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Tämä tiekartta tiivistää Suomen Akatemian yhteydessä toimivan Strategisen tutkimuksen neuvoston rahoittaman EL-TRAN-konsortion (2015–2021) työn ilmastoneutraaliin ja resurssitehokkaaseen sähköenergiajärjestelmään siirtymiseksi. Tiekartta erottaa kolme vaihetta tässä energiasiirtymässä, jossa sähköstä tulee asteittain energiajärjestelmän perusta. Ensimmäisessä vaiheessa uusiutuvan sähkön tuotanto kasvaa voimakkaasti. Siitä muodostuu useimmissa maissa keskeisin energiaresurssi olemassa olevien ilmastoneutraalien tai vähähiilisten resurssien kuten vesivoiman, bioenergian ja ydinvoiman rinnalle. Toisessa vaiheessa lisääntynyt sääriippuvan, vaihtelevan sähköntuotannon määrä vaatii lisääntyvää varavoima- ja energiavarastokapasiteettia sekä kulutuksen joustoa myös kansainvälisten energiamarkkinoiden avulla. Näillä keinoilla hallitaan ajoittaisia ali- ja ylituotantotilanteita, ylläpidetään tuotannon ja kulutuksen välistä tasapainoa ja taataan sähköistyvän yhteiskunnan toimintakyky. Kolmannessa vaiheessa liikennesektorin, rakennusten ja teollisuuden energiankäyttö siirtyy yhä enemmän sähköön sektorikytkennän ansiosta. Energiajärjestelmää hallitaan älyverkkojen avulla. Järjestelmään kuuluu sekä pienten tuottajakuluttajien hajautettuja resursseja, kuten energiayhteisöjä ja mikroverkkoja, että keskitettyjä suurten voimalaitosten verkkoinfrastruktuureja tietojärjestelmineen. Ylituotantosähköä voidaan käyttää nestemäisten ja kaasumaisten ilmastoneutraalien polttoaineiden tuotantoon. Suomi on parhaillaan siirtymässä kohti energiasiirtymän toista ja kolmatta vaihetta. Toinen vaihe ei kuitenkaan Suomen tapauksessa ole erityisen dramaattinen maan vesivoima- ja bioenergiaresurssien johdosta, samalla kun rajat ylittävä sähkönsiirtoinfrastruktuuri liittää maan osaksi pohjoiseurooppalaisia sähkömarkkinoita. Koska yksikään maa ei kuitenkaan toistaiseksi ole täysin siirtynyt kolmanteen vaiheeseen, monenlaisia haasteita on odotettavissa. Tästä syystä tämä tiekartta esittelee yli sata eri toimijoille kohdennettua suositusta uusiutuvan sähköntuotannon lisäyksen jatkamiseksi, näin syntyvien resurssien käyttämiseksi liikenteen ja rakennusten sähköistämiseen, älyverkkojen kehittämiseksi, jatkossa tarvittavan kansainvälisen yhteistyön tukemiseksi sekä energiasiirtymän tuomien vientimahdollisuuksien hyödyntämiseksi teknologian, infrastruktuurien ja konseptien avulla.

The availability of hydrogen transport containers is studied by using data from three manufacturers of hydrogen transport containers (Umoe Advanced Composites (UAC), Wystrach, and Hexagon). One container type from UAC is glass fibre based low CAPEX alternative, while the two others are more costly carbon fibre alternatives. The container data has been combined here with the traffic regulations reported in Deliverable 2.3.The main outcome is the maximum amounts of hydrogen that could be transported on Nordic roads using hydrogen transport containers. The focus is on the maximum amounts of hydrogen only; not on the operation efficiency nor overall economics (e.g., accounting for things like number of fillings, or container/compressor/other equipment utilisation rate).The operation time of loading or unloading containers may have significant importance on total cost of ownership (TCO). Therefore, especially for short distance transport this is an important parameter and may favour some configurations. This is also omitted in this study.If hydrogen is transported to the hydrogen refuelling station (HRS), the selected pressure level should be optimised as a part of overall hydrogen supply chain optimisation. It seems that higher pressure levels are preferred in the future, as this will lower cost of compression onsite the HRS as well as improving the HRS reliability.The focus in this study is large scale hydrogen gas transport. Therefore, 40 ft and 45 ft containers are the most interesting container sizes. However, in many cases, also 20 ft containers (including hook load model) may be of interest for lower loading and unloading times, especially for HRS with lower hydrogen dispensing amounts.This outcome can be used for building hydrogen supply chains based on centralised or semi-centralised hydrogen production and transport to single hydrogen refuelling stations or “hydrogen hubs” that can refuel heavy-duty vehicles as well as other transportation equipment (maritime, trains etc).The summary of results for Nordic countries is shown in Table 1. The results are dependent on available container solutions. Especially for new pressure levels (due to new EN 17339 standard) results should be taken as illustrative.

Electrification of the transport sector already began and the Nordic countries, specifically Norway and Iceland, have taken major steps resulting in battery electric vehicles (BEVs) already accounting for a substantial percentage of the total sales. The world is looking towards the Nordics as they are providing global examples for success. However, little is happening regarding larger vehicles as battery solution still are not able to provide heavy-duty users (e.g., buses, trucks and lorries) the mobility they need. Fuel cell electric vehicles using hydrogen as a fuel can solve this. The project focuses on providing infrastructure for a large-scale deployment of trucks, buses and lorries. The goal is to further stimulate the global technological lead, which the Nordic countries have by stimulating the very first hydrogen infrastructure roll-out for larger vehicles while at the same time map how the infrastructure build-up needs to be done, so that the transition to hydrogen vehicles can happen smoothly. Such roll-out will also benefit the use of hydrogen for trains and the maritime sector. Furthermore, in addition of sourcing the hydrogen as a by-product from the industry, in the Nordic region we have the unique opportunity to produce the hydrogen in a green manner exploiting renewable electricity production. This publication from the Next Wave project, co-financed by Nordic Innovation, offers a prospectus of using hydrogen in heavy-duty equipment, including non-road mobile machinery.

None of the today’s energy storages are feasible to serve the revolution from fossil to renewable energy due to their limited storage times and capacities. Liquid organic hydrogen carrier (LOHC) concept is promising solution to safely carry hydrogen with flexible storage times and capacities, and being compatible with the existing infrastructure for liquid fuels. LOHC liquid can be reversibly hydrogenated and dehydrogenated using catalysts, however, at relatively high temperature (e.g. 300 °C). Development needs identified were tackled in the LOHC-NESS project with focus on LOHC system based on dibenzyl toluenes (DBT) already on market. In the feasibility screening, the logistics of by-product hydrogen from chlorate and chlor-alkali plants to light industry was identified as a possible low-hanging fruit for the LOHC con-cept to enter the markets. LOHC could also be a feasible option for large-scale import of re-newable hydrogen. In the catalyst development, Pt on a titania nanopowder catalyst was found to be active for dehydrogenation of H18-DBT at lower temperature than reported ear-lier. This catalyst was tested in reactor and in own proof-of-concept station, which confirmed that catalyst wash coated on a tube was active. However, in the own station, hydrogen re-leased from H18-DBT was modest, possibly due to lower actual than set temperatures. A commercial LOHC release plant was leased from Hydrogenious GmbH for demonstration in several operation points, and for the long-term stability of operation. The largest degree of de-hydrogenation (72%) was achieved with the highest temperature (310 °C) and lowest flow tested. The decomposition of LOHC liquid in product gas and in outlet liquid was substantial in own station and in leased unit. Recovering benzene/MCH would improve economy of system. Fuel cell operation was studied with different toluene levels, also together with CO. According to these results, hydrogen from dehydrogenation of H18-DBT requires purification system, if hydrogen is used in automotive PEMFC.

As a part of the Next Wave project Hydrogen Denmark has been responsible for conductingan analysis describing the innovation and business potential for a roll-out of hydrogen and fuelcell buses in the Nordic region. All project partners have participated in this analysis andprovided data and information about the current status in these countries regarding hydrogen as a means for decarbonizing the transport sector in general and in relation to buses in particular. While there are not a great number of hydrogen and fuel cell buses on the streets in the NordicRegion currently and the hydrogen infrastructure is not yet sufficiently constructed, the potentialfor a roll out of hydrogen buses is vast. This analysis has boiled down to five recommendations going forward with initiatives forimplementation of hydrogen and fuel cell buses: infrastructure, comprehensive strategies, investments, scale and a strengthening of Nordic collaboration. Hydrogen and fuel cell technologies not only represent a means of decarbonizing the transport sector but also great business opportunities, that can create jobs, new industries, and export markets. The Nordic Region is a world leader in renewable energy and green hydrogen and fuelcell solutions are a natural next step. These new solutions present the Nordic Region with opportunities for future economic growth that is both sustainable and viable.

Electrification of the transport sector already began and the Nordic countries, specifically Norway and Iceland, have taken major steps resulting in battery electric vehicles (BEVs) already accounting for a substantial percentage of the total sales. The world is looking towards the Nordics as they are providing global examples for success. However, little is happening regarding larger vehicles as battery solution still are not able to provide heavy-duty users (e.g.,buses, trucks, and lorries) the mobility they need. The Next Nordic Green Transport Wave – Large Vehicles project will deliver an analysis on large-scale transport of hydrogen with mobile pipeline, a description of the innovation and business potential for a roll-out of FC buses in the Nordic region, as well as a coordinated action plan for stimulating the FC truck demand and a prospect for utilising hydrogen in heavy-duty equipment. Finally, the project will contribute to national and Nordic hydrogen strategy processes even providing input to a possible Nordic hydrogen strategy. In this deliverable, the most important boundary conditions for hydrogen transport from centralised production plants to HRS or industrial users are analysed for each Nordic country. The two most important boundary conditions are: 1) local regulations for the maximum length and weight of thetrucks carrying the hydrogen, and 2) availability of suitable hydrogen transport containers. The regulations are reported here, while the availability and applicability of hydrogen transport containers is reported in Deliverable 2.4. The study of local regulations includes maximum length and weight of the trucks. In addition, also allowable vehicle height, width, and vehicle configurations, as well as safety regulations and other country-specific framework conditions, are accounted for. In Sweden and Norway, different road classes apply. For Sweden these are reported for two road classes, while for Norway only roads with the 19.5 m classification are considered in the analysis.

There is a different level of industrial production and use of hydrogen in Nordic countries. Norway and Finland, are the largest producers and consumers of hydrogen. In Sweden the amounts are slightly less, but there are large number of industrial sites with significant production and use of hydrogen. In Denmark and Iceland current use of hydrogen is at a lower level. In all Nordic countries there are significant possibilities for expansion of hydrogen use for new applications and for replacing current fossil fuel-based hydrogen production by low carbon hydrogen.

An overview for the availability of by-product hydrogen in Finland, Sweden and Norway was prepared. Significant amounts of by-product hydrogen are produced in Finland, Sweden and Norway by chlor-alkali or sodium chlorate industry. However, it seems that utilisation of this hydrogen is currently very high in Sweden and Norway. Only in Finland there are sites (Äetsä, Joutseno) where significant amounts of hydrogen are vented or utilised only in heat production. Either Iceland or Denmark has any by-product hydrogen production. Electrification of the transport sector already began and the Nordic countries, specifically Norway and Iceland, have taken major steps resulting in battery electric vehicles (BEVs) already accounting for a substantial percentage of the total sales. The world is looking towards the Nordics as they are providing global examples for success. However, little is happening regarding larger vehicles as battery solution still are not able to provide heavy-duty users (e.g., buses, trucks and lorries) the mobility they need. Fuel cell electric vehicles using hydrogen as a fuel can solve this. The project focuses on providing infrastructure for a large-scale deployment of trucks, buses and lorries. The goal is to further stimulate the global technological lead, which the Nordic countries have by stimulating the very first hydrogen infrastructure roll-out for larger vehicles while at the same time map how the infrastructure build-up needs to be done, so that the transition to hydrogen vehicles can happen smoothly. Such roll-out will also benefit the use of hydrogen for trains and the maritime sector. Furthermore, in addition of sourcing the hydrogen as a by-product from the industry, in the Nordic region we have the unique opportunity to produce the hydrogen in a green manner exploiting renewable electricity production. Already, Nordic industries have taken international lead in the field of hydrogen and fuel cells and a unique cooperation exists between “hydrogen companies” via the Scandinavian Hydrogen Highway Partnership (SHHP) cooperation. Jointly they have marketed the Nordic platform for hydrogen and, at the same time, paved the way for vehicle manufacturers to deploy such vehicles in the Nordic countries. When it comes to hydrogen, the Nordics have globally leading companies both within the infrastructure and the fuel cell business. The project therefore sets forward four key activities in a unique project where technical innovation and deployment strategies are intertwined. The project will deliver an analysis on large-scale transport of hydrogen with mobile pipeline, a description of the innovation and business potential for a roll-out of FC-buses in the Nordic region, as well as a coordinated action plan for stimulating the FC truck demand and a prospect for utilising hydrogen in heavy-duty equipment. Finally, the project will contribute to national and Nordic hydrogen strategy processes even providing input to a possible Nordic hydrogen strategy.

The development and technical aspects of a hydrogen fuel cell power system and accompanying hydrogen fuel storage intended for maritime applications is presented. The fuel cells are proton exchange membrane (PEM) type and the power unit has a nominal net AC power output of 165 kW. The hydrogen storage capacity is ca. 80 kg, at a designed 300 bar maximum storage working pressure. For development, testing and safety reasons the fuel cell power system, the related electrical equipment and the hydrogen storage are constructed in a modular fashion, into two modified sea containers with dedicated compartments for each of these three functions. The system is tested both on land as well as on-board the research vessel Aranda, while operating on the Baltic Sea.

The power ramp rate capabilities of a 5 kW proton exchange membrane fuel cell (PEMFC) system are studied theoretically and experimentally for grid support service applications. The fuel supply is implemented with a fixed-geometry ejector and a discrete control solution without any anode-side pressure fluctuation suppression methods. We show that the stack power can be ramped up from 2.0 kW to 4.0 kW with adequate fuel supply and low anode pressure fluctuations within only 0.1 s. The air supply is implemented with a centrifugal blower. Air supply ramp rates are studied with a power increase executed within 1 and 0.2 s after the request, the time dictated by grid support service requirements in Finland and the UK. We show that a power ramp-up from 2.0 kW to 3.7 kW is achieved within 1 s with an initial air stoichiometry of 2.5 and within 0.2 s with an initial air stoichiometry of 7.0. We also show that the timing of the power ramp-up affects the achieved ancillary power capacity. This work demonstrates that hydrogen fueled and ejector-based PEMFC systems can provide a significant amount of power in less than 1 s and provide valuable ancillary power capacity for grid support services.

An ejector primary gas flow control solution based on three solenoid valves is designed, implemented and tested in a 5 kW proton exchange membrane fuel cell (PEMFC) system with ejector-based anode gas recirculation. The robust and cost effective combination of the tested flow control method and a single ejector is shown to achieve adequate anode gas recirculation rate on a wide PEMFC load range. In addition, the effect of anode gas inert content on ejector performance in the 5 kW PEMFC system is studied at varying load and anode pressure levels. Results show that increasing the inert content increases recirculated anode gas mass flow rate but decreases both the molar flow rate and the anode inlet humidity. Finally, the PEMFC power ramp-rate limitations are studied using two fuel supply strategies: 1) advancing fuel supply and venting out extra fuel and 2) not advancing fuel supply but instead using a large anode volume. Results indicate that the power of the present PEMFC system can be ramped from 1 kW to 4.2 kW within few hundred milliseconds using either of these strategies.

The invention relates to a method of determining water accumulation in and or removal from a fuel cell, the method comprising circulating fuel gas in the anode side of the fuel cell for producing electric energy in a fuel cell process, providing at least two purge pulses from the fuel circulation, analyzing the composition and/or volume of purged gas of said at least two gas purge pulses for determining the amount of water accumulation in and/or removal from the fuel cell.Patent family as of 26.10.2021DE602014060104 D1 20200220 DE201460060104T 20140513 EP3000146 A1 20160330 EP20140800507 20140513 EP3000146 A4 20170503 EP20140800507 20140513 EP3000146 B1 20200115 EP20140800507 20140513 JP2016518692 T2 20160623 JP20160514451T 20140513 JP6773555 B2 20201021 JP20160514451T 20140513 US10622651 BB 20200414 US20140893082 20140513 US2016099478 AA 20160407 US20140893082 20140513 WO14188061 A1 20141127 WO2014FI50358 20140513Link to current patent family on right

The general requirements for PEM fuel cell catalyst support materials are high electronic conductivity, high specific surface area and high electrochemical and chemical stability. Current structures typically consist of Pt particles on carbon black support material, but the mass activity of these high surface area nanoparticulate catalysts as well as stability of carbon support is limited. New approach for automotive PEM fuel cell catalysts are being developed in project Catapult. In this new approach platinum is deposited as an extremely thin layer on corrosion resistant supports of various morphologies including fibrous and tubular structures. VTT's has been developing two types of structures: core-shell carbon-ceramic sub-µm fibrous and ceramic sub-µm tubular catalyst supports utilizing atomic layer deposition (ALD) method on electrospun sub-µm fibres. Within this presentation we will present production supports made by making oxide layers, firstly, on carbonized electrospun fibres in order to obtain core shell fibrous supports and, secondly, on sacrificial polymeric fibres in order to make tubular supports for platinum coating. Advances of electrospinning compared to traditional processing methods will be discussed.

The invention relates to a system and a method for eliminating reverse current decay in the fuel cells. According to the invention, the system comprisesa fuel cell having an anode and a cathode;a fuel feed system for supplying the anode of the fuel cell with fuel and forming an anode system;a bypass line fitted in parallel and in flow connection with said anode system and capable of circulating fuel past the anode;an oxygen reduction unit; anda pressure unit for circulating gas in at least part of said anode system and said bypass line.The bypass line is adapted to receive and circulate a flow of hydrogen during a fuel cell shutdown in order to mix the hydrogen with any oxygen present in the anode system, and to remove the oxygen from the anode system in said oxygen reduction unit by catalytic conversion. A control unit for receiving sensing signals representative of the state of the oxygen reduction process and controlling the amount of hydrogen passing through the system in response to said sensor is also describedPatent family as of 23.11.2021EP3161888 A1 20170503 EP20150814316 20150629 EP3161888 A4 20171122 EP20150814316 20150629 FI125775 B 20160215 FI20140005635 20140630 FI20145635 A 20151231 FI20140005635 20140630 JP2017527952 T2 20170921 JP20160575158T 20150629 JP6506783 B2 20190424 JP20160575158T 20150629 US10483569 BB 20191119 US20150320824 20150629 US2017200959 AA 20170713 US20150320824 20150629 WO16001487 A1 20160107 WO2015FI50477 20150629Link to current patent family on right

The general requirements for PEM fuel cell catalyst support materials are high electronic conductivity, high specific surface area and high electrochemical and chemical stability. Current structures typically consist of Pt particles on carbon black support material, but the mass activity of these high surface area nanoparticulate catalysts is restrainer for a large-scale commercialization of PEM fuel cell for vehicles. Reduction of platinum content per vehicle and increase of mass activity are solutions paving the way for a larger utilization of the PEM fuel cells. New approach for automotive PEM fuel cell catalysts are being developed in project Catapult. In this new approach platinum is deposited as an extremely thin layer on corrosion resistant supports of various morphologies including fibrous and tubular structures. VTT's approach is to produce two type of structures: core-shell carbon-ceramic sub-µm fibrous and ceramic sub-µm tubular catalyst supports utilizing atomic layer deposition (ALD) method on electrospun sub-µm fibres. Within this presentation we will present supports made by making Ti-Nb oxide layers , firstly, on carbonized sub-µm fibres in order to obtain core shell fibrous supports and, secondly, on sacrificial polymeric fibres in order to make tubular supports for platinum coating.

Possibility to control the adhesion properties is important in various industrial applications. Since the topmost surface layers have the greatest role in adhesion thus making surface-controlled atomic layer deposition (ALD) reactions appealing method for tailoring surface adhesion properties. In this presentation we show that ALD and molecular-layer-deposition (MLD) can be used to adjust wetting characteristics of polymers and metals. Recently we have been modifying surface properties for various applications including ink-jet printed films, adhesion promoting layers for extrusion coatings and anti-ice coatings. In addition to conventional inorganic metal oxides, such as Al2O3, we have tested also inorganic-organic hybrid MLD materials. Various tools, such as XPS, FT-IR and TOF-ERDA, were used to characterize these films, and wetting behavior was determined using contact angles measurements with the sessile drop method.

The general requirements for PEM fuel cell catalyst support materials are high electronic conductivity, high specific surface area and high electrochemical and chemical stability. Current structures typically consist of Pt particles on carbon black support material, but the mass activity of these high surface area nanoparticulate catalysts is restrainer for a large-scale commercialization of PEM fuel cell for vehicles. Reduction of platinum content per vehicle and increase of mass activity are solutions paving the way for a larger utilization of the PEM fuel cells. New approach for automotive PEM fuel cell catalysts are being developed in project CATAPULT (novel CATAlyst structures employing Pt at Ultra Low and zero loadings for auTomotive MEAs; Funded by EC FP7, Fuel Cells and Hydrogen Joint Technology Initiative, grant agreement n°.325268). In this new approach platinum is deposited as an extremely thin layer on corrosion resistant supports of various morphologies including fibrous and tubular structures. VTT's approach is to produce two types of structures: core-shell carbon-ceramic sub-µm fibrous and ceramic sub-µm tubular catalyst supports utilizing atomic layer deposition (ALD) method on electrospun sub-µm fibres. Within this presentation we will present results of Nb-Ti-oxide coatings made, firstly, on carbonized sub-µm fibres in order to obtain core shell fibrous supports and, secondly, on sacrificial polymeric fibres in order to make tubular supports for platinum coating also made by ALD method. Support production and the properties of the support materials are presented, and deposition of Pt catalyst layer is discussed in this presentation.

The invention relates to a system and method for reducing impurities on the anode or cathode side of a fuel cell. The system comprises the anode or cathode of a fuel cell, a fuel or oxidizer feed line for feeding fuel or oxidizer to the anode or cathode respectively, and a circulation line connected to the fuel or oxidizer feed line for circulating part of the fuel or oxidizer through it. According to the invention, at least one filter for removing impurities in the fuel or oxidizer is arranged in the circulation line. With the aid of the invention, enriched impurities in the circulation can be cost-effectively removed, in order to increase the operating life of the fuel cell.Patent family as of 14.9.2021DE602010029598 D1 20160128 DE201060029598T 20101001 EP2483960 A1 20120808 EP20100819961 20101001 EP2483960 A4 20140212 EP20100819961 20101001 EP2483960 B1 20151216 EP20100819961 20101001 FI122525 B 20120315 FI20090006010 20091002 FI20096010 A 20110403 FI20090006010 20091002 FI20096010 A0 20091002 FI20090006010 20091002 WO11039421 A1 20110407 WO2010FI50761 20101001Link to current patent family on right

In this report different [.]-CHP technologies were reviewed. Typical features of [.]-CHP units based on internal combustion engine are: low costs, high efficiency, wide power range and ability to run on different fuels. Internal combustion engine power plants are modular, i.e. standardised units can easily be combined. Their weak points include noise, high emissions and high maintenance costs. Advantage of gas turbines is small size. Disadvantages include poor efficiency at part load and high investment cost. Advantages of Stirling engine, when compared with internal combustion engines, include stable combustion, low noise and emissions and longer maintenance intervals. Advantages of fuel cells are: high electrical efficiency (also at part load), low noise and emissions. Disadvantages are very high costs and fuel quality requirements. Besides natural gas and heating oil, wood chips or other biomass may be used in ICE, Stirling engines or microturbines. Gasification stage and gas purification is required with ICE and microturbine. The benefit is the wide availability, renewability and often low cost of biomass. Finally, [.]-CHP can use solar radiation as energy source. The disadvantage will be that output cannot be modulated according to user and system needs.

PEMFC systems are usually operated in dead-end mode with hydrogen recirculation and periodic purge. This enables high hydrogen utilization, but also makes the system prone to accumulation of inert gases, condensed water and fuel contaminants. Optimizing the anode balance of plant (BoP) and developing a control strategy to manage these drawbacks is essential to PEMFC system performance, life-time and cost. The most important parameters to optimize from the view of anode control strategy are: i) purging cycle to remove inert gases and excess water from the anode; and ii) anode gas recirculation rate to humidify inlet gas and reduce mass transfer losses. These parameters are always system dependent. In this work, a PEMFC test bench equipped with an on-line hydrogen concentration sensor has been built to facilitate different system level studies, with emphasis on anode side BoP and control strategy optimization. Some preliminary results needed for anode purge cycle optimization are presented

A measurement system for current distribution mapping for a PEFC has been developed. The segmented anode is constructed so as to have high thermal conductivity in order to prevent the formation of large temperature gradients between the electrodes. The construction is therefore feasible for use at high current densities. Both segmented and unsegmented gas diffusion layers are used. The effect of inlet humidification and gas composition at the cathode side is studied. In addition, two different flow geometries are studied. The results show that the measurement system is able to distinguish between current distribution originating from differences in proton conductivity, species concentration and gas diffusion layer properties.

In this work characterisation methods and fuel cell hardwarewere developed for studying the components of the polymerelectrolyte fuel cell (PEFC). Humidifiers and other componentswere tested in order to develop reproducible and reliableexperimental techniques. A set-up for testing larger cells andstacks was developed. A new type of polymer electrolyte membrane fuel cell wasdeveloped for laboratory investigations. Current collectormaterial and gas flow channels can easily be modified in thisconstruction. The electrode potentials can be measured at thegas backing layers, thereby allowing measurement of contactresistances. The use of a reference electrode is alsopossible. Contact resistances were studied in situ as a function oftime, clamping pressure, gas pressure and current density.Ex-situ measurements were used to validate the in-situ contactresistance measurements. The validity and error sources of theapplied in-situ measurement methods with reference electrodesand potential probes were studied using both computersimulations and experiments. An in-house membrane electrode assembly (MEA) productionline was developed. In-house produced MEAs were utilised inboth membrane degradation and mass transport studies. The durability testing of PVDF based membranes membranes wasstudied both by fuel cell experiments and ex-situ testing.Raman spectra were measured for used membranes. A current distribution measurement method was developed. Theeffect of inlet humidification and gas composition at thecathode side was studied. In addition, two different flow fieldgeometries were studied. The results of current distributionmeasurements were used to validate a PEFC model. Methods for characterising gas diffusion layer (GDL)performance by fuel cell testing and ex-situ measurements weredeveloped. The performance of GDL materials was tested withvarying cell compression and cathode humidity. Porosity, poresize distribution and contact angle were determined. Electricalcontact resistance, thermal impedance and gas permeabilitieswere measured at different compression levels. Development work on a stack with stainless steel net wascarried out as well as characterisation studies of differentstack components. Thermal impedances and flow fieldpermeability were measured. Mass transport limitations in the cathodes were studied byvarying the electrode thickness, partial pressure and humidityof oxygen. Keywords:polymer electrolyte membrane fuel cell (PEFC),contact resistance, clamping pressure, stainless steel,membrane degradation, current distribution, gas diffusionlayer, stack, thermal impedance, permeability. NR 20140805