Lasergravieren von Prägeplatten

Laser engraving of embossing plates

We are the leading specialist in the field of producing embossing plates for fuel cell bipolar plates as well as the Machining of support structures for use in PEM-electrolyzers. Our high-precision laser micromachining technologies enable us to deliver fuel cell technology and hydrogen production requirements. By using hydrogen as a clean energy source, we make an essential contribution in the direction of renewable energy.

Proton Exchange Membrane (PEM) Fuel Cell: What is it, and how does it work?

The proton exchange membrane (PEM) fuel cell is a progressive technology that produces clean electricity by converting hydrogen and oxygen into electric energy. The PEM-fuel cell consists of many cells separated by a conductive membrane. Hydrogen is supplied on the anode side, while oxygen or air is provided on the cathode side. The chemical reaction between hydrogen and oxygen in the counter ward of the membrane causes the production of electric energy and water as the only side product.

Why are the PEM Fuel Cell and Hydrogen currently so urgently needed?

Both PEM-fuel cells and hydrogen play a vital role in shaping a sustainable and environmentally friendly energy future. With longer operating ranges and faster refueling, the PEM-fuel cells became a necessary alternative to battery-powered motor vehicles. Furthermore, they serve as a decentral power supply in your home, especially in combination with solar cells, to save green energy and only use it when necessary. The wide application of hydrogen as a clean energy source can help reduce CO₂ emissions and slow down climate change. 

Proton Exchange Membrane (PEM) Electrolyzer: Deployment and Utilization

The proton exchange membrane electrolyzer is a crucial element in hydrogen production and plays an essential role in using renewable energies. The electrolyzer uses the PEM-fuel cell technology inversely by obtaining hydrogen and oxygen from water with electrical energy. Through the application of electrical voltage to the PEM-membrane, water is split into its original parts – hydrogen and oxygen. The extracted hydrogen can now be stored as green energy and later used, for example, to power vehicles, heat buildings, or supply industrial processes. PEM-electrolyzers are effective environmental instruments for producing green hydrogen and are crucial in shaping a sustainable hydrogen economy.

New National Hydrogen Strategy of the Federal Government of July 27, 2023

The federal government has noticed hydrogen’s massive potential for the Energiewende, pursuing a new ambitious hydrogen strategy. Until 2023 the generation capabilities are supposed to be doubled to 10 gigawatts, which could cover 20-30 percent of Germany’s hydrogen demand. This strategy would need expanding plants, storage facilities, and services. A particular focus is on increasingly producing hydrogen from renewable energies to achieve sustainability targets. The vision is to make Germany climate-neutral by 2045.

Components of the PEM Fuel Cell (PEMFC stack)

In the bipolar stack design, the individual cells are electrically contacted via a common bipolar plate. Through the bipolar plate on one side, the fuel gas leads to the respective electrodes, and on the other side, air or oxygen leads there. Its name does the bipolar plate get of the voltage applied on both sides: minus on the anode side (hydrogen), plus on the cathode side (oxygen). The stack voltage describes the sum of the single-cell voltages, which are dissipated via current collectors or pantographs at the beginning and end of the cell stack. The stack voltage depends on the size of the active space meaning that doubling the space also doubles the electricity.

Embossing plate – design by Fraunhofer IWU

The PEM fuel cell consists of multiple layers and components arranged in a stack and works together to make energy conversion possible. Here are the essential components:

At the anode side of the fuel cell, hydrogen is supplied as fuel gas. The protons pass through the proton exchange membrane while the electrons pass through an external circuit to generate electric energy.

At the cathode side of the fuel cell, oxygen (out of the air) is supplied. The oxygen molecules react with the protons, transported through the membrane, and the electrons from the anode side to form water.

Directly next to the anode and cathode is the gas distribution system. This layer provides an even distribution of the fuel gas (hydrogen) on the anode side and oxygen on the cathode side over the complete surface of the electrodes. Efficient gas distribution is necessary for an even reaction and to avoid hotspots.

The diffusion layer lies between the gas distribution layer and the electrode. Its task is to optimize the gas exchange by transporting the fuel gas and oxygen evenly to the reaction layers.

Directly next to the diffusion layer is the reaction layer. Fuel gas (hydrogen) and oxygen meet with the protons that diffuse through the membrane on this layer. At this point, the electric reaction takes place, which releases electrons and protons.

You can find the proton exchange membrane (PEM) in the middle of the fuel cell. This membrane is one of the central components of the PEM-fuel cell as it conducts the protons but is electrically insulating so that electrons cannot pass through it. The PEM makes the separation of fuel gas (hydrogen) and oxygen and makes the proton transport between the electrodes possible.

The interaction of the components – anode, cathode, gas distribution, diffusion layer, reaction layer, and membrane – makes it possible for the PEM-fuel cell to generate environmentally friendly electricity without producing harmful emissions.