Hydrogen storage based on highly porous materials that allow hydrogen to be adsorbed onto their surface.
Hydrogen storage using highly porous materials that allow hydrogen to be adsorbed onto their surface.
Supplies PEM fuel cells with hydrogen, including pressure regulation and recirculation of excess hydrogen.
The entirety of systems that consolidate the components necessary for the operation of a fuel cell – such as the cooling, anode, and cathode circuits. The anode circuit ensures the supply of the fuel cell with fuel (hydrogen), while the cathode circuit ensures the supply with oxygen.
Core component of the fuel cell that ensures the supply of the reactant gases and the removal of the water product through integrated flow channels. In series-connected cells (see ‘Fuel Cell Stack’), the system is cooled by means of the bipolar plate, which requires electrical conductivity, gas tightness, corrosion resistance, and mechanical stability. These requirements are met either by metallic bipolar plates made of stainless steel coated with a corrosion protection layer, or by graphite–polymer composite bipolar plates. In most cases, bipolar plates are assembled from two bipolar half-plates.
Electrochemical energy converter that continuously and directly transforms the chemical energy of a fuel – most commonly hydrogen – into electrical energy.
Components of individual electrochemical cells. In the polymer electrolyte membrane (PEM) fuel cell, the sandwich-like structure consists of two bipolar half-plates, two gas diffusion layers, and a catalyst-coated membrane at the center of the cell.
All components of the fuel cell stack and the Balance of Plant (BoP).
System for monitoring the voltage of each individual cell to ensure the proper functioning of the entire fuel cell.
Fuel cell that uses methanol as a fuel and is applied in small mobile devices as well as for off-grid power generation. An advantage is the easier storage of methanol compared to hydrogen, although the toxicity of methanol must be taken into account. In addition to water, CO₂ is produced when methanol is used. The design and the materials used in the DMFC are almost identical to those of the PEM fuel cell.
Departure from conventional drivetrains and transition to electromobility with the goal of decarbonising the transport sector. ‘Electrification’ refers to the use of electric drive systems such as batteries (BEV) and fuel cells (FCEV and/or FC-REX), with a trend towards FCEVs particularly observable in the truck segment.
Decomposition of a chemical compound using electric current (see also ‘water electrolysis’).
The liquefaction of hydrogen at an ambient pressure of 1 bar and below the boiling point of minus 253 degrees Celsius. The advantages of liquid hydrogen include its higher volumetric energy density compared to the gaseous state and the fact that liquid hydrogen tanks do not have to withstand high pressure. Disadvantages include the additional effort required for tank insulation as well as evaporation losses (boil-off), which occur despite insulation due to heat ingress into the tank.
The liquefaction of hydrogen at an ambient pressure of 1 bar and below the boiling point of −253 °C. Advantages of liquid hydrogen include its higher volumetric energy density compared to the gaseous state and the fact that liquid hydrogen tanks do not have to withstand high pressure. Disadvantages include the additional effort required for tank insulation as well as evaporation losses (boil-off), which occur despite insulation due to heat ingress into the tank.
Electric vehicles powered by an electric motor, where the required electrical energy is generated through the electrochemical reaction of a fuel cell. In most cases, an additional battery is installed to temporarily store the generated electricity in order to balance differences between demanded and supplied power.
A stack of series-connected cells. Since the output of a single fuel cell is not sufficient to power an electric vehicle, hundreds of cells are stacked together to form a fuel cell stack, with the number of cells depending on the required power. In addition to the individual cells, the stack consists of end plates, manifold plates, and a monitoring unit.
Consisting of a porous carbon-based substrate in the form of carbon paper or fabric, as well as a layer of graphite particles with a polymer binder, it ensures uniform diffusion of the reactant gases both through the layer and within the plane, while also improving water transport out of the cell.
A substance that lowers the activation energy of a reaction without being consumed in the process. In fuel cells, the catalytic layer on the anode and cathode side is the site of the electrochemical reaction. Its tasks include the mass transport of the reactants, the interfacial reaction at the electrochemically active sites, proton transport into the electrolyte phase, and electron conduction. Platinum is the metal with the highest catalytic activity for the cathodic and anodic reactions of the PEM fuel cell and is therefore used at both the cathode and the anode. Since platinum is an expensive noble metal, fine platinum particles are usually dispersed on carbon particles to increase platinum utilization and reduce the platinum loading.
Includes the conditioning of the supplied combustion air, which involves its filtration and compression as well as the regulation of humidity.
Processes in which materials are produced, stored, transported, and applied at temperatures below −160 °C.
In fuel cells, the cooling circuit is similar in design to that of an internal combustion engine, but requires an additional ion exchanger to control the conductivity of the coolant. Compared to a combustion engine of equivalent power, the coolant flow rate must be significantly higher, since heat cannot be removed to the same extent via exhaust gases.
Core component of PEM fuel cells, consisting of a catalyst-coated membrane, gas diffusion layers, and optional sub-gaskets. The MEA separates the cathode and anode chambers of a cell and serves, among other functions, for proton transport.
Currently the most promising type of fuel cell for use in mobile applications. The naming of fuel cells is based on the electrolyte used. In the PEM fuel cell, a solid polymer membrane acts as the proton exchange electrolyte. The operating temperature of low-temperature PEMFCs ranges between 60 and 85 °C. Hydrogen is used as the fuel.
A variant of water electrolysis in which the design of the electrolyser is similar to that of the PEMFC. Its main advantages over other electrolysis technologies lie in its ability to operate dynamically.
Medium-temperature fuel cell that uses phosphoric acid as the electrolyte.
All production steps required for the fabrication of the catalyst-coated membrane, the gas diffusion layer (GDL), and the bipolar plate. Typically, the coated membrane and the GDL are subsequently combined in an additional step to form the membrane electrode assembly (MEA).
A core component of the PEM fuel cell. It conducts protons from the anode to the cathode, while at the same time acting as an electrical insulator and as a barrier separating the reactant gases. With catalyst coatings on both sides, it enables the controlled reaction of hydrogen and oxygen to form water. The membranes are typically made of perfluorosulfonic acid (PFSA) and include a reinforcement layer with a thickness between nine and 25 micrometres.
Valve through which nitrogen is released from the fuel cell stack.
In the context of FCEVs, a powertrain configuration in which a relatively low-power fuel cell system is installed. It is primarily used to charge a traction battery, which is dimensioned as the main energy storage system.
High-temperature fuel cell that uses a molten mixture of alkali carbonates as the electrolyte.
The chemical element with the lowest density and atomic number 1, which under standard conditions occurs as molecular hydrogen in a colorless and odorless gaseous form.
Produced via steam reforming of fossil fuels such as coal, natural gas, or oil. In contrast to grey hydrogen, the separated CO₂ is captured and stored underground using carbon capture and storage (CCS) technology.
Produced via steam reforming of fossil fuels such as coal, natural gas, or oil. In this process, the separated CO₂ is released unused into the atmosphere (see “water electrolysis”).
Produced via water electrolysis using renewable energy sources such as wind, water, or solar power (see “water electrolysis”).
Brennstoffzellen, die Wasserstoff als Brennstoff verwenden. Eine Ausnahme bildet die Direktmethanol-Brennstoffzelle (DMFC), wobei auch Modelle wie die Festoxid-Brennstoffzelle (SOFC) existieren, die sowohl mit Wasserstoff als auch mit Methan oder methanhaltigen Gasen betrieben werden können.
The decomposition of water into hydrogen and oxygen using electrical energy with the goal of producing hydrogen. This process takes place in an electrolyser, typically through alkaline electrolysis or PEM electrolysis.
Production, distribution, provision, and refuelling of hydrogen for applications across all sectors.
A central factor for the potential success of fuel cells in the mass market for mobile applications. Currently, the production of grey hydrogen is considered the most economical solution due to its relatively low production costs.
