Fadonougbo, Julien O. Kim, Han-Jin Suh, Byeong-Chan Yim, Chang Dong Na, Tae-Wook Park, Hyung-Ki Suh, Jin-Yoo 2024-01-12T03:32:53Z 2024-01-12T03:32:53Z 2022-02-23 2022-01 0360-3199 https://pubs.kist.re.kr/handle/201004/76812 In this investigation, we report the cyclic performance, microstructure and thermal properties of near eutectic Mg-Ni alloys with different Ni contents (4.4, 11.3 and 16.3 at%). The starting cast ingots are mechanically chipped to flakes of about 400 mm, all displaying composite structures characterized by a typical eutectic microstructure with rather coarse features (1-5 mm). The flakes are cycled 1000 times at 330 degrees C under 30/1 bar H2 for the absorption/desorption processes. The hydrogen storage capacity is maintained throughout the cycling: 5.09, 4.46 and 3.49 wt% H2 for Ni16.3, Ni11.3 and Ni4.4 (at%), respectively. No significant microstructural change is observed, indicating the excellent stability of the alloys at elevated temperatures. Nevertheless, a marked porosity, and spheroidal Mg2Ni clusters can be noted after cycling, however their exact contribution to reaction kinetics has yet to be fully elucidated. An attempt is made to estimate the dehydrogenation activation energy of Ni16.3, and the calculated value seems comparable to that obtained for an early cycling stage (10 cycles). In the light of the superior stability under cyclic service and the low decomposition temperature, the Mg-Mg2Ni system is shown to possess an excellent potential for long-term hydrogen and heat storage applications. English Pergamon Press Ltd. On the long-term cyclic stability of near-eutectic Mg-Mg2Ni alloys Article 10.1016/j.ijhydene.2021.11.025 1 International Journal of Hydrogen Energy, v.47, no.6, pp.3939 - 3947 International Journal of Hydrogen Energy 47 6 3939 3947 N scie scopus 000744011300001 2-s2.0-85120438497 Chemistry, Physical Electrochemistry Energy & Fuels Chemistry Electrochemistry Energy & Fuels Article HYDROGEN STORAGE PROPERTIES HYDRIDING PROPERTIES SORPTION KINETICS METAL-HYDRIDES MG MAGNESIUM NI MG2NIH4 DESORPTION MICROSTRUCTURE Metal hydrides Hydrogen solid-state storage Mg-Ni eutectic alloys Cyclic performance