The research focuses on investigating the potential of using pristine and lithium-decorated δ-5 boron monolayer for hydrogen storage applications. Through density functional theory simulations, various aspects such as adsorption energy, lithium binding, storage capacities, desorption temperatures, and electronic properties were analyzed. The optimized configuration with two lithium atoms per unit cell exhibited a favorable adsorption energy for hydrogen molecules and high storage capacities. The study revealed gravimetric and volumetric hydrogen storage capacities of 8.0 wt% and 76.3 g/L, respectively, with hydrogen release occurring at 246 K. By elucidating the dynamic and thermal characteristics of lithium-decorated boron monolayers, the research provides valuable insights for the future development of efficient hydrogen storage mediums. The investigation of the δ-5 boron monolayer's hydrogen storage potential opens new possibilities for sustainable energy storage solutions.