Working principle of hydrogen-oxygen fuel cells
A hydrogen-oxygen fuel cell uses hydrogen as fuel and oxygen as oxidant. It converts chemical energy into electrical energy through the combustion reaction of the fuel, and works on the same principle as a primary cell.
When a hydrogen-oxygen fuel cell is operating, hydrogen is supplied to the hydrogen electrode and oxygen to the oxygen electrode. Hydrogen and oxygen react with a catalyst at the electrodes, passing through an electrolyte to form water. At this point, the hydrogen electrode has excess electrons and is negatively charged, while the oxygen electrode is positively charged due to a lack of electrons. Once the circuit is switched on, this combustion-like reaction process can continue continuously.
During operation, fuel (hydrogen) is supplied to the negative electrode, and oxidant (oxygen) is supplied to the positive electrode. Hydrogen decomposes into positive ions (H+) and electrons (e-) at the negative electrode under the action of a catalyst. Hydrogen ions enter the electrolyte, while electrons move towards the positive electrode along an external circuit. The electrical load is connected to this external circuit. At the positive electrode, oxygen and hydrogen ions from the electrolyte absorb electrons arriving at the positive electrode to form water. This is the reverse process of water electrolysis.
Features of hydrogen-oxygen fuel cells
Because hydrogen-oxygen fuel cells convert the energy released from a chemical reaction into electrical energy, they are clean and environmentally friendly, with water being their primary byproduct. Secondly, hydrogen-oxygen fuel cells can continuously generate electricity; as long as hydrogen and oxygen are continuously supplied, the chemical reaction will continue indefinitely. Thirdly, hydrogen-oxygen fuel cells emit relatively little waste and produce very low noise.
