Definition of fuel cell type for electric buses

A fuel cell is an energy conversion device that directly converts chemical energy from fuel into electrical energy. It may appear to have positive and negative electrodes and electrolytes, similar to a battery, but in essence, it cannot "store electricity" but is a "power plant". There are also various types of fuel cells, and after years of exploration, the most promising one for use in automobiles is proton exchange membrane fuel cells. Its working principle is: hydrogen gas is sent to the negative electrode, and through the action of a catalyst (platinum), two electrons in the hydrogen atom are separated. These two electrons are attracted by the positive electrode and generate a current through an external circuit. Hydrogen ions (protons) that have lost electrons can pass through a proton exchange membrane (i.e. a solid electrolyte), and recombine with oxygen atoms and electrons at the positive electrode to form water. Since oxygen can be obtained from the air, as long as hydrogen is continuously supplied to the negative electrode and water (steam) is taken away in a timely manner, fuel cells can continuously provide electricity.
The advantages of fuel cells are:
Energy conversion efficiency
The energy conversion efficiency of fuel cells can reach as high as 60-80%, which is 2-3 times that of internal combustion engines.
Non polluting environment
The fuel of a fuel cell is hydrogen and oxygen, and the product is clean water. It does not produce CO and CO2, nor does it emit sulfur and particles, nor does it react at high temperatures, nor does it produce NOX. If a car mounted methanol reforming catalyst is used to supply hydrogen, only a small amount of CO and less CO2 will be generated.
Long lifespan
The fuel cell itself operates without noise, motion, or vibration, and its electrodes only serve as a place for chemical reactions and conductive channels. They do not participate in chemical reactions, have no loss, and have a long lifespan.