobility company. Toyota announced Woven City at CES 2020, converting its recently closed Higashi-Fuji factory, which built over 7.5 million Toyota vehicles during a 53-year run, into a blank slate for new technologies, automotive and otherwise.
The global trend towards green and low-carbon development is that hydrogen fuel cells, as a new type of green power device, have the characteristics of zero emissions and no pollution. Its basic principle is that hydrogen fuel directly converts chemical energy into electrical energy through electrochemical reactions, achieving energy conversion between fuel cells and internal combustion engines, thereby providing sustained and stable power. The PEMFC has attracted significant attention due to advantages such as fast start-up times and long lifespans. However, excessive temperature during the reaction process of solid-state hydrogen proton fuel cells can lead to a decrease in efficiency. This article studies the temperature control device of solid-state hydrogen fuel cells and finds that active temperature control technology can achieve precise temperature regulation, but it consumes more energy; the passive temperature control scheme can reduce energy consumption, but the response speed to low-temperature start-up is limited; The application of intelligent algorithm fuzzy PID significantly improves the temperature control accuracy under dynamic loads and effectively enhances the hydrogen release rate.
Fuel cell electric vehicles are described on cell, stack and system levels. In driving operation, multi-physics coupling across subsystems (reactant supply, humidification, thermal management, etc.) reshapes cell- and stack-level boundary conditions, impacting performance and degradation mechanisms. Isolated single-topic approaches on one specific level may have limited transferability, as cross-level interdependencies under changing operating conditions can negate improvements or shift limiting factors. This underscores the development of validation environments (VEs) that represent cross-level interactions and evolve as experimental evidence redirects research questions. Models such as the V-Model provide phase-oriented logic for developing VEs when validation scope, boundary conditions and acceptance criteria can be specified upfront and remain stable. However, in PEMFC VE development, experimental conclusions frequently reshape hypotheses, operating conditions and research topics across successive cycles. Consequently, existing approaches often provide limited methodological support for a traceable and repeatable evolution of VEs where iterative reconfiguration is essential. To address this need, we developed the Development Model of the Validation Environment (eMVU, German for Entwicklungsmodell der Validierungsumgebung) for PEMFC technology to enable a structured, model-based and iterative evolution of VEs. Embedded in the system triple of product engineering, the eMVU guides the iterative transformation of objectives into validation configurations (VCs) through model-based derivation of boundary conditions, test requirements and extension measures. It structures each development cycle into the five phases design, specification, implementation and commissioning, experiments and results processing, as well as derivation of measures with feedback of the resulting insights into the objectives of the subsequent cycle. The framework is demonstrated by realizing a fully functional baseline VE and deriving an additional VC enabling semi-automated operation across eMVU cycles. Their implementation and operation provide experimental evidence that both the eMVU and the resulting VE enable traceable, repeatable and targeted assessment of cross-level interdependencies with measurable impact on cell and stack behavior.
Two of the biggest hurdles to adoption of hydrogen fuel cells are still the availability of hydrogen and its affordability. Now Bosch has taken what is a small step toward addressing availability at its Farmington Hills, Michigan, engineering center, where the company just unveiled its new electrolyzer, which uses electrical current to split water into oxygen and hydrogen to power fuel cells.
A single pilot, full-scale, proton exchange membrane fuel cell powered helicopter is flight tested with 700 bar compressed gaseous hydrogen as fuel. Models are developed for the fuel cell, hydrogen and the helicopter and validated with flight test data. The data covers powerplant architecture, stack electrical characteristics, hydrogen flow, detailed component weights, radiator drag, and full aircraft power measured in hover and forward fight. The validated models are then used to conceptually explore the conversion of a larger, more capable, turbine engine Robinson R66-like airframe with liquid hydrogen supplied fuel cell. Predictions indicate that payloads of 300−600 lb can be carried over a range of 200 nautical miles with current fuel cell technology if hydrogen storage weight fractions of 0.2−0.3 can be achieved and the tank and baggage compartment both are used for fuel. The key conclusion is that hydrogen fuel cell helicopters are feasible and the test data and validations presented here open the door for advancing its performance in the future.
Fuel cell systems have achieved a significant level of technological maturity in ground-based mobility over the past two decades. In particular, commercially available fuel cell propulsion systems are now in serial production for passenger cars and city buses, and are already in regular commercial operation. In the segment of heavy-duty vehicles - such as trucks and other long-haul applications - small-series production and technology demonstrators are currently available and are on the verge of entering the mainstream market. These developments have resulted in well-proven system architectures, sophisticated balance-of-plant components, and established supply chains. In contrast, the utilization of fuel cell propulsion in aviation is still at a very early stage. At present, only a handful of individual prototypes and technology demonstrators - mostly for small aircraft - exist, while serial production remains far in the future. Particularly in the field of lightweight, small, electrical vertical take-off and landing (eVTOL) aircraft there is a unique opportunity to leverage the proven fuel cell systems developed for ground vehicles, adapt them, and further develop them to meet aviation-specific requirements. Such an approach can shorten development timelines and reduce technical risks. Transferring existing fuel cell technologies into aviation, however, is far from a straightforward process. One decisive difference lies in the required specific power density. Aircraft - especially eVTOL - demand significantly higher power densities than those delivered by current commercial fuel cell systems from the automotive sector. This requires a direct adjustment of the stack design and system architecture. Likewise, thermal management poses particular challenges. Whereas piston engines and gas turbines discharge a large portion of their waste heat via exhaust gases, fuel cells must remove all waste heat directly through their cooling systems. This requires efficient radiators capable of transferring heat from the coolant to ambient air. Larger radiator surfaces, however, increase both total aircraft mass and aerodynamic drag, making compact radiator designs essential for aviation applications.
Electric Vertical Take-Off and Landing (eVTOL) aircraft are poised to transform urban and regional mobility by offering zero-emission, congestion-free transportation. As regulatory frameworks evolve and advanced air mobility (AAM) gains traction, manufacturers are exploring propulsion strategies that improve range, power delivery, and overall system efficiency. A key challenge in eVTOL development is balancing range with payload capacity. While larger battery packs can extend range, they also increase system weight, reduce payload, and prolong charging times, limiting operational flexibility and turnaround time. Hydrogen fuel cells, supported by liquid hydrogen (LH₂) present a promising alternative for eVTOL propulsion. This study proposes a methodology for optimizing fuel cell propulsion systems tailored to eVTOL applications. A multi-physics modeling framework for eVTOL flight dynamics and propulsion system was developed, representing the target eVTOL configuration. For a defined flight path including vertical takeoff, hover, cruise, and landing, a Genetic Algorithm (GA) based optimization was conducted on propulsion system. The algorithm down-selected battery size, fuel cell stack specifications, and hydrogen tank capacity to meet mission requirements while minimizing propulsion system weight. The modeling framework was also used to evaluate trade-offs between payload and performance as functions of component sizing, battery chemistry and energy distribution strategy.
Two of the biggest hurdles to the adoption of hydrogen fuel cells are still the availability of hydrogen and its affordability. Bosch recently took a small step toward addressing availability at its Farmington Hills, Michigan, engineering center, where the company unveiled a new electrolyzer that uses electrical current to split water into oxygen and hydrogen to power fuel cells.
With the growth of energy demand, fuel cells as efficient and clean energy devices, have attracted increasing attention. However, the high cost of membrane electrode assembly (MEA) restricts their large-scale application. Therefore, reducing the platinum usage and improving performance have become key research point. In this work, MEA was prepared and excellent performance of 1.52 W·cm-2 was achieved at a low platinum loading. The influence of different ionomer/carbon (I/C) ratio on the performance of fuel cells was systematically investigated. It was found that the performance of the MEA was the highest when the I/C ratio is 0.6. Quantifying hydrophilic and hydrophobic characteristics of catalyst layers with varying ionomer contents revealed that the proton conduction efficiency is optimal when the I/C ratio is 0.6. This balance established efficient proton conduction pathways, from the results of proton conduction impedance testing. SEM analysis demonstrated that pore structure integrity was compromised at non-optimal I/C ratios, exhibiting pore blockage or cracking. The CV test results confirmed that the electrochemical active surface area (ECSA) reaches a maximum of 40 m2gPt-1 when the I/C ratio is controlled at 0.6. And the EIS tests indicated that the lowest charge transfer impedance. Combined the physical and electrochemical characterization results with I-V curves, it was clear that the proper ratio of the low I/C region benefits the mass transfer and proton conductions. This study provides theoretical and technical support for performance enhancement and has the potential for the large-scale application of low-platinum MEA in fuel cells in the future.
Batteries are nearing their limits in terms of how much power they can store for a given weight. That’s a serious obstacle for energy innovation and the search for new ways to power airplanes, trains, and ships. Now, researchers at MIT and elsewhere have come up with a solution that could help electrify these transportation systems.
Scalable, Cost-Effective Alternative to Helicopters Financed by the US Navy
Hydrogen Fuel Cell Engine for Heavy Duty Electric Propulsion and Power Generation
This paper presents an analysis of the Indian patent landscape concerning alternative fuels, with a specific focus on hydrogen fuel cells and hydrogen internal combustion engines (H2 ICEs). The study aims to provide insights into the innovation trends, key players, white spaces and technological advancements, in this evolving sector within the Indian context. The study is based on the granted patents and disclosures in the said area, and also focuses on the key problems and solutions. Based on a review of patent publications from January 2024 to March 2025, it was observed that a significant number of patent records pertain to the broader domain of hydrogen internal combustion engine disclosures. Specifically, 540 extended families patent publications were screened focusing on hydrogen internal combustion engine as a domain of disclosure. Further analysis revealed that greater 75 % of applicants were from the industry sector, indicating a strong commercial interest in these technologies. Key OEM players in the mobility space, Tier-I and Tier-II technology solution providers are prominent applicants in the said technology, particularly in areas like fuel systems, storage and material compatibilities The study engages key search strategies around the technical domains in area of hydrogen as an alternative fuel with respect to IC engines and fuel cells, which will enable the technical diaspora around the research and disclosures in this area. The technical teams would also get a learned view on the problems and solutions associated with these technologies.
Fuel cell technology is gaining prominence as a clean, efficient, and scalable power solution for electric mobility, addressing key limitations of conventional battery systems such as long charging times, limited range, and declining performance in high-utilization applications. Proton Exchange Membrane Fuel Cells (PEMFCs) offer high energy density, rapid refueling, and robust operation under varying load conditions, making them particularly suitable for light electric vehicles such as two-wheelers, e-rickshaws & range extenders. Within the broader category of PEMFCs, air-cooled fuel cells present unique advantages for mobility applications. Their simplified architecture eliminates the need for complex liquid cooling systems, leading to lower system weight, reduced component count, and easier integration. This translates into a compact, lightweight, and cost-effective power unit—ideal for vehicles where space, weight, and maintenance constraints are critical. The market for air-cooled fuel cells is expanding globally, driven by demand for lightweight and portable mobility solutions. Specific application segments include electric two-wheelers (300–500 W), which are rapidly gaining ground in Asian markets; e-rickshaws (2–3 kW), a promising Indian market segment seeking alternatives to fossil fuel and lead-acid battery systems. Additionally, the system is well-suited for use as a range extender in electric mobility platforms, offering extended operational duration without compromising on vehicle packaging or efficiency. This work presents an indigenously developed air-cooled PEMFC system designed specifically for low power mobility applications. Indigenous Pt/C catalyst for fuel cell application which meets DoE durability target (30k AST cycles) has been developed. The stack comprises of an innovative flow field configuration for uniform reactant distribution, and advanced thermal management strategy that ensures efficient heat dissipation. The indigenously developed fuel cell stack tailored for Indian weather conditions (5°-45°C, 30-100% RH) achieves critical performance targets including high power density (400-500 W/L), small footprint & mass (600-700 W/kg) at par with leading commercial fuel cell solution providers. This development signifies a critical step toward self-reliant, sustainable, and high-performance power solutions for next-generation electric & green mobility in India and beyond
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