It is primarily used in fuel cell vehicles. Currently, high-pressure hydrogen storage cylinders for commercial use are categorized into four types: Type I, Type II, Type III, and Type IV. Type I and Type II cylinders are primarily made of metal and are mainly used for stationary hydrogen storage at hydrogen refueling stations. Type III and Type IV cylinders are both wrapped with carbon fiber, significantly increasing their working pressure and serving as the mainstream solution for on-board hydrogen storage.