Reversible de-/hydriding characteristics of a novel Mg_(18)In_1Ni_3 alloy

摘要

The present work demonstrates the reversible hydrogen storage properties of the ternary alloy Mg_(18)In_1Ni_3, which is prepared by ball-milling Mg(In) solid solution with Ni powder. The two-step dehydriding mechanism of hydrogenated Mg_(18)In_1Ni_3 is revealed, namely the decomposition of MgH_2 is involved with different intermetallic compounds or Ni, which leads to the formation of Mg_2Ni(In) solid solution or unknown ternary Mg-In-Ni alloy phase. As a result, the alloy Mg_(18)In_1Ni_3 shows improved thermodynamics in comparison with pure Mg. The Ni addition also results in the kinetic improvement, and the minimum desorption temperature is reduced down to 503 K, which is a great decrease comparing with that for Mg-In binary alloy. The composition and microstructure of Mg-In-Ni ternary alloy could be further optimized for better hydrogen storage properties.