Effect of nano-sized Ce2S3 on reversible hydrogen storage properties of LiBH4

Abstract

Ce2S3 with a diameter ca. 100–200 nm was synthesized by a solvothermal method and doped into LiBH4. Ce2S3 reacts with LiBH4, forming Li2S and CeB6 as the dehydrogenated products, and they become active substances in the re-hydrogenation reaction to improve the reversibility of the LiBH4 system. The composite of LiBH4 with 20 wt.% Ce2S3 exhibits favorable re-hydrogenation ability, its hydrogen absorption still reaches 3.6 wt.% at the 4th cycle. After dehydrogenation, The initial dehydrogenation temperature of the LiBH4 + 20 wt.% Ce2S3 composite is decreased to 250 °C, which is 80 °C lower than that of the pristine LiBH4 system. Furthermore, within 3000 s, the LiBH4 + 20 wt.% Ce2S3 composite can release about 4.0 wt.% hydrogen at 400 °C, which is 1.67 times higher than that of the pristine LiBH4. The activation energy (Ea) of dehydrogenation reaction of LiBH4 is reduced from 181.80 kJ/mol to 157.82 kJ/mol.