Modeling of electrochemical hydrogen storage in metal hydride electrodes

The recently presented Electrochemical Kinetic Model (EKM), describing the electrochemical hydrogen storage in hydride-forming materials, has been extended by the description of the solid/electrolyte interface, i.e. the charge transfer kinetics and electrical double layer charging. A complete set of equations has been derived, describing the equilibrium hydrogen partial pressure, the equilibrium electrode potential, the exchange current density and the electrical double layer capacitance as a function of hydrogen content in both solid-solutions and two-phase coexistence regions. The model has been applied to simulate isotherms of Pd thin films with a nominal thickness of 200 and 10 nm. The model demonstrates good agreement between the simulation results and experimental data.