Hydrogen storage in polylithiated BC3 monolayer sheet (original) (raw)
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Hydrogen storage on pristine and Li-decorated BC6N monolayer from first-principles insights
Molecular Physics, 2020
In the study conducted in the present research hydrogen storage properties of pristine and Lidecorated BC 6 N monolayer are considered by first-principles calculations. It is predicted that the double-sided Li-decorated monolayer of BC 6 N will reach a suitable substrate that adsorbs up to eight molecules of H 2 with hydrogen storage capacities of 12.60 wt% and adsorption energies within in the range of 0.23-0.29 eV. Hydrogen desorption from 2Li/BC 6 N (8H 2) system can occur at T D = 297 K and P = 1 atm which is at the ambient conditions. Potential usage of 2Li/BC 6 N adsorptive medium for practical hydrogen storage purposes is concluded from the results of the present study.
RSC Advances, 2017
We report, for the first time we believe, a detailed investigation on hydrogen storage efficiency of scandium (Sc) decorated boron carbide (BC 3) sheets using spin-polarized density functional theory (DFT). We analyzed the energetics of Sc adsorption and explored the most favorable adsorption sites of Sc on BC 3 sheets with 3.12%, 6.25%, and 12.5% coverage effects. Our investigations revealed that Sc strongly binds on pristine BC 3 sheet, with a minimum binding energy of $5 eV, which is robust enough to hinder Sc-Sc metal clustering. Sc, the lightest transition metal, adsorbs a large number of H 2 molecules per atom, resulting in a reasonable storage capacity. With 12.5% Sc-coverage, functionalized BC 3 sheets could attain a H 2 storage capacity of 5.5 wt% with binding energies suitable for a practical H 2 storage medium.
Science of Advanced Materials, 2013
In the quest for promising hydrogen storage materials, we have performed first principles calculations on CLi 3 and OLi 2 decorated hexagonal boron nitride (h-BN), sheet. The strong binding of the polylithiated species to pristine and doped BN sheet and the large distance between these functionalized species ensure their uniform distribution over the sheet without being clustered. MD simulations have also confirmed the stabilities of both functionalized systems. Bader analysis and density of states reveals the bonding nature in the systems. A reasonably high H 2 storage capacity with the adsorption energies within the desired window suggests that these systems hold promise as efficient H 2 storage mediums.
Chemical engineering of prehydrogenated C and BN-sheets by Li: Application in hydrogen storage
Our first-principles calculations show that if the hydrogen atoms on one of the faces of a graphane sheet prehydrogenated graphene are substituted with Li atoms, the resulting monolayer attains a good hydrogen storage capacity of around 3.8 wt % close to the revised Department of Energy DOE target. It is observed that Li atoms are strongly hybridized with the monolayer and donate their electrons to the substrate such that their binding energy to the surface becomes around 3.27 eV, which is far larger than the cohesive energy of Li in its metal bulk structure. It indicates that Li atoms on the monolayer are not aggregated or clusterized at high doping concentration and high temperature. Our calculation shows that the binding energy of H2 molecules with the monolayer surface is around 0.1 eV resulting from the electrostatic interaction of the polarized charge of hydrogen molecules with the induced electric field by positively charged Li atoms. Similarly, we have examined the hydrogen storage capacity of Li-substituted prehydrogenated boron nitride BN sheet; it is observed that it also has a very good hydrogen storage capability similar to Li-substituted graphane sheet.
Hydrogen Storage in Bilayer Hexagonal Boron Nitride: A First-Principles Study
Using first-principles calculations, we report on the structural and electronic properties of bilayer hexagonal boron nitride (h-BN), incorporating hydrogen (H 2) molecules inside the cavity for potential H 2-storage applications. Decrease in binding energies and desorption temperatures with an accompanying increase in the weight percentage (upto 4%) by increasing the H 2 molecular concentration hints at the potential applicability of this study. Moreover, we highlight the role of different density functionals in understanding the decreasing energy gaps and effective carrier masses and the underlying phenomenon for molecular adsorption. Furthermore, energy barriers involving H 2 diffusion across minimum-energy sites are also discussed. Our findings provide significant insights into the potential of using bilayer h-BN in hydrogen-based energy-storage applications.
Chemphyschem : a European journal of chemical physics and physical chemistry, 2017
First-principles electronic structure calculations were carried out on hexagonal boron nitride (h-BN) sheets functionalized with small molecules, such as OLi, ONa, and Li2 F, to study their hydrogen (H2 ) storage properties. We found that OLi and ONa strongly adsorb on h-BN sheets with reasonably large inter-adsorbent separations, which is desirable for H2 storage. Ab initio molecular dynamics (MD) simulations further confirmed the structural stability of OLi-BN and ONa-BN systems at 400 K. On the other hand, Li2 F molecules form clusters over the surface of h-BN at higher temperatures. We performed a Bader charge investigation to explore the nature of binding between the functionalized molecules and h-BN sheets. The density of states (DOS) revealed that functionalized h-BN sheets become metallic with two-sided coverage of each type of molecules. Hydrogenation of OLi-BN and ONa-BN revealed that the functionalized systems adsorb multiple H2 molecules around the Li and Na atoms, with ...
Journal of The Electrochemical Society
Two-dimensional (2D) materials are a promising candidate for the anode material of lithium-ion battery (LIB) and sodium-ion battery (NIB) for their unique physical and chemical properties. Recently, a honeycomb borophene (h-borophene) has been fabricated by molecular beam epitaxy (MBE) growth in ultra high vacuum. Here, we adopt the first-principles density functional theory calculations to study the performance of monolayer (ML) h-borophene as an anode material for the LIB and NIB. The binding energies of the ML h-borophene-Li/Na systems are all negative, indicating a steady adsorption process. The diffusion barriers of the Li and Na ions in h-borophene are 0.53 and 0.17 eV, respectively, and the anode overall open-circuit voltages for the LIB and NIB are 0.747 and 0.355 V, respectively. The maximum theoretical storage capacity of h-borophene is 1860 mAh·g−1 for NIB and up to 5268 mAh·g−1 for LIB. The latter is more than 14 times higher than that of commercially used graphite (372 ...
ACS Omega, 2021
Lightweight two-dimensional materials are being studied for hydrogen storage applications due to their large surface area. The characteristics of hydrogen adsorption on the h-BN bilayer under the applied electric field were investigated. The overall storage capacity of the bilayer is 6.7 wt % from our theoretical calculation with Eads of 0.223 eV/H2. The desorption temperature to remove the adsorbed H2 molecules from the surface of the h-BN bilayer system in the absence of an external electric field is found to be ∼176 K. With the introduction of an external electric field, the Eads lies in the range of 0.223–0.846 eV/H2 and the desorption temperature is from 176 to 668 K. Our results show that the external electric field enhances the average adsorption energy as well as the desorption temperature and thus makes the h-BN bilayer a promising candidate for hydrogen storage.