Boosting the Dehydrogenation Properties of LiAlH4 by Addition of TiSiO4

Given its significant gravimetric hydrogen capacity advantage, lithium alanate (LiAlH4) is regarded as a suitable material for solid-state hydrogen storage. Nevertheless, its outrageous decomposition temperature and slow sorption kinetics hinder its application as a solid-state hydrogen storage material. This research's objective is to investigate how the addition of titanium silicate (TiSiO4) altered the dehydrogenation behavior of LiAlH4. The LiAlH4-10 wt% TiSiO4 composite dehydrogenation temperatures were lowered to 92 degrees C (first-step reaction) and 128 degrees C (second-step reaction). According to dehydrogenation kinetic analysis, the TiSiO4-added LiAlH4 composite was able to liberate more hydrogen (about 6.0 wt%) than the undoped LiAlH4 composite (less than 1.0 wt%) at 90 degrees C for 2 h. After the addition of TiSiO4, the activation energies for hydrogen to liberate from LiAlH4 were lowered. Based on the Kissinger equation, the activation energies for hydrogen liberation for the two-step dehydrogenation of post-milled LiAlH4 were 103 and 115 kJ/mol, respectively. After milling LiAlH4 with 10 wt% TiSiO4, the activation energies were reduced to 68 and 77 kJ/mol, respectively. Additionally, the scanning electron microscopy images demonstrated that the LiAlH4 particles shrank and barely aggregated when 10 wt% of TiSiO4 was added. According to the X-ray diffraction results, TiSiO4 had a significant effect by lowering the decomposition temperature and increasing the rate of dehydrogenation of LiAlH4 via the new active species of AlTi and Si-containing that formed during the heating process.

Automated summary

This research aims to investigate the effect of adding titanium silicate (TiSiO4) on the dehydrogenation behavior of lithium alanate (LiAlH4). The addition of 10 wt% TiSiO4 resulted in lower dehydrogenation temperatures for LiAlH4, with the first-step reaction occurring at 92 degrees C and the second-step reaction at 128 degrees C. The TiSiO4-added LiAlH4 composite was able to release more hydrogen (about 6.0 wt%) compared to undoped LiAlH4 at 90 degrees C for 2 hours. The addition of TiSiO4 also reduced the activation energies for hydrogen liberation from LiAlH4.