Study the effect of SrFe12O19 on MgH2/LiAlH4 composite for solid-state hydrogen storage

The MgH2/LiAlH4 destabilised system was studied experimentally using the method of ball milling. The desorption/absorption performances and reaction mechanism of the 4MgH2 + LiAlH4 composite system with SrFe12O19 additive have been investigated for the first time. Analysis of the temperature-programme-desorption showed that the 5 wt% SrFe12O19-doped 4MgH2 + LiAlH4 composite started to release hydrogen at 80 °C and 260 °C for the first two desorption stages, which were reduced by 40 °C and 10 °C as compared to the undoped composite. The sorption kinetics of 5 wt% SrFe12O19-doped 4MgH2 + LiAlH4 were also improved as compared to the undoped 4MgH2 + LiAlH4. Activation energy calculation based on the Kissinger plot displayed that the apparent activation energy for the decomposition of MgH2-relevant had been reduced from 121 kJ/mol for the undoped composite to 104 kJ/mol for the composite with SrFe12O19. The X-ray diffraction results suggested that the new species of Al2Sr and Li2Fe3O4 that were formed in situ during the heating process were believed to play a catalytic role, thus responsible for the enhancement of the hydrogen storage properties of 4MgH2 + LiAlH4 composite system with SrFe12O19.