High-temperature failure behaviour and mechanism of K-based additives in Li–Mg–N–H hydrogen storage systems

摘要: We report the high-temperature failure behaviours and mechanisms of K-based additives in Mg(NH2)2–2LiH hydrogen storage system. The onset release from a Mg(NH2)2–2LiH–0.08KF sample is approximately 80 °C; this 50 °C reduction comparison with pristine Mg(NH2)2–2LiH. However, positive effects disappear when uptake KF-added samples are performed at higher temperatures (>200 °C). change crystal structure dehydrogenation product, enlargement grain particle sizes dehydrogenation/hydrogenation products, increase inhomogeneous degree mixing distribution should be three most important reasons for increased operating temperature during follow-up cycles. In particular, ability to lower system can sufficiently recovered after ball milling. Therefore, treatment only phenomenological instead being natural. Strictly limiting K-added critical maintaining superior effect additives.