Lighter fluid can power your car

Fuel cell: hydrogen as an energy carrier

Fuel cells convert the chemical energy of hydrogen directly into electricity. They have a very high efficiency of theoretically 70 to almost 100 percent. The efficiency of internal combustion engines is around 40 percent, and that of electric motors around 90 percent. In a fuel cell car, the electricity for the car's electric motor is generated using a fuel cell.

Fill up quickly and go a long way - advantages of fuel cell cars

Fuel cell cars do not emit any exhaust gases, only harmless water vapor. Their range is also much longer than that of battery-powered electric cars: around 500 kilometers on a full tank compared to 200 to 300 kilometers. The necessary hydrogen can be refueled in a few minutes. Charging an electric car, on the other hand, takes at least half an hour.

Expensive and there are no gas stations - disadvantages of fuel cell cars

Unfortunately, fuel cell cars cost almost twice as much as comparable combustion models. One of the reasons for this is that the technology is very complex and the expensive precious metal platinum is built into the fuel cells. Another disadvantage: the necessary infrastructure is also very expensive and therefore hardly available. In 2016 there were fewer than 30 public hydrogen filling stations in Germany. At least 1,000 would be necessary for a comprehensive network.

This is how a fuel cell works

  • The reaction of hydrogen and oxygen is a redox reaction: hydrogen is oxidized (releases electrons), oxygen is reduced (takes electrons), energy is released and water is created.
  • In a fuel cell, for example, these two partial reactions are separated by a membrane so that the electrons flow through an external circuit. The usable energy is released in the form of electricity and can drive an electric motor.
  • The principle on which the fuel cell is based was discovered as early as 1838. It was not until the second half of the 20th century that fuel cells were used technically on a larger scale, although their use remained limited to niche applications for a long time, for example in space travel or in the military.

Hydrogen - available everywhere, just not in its pure form

  • Hydrogen is the most common chemical element in the universe. It is also found in larger quantities on earth, especially as water, but also in almost all organic compounds, e.g. B. also in petroleum.
  • On earth, hydrogen occurs almost exclusively chemically bound and has to be released from its compounds using energy - e.g. B. by the electrolysis of water - H2O.
  • Electricity is required for electrolysis. If this comes from renewable energies, hydrogen is one of the most environmentally friendly energy sources.

Fuel cells in cars

  • Fuel cell cars not only need fuel cells to generate energy, they also need an electric motor and hydrogen tanks.
  • The fuel cell in the car is actually a whole stack of several hundred individual fuel cells.
  • The electric motor is used to drive the car.
  • The high-pressure tanks in the rear of the vehicle are filled with gaseous hydrogen. They have to be particularly robust, as hydrogen is highly flammable and explosive in combination with air. That is why they consist of several layers and composite materials.

 

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