For Fuel Cell Electric Vehicles Research Articles

Real-time optimization for integrated R2 charging and refueling stations in a multi-carrier energy system considering hydrogen chain management

This study presents a real-time optimization-based strategy for sustainable energy management using an energy hub that integrates combined heat and power (CHP) units, heat pumps, and fuel-cell technology to meet community electricity, heating, and cooling demands. It incorporates renewable-based R2 stations that leverage photovoltaic and wind power, integrated with hydrogen production and storage, to supply stationary energy consumers and the transportation sector. The system provides hydrogen for fuel cell electric vehicles (FCEVs) and electricity for electric vehicles (EVs). Integrating the R2 station with the primary energy hub optimizes the use of locally generated power, reducing dependence on external sources. Hydrogen fuel is produced on-site and off-site, focusing on solving the capacitated routing problem for efficient delivery. The system's architecture is modeled using a mixed-integer linear programming (MILP) approach. According to the results, no energy is drawn from the grid to meet the end-user's electricity demand.

Multi-energy station design for future electric vehicles: A synergistic approach starting from scratch

In transitioning to electric vehicles (EVs), deploying charging infrastructure for battery electric vehicles (BEVs) and hydrogen refueling infrastructure for fuel cell electric vehicles (FCEVs) is a key challenge. This paper presents a multi-energy EV station, accommodating both electricity and hydrogen refueling needs. This dual functionality increases system flexibility and simultaneously supports the adoption of BEVs and FCEVs. Unlike existing studies that consider only limited design options in EV station designing, this study modeled and optimized fifteen multi-energy EV station designs, combining renewable and non-renewable resources. These designs were evaluated against sustainability criteria covering technical, economic, environmental, and sociopolitical dimensions. The decision-making model used the AHP to weigh various criteria and employed methods such as GRA, MOORA, EDAS, TOPSIS, and VIKOR for ranking design alternatives. The planning model identified Design 14 as the optimal choice for the targeted site. This optimal design is cost-effective, offering a levelized cost of electricity (LCOE) of 0.046 $/kWh and a levelized cost of hydrogen (LCOH) of 3.907 $/kg. It outperforms the baseline design economically, reducing the LCOE by 1.97 times and LCOH by 1.35 times. Environmentally, it decreases emissions by 514.2 t/year compared to the grid. The station can operate safely with established safety measures. Results are benchmarked against other studies from various sites, and a sensitivity analysis on uncertain parameters elucidated expected variations in the outcomes. The presented EV station planning model can be applied worldwide, considering the meteorological conditions of the specific site.

An optimal standalone wind-photovoltaic power plant system for green hydrogen generation: Case study for hydrogen refueling station

Sustainability goals include the utilization of renewable energy resources to supply the energy needs in addition to wastewater treatment to satisfy the water demand. Moreover, hydrogen has become a promising energy carrier and green fuel to decarbonize the industrial and transportation sectors. In this context, this research investigates a wind-photovoltaic power plant to produce green hydrogen for hydrogen refueling station and to operate an electrocoagulation water treatment unit in Ostrava, Czech Republic's northeast region. The study conducts a techno-economic analysis through HOMER Pro® software for optimal sizing of the power station components and to investigate the economic indices of the plant. The power station employs photovoltaic panels and wind turbines to supply the required electricity for electrolyzers and electrocoagulation reactors. As an off-grid system, lead acid batteries are utilized to store the surplus electricity. Wind speed and solar irradiation are the key role site dependent parameters that determine the cost of hydrogen, electricity, and wastewater treatment. The simulated model considers the capital, operating, and replacement costs for system components. In the proposed system, 240 kg of hydrogen as well as 720 kWh electrical energy are daily required for the hydrogen refueling station and the electrocoagulation unit, respectively. Accordingly, the power station annually generates 6,997,990 kWh of electrical energy in addition to 85595 kg of green hydrogen. Based on the economic analysis, the project's NPC is determined to be €5.49 M and the levelized cost of Hydrogen (LCH) is 2.89 €/kg excluding compressor unit costs. This value proves the effectiveness of this power system, which encourages the utilization of green hydrogen for fuel-cell electric vehicles (FCVs). Furthermore, emerging electrocoagulation studies produce hydrogen through wastewater treatment, increasing hydrogen production and lowering LCH. Therefore, this study is able to provide practicable methodology support for optimal sizing of the power station components, which is beneficial for industrialization and economic development as well as transition toward sustainability and autonomous energy systems.

Deep neural network-based modeling and optimization methodology of fuel cell electric vehicles considering power sources and electric motors

This study proposes a modeling and optimization methodology for fuel cell electric vehicles (FCEVs). Among FCEV components, the traction motor, lithium-ion battery, fuel cell stack, and air supply system are mainly investigated. The FCEV modeling is performed based on the vehicle specifications, electromagnetic finite element analysis, and experimental data. To conduct design optimization, deep neural networks (DNNs) are adopted and trained to predict vehicle performance considering the fluctuation of applied direct current voltage. At this stage, the adaptive layering and sampling algorithm was suggested, which enables efficient DNN construction. To confirm the feasibility of the suggested training algorithm, the number of hidden layers and sampling points of constructed DNNs are investigated. Finally, DNN-based fuel economy optimization is performed considering the driving performance. The effectiveness of the proposed optimization methodology is validated by additional optimization results.

Carbon abatement cost evolution in the forthcoming hydrogen valleys by following different hydrogen pathways

The need to develop a forthcoming hydrogen economy emphasises the emerging concept of ‘hydrogen valleys', where hydrogen production and consumption are being developed. This study assesses the Levelized Cost of Hydrogen (LCOH) and Carbon Abatement Cost (CAC) for various hydrogen end-use applications within the context of a hydrogen valley located in the southern Italy over different time horizons (Today 2023, Mid-Term 2030, Long-Term 2050). Examined applications include blending into the gas grid, reconversion into electricity for grid balancing by means of fuel cells, hydrogen refuelling stations for fuel cell electric vehicles (FCEVs), synthetic methane production, and electro-fuel synthesis. Employing a parametric approach, the study compares LCOH and decarbonisation costs across different pathways. Results indicate current LCOH production values of 3.66–4.90 €/kgH2, projected to decrease to 1.41–1.94 €/kgH2 by 2050. Decarbonisation cost analysis identifies blending and FCEV scenarios as the most cost-effective, contrasting with Power-to-Power scenarios, particularly in the mid and long terms.

Implementation of Non-Isolated High Gain Interleaved DC-DC Converter for Fuel Cell Electric Vehicle Using ANN-Based MPPT Controller

A high conversion ratio DC-DC converter is crucial for fuel cell electric vehicles (FCEV). A fuel cell-based non-isolated high gain integrated DC-DC converter for electric vehicles is proposed in this paper. The system comprises an interleaved boost converter (IBC) at the source end, a switched capacitor cell, coupled inductors, a passive clamp circuit, and a voltage multiplier circuit (VMC). Its significance is to achieve the voltage conversion gain of 12.33 at a conversion ratio of 0.45. The idea is to use a proton exchange membrane fuel cell to power electric vehicles through a high-gain DC-DC converter. The use of an ineffective MPPT can result in lower energy conversion efficiency. Thus, this system incorporates a maximum power point tracking (MPPT) controller based on a neural network, which relies on the radial basis function network (RBFN) algorithm to track the maximum power point of the PEMFC accurately. The comparative study of the fuel cell electric vehicle (FCEV) structure with the RBFN-based MPPT technique was evaluated with that of the fuzzy logic technique using the MATLAB/Simulink platform (R2021b (MATLAB 9.11)). A 1.5 kW experimental prototype is designed with a switching frequency of 10 kHz to validate the design analysis, and its pursuance is compared between RBFN and FLC-based controllers. This manuscript will be a significant contribution towards evidencing a sustainable environment.

Powering the Future: Progress and Hurdles in Developing Proton Exchange Membrane Fuel Cell Components to Achieve Department of Energy Goals—A Systematic Review

This comprehensive review explores recent developments in Proton Exchange Membrane Fuel Cells (PEMFCs) and evaluates their alignment with the ambitious targets established by the U.S. Department of Energy (DOE). Notable advancements have been made in developing catalysts, membrane technology advancements, gas diffusion layers (GDLs), and enhancements in bipolar plates. Notable findings include using carbon nanotubes and graphene oxide in membranes, leading to substantial performance enhancements. Innovative coatings and materials for bipolar plates have demonstrated improved corrosion resistance and reduced interfacial contact resistance, approaching DOE targets. Nevertheless, the persistent trade-off between durability and cost remains a formidable challenge. Extending fuel cell lifetimes to DOE standards often necessitates higher catalyst loadings, conflicting with cost reduction objectives. Despite substantial advancements, the ultimate DOE goals of USD 30/kW for fuel cell electric vehicles (FCEVs) and USD 600,000 for fuel cell electric buses (FCEBs) remain elusive. This review underscores the necessity for continuous research and innovation, emphasizing the importance of collaborative efforts among academia, industry, and government agencies to overcome the remaining technical barriers.

H2 as Clean Energy for Sustainable Future

H2 is considered a clean fuel used in Fuel cell technology for electricity generation with zero greenhouse gas (GHG) emission. The demand for H2 gas, typically for fuel cell electric vehicles (FCEVs), is increasing. However, the current H2 production relies on natural gas and coals related to carbon oxide gas emission, which gives back to global warming concerns. Low-carbon production processes are needed to contribute to the United Nation's sustainable development goals (SDGs). Water-splitting reaction using photocatalysis or electrocatalysis is a promising method for producing H2 from water, which is the earthabundant resource. These H2 production methods based on catalytic technologies require highly active catalyst materials with long-term stability. The development of non-conventional materials with consideration of nanostructure, multijunction, and defect engineering is explored to achieve highly active catalyst materials. This mini-review discusses a basic understanding of H2 production from water-splitting reactions via photocatalysis and electrocatalysis, with outstanding examples of recent works reported. Last part, we provide a short study on the H2 global market and policy in order to conclude the future direction of H2 energy.

Review of Decompression Damage of the Polymer Liner of the Type IV Hydrogen Storage Tank.

The type IV hydrogen storage tank with a polymer liner is a promising storage solution for fuel cell electric vehicles (FCEVs). The polymer liner reduces the weight and improves the storage density of tanks. However, hydrogen commonly permeates through the liner, especially at high pressure. If there is rapid decompression, damage may occur due to the internal hydrogen concentration, as the concentration inside creates the pressure difference. Thus, a comprehensive understanding of the decompression damage is significant for the development of a suitable liner material and the commercialization of the type IV hydrogen storage tank. This study discusses the decompression damage mechanism of the polymer liner, which includes damage characterizations and evaluations, influential factors, and damage prediction. Finally, some future research directions are proposed to further investigate and optimize tanks.

Energy Management Strategy Considering Fuel Economy and Life of Fuel Cell for Fuel Cell Electric Vehicles

The optimization of energy management strategy (EMS) for fuel cell electric vehicles (FCEV) is mainly applied to reduce fuel consumption. However, serious power fluctuations affect the durability of the fuel cell, which is still a challenge for the FCEV. In order to optimize the fuel cell’s service life and economy, this paper proposes an EMS scheme based on fuzzy control. In the proposed EMS, the first layer uses the power following strategy to address the output power distribution issue between the battery and the fuel cell. In order to limit the rapid shift in fuel cell power, the second layer employs a fuzzy control method. Considering the variety of constraints, such as fuel cell power fluctuation and hydrogen consumption, the particle swarm optimization algorithm is used to optimize the membership function of the fuzzy controller. The performance and the operating characteristics of the fuel cells are then evaluated using a test bench. Afterward, the proposed EMS is verified by AMEsim joint simulation. The optimized strategy increased the driving range by 4.7% and 5.9% in world light vehicle test cycle (WLTC) and new European driving cycle (NEDC) conditions, respectively. It also reduces the fuel cell degradation by 21.4% and 19.8%.

South Korea's national pursuit for fuel cell electric vehicle development: The role of government R&D programs over 30 years (1989–2021)

This paper explains the role of the Korean government's National R&D Program over three decades for fuel cell electric vehicle (FCEV) development. The R&D programs had started far before FCEV was considered feasible. We call this as a national pursuit, since the R&D programs has been participated by not only car manufacturers but also various research institutions, including universities, in Korea's national innovation system. The Korean government has implemented a series of National R&D Programs throughout many stages, from selection of technology, building infrastructure and legislations, demonstration, and subsidizing mass-produced FCEVs. The authors analyzed all the government R&D programs from 1989 to 2021 to show the evolutionary changes in contexts and contents of the programs that have reflected varying expectations, government's industrial strategy, and the maturity of technologies through periods. This paper claims that Korea's FCEV development has been regarded as a long-run national industrial strategy, and the development has been persistently pursued in a national innovation systemic manner, such as combining public R&D sector with industries and strong institutional and organizational supports by government.

Enhanced chemical durability of polymer electrolyte membrane fuel cells by crown ether grafted carbon nanotube

Low chemical stability of membrane-electrode assembly (MEA) remains a major obstacle to commercialization of polymer electrolyte membrane fuel cells (PEMFCs) for fuel cell electric vehicles (FCEVs). In this study, we doubly anchored cerium-ion in the catalyst layer by forming a complex with the 15-crown-5-ether and additionally grafting to the multiwall carbon nanotube (Ce/CRE-graft-CNT) as a long-lasting radical scavenger. To confirm the effect of Ce/CRE-graft-CNT on chemical durability, the binding energy between the cerium-ion and crown ether was identified with DFT calculations. The incorporation of Ce/CRE-graft-CNT into catalyst layer decreases decay rate of open circuit voltage (OCV) by 4 times from 2.13 to 0.56 mV h−1 for 210 h operation. The performance retention of the Ce/CRE-graft-CNT (70.8 %) at 0.6 V is also higher than that of the Ce/CRE-blend-CNT (44.8 %). The results indicate that the doubly anchored Ce/CRE-graft-CNT has a more retention capability as a radical scavenger. Therefore, a tightly bounded cerium-ion/crown ether complex with CNT can provide a strategy to improve the chemical durability of MEAs.

Two-stage model predictive control for a hydrogen-based storage system paired to a wind farm towards green hydrogen production for fuel cell electric vehicles

This study proposes a multi-level model predictive control (MPC) for a grid-connected wind farm paired to a hydrogen-based storage system (HESS) to produce hydrogen as a fuel for commercial road vehicles while meeting electric and contractual loads at the same time. In particular, the integrated system (wind farm + HESS) should comply with the “fuel production” use case as per the IEA-HIA report, where the hydrogen production for fuel cell electric vehicles (FCEVs) has the highest unconditional priority among all the objectives. Based on models adopting mixed-integer constraints and dynamics, the problem of external hydrogen consumer requests, optimal load demand tracking, and electricity market participation is solved at different timescales to achieve a long-term plan based on forecasts that then are adjusted at real-time. The developed controller will be deployed onto the management platform of the HESS which is paired to a wind farm established in North Norway within the EU funded project HAEOLUS. Numerical analysis shows that the proposed controller efficiently manages the integrated system and commits the equipment so as to comply with the requirements of the addressed scenario. The operating costs of the devices are reduced by 5%, which corresponds to roughly 300 commutations saved per year for devices.

Analysis of the Integration of Aramid Fiber Tension Struts in a Box-shaped Pressure Vessel

Shared vehicle architectures for fuel cell electric vehicles (FCEVs) and battery electric vehicles (BEVs) allow significant cost reduction in development and production by enabling economies of scale. Therefore, a box-shaped design for a type 4 pressure vessel is developed, which allows an efficient storage of hydrogen in conventional battery design spaces. For a load capable design, the top and bottom of the tank wall are connected with tension struts made of aramid fibers. Based on an analytical design, the geometry of the vessel is defined and a manufacturing process is developed using tufting as key technology for the insertion of the aramid fiber tension struts. The load transfer between the CFRP tank wall and the tension struts is crucial for the mechanical strength of the containment. Fiber loops are evaluated by guiding the tension struts through the CFRP tank wall and deflecting the load. In tensile tests, strengths of at least 1720 MPa are measured for this configuration. The tightness of the containment is ensured by a polymer liner and its adhesion to the struts. The interface between aramid fiber struts and the liner is investigated on strut-level analytically and in experiments. Different shear moduli of the investigated polymers show a major influence on the shear stress in the liner. For the application in the tension-braced pressure vessel, liner materials with the lowest possible modulus should be used to reduce the stress peaks in the liner. Finally, a design corridor for the dimensions of the tension struts and preferred material properties for the liner can be derived. For the investigated material, a strut diameter of 1 mm with a strut spacing of 3 to 5 mm is recommended.

Eco-Audit of MOFs as H₂ Storage Materials for Vehicle Applications, Using Novel Refueling Model

Metal-organic frameworks (MOFs) are a heavily researched candidate for fuel-cell electric vehicle (FCEV) hydrogen storage. However, little analysis has been done on the environmental impact of potential MOF vehicles compared to established alternative vehicles, such as compressed hydrogen or battery-electric vehicles. In this work, a preliminary eco-audit was conducted for a FCEV using an MOF hydrogen storage system based the best current MOF Ni₂(m-dobdc) (Ni-MOF-74). (1) Cost and environmental impact analyses were performed for both the production and use phases of an MOF-FCEV. The cost and environmental impact of MOF production was compared to that of Lithium Nickel Manganese Cobalt Oxide (LiNMCO) batteries, the current state-of-the-art for BEVs. (2) Environmental impact was assessed using embodied energy estimates based on reported values for LiNMCO BEVs. These highlighted MOF vehicles as a competitor to current renewable energy vehicle technologies. For the use phase, a hydrogen refueling station that produces hydrogen onsite by proton exchange membrane (PEM) electrolysis from grid electricity was compared to an equivalent population of battery electric vehicles (BEVs) charged at distributed recharging stations. FCEVs using the proposed refueling model were able to compete with BEVs both in terms of electricity CO₂ footprint and cost in the simulated solar-dominated Californian grid, but not in the hydro- and nuclear-heavy Ontario grid.

Review on State of Health Definition in Relation to Proton Exchange Membrane Fuel Cells in Fuel Cell Electric Vehicles

<div class="section abstract"><div class="htmlview paragraph">Owing to its advantages of high energy density, quick start-up, and no emissions, the proton exchange membrane fuel cell (PEMFC) is one of the most promising power sources in transportation and has been used for automotive application for years. However, shortcomings in fuel cell key performances, such as lifetime and efficiency, characterized by state of health (SOH), restrict the large-scale commercialization for fuel cell electric vehicles (FCEV), raising demands for real-time state monitoring. Nowadays, most researchers have explored the reasons for state change from models or experiments. Nevertheless, it is in need of system-level researches on definition methods of SOH against the actual automotive application. Lacking accurate quantitative indicators, existing studies on health states are often qualitative and hence fail to consider intermediate processes. In addition, too many health indicators that describe typical physical characteristics can be used for SOH definition, which raises higher demands for the computational cost. Moreover, most researches focus on long-term degradation and overlook the importance of short-term performance changes. The research on the definition of health states aims to execute the control strategy more effectively after system monitoring, which is also influenced by key components coupled with PEMFC in powertrain system, including battery and DC/DC converter. Therefore, focusing on FCEV and based on the literature research method, latest technologies on SOH definition of PEMFCs and related estimation methods are reviewed. Based on comprehensive analyses, this paper proposes the development direction of researches on the SOH study for FCEVs, and provides helpful guidelines for the monitoring performance and optimizing control from system level for practical applications.</div></div>

Energy management strategy based on velocity prediction using back propagation neural network for a plug‐in fuel cell electric vehicle

The stochastic driving cycles pose a challenge to the actual implementation of the control strategy for fuel cell electric vehicles (FCEVs). Considering the problem, this research proposes a predictive control strategy based on velocity prediction. Firstly, a novel velocity prediction method is developed, which considers the prediction error of back propagation neural network (BPNN)-based method. Then, it is incorporated into the predictive control strategy for a plug-in FCEV. Finally, simulation studies are conducted to verify the effectiveness and superiority of the proposed predictive control strategy. Simulation results show that the proposed velocity prediction method can adaptive to different driving cycles with high accuracy. In another case, with the velocity prediction used in the predictive control strategy, hydrogen consumption reduces by 17.07% when compared with the traditional rule-based strategy. All the results indicate that the designed velocity prediction approach made it possible to forecast vehicle velocity with relatively high precision and promising to promote the energy management strategy (EMS) to reduce the hydrogen consumption of the plug-in FCEV.

Core-Shell Fe@Pt Nanoparticles Supported on MOx/C As Enhanced Electrocatalysts for Cathode of PEMFC

For fuel cell electric vehicle (FCEV), the amount of platinum electrocatalyst is required around 10 g per fuel cell stack of 80 kW, and non- or low-platinum electrocatalysts needed to reduce the amount of platinum per vehicle considering the production cost. Therefore, a large-scale synthesis method for low-platinum electrocatalyst is necessary for the commercialization of FCEV. Ultrasound-assisted polyol synthesis (UPS) is a one-pot method for the preparation of small and uniform size core-shell nanoparticles on the support and is suitable for mass production of platinum shell electrocatalyst in this respect. Platinum(Ⅱ) acetylacetonate, Iron(Ⅲ) acetylacetonate, and carbon support were dispersed in ethylene glycol, which is reducing agent, and irradiated with ultrasound for 3 h to reduce to the metal nanoparticles, followed by washing and drying to obtain a powder. The characterization was observed by analysis such as solution color visualization, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and electrocatalytic performance. Also, the synthesized samples were calcined at various temperatures to cause the atomic rearrangement to the most stable arrangement. The atomic accumulation of boundary between each atom and compression of platinum lattice that affects activity or durability of electrocatalyst has changed at specific temperature. And both synthesized samples with optimized synthesis condition for mass production and samples with the heat-treatment process show improved electrochemically active surface area (ECSA) and Oxygen reduction reaction (ORR) catalytic activity in the half-cell test and durable catalytic activity in the performance evaluation of membrane-electrode assembly (MEA) compared to existing Platinum catalyst. As renewable energy conversion and storage system is one of the main challenges, FCEV is developed to solve pollution from CO2 emission and oil depletion issues. Our low-platinum nanoparticle with uniform distribution synthesized in a sonochemical method could replace precious metal catalysts used in fuel cells.

Technologies for the Safe Use of Hydrogen and Construction of the Safety Standards System

The industry of hydrogen energy for fuel cell electric vehicles (FCEVs) is in a rapid start-up stage in China. Understanding of the danger of hydrogen and safe use of the hydrogen energy are the basis for the healthy development of the FCEV industry. In this study, we analyze the physical and chemical properties of hydrogen and the compatibility issues for hydrogen and materials and then propose three basic principles for the safe use of hydrogen. Subsequently, the research outputs and technical measures for the safe use of high-pressure hydrogen energy in Japan are thoroughly introduced and some suggestions are presented for the safe use of hydrogen in accordance with the Chinese situation. First, China should conduct overall planning and design, increase investment in science and technology, and form a research system that takes the National Hydrogen Safety Laboratory as the main body and has active participation from social science and technology forces. Moreover, it should perfect its hydrogen safety standards system for vehicles and build a 70 MPa hydrogen-related equipment manufacturing system.

Operando and Ex-Situ Investigation of PEMFC Degradation

One of the key requirements for fuel cell electric vehicles (FCEVs) is longevity with a targeted lifetime of the fuel cell of 5000 - 6000 h. This lifetime needs to be assured in dynamic PEMFC operation including critical events. To mitigate performance degradation a fundamental understanding of the degradation phenomena that occur during different operation conditions are required. Therefore operando electrochemical investigations including monitoring of local operation conditions have been carried out in a broad scope of operation conditions to i) study impact of operation conditions on degradation and ii) identify phenomena that accelerate performance decay (so called accelerated stress tests - AST). Our results show that dynamic load cycling leads to lower performance losses compared to operation at constant current [1]. Moreover, operation in the low current range (i.e. high potential range) exhibited highest irreversible and reversible degradation which is caused by a significantly increased ohmic and mass transport resistance. The observed performance losses are closely linked with inhomogeneous current density distributions. Ex-situ measurements show that MEA regions with particularly high local current densities exhibit more pronounced platinum band formation in the membrane, as shown in the Figure, which is correlated with irreversible cathode degradation. In order to understand the impact of specific operation conditions occurring during load cycling as required for automotive operation specific in-situ ASTs were performed focusing on high potential operation, mechanical stress, temperature cycling and high load operation. Although in-situ ASTs exist for the membrane and the catalyst layer, no in-situ ASTs are available for the GDL so far. Hence our current activity is focused on the development of GDL specific ASTs and quantification of their impact on degradation of individual MEA components. To quantify impact of these ASTs on degradation of individual MEA components aged components were analyzed not only by ex-situ methods, but also by electrochemical characterization in combination of with pristine MEA components. The results clearly show that, for instance, mechanical stress due to freezing water during freeze-thaw cycling has negative effect on mass transport capabilities of the MEA. In this context also mitigation strategies to avoid icing in the cell is proposed which mitigates performance decay [2]. In addition of studying degradation effects caused by operation conditions, we also provide an analysis of effects of different externally introduced contaminants. These include silicon (e.g. from gasket) and nickel (e.g. from defective coatings) which effects on local MEA degradation was studied with DLR’ segmented cell in different operation conditions [3]. Apart from understanding degradation on material level, our activities cover the development of methods for on-line fault diagnostics and state-of-health monitoring in order to identify critical operation conditions characterized by gradients in various parameters and uneven flow distribution between the single cells [4]. The presented work is focused on fault monitoring in PEMFC stacks by evaluation of local performance phenomena and impedance analysis. Combined studies of local current density measurements and impedance data for all single cells in the stack will be presented and links between impedance response, local effects within the cells, and stack fault modes will be highlighted. Acknowledgements: This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement No 779565 (ID-Fast). This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme.