What is the principle of hydrogen fuel cell?

The principle of hydrogen energy fuel cell is the reverse reaction of electrolytic water, which provides hydrogen and oxygen to anode and cathode respectively. After the hydrogen diffuses outward through the anode and reacts with the electrolyte, the released electrons reach the cathode through the external load. Hydrogen fuel cell refers to a device that generates electric energy through the chemical reaction between hydrogen and oxygen (there has also been a "hydrogen internal combustion engine" driven solely by burning hydrogen, such as BMW's hydrogen energy 7 series). The driving force of hydrogen fuel cell vehicle comes from the motor on the vehicle, just like pure electric vehicle, so hydrogen fuel cell vehicle can be understood as "electric vehicle with hydrogen fuel generator". Advantages of hydrogen fuel cell: no pollution: hydrogen fuel cell has no pollution to the environment. Through electrochemical reaction, rather than combustion (gasoline and diesel) or energy storage (battery). Combustion releases pollutants such as carbon monoxide gas and dust. Fuel cells only produce water and heat. Noisy: The hydrogen fuel cell runs quietly, and the noise is only about 55dB, which is equivalent to the level of normal calls. This makes the fuel cell suitable for indoor installation or outdoor places with limited noise. High efficiency: The power generation efficiency of hydrogen fuel cells can reach more than 50%, which is determined by the conversion nature of fuel cells. Chemical energy is directly converted into electrical energy without intermediate conversion between thermal energy and mechanical energy (generator).