Unique properties of three-component composite system based on magnesium hydride with the addition of catalytic nanosized nickel and thermally conductive carbon nanotubes: the effect of defective structure on kinetic and thermodynamic characteristics

Hydrogen storage using magnesium hydride (MgH 2 ) with catalytic modifiers is a promising alternative energy method. This work studied a composite of MgH 2 with 15 wt% nanoscale nickel powder (produced by Electrical Explosion of Wires) and 1 wt% single-walled carbon nanotubes (CNTs) as a heat-conducting additive, milled at 25 Hz for 120 min. The material exhibited significantly improved properties: desorption activation energies of 50, 58, and 110 kJ/mol (vs. 161 kJ/mol for pure MgH 2 ), 5.5 wt % hydrogen capacity, and 0.7 μm average particle size. In situ XRD confirmed phase purity and hydride dissociation during heating, correlating with thermal desorption analysis. In situ Doppler broadening spectroscopy, through evaluation of S and W parameters at specified pressure and temperature, revealed how the defect structure formed during planetary ball milling influences hydrogen interaction.