Fuel cells generate electricity by converting the chemical energy found in fuels into electrical energy through a reaction with oxygen.

Unlike traditional batteries, which store energy in an electrochemical form and release it as needed, fuel cells continuously produce electricity as long as they are supplied with fuel and oxygen. Typically, the fuel used is hydrogen, while the oxygen is sourced from the ambient air.

A fuel cell comprises two electrodes: an anode and a cathode, separated by an electrolyte. Hydrogen fuel is introduced at the anode, and oxygen enters at the cathode. At the anode, a catalyst facilitates the splitting of hydrogen into positive hydrogen ions (protons) and negatively charged electrons. The electrolyte permits the protons to pass through to the cathode, but it restricts the flow of electrons, thereby creating an electric current through an external circuit.

At the cathode, the electrons and protons combine with oxygen from the air to form water, which is the sole by-product of this reaction. This characteristic makes fuel cells a clean and efficient energy source. However, the catalysts used in fuel cells are often made from precious metals, such as platinum, which can lead to higher production costs.

Fuel cells have diverse applications, ranging from powering electric vehicles to providing energy for buildings and electronic devices. They represent a promising technology for a sustainable future, as they generate electricity without the combustion of fossil fuels and emit only water as a by-product. Nevertheless, challenges remain, including the need to discover more affordable and durable materials for catalysts and to enhance the efficiency of hydrogen production processes.