Towards a consistent understanding of the metal hydride reaction kinetics: Measurement, modeling and data processing

Hydriding/dehydriding reaction kinetics of metal hydrides (MH) is an important yet controversial issue. In the last few decades, numerous studies have been dedicated to elaborate the reaction phenomena for various hydride materials. Some crucial aspects sketching the physical picture of the reaction, e.g. the controlling mechanism, Avrami exponent as well as apparent activation energy, are frequently discussed using the solid-state kinetic models. It is noted, however, that the results show considerable disagreement even for the material prepared in a single batch. From the literature review, it appears that no consistent understanding on the reaction kinetics of hydride materials could ever be achieved, unless carefully selected models and appropriate statistical processing techniques are used to interpret data obtained from well-designed experiments.