The basic principle of a hydrogen fuel cell is the reverse reaction of the electrolysis of water. Hydrogen and oxygen are supplied to the anode and cathode, respectively, after the hydrogen diffuses outward through the anode and reacts with the electrolyte. , it releases electrons and reaches them via an external cathode.
The electrodes of hydrogen fuel cells are generally made of precious metals such as platinum, palladium and rhodium. A precious metal catalyst on the anode promotes the hydrogen oxidation reaction, thereby producing electrons. A precious metal catalyst on the cathode promotes the oxygen reduction reaction, which accepts electrons and forms water. Physical insulation between the electrodes and the electrolyte prevents explosions from mixing oxygen and hydrogen.
An electrolyte is an ionizable substance, usually a solid polymeror a liquid solution. They have good ion transport and electron transport blocking properties, which can prevent the direct transfer of electrons between electrodes while allowing the transfer of ions to the cathode. Typical electrolytes include solid polymer membranes and liquid electrolyte solutions.
Characteristics of hydrogen fuel cells
1. No pollution: Hydrogen fuel cells do not pollute the environment. This is by electrochemical reaction, rather than combustion (gasoline, diesel) or energy storage (battery) - the most typical traditional backup power solution. Combustion releases pollutants such as COx, NOx, SOx gases and dust.
As mentioned above, fuel cells only produce water and heat. If hydrogen is produced from renewable energy sources (photovoltaic panelsues, wind energy, etc.), the entire cycle is completely emission-free.
2. Quiet: Hydrogen fuel cells operate quietly, with only about 55 dB of noise, which is equivalent to the level of a normal conversation. This makes the fuel cell suitable for indoor installation or where there are exterior noise restrictions.
3. High efficiency: The power generation efficiency of hydrogen fuel cells can reach more than 50%. This is determined by the conversion properties of the fuel cell, which directly converts chemical energy into electrical energy without need. for the intermediate transformation of thermal energy and mechanical energy (generator).