Development of copper-coated and expanded natural graphite-added LaNi5 hydrogen stroge material

In this study, the effects of copper coating and/or ENG (expanded natural graphite) addition on the hydrogen storage performance of LaNi5 are studied both experimentally and theoretically. Within the scope of the theoretical study, a two-dimensional axisymmetric mathematical model covering complex heat and mass transfer, taking into account the flow occurring during the charge/discharge process in the reactor, is developed and solved numerically. The developed mathematical model contributes to understanding and interpreting the basic mechanism of hydride/dehydride formation. The developed model is validated using experimental data on the amount of stored hydrogen and reactor temperatures. In experimental studies, the thermal conductivity of LaNi5 is increased by ~9 and ~13 times by copper coating or ENG addition. A significant reduction in hydrogen charging times is observed. On the other hand, as copper coating and ENG addition increase, the amount of stored hydrogen tends to decrease. Based on these results, various new samples are prepared by mixing the decided copper-coated LaNi5 and ENG-added LaNi5 powders. A storage material is chosen that both reduce the charging time without reducing the storage amount. The thermal properties of the optimized storage material are improved by approximately 350%.