At present, fuel cells are also used as batteries for electric vehicles. Fuel cells are different from internal combustion engines. They do not convert chemical energy into heat energy and then into useful work like internal combustion engines. It is also different from the mutual conversion of charge and discharge, electrical energy and chemical energy of ordinary batteries. process, but directly converts the chemical energy of the fuel into electrical energy, so the heat loss is small and the energy conversion efficiency is high. Compared with internal combustion engines, it is 50%~100% higher than that of ordinary batteries. It is 100%~200% higher than ordinary batteries. The operation process of hydrogen fuel cells uses the chemical reaction of hydrogen and oxidation to directly convert into electrical energy. Only water is discharged, which is zero pollution and hydrocarbons. During the operation of the fuel cell, in addition to discharging water, it also produces CO2 and a very small amount of CO, HC, NOX and other harmful gases, which is ultra-low pollution. Generally, fuel cells and supercapacitors are used together to solve the operating temperature requirements of fuel cells. Fuel cells and supercapacitors are complementary and are an ideal hybrid power mode and one of the development directions of hybrid vehicles.