Fuel cell, also known as electrochemical generator, is a kind of cell that mainly uses oxygen or other oxidants to carry out oxidation-reduction reaction and convert chemical energy in fuel into electrical energy. It is the fourth generation technology after hydropower, thermal power and atomic power. Fuel cell is a new power source with a bright future. Generally, hydrogen, carbon, methanol, borohydride, gas or natural gas are used as the fuel, as the negative electrode, oxygen in the air is used as the positive electrode, and the active substances (fuel and oxidant) of fuel cell enter at the same time of reaction. Therefore, this kind of battery is actually just an energy conversion device, which can directly convert chemical energy into electrical energy in an electrochemical way without going through a thermal engine process, and is not limited by the Carnot cycle effect, so the energy conversion efficiency is high.