The excellent performance of AClH3 (A=Rb, Cs, K) perovskite hydrides for hydrogen storage applications

Hydrogen energy is a flexible and sustainable renewable energy source with great potential to counteract climate change. Advancements in hydrogen generation and storage technology offer a greener, more sustainable energy future. Recently, perovskite hydrides have gained a huge attention due to their potential to be used for high-capacity hydrogen storage materials. These materials provide reversible and efficient methods for storing and releasing hydrogen for fuel cell technology. Their tunable features and varied structures pave the way for addressing difficulties in the hydrogen economy, providing a pathway to sustainable energy solutions. A detailed theoretical examination of the physical attributes of AClH3 (A = Rb, Cs, K) is conducting using the FP-LAPW approach. Structural and thermo-dynamical stability are considered via computed tolerance factor and formation energy values. The GGA and mBJ approximations are used to handle the exchange-correlation effects. The structural analysis of our studied compound is address using the GGA approximation while electronic and optical characteristic are computed using the mBJ approximation. Direct bandgaps of 1.04 eV, 1.01 eV, and 1.02 eV are revealed for RbClH3, CsClH3, and KClH3 from electronic properties revealing the semiconducting nature of these perovskite hydrides. The optical characteristics of AClH3 (A = Rb, Cs, and K) underwent a thorough examination, and the results showed that these perovskite hydrides exhibit strong absorption in the visible range, which suggests that they are strong candidates for renewable energy applications, including solar panels, solar cells, and portable solar chargers. Furthermore, the hydrogen storage capacity, such as gravimetric and volumetric storage capacities, are computed as 3.88 wt% (33.55 gH2/L), 3.35 wt% (31.10 gH2/L), and 3.76 wt% (35.48 gH2/L) for RbClH3, CsClH3 and KClH3. Furthermore, desorption temperatures for RbClH3, CsClH3, and KClH3 are higher than 350K, which makes them appropriate for hydrogen storage applications.