Enhanced hydrogen storage properties of a Mg–Ag alloy with solid dissolution of indium: a comparative study

Abstract

A comparative study of Mg 5.7 In 0.3 Ag and Mg 6 Ag alloys was conducted to reveal the effects of indium (In) solid solutions on the hydrogen storage properties of Mg-based alloys. Different from the Mg 6 Ag alloy, the as-cast Mg 5.7 In 0.3 Ag alloy was composed of a Mg(In) solid solution and Mg 3 Ag. However, an initial hydrogen absorption/desorption treatment (i.e., activation) propelled the In atoms in Mg(In) toward Mg 3 Ag, forming (Mg, In) 3 Ag in the activated sample. This transformation involving the dissolution of In atoms from Mg into solid Mg 3 Ag not only greatly improved the thermodynamics of hydrogen desorption but also enhanced its catalytic effect on hydrogen desorption from additional MgH 2 . The (Mg, In) 3 Ag-H 2 system exhibited altered thermodynamics, as its enthalpy change of the hydrogen desorption was 62.6 kJ mol À1 H 2 . Moreover, the activation energy of the hydrogen desorption from the Mg 5.7 In 0.3 Ag sample was lowered to 78.2 kJ mol À1 .

Hydrogen Sorption Behavior of Cast Ag-Mg Alloys

“…This is confirmed by hydrogen sorption kinetics studies of Alloy 8, Alloy 9, and Alloy 10 (AgMg, Ag60Mg40, and Ag 3 Mg) samples, which do not absorb hydrogen, and structural analysis performed after hydrogen sorption measurements. Similar observations have also been reported previously [ 14 , 15 , 19 ].…”

“…Alternatively, these low values might be related to the presence of an insignificant amount of residual magnesium or hydrogen absorbing phase. The thermodynamic discussion and reaction mechanisms for Mg-Ag phases with hydrogen have already been shown in the literature [ 14 , 15 , 18 , 19 ], and for that reason, they will no longer be explored in this paper. We discuss only the kinetics of the absorption and the properties of the manufactured material.…”

Influence of long-term ageing upon the capacity of hydrogen storage in two novel Mg-Ni-In-C alloys

“…Improvement in sorption characteristics was recently confirmed in In-containing alloys Mg-Ag [35], Mg-In-Ni [36] as well, and in an experimental survey [14].…”

Progress and Trends in Magnesium‐Based Materials for Energy‐Storage Research: A Review

“…Later, the groups of Luo and Lu reported that alloying with Y and Ni to form solid solutions of Mg−In−Y and Mg−In−Ni, respectively, could further destabilize the thermodynamics of Mg‐based alloys. In addition to the Mg−In solid solution alloy systems, the Mg−Cd, Mg−Si, and Mg−Ag systems also show improved hydrogen‐storage kinetics and thermodynamics compared with those of pure Mg−MgH 2 .…”