Efficient storage of hydrogen is a key issue to establish hydrogen infrastructure. In the efforts of searching suitable hydrogen storage alloys, several systems have been explored so far. All of them suffers from some drawbacks such as low gravimetric capacity, high stability, slow sorption kinetics, etc. Lithium borohydride (LiBH4) is one of the leading contender among the hydrogen storage materials owing to its high hydrogen content of 18.5 wt%. However, its high stability needs a high operating temperature (>450 °C) for the decomposition. Recently, a thermochemical reaction between Bi2X3 and LiBH4 was observed at 120 °C while performing experiments on the anode properties of Bi2X3 (X = S, Se, & Te) for Li-ion batteries. This indicated the possibility of destabilization of LiBH4 and its low-temperature decomposition. This work presents the effect of Bi2Se3 addition to the decomposition properties of LiBH4 using XRD and XPS techniques. The first step decomposition was observed to be initiated at around 180 °C, which is much lower than 450 °C for the pristine LiBH4. A further reduction in the onset temperature is observed when the bulk Bi2Se3 is replaced by the nanosheets of this material. The mechanism of this destabilization is reported herein. •Bi2Se3, an interesting anode material is found an impressive destabilizing agent for LiBH4.•The addition of bulk Bi2Se3 to LiBH4 reduce the onset decomposition temperature to 180 °C.•The use of Bi2Se3 nanosheets enhance the sorption kinetics further and the onset temperature is shifted to 60 °C.