Estimation of the State of Charge of a Hydride Hydrogen Tank for Vehicle Applications

Metal hydrides have been receiving a great attention as an effective and safe way to store hydrogen. Metal hydride-based hydrogen tank has a huge potential for the application of on-board hydrogen storage on the fuel cell electric vehicles. When the metal hydrides aging with cycle, the capacity of the hydrogen tank decreases. In this work, a mathematical model to estimate the hydrogen supply capability and observe degeneration conditions with cycle life of a hydride tank is presented. The used method is based on the exploitation of properties of Pressure-Composition-Temperature (PCT) isotherm of hydrogenation process in the hydride tank and the empirical modeling using experimental data. The established model can be used to describe the hydrogen supply capability and the concentration in the tank with equilibrium pressure and temperature under static state. This model could also be used to determine the aging degree of the tank after several charge and discharge cycles.