Mechanical Engineering Wiki / Fuel cell
Fuel cell
In a fuel cell, a fuel reacts with an oxidizing agent. This produces electrical energy, heat and water as reaction products. Today, fuel cells are mainly operated with hydrogen as fuel, which is why they are often referred to as hydrogen cells. Areas of application include fuel cell heating systems, marine and aerospace applications and rail transportation. They have also been under discussion for a number of years as a drive system for vehicles - fuel cells are intended to help establish climate-friendly road traffic.
What is a fuel cell?
A fuel cell is a galvanic cell whose main task is to generate thermal and electrical energy. No additional external energy is required for this, which is why it is also referred to as "cold combustion". In the fuel cell, hydrogen is fed to the anode via the tank, while oxygen from the ambient air is fed to the cathode. The reaction between the two substances releases thermal and electrical energy without generating nitrogen oxides. The permanent supply of hydrogen and oxygen also enables continuous energy generation. Important: A fuel cell is an energy converter and not an energy storage device - this is the decisive difference to a battery.
Failed areas of application for fuel cells
Fuel cells offer the possibility of self-sufficient energy generation with a particularly low weight. This is an advantage in many areas, which is why the technology is used in the aerospace industry, for example. Many companies therefore also wanted to introduce fuel cells as a mobile power supply for electronic devices. For example, solutions for portable charging devices for smartphones, which could be charged on the move using a fuel cell, were under discussion. However, there have been no actual market launches to date. Experts also assume that the demand for fuel cells to power small electronic devices will probably not prevail. Batteries used instead are already proving to be small, compact and powerful enough.
Fuel cells in motor vehicles
Fuel cells are being considered as an alternative to classic combustion engines. Although battery electric vehicles (BEV) are currently favored in Germany, fuel cells are playing a greater role in e-mobility in Japan. Here, vehicles with fuel cells are considered an important alternative on the road to the energy transition and are on the roads as fuel cell vehicles or fuel cell electric vehicles (FCEV ). Compared to traditional electric cars with batteries, vehicles with a fuel cell offer shorter charging times and greater ranges. The disadvantages, however, are that green hydrogen in particular is not yet (sufficiently) available to operate fuel cells and that the cost-effective series production of cars with fuel cells is still a long way off.
Advantages of the fuel cell
When it comes to the advantages of fuel cells, it is first necessary to examine what the fuel cell is being compared with. As a drive system in a motor vehicle, the fuel cell offers a number of advantages over diesel engines - the reduced CO2 emissions alone are remarkable. When comparing a fuel cell with a conventional battery, however, the differences are not quite as great: Fuel cells offer the advantage of lower weight, but are associated with significantly higher investment costs.
With regard to the automotive industry, it may be an opportunity not to view battery and fuel cell technology separately as competing offers, but to recognize the advantages of possible hybrid forms. However, some experts believe that fuel cells are the better choice from the outset, especially for large, heavy vehicles - the additional burden of heavy batteries can be avoided with their help.