What is a hydrogen fuel cell

Fuel cell: advantages and disadvantages of fuel cells

The fuel cell is a power source with the help of which chemical energy is converted directly into electrical energy by electrochemical oxidation of an easily oxidizable substance with an oxidizing agent. The electrochemical oxidation of the fuel cell is also known as cold combustion. The easily oxidizable substance can be, for example, hydrogen, hydrazine or methanol. Oxygen and air, for example, serve as oxidizing agents. The reaction components are fed continuously and separately to the corresponding electrodes, between which there is an electrolyte.

However, the fuel cell is not an energy storage device or electricity storage device. The fuel cell is a galvanic cell. The hydrogen-oxygen fuel cell is particularly common, which is why it is often referred to as a fuel cell for short. The hydrogen-oxygen fuel cell is also the most widely researched type of fuel cell.

Advantage of the fuel cell

Nowadays, the generation of electrical energy from chemical energy sources mostly takes place through combustion and the use of the resulting hot gases. A heat engine drives a generator. This happens by converting the thermal energy into mechanical work. The fuel cell, on the other hand, has a key advantage: it is able to achieve the transformation without converting it into heat and power. This means that the fuel cell initially has gigantic potential to be used, for example, in mobile devices or in fuel cell vehicles. For example, it can also be used in an electric car: the fuel cell then also functions as a range extender and improves the range of electric cars.

In the field of thermodynamics, the fuel cell represents an internal combustion engine that converts chemical energy into electrical energy, which, like mechanical work, has an energy share of 100 percent. In practice, the efficiencies achieved so far by fuel cells are significantly higher than those of Otto or diesel engines, but not significantly better than those of modern gas turbines, which can operate at higher temperatures.

Disadvantage: energy-intensive production of hydrogen

The biggest disadvantage of the fuel cell is that hydrogen first has to be produced in order to operate. This production of hydrogen is currently still extremely energy-intensive, which is why the hydrogen fuel cell has not yet become a real alternative. Most recently, the US start-up Lilliputian Systems announced that it wants to produce fuel cells for sensible and environmentally friendly use in consumer electronics products. Will it become more than just an announcement?

Types of fuel cells

In the case of fuel cells, a distinction is made between:

  • SOFC - Solid Oxide Fuel Cell
  • PEMFC - Proton Exchange Membrane Fuel Cell
  • AFC - Aklkaline Fuel Cell
  • MCFC - Molton Carbonate Fuel Cell
  • DMFC - Direct Methanol Fuel Cell
  • PAFC - Phosphor Acid Fuel Cell

The latest fuel cell news is available fresh every day in the Cleantech business magazine Cleanthinking.de.