Importance of thermal conductivity and stress level during a phase (hydride) transformation in magnesium

There are many different systems of an autonomous energy storage including accumulators and devices for renewable energy. Systems based on reversible metal hydrogenation have recently been introduced. The selection metals is considerations temperature pressure conditions the hydrogenation/dehydrogenation cycle, as well desired hydrogen capacity. Magnesium one main challenging with respect to these since having a capacity up 7.6 w.%. For Mg forming MgH2, it was soon established that size particles plays critical role kinetics (rate) hydride formation accelerates when decreases. present study shows overall diameter characteristic controlling because distinct issues. A distribution entails strong dispersion transferring heat reaction, which characterizes MgH2 phase transition. Moreover, accompanied by great increase unit-cell volume, developing noticeable internal stresses within surface layers particles, thus turning systematic flaking decrease sizes powder particles. results numerical modeling comply experimental data. This makes possible predict best initial able achieve fast during hydrogenation. Furthermore, analysis demonstrates kinetics, not only using fine powders, but also deviation from average particle minimized.