Potential Hydrogen Storage Research Articles

Unlocking underground hydrogen storage potential: Geochemical characterization of North Dakota's geological formation

Underground hydrogen storage offers a promising solution for sustainable energy, with geologic formations such as salt caverns, aquifers, and depleted hydrocarbon reservoirs identified as suitable options for safely storing hydrogen. Some studies have been carried out to investigate hydrogen-rock-fluid interactions. However, none have simultaneously combined experimental analysis and geochemical modeling of the equilibrium and kinetic reactions using a well-characterized North Dakota carbonate formation as a case study to investigate its geochemical characterization and implications. This research explores the mineralogical and fluid composition of specific depleted hydrocarbon reservoirs in North Dakota while investigating the intricate geochemical interplays between hydrogen gas, fluid, and rock formations. This study focused on the Red River Formation, a primary hydrocarbon-producing entity in North Dakota, to unveil its potential for underground hydrogen storage (UHS). This formation's stratigraphic complexity and extensive hydrocarbon yield underscores its significance. We conducted experiments combining analytical tests and geochemical modeling using core samples from the Red River Formation. X-ray diffraction (XRD), X-ray fluorescence (XRF) spectroscopy, and scanning electron microscopy (SEM) techniques were employed to decipher mineralogical and elemental constituents. This study covers areas such as the Bicentennial, Coyote Creek, Horse Creek, and Medicine Poll Hills Fields and identified common minerals such as calcite, dolomite, anhydrite, and quartz, along with essential elements such as oxygen, magnesium, aluminum, and silicon. Geochemical simulations were also performed to evaluate the equilibrium and kinetic reactions expected during hydrogen gas injection into this formation. Our findings revealed stable mineral phases, the absence of detrimental environmental impacts, promising prospects for hydrogen storage in the studied carbonate reservoirs without geochemical alterations and promising a sustainable pathway toward net-zero carbon emissions.

Reversible hydrogen storage in Y2C MXene under the influence of functional groups (F, Cl, OH)

The hydrogen storage potential of the bare MXenes Y2C and terminated Y2CT2, where T is O, OH, or F, were studied using density functional theory (DFT). Hydrogen adsorption and desorption behaviors are simulated by ab initio molecular dynamic simulations. The interaction of the H2-molecules on the Y2C-family was investigated within the projected density of states. Only bare Y2C and Y2C(OH)2 provided Kubas-type interactions. The calculated maximum capacity of H2 in bare Y2C can reached up to 5.041 wt%, whereas the reversible capacity of H2 was up to 2.036 wt%. In Y2C(OH)2, the maximum capacity of H2 storage is 3.477 wt% and the reversible capacity was 1.769 wt%. This indicated that Y2C and Y2C(OH)2 are practical candidates for hydrogen storage applications.

First-principles calculations of phase stability, electronic structure, mechanical properties and thermal conductivities of TMH2 (TM=V, Nb, Ta) metal hydrides

TMH2 (TM = V, Nb, Ta) metal hydrides can be used as potential hydrogen storage materials. However, there have been no available data on the mechanical and thermodynamic properties of these hydrides, especially TaH2. Herein, based on first-principles calculations, the phase stability, electronic structure, mechanical properties and thermal conductivities of TMH2 (TM = V, Nb, Ta) hydrides are investigated. The results show that VH2, NbH2, and TaH2 are thermodynamically and dynamically stable. The calculated electronic structures show that these three hydrides possess electron orbital hybridization among atoms and strong chemical bonding. The chemical bonds in TMH2 are mainly ionic and partially covalent. According to the calculated Poisson's ratios, Pugh’s ratio and Cauchy pressures, VH2, NbH2, and TaH2 are ductile. Moreover, these three hydrides have elastic anisotropy and good damage tolerance. Finally, the predicted thermodynamic properties indicate that TMH2 can be used as potential thermal insulating materials.

Advanced computational screening of X2CaH4 (X = Rb and Cs) for hydrogen storage applications

Utilizing cutting-edge computational screening methods, this study explores the hydrogen storage capacity of two complex metal hydrides, Cs2CaH4 and Rb2CaH4. We perform a thorough analysis of their structural, electrical, optical, and hydrogen storage properties using density functional theory (DFT). Within the I4/mmm space group, both compounds display stable tetragonal crystal structures, and their thermodynamic stability is confirmed by their formation energies. Notably, compared to Rb2CaH4, Cs2CaH4 is more stable. With band gaps of 2.99 eV for Cs2CaH4 and 3.28 eV for Rb2CaH4, the electronic properties show insulating behavior, which is beneficial for reducing electronic interference during hydrogen absorption and desorption. A comparative research reveals that the potential gravimetric hydrogen storage capacities of Cs2CaH4 (1.28%) and Rb2CaH4 (1.86%) are comparable to, albeit marginally less than, those of materials that are frequently explored, such as lithium borohydride. With their individual absorption and reflectivity peaks, the optical characteristics offer more information about how they interact with electromagnetic radiation, information that may be useful for improving their performance in real-world applications. Our results imply that Cs2CaH4and Rb2CaH4 have considerable potential for use in practical hydrogen storage systems, especially in situations where stability and minimal electronic interference are essential. Subsequent research endeavors may concentrate on enhancing the hydrogen storage capacity of these materials, so rendering their incorporation into existing hydrogen storage methods more feasible.

A Review on Liquid Hydrogen Storage: Current Status, Challenges and Future Directions

The growing interest in hydrogen (H2) has motivated process engineers and industrialists to investigate the potential of liquid hydrogen (LH2) storage. LH2 is an essential component in the H2 supply chain. Many researchers have studied LH2 storage from the perspective of tank structure, boil-off losses, insulation schemes, and storage conditions. A few review studies have also been published considering LH2 storage; however, most are simply collections of previous articles. None of these review articles have critically evaluated the research articles. In this review study, recent reports, conceptual studies, and patents have been included and critically discussed. Further, challenges and recommendations have been listed based on the literature review. Our results suggest that the multi-layer insulation scheme and integrated refrigeration system can effectively reduce boil-off losses. However, boil-off losses from storage tanks during transportation are the least discussed and must be addressed. The cost of an LH2 storage tank is high, but it can be reduced with advancements in materials and the utilization of latest technologies. The present challenges and future directions for LH2 storage include minimizing and utilizing boil-off losses, improving insulation schemes, and ensuring cost-effective large-scale LH2 storage. This review study can be fundamental for process engineers and new academic researchers to design energy-efficient and cost-effective LH2 storage systems.

Green ammonia imports could supplement long-duration energy storage in the UK

Abstract There is growing recognition of the need for long-duration energy storage to cope with low frequency (i.e. seasonal to multi-annual) variability in renewable energy supplies. Recent analysis for the UK has estimated that 60–100 TWh of hydrogen storage could be required to provide zero-carbon backup for renewable energy supplies in 2050. However, the analysis did not consider the potential role of green energy imports as a supplement to domestic energy storage. Using a global spatially-explicit model of green hydrogen/ammonia production and shipping we estimate the lowest import costs for green ammonia to the UK, and compare them with the levelized costs of energy storage across scenarios of varying domestic renewable energy production. The results indicate that imported green ammonia could offer a cost-comparable alternative to domestic hydrogen production, storage and power generation, whilst increasing energy system resilience through supply diversification, at a similar or cheaper delivered energy cost compared to a hydrogen-only storage system. In countries lacking the geological potential for low-cost hydrogen storage, green ammonia imports could have an even more significant role.

Fabrication of V2O3-TiO2-rGO ternary heterojunction composite to enhance the hydrogen storage performance of MgH2

The application prospects of MgH2 as a potential solid hydrogen storage material are limited by its stable thermodynamic properties and slow hydrogenation/dehydrogenation kinetics. In this study, a ternary heterogeneous composite material V2O3-TiO2-rGO (V-T-rGO) was synthesized using the ultrasonic hydrothermal method and doped into MgH2 through ball milling to improve its hydrogen storage performance. The experimental results demonstrated that the MgH2 + V-T-rGO samples exhibit superior hydrogen storage properties compared with single-doped V2O3, TiO2, rGO or V-T materials. Specifically, it can uptake hydrogen at room temperature, and adsorbs 5.00 wt% H2 in just 4 min at 150 °C, and releases 5.87 wt% H2 within 6 min at 325 °C, demonstrating a faster reaction rate and successful hydrogen absorption. Additionally, the hydrogenation/dehydrogenation activation energies of MgH2 + V-T-rGO samples are measured at 27.1/72.3 kJ·mol−1, representing a reduction of 51.2/59.2 kJ·mol−1 compared to MgH2 alone. Mechanistic analysis revealed that the multiphase composite system produced synergistic catalytic effects, providing abundant active sites and hydrogen diffusion channels to enhance the hydrogen storage performance of MgH2. This study presents an innovative approach for constructing transition metal oxide heterostructured materials and holds significant reference value for applications in the field of hydrogen storage.

WO2–N co-doped 2D Carbon nanosheets as multifunctional additives for enhancing the electrochemical hydrogen storage performance of Co2B

Co2B, with its high theoretical hydrogen storage capacity, is a potential solid-state hydrogen storage material. However, its poor cycling life limits its practical application. In this work, in order to improve the cycling stability and reversibility of hydrogen absorption and desorption of Co2B, we propose to use WO2–N–C nanosheets as dopants to mix with Co2B, thereby enhancing its practical performance. Two-dimensional tungsten oxide-nitrogen-carbon (WO2–N–C) nanosheets was syntheized via a liquid-phase approach, using a tungstenate-polydopamine precursor followed by thermal treatment. Subsequently, these WO2–N–C nanosheets were compounded with cobalt boride (Co2B) particles through ball milling at various ratios of 1%, 3%, and 5%, which were confirmed by XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) methods. Employing a comprehensive suite of electrochemical analyses, including corrosion potential measurements, polarization curves, step voltammetry, and electrochemical impedance spectroscopy (EIS), we found that the incorporation of WO2–N–C significantly enhances the corrosion resistance and electrochemical activity of Co2B. Furthermore, cyclic life tests revealed that the WO2–N–C-doped Co2B composites exhibit superior discharge capacities and capacity retention rates compared to pristine Co2B. Notably, the 3% WO2–N–C-doped Co2B composite demonstrated the optimal electrochemical performance, achieving a maximum discharge specific capacity of 555 mAh g−1 and maintaining 82% of its initial capacity after 50 cycles. Our findings underscore the dual role of WO2–N–C in not only augmenting the surface electrochemical activity of Co2B but also providing a protective surface layer, thereby enhancing its overall electrochemical performance.

Hydrogen storage potential of XNiH3 (X= Sr and Ba) compounds: A comprehensive DFT analysis

The increasing need for sustainable energy solutions emphasizes the significance of effective hydrogen storage materials. This work provides a thorough analysis using density functional theory (DFT) to assess the capacity of XNiH3 (X = Sr and Ba) compounds, where X denotes strontium (Sr) and barium (Ba), for storing hydrogen. We employed the Cambridge Serial Total Energy Package (CASTEP) approach to optimize the geometries and determine the structural, electrical, optical, and mechanical properties of SrNiH3 and BaNiH3. The findings indicate that SrNiH3 demonstrates a higher gravimetric hydrogen storage capacity (2.03 %) in comparison to BaNiH3 (1.52 %). Both compounds exhibit metallic behavior, characterized by the absence of band gaps, which indicates a high level of electrical conductivity. The optical investigations reveal prominent absorption peaks at 25.32 eV for SrNiH3 and 18.82 eV for BaNiH3, accompanied by substantial energy loss functions and refractive behaviors. Based on mechanical studies, it has been determined that both compounds are mechanically stable. However, SrNiH3 exhibits a larger bulk modulus and Young's modulus compared to BaNiH3. The results highlight the potential of SrNiH3 and BaNiH3 as suitable options for storing hydrogen, which can contribute to the progress of clean energy technology.

Hydrogen storage with gravel and pipes in lakes and reservoirs

Climate change is projected to have substantial economic, social, and environmental impacts worldwide. Currently, the leading solutions for hydrogen storage are in salt caverns, and depleted natural gas reservoirs. However, the required geological formations are limited to certain regions. To increase alternatives for hydrogen storage, this paper proposes storing hydrogen in pipes filled with gravel in lakes, hydropower, and pumped hydro storage reservoirs. Hydrogen is insoluble in water, non-toxic, and does not threaten aquatic life. Results show the levelized cost of hydrogen storage to be 0.17 USD kg−1 at 200 m depth, which is competitive with other large scale hydrogen storage options. Storing hydrogen in lakes, hydropower, and pumped hydro storage reservoirs increases the alternatives for storing hydrogen and might support the development of a hydrogen economy in the future. The global potential for hydrogen storage in reservoirs and lakes is 3 and 12 PWh, respectively. Hydrogen storage in lakes and reservoirs can support the development of a hydrogen economy in the future by providing abundant and cheap hydrogen storage.

Theoretical investigation of mixed-metal metal-organic frameworks as H2 adsorbents: insights from GCMC and DFT simulations

ABSTRACT Molecular hydrogen ( H 2 ) is a renewable energy carrier, however, its practical applications are limited due to the challenges of developing safe and efficient H 2 storage devices. Metal Organic Frameworks (MOFs) containing at least two different metal ions in their structures are called as mixed-metal MOFs (MM-MOFs) and they could adsorb H 2 in higher amounts compared to structures containing single metal nodes. We theoretically examined the H 2 storage capacities of 26 MM-MOFs having various physical and chemical properties applying Grand Canonical Monte Carlo (GCMC) and Density Functional Theory (DFT) simulations. H 2 adsorption isotherms were calculated using a five-site anisotropic H 2 model. QIXSOG, YOMVIG, OSOYUR, Cu-Mg-BTC, Fe-Mg-BTC, and Cr-Mg-BTC were selected as top-performing MM-MOFs maximising H 2 adsorption gravimetrically and volumetrically at near-ambient conditions (233 K and 100 bar), approaching the DOE targets. YOMVIG has the largest H 2 adsorption enthalpy, calculated as − 9.93 kJ/mol at 233 K and 100 bar. DFT simulations have been conducted to analyse preferable H 2 adsorption sites as well as identify guest-host interactions. Electron density difference analysis showed that adsorbed H 2 molecules in the OSOYUR, Cr-Mg-BTC, Cu-Mg-BTC, and Fe-Mg-BTC are polarised. Our study challenges existing literature by identifying promising MM-MOFs as potential next-generation hydrogen storage adsorbents at near-ambient conditions.

Reversible hydrogen storage with Na-modified Irida-Graphene: A density functional theory study

Two-Dimensional carbon-based materials as a potential hydrogen storage medium have attracted great attention. In this study, various key aspects such as structure, electronic properties, stability, and hydrogen storage performance of Na-modified Irida-Graphene (IG) were thoroughly investigated using density functional theory (DFT) calculation methods. The calculation results show that the binding energy of Na atoms with the substrate is 1.51 eV, far exceeding the cohesive energy. The AIMD results reflect the good thermal stability of the model. One Na atom can adsorb up to 5H2 molecules. The IG loaded with eight Na atoms on both sides can adsorb 32H2 molecules, achieving a hydrogen storage capacity of 7.82 wt%, far exceeding the US DOE target of 5.5 wt%. The calculated Van ’t Hoff equation indicates a desorption temperature of 248 K for the model. Moreover, reversible hydrogen storage can be achieved at medium to low pressures, with desorption temperatures ranging from 285 K to 417 K. These results suggest that Na-Modified IG models are candidate materials for reversible hydrogen storage under near-ambient conditions.

Exploring the hydrogen storage in novel perovskite hydrides: A DFT study

This work employs density functional theory calculations to investigate the structural, hydrogen storage, mechanical, electronic, optical, and bonding characteristics of perovskite hydrides KNaX2H6 (X = Mg, Ca) for potential hydrogen storage applications. Negative formation energies, positive phonon dispersions, and appropriate tolerance factor values confirm the thermodynamic, dynamic, and cubic structural stability of these compounds. KNaMg2H6 exhibits a promising gravimetric hydrogen storage capacity of 5.19%, while KNaCa2H6 shows 4.09%. Both compounds display semiconducting behavior with indirect energy band gaps of 3.31 eV and 3.17 eV, respectively. Key mechanical properties, including bulk modulus, shear modulus, and Poisson's ratio, were evaluated using computed elastic constants. The desorption temperature for KNaMg2H6, determined to be 470.4 K, renders it suitable for practical applications. Partial Bader charge analysis reveals both ionic and slightly covalent bonding interactions. Optical analysis demonstrates strong ultraviolet absorption capabilities with a redshift in the absorption spectrum. The computed properties indicate these materials hold promise for hydrogen storage applications.

Effect of rotation speed on hydrogen storage properties of Ti45Zr38Ni17 alloy ribbons produced by melt spinning

Abstract Ti/Zr-based icosahedral (i) quasicrystals are believed to have a Bergman-type cluster with a large number of tetrahedral interstitials, making them attractive as potential hydrogen storage materials. In this study, Ti45Zr38Ni17 alloy ribbons were prepared by melt spinning at different rotation speeds, and the effect of the rotation speed on the microstructures and hydrogen storage capacities was investigated. The i-phase with a small amount of Ti2Ni phase and/or some minor crystal phase was identified after melt spinning, but the amount of amorphous phase increased and the Ti2Ni and the other crystal phases decreased with increasing rotation speed. After gaseous hydrogen loading at 573 K and a pressure of 3 MPa, a hydride phase was observed in the samples with more amorphous phase, suggesting that the amorphous phase turned into the hydride phase. The maximum gaseous hydrogen capacity (H/M), 1.31, was obtained for the sample with more i-phase. After electrochemical hydrogen loading, a slightly higher maximum discharge capacity was observed in a less-quality quasicrystal sample at the first loading, that decreased drastically after the second cycle, but gradually increased with increasing cycling up to 20 cycles. The maximum hydrogen discharge capacity obtained in sample with more i-phase, reached about 10 mAh/g, while the less-amount one 4 mAh/g, suggesting the i-phase has higher hydrogen capacity than the crystal and the amorphous phases.

Potential of hydrogen and thermal storage in the long-term transition of the power sector: A case study of China

Hydrogen and thermal storage can reduce cost of long-term and large-scale energy storage with high efficiency and low or even zero carbon emissions. Their potential in the low-carbon transition pathway of an energy system with rapid growth of energy demand, large shifting of energy supply structure and limited investment budget remains unclear. A long-term power generation planning model is proposed in this paper, featuring detailed technical and economic characteristics of hydrogen and thermal storage. The power supply system of China is selected as a case study, due to its urgent need for low-carbon transition and complex spatial characteristics. Results show that the application of hydrogen and thermal storage can benefit the development of volatile renewable power generation technologies, facilitate the transition towards zero or even negative carbon emissions while simultaneously reducing power supply costs. Hydrogen is expected to be mainly produced in spring and consumed in summer while heat is expected to be primarily generated in autumn and consumed in winter. Shifting from thermal storage to hydrogen storage might happen around 2050 in accordance to the low-carbon transition progress.

A density functional theory study of defective and doped structures of MgB2 and their interaction with hydrogen

The LiBH4+MgH2 system exhibits promising potential for solid-state hydrogen storage, yet the sluggish rehydrogenation of MgB2 poses a significant challenge. In this study, we utilize density functional theory (DFT) simulations to investigate the energetics of hydrogen in pure, defective, and doped MgB2 in equilibrium with molecular hydrogen. Our findings reveal that the B-Frenkel defect process is the thermodynamically most favorable in MgB2. The calculated solution energy for hydrogen at the interstitial site indicates low hydrogen solubility, even at mild temperatures. Incorporating hydrogen into a pre-existing B vacancy enhances the process, facilitated by doping of O on the B site. Additionally, Li doping on the Mg site enhances incorporation by forming strong Li–H bonds, predicting lower activation barriers for hydrogen dissociation and diffusion. Doping MgB2 with O and F at the B site significantly enhances hydrogen solubility. These dopants make MgB2 a promising material for high-capacity and fast-kinetics hydrogen storage applications, and further research into these effects can lead to advancements in energy storage technology.

Hydrogen adsorption on titanium-decorated carbyne C12 ring: a DFT study

Abstract In the current landscape of increasing focus on green technology, hydrogen fuel emerges as a pivotal alternative energy source. While existing technology facilitates hydrogen use in fuel cells, the practicality of this fuel could be significantly enhanced with a more efficient and safer storage approach. Researchers are actively exploring one-dimensional systems as potential hydrogen storage solutions, yielding promising outcomes. A notable study delved into the hydrogen storage capacity and performance of a Ti-decorated carbyne ring using density functional theory calculations. The researchers observed a robust, non-deforming bond between the Ti adatom and the carbyne ring, displaying characteristics akin to ionic bonding. Detailed analyses of electronic properties, including density of states and band structure, highlighted a strong interaction through the alignment of p-orbitals with the Ti atom. Upon the adsorption of H2 onto the decorated carbyne ring, it was noted that the Ti-decorated systems could each adsorb up to six H2 molecules, exhibiting weak physisorption energies within the Van der Waals range. The charge density profile indicated a dipole-dipole interaction, affirming the potential of the material as a viable H2 storage medium. In conclusion, as green technology advances, hydrogen fuel, especially when stored innovatively with materials like the Ti-decorated carbyne ring, emerges as a crucial component in the pursuit of sustainable energy solutions.

Thermal and spectroscopic (IR, NMR) studies of bulk ammonia borane – Polyethylene oxide composites: A potential hydrogen storage system

We utilized differential scanning calorimeter (DSC), Fourier-transformed infrared spectroscopy (FT-IR), and solid-state nuclear magnetic resonance spectroscopy (NMR) techniques to understand the dehydrogenation mechanism of ammonia borane (AB) and its polymer composites. The results indicated that the polymeric composites with higher polyethylene oxide (PEO) mass ratio involve the possible breakdown of dative bond and the formation of new interaction (H-bonding) between the AB and the polymer. The activation energies were calculated in the temperature range of 25 °C and 300 °C which were found to be lower than the pristine AB. 15N and 11B NMR studies at room temperature showed evidence for a possible interaction, H-bonding, between AB and PEO. The NMR experiments at 85 °C were conducted to investigate the isothermal decomposition during several hours. Results indicated that the pristine AB takes longer incubation time, however the polymeric composite readily decomposes at 85 °C. Both showed proof for the formation of byproducts. Moreover, IR study showed evidence to support the interaction between AB and PEO.

Artificial intelligence-driven assessment of salt caverns for underground hydrogen storage in Poland

This study explores the feasibility of utilizing bedded salt deposits as sites for underground hydrogen storage. We introduce an innovative artificial intelligence framework that applies multi-criteria decision-making and spatial data analysis to identify the most suitable locations for storing hydrogen in salt caverns. Our approach integrates a unified platform with eight distinct machine-learning algorithms—KNN, SVM, LightGBM, XGBoost, MLP, CatBoost, GBR, and MLR—creating rock salt deposit suitability maps for hydrogen storage. The performance of these algorithms was evaluated using various metrics, including Mean Squared Error (MSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), Root Mean Square Error (RMSE), and Correlation Coefficient (R2), compared against an actual dataset. The CatBoost model demonstrated exceptional performance, achieving an R2 of 0.88, MSE of 0.0816, MAE of 0.1994, RMSE of 0.2833, and MAPE of 0.0163. The novel methodology, leveraging advanced machine learning techniques, offers a unique perspective in assessing the potential of underground hydrogen storage. This approach is a valuable asset for various stakeholders, including government bodies, geological services, renewable energy facilities, and the chemical/petrochemical industry, aiding them in identifying optimal locations for hydrogen storage.

First-principles calculations to investigate Mg3XH8 (X = Ca, Sc, Ti, V, Cr, Mn) materials for hydrogen storage

An ideal hydrogen storage material is a key topic in efficient hydrogen energy utilization. We have explored several potential hydrogen storage materials Mg3XH8 (X = Ca, Sc, Ti, V, Cr, Mn) by first-principles calculations. The studied materials all belong to lightweight hydrogen storage materials. The normal phonon dispersion spectrum indicates, without regard to other materials, at least Mg3TiH8 and Mg3VH8 are completely stable in dynamics, which is also demonstrated by elastic stability criteria. The elastic properties show that they are all ductile materials with the applicable potential in flexible fields. Besides, they are gapless and metallic in band structures. With the correction of Hubbard values, all transition metal based Mg3XH8 materials are magnetic materials with magnetic moments of 0.34 μB for Mg3ScH8, and 2.14 μB for Mg3TiH8, 1.29 μB for Mg3TiH8, 2.65 μB for Mg3TiH8 and 4.86 μB for Mg3MnH8, respectively. Whereas Mg3CrH8 and Mg3MnH8 exhibit highly light active in infrared and visible region. Considering overall structural stability, excellent mechanical properties, high gravimetric hydrogen density (6.21% and 6.07%) and moderate hydrogen desorption temperature (∼350 K), Mg3TiH8 and Mg3VH8 are considered as the candidates for promising hydrogen storage materials. Besides, Due to half-metallic nature, they are also potential in spin electronic devices.