In the second half of the 20^th century, humanity has realized that fossil fuels like coal and oil are running low. The development of alternative energy sources has been steadily progressing ever since. A promising approach is the fuel cell: a galvanic element that generates electrical energy from the reaction of elemental hydrogen with oxygen. The running chemical reaction is:

H₂ + ¹/₂ O₂ → H₂O + electrical energy

In the pupil laboratory NatLab the new chemical experiment "fuel cell" was designed for high school students. Within three hours, the students record fuel cell characteristics and switch cells in parallel and in series. Particular attention is paid to the heart of the cell, a semipermeable membrane made of perfluorinated sulfonic acid. This ionomer allows only protons to pass through, thereby enabling the "cold burning" of hydrogen gas. Other commercial fluoropolymers are widely used in chemical-industrial processes. Specially fluorinated ionomers, e.g. Nafion^®, are also counted among the high performance plastics.