Enhanced dehydrogenation kinetic properties and hydrogen storage reversibility of LiBH4 confined in activated charcoal

LiBH4 was confined into activated charcoal (AC) by melt infiltration method (M), and its effects on the hydrogen sorption properties were investigated. The N-2 adsorption results reveal that melt infiltration method can effectively incorporated LiBH4 into AC. It can maintain the structural integrity of the scaffold and ensure the confinement effect. The nano-confined LiBH4/AC starts to release hydrogen at around 190 degrees C, which is 160 degrees C lower than that of pure LiBH4, and reaches a hydrogen desorption capacity of 13.6% at 400 degrees C. When rehydrogenated under the condition of 6 MPa H-2 and 350 degrees C, it has a reversible hydrogen storage capacity of 6%, while pure LiBH4 shows almost no reversible hydrogen storage capacity under the same condition. Mass spectrometry analysis (MS) results suggest that no diborane or other impurity gases are released in the decomposition process. The apparent activation energy of dehydrogenation of LiBH4 after confinement into AC decreases from 156.0 to 121.1 kJ/mol, which leads to the eminent enhancement of dehydrogenation kinetics of LiBH4.