Enhanced dehydriding thermodynamics and kinetics in Mg(In)–MgF2 composite directly synthesized by plasma milling

• P-milling solves the kinetic and synthetic problems of Mg(In) simultaneously.
• Mg(In) solid solution catalyzed with in situ formed MgF2 is prepared.
• Mg(In) solid solution shows improved desorption kinetics (Ea = 127.7 kJ/mol).
• Dual tuning of the thermodynamic and kinetic properties of MgH2 is realized.

The reversible formation of Mg(In) solid solution provides a new way to tune the dehydriding thermodynamics of MgH2. However, the preparation of this solid solution is quite difficult and its dehydriding kinetics is rather sluggish. This work offers a novel technique, plasma milling (P-milling), to solve the two problems simultaneously. The efficiency of the synthesis of Mg(In) solid solution, with a hydrogen capacity of up to 5.16 wt.%, is improved significantly. Meanwhile, the kinetics is also modified by the catalyzing effect of in situ synthesized MgF2.