Storage Capacity Research Articles

Dynamics of hydrogen storage in subsurface saline aquifers: A computational and experimental pore-scale displacement study

The catastrophic effects of climate change can be mitigated by transitioning to renewable energy sources such as wind, solar, and hydropower while utilizing hydrogen (H2) as an energy carrier. As renewable fuel sources are intermittent and location-specific, large-scale, long-term storage options for H2 must be explored with high necessity. Subsurface hydrogen storage in saline aquifers provides a vital scope to store H2 gas in available pore voids with minimal environmental risk. In this work, a highly heterogeneous porous micromodel was used to study the immiscible two-phase dynamics at high-temperature, high-pressure saline aquifer conditions using computational fluid dynamics (CFD) simulation based on volume of fluid (VOF) method. A set of microfluidic experiments were carried out under atmospheric conditions to validate the numerical model. The VOF model was observed to show good agreement with microfluidic experiments. An unstable displacement pattern with viscous fingering was observed during various flow conditions that captured high pressure (15 and 25 MPa) and temperature conditions (323 and 343 K). It was observed that fingering displacement of brine limits the storage spaces for hydrogen, which consequently follows the high permeable path. As a result, only 0.272 fraction of brine was invaded by the H2 at a temperature of 323 K and pressure of 15 MPa. A comparison between H2-brine and nitrogen (N2)-brine flow dynamics revealed a 46% less storage capacity of porous media for H2. Formations bearing high temperature (343 K) showed an 11.27% increase in H2 storage capacity, while pressure increase had negligible effect. At low capillary number (Ca), more snap-off effects resulted in higher trapping of H2 gas. This study aims to provide meaningful insights into the complexities of flow dynamics and displacement patterns that are crucial for optimizing hydrogen storage efficiency in saline aquifers and for potential ‘white’ hydrogen production.

Enhanced electron storage capacity achieved by coupling NiO with WO3/BiVO4 for persistent photocathodic protection of 316 stainless steel

Employing a photoanode with energy self-storage capability is crucial to provide continuous photocathodic protection (PCP) for metal under intermittent irradiation. In this work, NiO, a hole collector, was coupled with WO3/BiVO4 to improve photoelectrochemical properties and photocathodic protection ability for stainless steel (316 SS). The optimal WO3/BiVO4/NiO photoanode (WB2N2) exhibited 35.1% and 26.6% increase in energy storage capacity compared with WO3 and WO3/BiVO4 under illumination, respectively. The open-circuit potential (OCP) of 316SS coupled with irradiated WB2N2 was reduced from -143 mV (uncoupled OCP) to -726 mV, and the electrode potential can maintain at -540 mV after light was turned off. It was calculated that electrons of about 1.286×10-2C was transferred from WB2N2 to 316 SS after 50s illumination, which was 11.7 and 5.1 times of that WO3 and WB2 passed to 316SS, respectively, confirming the best persistent PCP performance of WB2N2 in the absence of light. The positive role of NiO on the PCP and persistent PCP performance was analyzed. The long-term OCP test and XRD analysis proved the stability of WO3/BiVO4/NiO in PCP performance and chemical composition.

Insights into effect of lignocellulosic biomass framework types on bio-based shape stable composite phase change materials

The utilization of biomass waste as framework materials to inhibit the leakage of phase change material (PCMs) has gained widespread attention. In this work, three new kinds of shape stable composite phase change materials (sscPCMs) were prepared which combined with stearic acid (SA) and peanut shell powders (PSP), poplar wood powders (PWP), and corn straw powders (CSP), respectively. The influence of lignocellulosic biomass types on the thermal energy storage performance of sscPCMs was studied by comparing three types of sscPCMs. The research results indicated that SA/CSP exhibited superior properties in terms of load capacity and thermal energy storage performance. According to leakage experiments the load capacity of SA/PSP, SA/PWP and SA/CSP was 31.67 %, 44.69 %, and 50.09 %, respectively. The phase change latent heat of SA/PSP, SA/PWP, and SA/CSP was 55.78, 84.27 and 98.47 J/g, respectively. In addition, the relationship between biomass component content and load rates was studied. The results showed that there was a positive correlation between the loading rates of SA and the ratio of holocellulose (cellulose + hemicellulose) to lignin. The results provided a promising approach for the selection of lignocellulosic biomass framework materials.

Unconventional Thick Cobalt Telluride Electrodes Enable Homogeneous Ion Flow for High Capacity, Fast and Safe Potassium Storage

The demand for high-energy density, fast-charging, and safe potassium-ion batteries (PIBs) is crucial for large-scale applications in electric vehicles and grid systems. Despite the potential of thick electrode designs by a conventional technique (CTEs) to boost energy density, they often encounter challenges such as reduced capacity, limited cycling lifespan, and localized short circuits. Here, we present a novel cobalt telluride composite anode by a simple tellurization and subsequent heat reduction, featuring Co1.67Te2 nanoparticles uniformly embedded within an N-doped carbon layer on a trace amount of reduced graphene oxide (CT@NC/rGO). By constructing low tortuosity electrodes (LTEs), a homogeneous distribution of potassium ions and current density is achieved, resulting in enhanced potassium storage performance. The CT@NC/rGO LTEs demonstrate excellent discharge capacities: 311.7, 276.5, and 243.7mAh g-1 after 500 cycles at 0.25Ag-1 for mass loadings of 1.4, 1.9, and 2.8mgcm-2, respectively. At a higher current density of 0.5Ag-1, discharge capacities after 650 cycles are 245.3, 175.6, and 159.2mAh g-1 for mass loadings at 1.6, 2.4, and 3.0mgcm-2, respectively. These improvements are attributed to enhanced pseudocapacitive behavior, reduced charge resistance, and accelerated ion diffusion kinetics, as evidenced by experimental and simulation studies. The proposed strategy for synthesizing high-density electrodes holds promise for developing high-performance metallic compound electrodes for PIBs and potentially extending to other types of energy storage systems.

In-situ capture defects through molecule grafting assisted in coal-based hard carbon anode for sodium-ion batteries

Sodium-ion batteries is not essential but also potential to support energy storage system due to the low cost. It's worth noting that low price and high carbon production helps coal extraordinary promise as hard carbon precursor. However, low initial coulombic efficiency (ICE) and practical Na+ storage specific capacity barrier their application owing to lots of defects. Herein, a grafting method is proposed to decrease defects, introducing glucose with simple one step carbonization process. Utilizing the reaction between glucose and coal reduces the defects, which generates a high ICE with less irreversible sodium ion consumption. Meanwhile the expanded carbon layer spaces enable the fast sodium ions transfer, leading to an optimized sodium storage performance. The grafted glucose obviously decreases the defects during the carbonization process and contributes extra sodium storage capacity. The optimal CG0.1 exhibits higher reversible capacity of 293 mAh∙g−1 and ICE of 84 % than pristine coal pyrolytic carbon (250 mAh∙g−1 and 79 %). Besides, it also delivers outstanding capacity retention with 95.3 % and 95.8 % after 1000 cycles at 0.3 A∙g−1 (240 mAh∙g−1) and at 1 A∙g−1 (207 mAh∙g−1)

Palladium effect on electrochemical hydrogen storage properties of nanoporous silicon

Coating porous silicon with metal catalysts such as palladium is considered a reliable method to improve the hydrogen storage performance of electrodes. Here, in order to evaluate the most effective use of Pd nanoparticle or Pd thin film, Pd nanoparticles with a size of 36 nm obtained by electroless method, and a Pd thin film with a thickness of 30 nm deposited by thermal evaporation were coated onto nanoporous silicon sample” and studied. The Pd deposits were confirmed by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The obtained electrode materials: PS and Pd/PS were characterized by different electrochemical characterization techniques: cyclic voltammetry (CV) and galvanostatic charge/discharge. The results showed that Pd NPs/PS achieved the highest hydrogen storage capacity with a value of 425.9 mA h g-1. These results confirm that using Pd nanoparticles as catalyst metal is more suitable to improving the hydrogen storage capacity of electrode materials.

Quantum capacitance behavior of Ti2CO2/MoS2 heterostructures with 3d and 4d transition-metal doping

The storage capacity of capacity, quantum capacitance behavior, and atomic stability of O-defected, S-defected, 3d and 4d transition-metal (3d-TMs: Sc, Ti, V, Cr, Mn, Fe, Co, and Ni; 4d-TMs: Y, Zr, Nb, Mo, Ru, Rh, Pd, and Ag) doped Ti2CO2/MoS2 heterostructures were studied by density functional theory (DFT). Pristine Ti2CO2/MoS2 exhibited a high quantum capacitance of 1038.62 μF/cm2 at the positive potential. The appearance of O-vacancy in Ti2CO2-layer enhanced the capacitance of Ti2CO2/MoS2 at negative bias, and S-vacancy induced an obvious improvement of quantum capacitance at 0 V. After introducing various transition metals into modified Ti2CO2/MoS2 heterostructures, the doping in pristine structures increased the capacitance value to be 1182.71 μF/cm2 (Y-doping), while TM-doping in S-vacancy defected Ti2CO2/MoS2 systems induced a slight decrease of capacitance at positive potentials. For TM-doped O-defected Ti2CO2/MoS2, only Sc- and Y-doped systems exhibited higher quantum capacitance than the pristine Ti2CO2/MoS2, which were 1093.60 and 1096.26 μF/cm2. Due to the obvious advantage of capacitance of pristine Ti2CO2/MoS2 than Ti2CO2 or MoS2 single-layer at the positive bias, it can be used as effective anodes for high-capacitance supercapacitors, while 3d or 4d TM-doping had no significant enhancement in capacitance behaviors. The findings in this study were supposed to be theoretical data base to design high-performance supercapacitors.

Evaluation of hydrogen storage capacity of two-dimensional Sc2N MXene: A DFT study

In this work, the efficiency of hydrogen storage on Sc2N MXenes monolayer is systematically investigated using first-principles calculations. After determining the structural stability of designed monolayer, adsorption sites for the storage of hydrogen atoms (H) and molecules (H2) are identified. The calculated binding energies have indicated that the hydrogen atoms have favorable adsorption at the center or H site of the Sc atoms and hydrogen molecules are found to be the most stable when adsorbed on the top/T site of Sc atoms. The binding energy assessment identified the chemisorption for hydrogen atoms and Kubas-type interactions for H2. To further ascertain the suitability of the Sc2N monolayer for hydrogen storage various analyses including binding energy, partial density of states (PDOS), electron localization function (ELF), Mullikan charge analysis and Hirshfeld charge analysis are conducted. In order to determine the thermal stability of the Sc2N monolayer, desorption temperature with respect to pressure and molecular dynamics study has also been conducted and found the monolayer thermally stable. Desorption isotherms condition with increasing pressure confirms the gravimetric storage uptake. The obtained results have revealed that the hydrogen storage capacity considered monolayer has reached up to 10.8 wt%, which is reasonably high. Hence, the obtained results of hydrogen atom and molecules adsorption have clearly established that Sc2N monolayer is as an exemplary, stable, reliable and efficient medium for hydrogen storage applications.

Effect of ratio of desulfurization gypsum to carbide slag on low-carbon phase change composites for energy storage

To recycle industrial wastes sufficiently, this work innovatively proposed a mixture of desulfurization gypsum and carbide slag as skeleton material to fabricate phase-change composites with NaNO3 as phase change material in a mass ratio of 5 to 5. Four phase-change composites were fabricated with different ratio of desulfurization gypsum to carbide slag by the cold compression-hot sintering method, and then key thermal and mechanical properties, microscopic morphology and chemical compatibility between components were investigated in detail. Results show that the mixture of desulfurization gypsum and carbide slag as skeleton material is feasible and reliable and an optimal mass ratio of desulfurization gypsum to carbide slag was obtained to be 3.5 to 1.5; the phase-change composite with the optimal mass ratio possesses good mechanical strength of up to 134.116 MPa and an energy storage capacity of 483.151 J/g in the range of 100 to 400 °C, as well as excellent thermal stability and chemical compatibility between components, inside which the NaNO3 is well encapsulated. Moreover, the phase-change composites fabricated in this work have far low energy consumption and carbon dioxide emission.

Tổng hợp vật liệu LiNi0,9Mn0,05Co0,05O2 bằng phương pháp phản ứng pha rắn (NMC9.5.5-PR) ứng dụng chế tạo pin ion liti

Nickel-manganese-cobalt (NMC) transition metal oxide-based layered structural materials are evaluated a promising material for applications as cathode in lithium-ion batteries. In this study, we have successfully synthesized nickel-rich NMC material LiNi0.9Mn0.05Co0.05O2 by solid-state reaction method (NMC9.5.5- PR). The CR2032-type lithium-ion battery is also successfully fabricated from NMC material to serve the study of electrochemical properties. The NMC9.5.5-PR material exhibits outstanding discharge specific capacity when providing a maximum specific capacity of up to 212.4 mAh/g at a current density of 10 mA/g. However, the cycle efficiency survey results show that the NMC9.5.5-PR material has some disadvantages (only maintaining 81.6% of the discharge specific capacity after 50 continuous charge-discharge cycles at current density of 10 mA/g). These electrochemical properties indicate that it is necessary to further improve the cyclic efficiency of NMC9.5.5-PR material but preserving its outstanding electrical energy storage capacity. Successfully accomplishing this goal, we believe that NMC-9.5.5-PR or a material based on NMC9.5.5-PR will be one of the suitable materials to fabricate positive electrodes used in lithium-ion batteries.

Borophene/graphene heterostructure for effective hydrogen storage with facile dehydrogenation

A theoretical investigation of the hydrogen adsorption on a β12-borophene monolayer and a β12-borophene/graphene bilayer heterostructure is performed to tailor the substrate properties via functionalization to increase its hydrogen (H2) physisorption strength and enhance its gravimetric capacity. The results using the density-functional theory show that the H2 adsorption energy significantly increases as the substrate changes from monolayer to bilayer heterostructure. This enhancement in H2 adsorption energy is attributed to the synergetic effects of the interlayer interaction in the heterostructure via analysis of the chemical bonding. The lithium decoration of the bilayer heterostructure has indeed increased both the H2 adsorption energy and gravimetric capacity. Further enhancement of these latter attributes is shown to be plausible to achieve through the application of an electric field normal to the surface and directed upward toward the molecules. The thermodynamic analysis based on the Langmuir adsorption model finds that the high storage capacity should be maintained high with an effective gravimetric capacity of 13.64 wt% at ambient conditions. Our findings demonstrated that the Li-decorated β12-borophene/graphene bilayer heterostructure should be a promising candidate for efficient hydrogen storage applications.

Water Scarcity Zonation Mapping using MCDM Method in District, NAMCHI, South Sikkim using QGIS

Abstract: A major worldwide issue, water scarcity has especially serious repercussion like India that have an abundance of water. There are only so many fresh water sources available to meet the growing demand for water brought on by urbanisation, industrialisation, and population expansion, Since the limited water supplies cannot satisfy the population’s needs, a state of water scarcity has resulted. The present research is conducted in CCCT Chisopani, Sikkim, India. Water scarcity is a major issue in the area we selected, the multiple criteria decision making (MCDM) approach will be used in this case study to solve the ranking water scarcity problem, and the next upcoming major problem for water scarcity is the growing population in the study area. Along with the households the area consists of 2 study institutes due to which the population may increase in the coming years effecting the water management. The first step was to conduct a survey in and around the study area by preparing questionnaire including total population of household, highest qualification in the house, storage capacity, tenants, local source, rain water harvesting, hours water received, water fetched manually or not? Type of roofs, distance to perennial source. After collection, the data was evaluated and standardised to guarantee comparability across numerous criteria. Further the study was continued with water scarcity index calculation making it easier to prepare the zonation map for the study area. The MCDM method exhibits how the method can be used against the water scarcity problem. The main focus of the study was to create a scarcity map for the study zone in QGIS using RS&GIS method.

Optimization of Flywheel Design for the Engine CT-195 to Reduce Weight & Minimized Cost

Abstract: A flywheel stores energy in the form of kinetic (rotational) energy. Whereas each energy storage system has its inherent advantages and disadvantages compared to the others, it is the overall system performance and simplicity of flywheels that make them especially attractive for a variety of applications. Flywheel is mechanical device which is used to store the kinetic energy. There are many causes of flywheel failure. But maximum tensile and bending stresses induced in the web and rim under the action of centrifugal forces are the main causes of flywheel Failure. By changing the dimensions and shape and the materials and use such materials which increases stored energy and maintain minimum stresses with reduce mass of flywheel. It shows that smart design of flywheel geometry could both have a significant effect on the Specific Energy performance and reduce the operational loads exerted on the shaft/bearings due to reduced mass at high rotational speeds. we will compare the theoretical values of moment of Inertia with the Creo-Mechanic values so that the clear objective of the project can be seen. Our Main object is to optimise the flywheel weight without changing other important parameter like moment of inertia and its kinetic energy storage capacity.

Future directions in geological research impacting renewable energy and carbon capture: A synthesis of sustainable management techniques

Geological research plays a pivotal role in shaping the future of renewable energy and carbon capture initiatives, offering insights into sustainable management techniques. This review synthesizes the future directions in geological research that impact renewable energy and carbon capture, focusing on sustainable management techniques. Future geological research will increasingly focus on enhancing the integration of renewable energy sources into existing energy systems. This includes the development of innovative geological mapping techniques to identify and characterize renewable energy resources with greater precision, aiding in the selection of optimal sites for energy production. Additionally, there will be a growing emphasis on utilizing geological data to assess the feasibility of carbon capture and storage (CCS) projects, particularly in volcanic regions, where the unique geological characteristics offer potential for efficient carbon sequestration. Another key aspect of future geological research is the advancement of monitoring and modeling techniques to evaluate the long-term performance and environmental impact of renewable energy and CCS projects. This includes the use of advanced geophysical and geochemical methods to monitor subsurface changes associated with energy extraction and carbon storage, ensuring the effectiveness and safety of these practices. Furthermore, future research will explore the potential of geological formations, such as deep saline aquifers and depleted oil and gas reservoirs, for large-scale carbon storage. This will involve developing strategies to enhance storage capacity and mitigate the risk of CO2 leakage, contributing to the sustainable management of carbon emissions. In conclusion, future geological research will play a critical role in advancing renewable energy and carbon capture technologies, offering sustainable management techniques that are essential for addressing climate change. By focusing on innovative mapping, monitoring, and modeling approaches, researchers can pave the way for a more sustainable energy future.

Mechanically and Electrically Stable Hybrid Aerogels as Free‐Standing Anodes for High‐Capacity Lithium‐Ion Battery

Molybdenum disulfide (MoS2) is a promising alternative to graphite anodes in battery materials. Therefore, it is critical to scrutinize their structural stability and charge storage capacity during battery operation. Herein, freestanding electrodes consisting of MoS2‐incorporated carbon nanotube aerogels are fabricated using a simple yet scalable hydrothermal method, as used in lithium‐ion batteries. The outer nitrogen‐doped graphitic carbon (NGr) layers support efficient charge transport, even under a substantial compressive environment, and improve the structural integrity, showing significant improvements in battery performance, such as a high rate capacity of 820 mAh g−1 at the current density of 5 A g−1 and 94% capacity retention after 170 cycles (1170 mAh g−1 at 1 A g−1 after 170 cycles), even in the absence of polymer binders and conductive additives. The resulting NGr/MoS2/single‐walled carbon nanotubes freestanding electrodes have great potential to increase the volumetric and gravimetric energy density of batteries.

Preparation and performance enhancement of MXene/Na2HPO4·12H2O@SiO2 phase change microcapsule

Currently, the leakage problem of phase change materials can be solved by the microencapsulation technology. Inorganic hydrated salt materials have the advantages of high latent heat density, high thermal conductivity and low cost. How to construct inorganic hydrated salt microcapsules with excellent heat storage capacity and photothermal conversion performance maintains a challenge. In this work, the MXene/Na2HPO4·12H2O@SiO2 (MXene/MPCMs) composite phase change microcapsules were designed and prepared. The Na2HPO4·12H2O was directly used as phase change material and TEOS was used as raw material to generate SiO2 wall material. The MXene played a key and important role in simultaneously enhancing their photothermal conversion efficiency while maintaining available latent heat. The prepared composite microcapsules (MPCM-1) showed more obvious heat storage and release characteristics, and the latent heat reached 169.62 J/g. Besides, when the hydrated salt was encapsulated in silica shell, the supercooling degree of hydrated salt was reduced from 14.2 °C to 10.1 °C. With the increase of MXene content, the maximum surface temperature of microcapsules significantly increased. Based on the results of surface temperature distribution, the photothermal conversion ability and heat transfer rate of microcapsules were effectively improved, which was mainly attributed to the remarkable light absorption conversion ability of MXene. When the MXene was added, the MXene/MPCMs still showed excellent heat storage properties (~ 156.64 J/g). At the same time, the MXene/MPCMs showed good chemical compatibility, crystallization characteristics and thermal stability. Considering available performance enhancement, the prepared microcapsules show good application prospect in solar energy utilization.

Hurricanes jeopardise carbon storage capacity.

Hurricanes jeopardise carbon storage capacity.

2D Exfoliation Chemistry Towards Covalent Pseudo‐Layered Phosphate Framework Derived by Radical/Strain‐Synergistical Process

2D compounds exfoliated from weakly bonded bulk materials with van der Waals (vdW) interaction are easily accessible. However, the strong internal ionic/covalent bonding of most inorganic crystal frameworks greatly hinders 2D material exfoliation. Herein, we first proposed a radical/strain‐synergistic strategy to exfoliate non‐vdW interacting pseudo‐layered phosphate framework. Specifically, hydroxyl radicals (•OH) distort the covalent bond irreversibly, meanwhile, H2O molecules as solvents, further accelerating interlayered ionic bond breakage but mechanical expansion. The innovative 2D laminar NASICON‐type Na3V2(PO4)2O2F crystal, exfoliated by •OH/H2O synergistic strategy, exhibits enhanced sodium‐ion storage capacity, high‐rate performance (85.7 mA h g‐1 at 20 C), cyclic life (2300 cycles), and ion migration rates, compared with the bulk framework. Importantly, this chemical/physical dual driving technique realized the effective exfoliation for strongly coupled pseudo‐layered frameworks, which accelerates 2D functional material development.

Flood Propagation Characteristics in a Plain Lake: The Role of Multiple River Interactions

Plain lakes play a crucial role in the hydrological cycle of a watershed, but their interactions with adjacent rivers and downstream water bodies can create complex river–lake relationships, often leading to frequent flooding disasters. Taking Poyang Lake as an example, this paper delves into its interaction with the Yangtze River, revealing the spatiotemporal patterns of flood propagation within the lake and its impact on surrounding flood control measures. The aim is to provide insights for flood management in similar environments worldwide. This study employs a comprehensive approach combining hydrological statistical analysis and two-dimensional hydrodynamic modeling, based on extensive hydrological, topographic, and socio-economic data. The results indicate that the annual maximum outflow from Poyang Lake is primarily controlled by floods within the watershed, while the highest annual lake water level is predominantly influenced by floods from the Yangtze River. The peak discharge typically reaches the lake outlet within 48 h, with the peak water level taking slightly longer at 54 h. However, water storage in the lake can shorten the time that it takes for the peak discharge to arrive. When converging with floods from the Yangtze River, the peak water level may be delayed by up to 10 days, due to the top-supporting interaction. Furthermore, floods from the “Five Rivers” propagate differently within the lake, affecting various lake regions to differing degrees. Notably, floods from the Fu River cause the most significant rise in the lake’s water level under the same flow rate. The top-supporting effect from the Yangtze River also significantly impacts the water surface slope of Poyang Lake. When the Yangtze River flood discharge significantly exceeds that of the “Five Rivers” (i.e., when the top-supporting intensity value, f, exceeds four), the lake surface becomes as flat as a reservoir. During major floods in the watershed, the water level difference in the lake can increase dramatically, potentially creating a “dynamic storage capacity” of up to 840 million cubic meters.

Concept Design of Typhoon Power Generation Ship Using System Simulation

A concept of a typhoon power generation ship for utilizing enormous typhoon energy is proposed. This paper developed a system simulator for evaluating and designing the concept of a typhoon power generation ship using typhoon track history. A developed simulator was applied to the case study to design a typhoon power generation ship ship that operated near Japan. The case study showed that the annual power generation of the typhoon power generation ship tends to saturate and become constant earlier when the number of typhoons is small, in contrast to the improvement of power storage capacity. This result indicates that the appropriate size of the typhoon power generation ship exists at the current technology level.