scholarly journals Hydrogen Storage Enhancement Attained by Fixation of Ti on MWNTs

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
J. J. Pérez-Bueno ◽  
M. L. Mendoza López ◽  
K. M. Brieño Enriquez ◽  
J. Ledesma García ◽  
L. A. Godínez Mora-Tovar ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Gold Electrode ◽  
Hydrogen Adsorption ◽  
Titanium Atom ◽  
Electrostatic Charge ◽  
Energy Sources ◽  
Main Concern ◽  
Practical Applications ◽  
Storage Devices ◽  
Hydrogen Molecules

Nowadays, hydrogen has a preponderant position among the potentially sustainable energy sources. Due to its power density, its storage is of main concern when considering a broad use in practical applications. Carbon nanotubes constitute promising candidates for the design and construction of hydrogen storage devices. This work explores the use of some procedures involving electrochemistry, aimed to bond atomic Ti on the outer surface of MWNTs. Each titanium atom has the potential of hosting two hydrogen molecules and relinquishing them by heating. Nevertheless, nanotubes are difficult to handle due to electrostatic charge and agglomeration, and in this context, two routes were tested as procedures to spread and stick nanotubes on an electrode: (1) a functionalization capable of attaching gold was tested in two forms, as either using 4 nm particles or a flat gold electrode. The fixation of Au particles was confirmed by HRTEM. (2) A simpler route that consisted on drying a CH2Cl2/nanotubes solution previously spread on a glassy carbon flat electrode. CH2Cl2was selected as the medium and TiCl4as the precursor for attaching atomic Ti to the nanotubes. The results revealed that hydrogen adsorption, estimated from voltamperometry, was five times higher on Ti-MWNTs than on bare nanotubes.

scholarly journals Impact of Crystallography on Design of Cathode Materials for Li-ion Batteries

2014 ◽  
Vol 70 (a1) ◽  
pp. C20-C20
Author(s):  
Evgeny Antipov ◽  
Nellie Khasanova
Keyword(s):  
Transition Metal ◽  
Cathode Materials ◽  
Fossil Fuels ◽  
Negative Impact ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Li Ion Batteries ◽  
Practical Applications ◽  
Storage Devices ◽  
Li Ion

Ninety percent of the energy produced today come from fossil fuels, making dramatically negative impact on our future due to rapid consumption of these energy sources, ecological damage and climate change. This justifies development of the renewable energy sources and concurrently efficient large storage devices capable to replace fossil fuels. Li-ion batteries have originally been developed for portable electronic devices, but nowadays new application niches are envisaged in electric vehicles and stationary energy storages. However, to satisfy the needs of these rapidly growing applications, Li-ion batteries require further significant improvement of their properties: capacity and power, cyclability, safety and cost. Cathode is the key part of the Li-ion batteries largely determining their performance. Severe requirements are imposed on a cathode material, which should provide fast reversible intercalation of Li-ions at redox potential close to the upper boundary of electrolyte stability window, possess relatively low molecular weight and exhibit small volume variation upon changing Li-concentration. First generation of the cathode materials for the Li-ion batteries based on the spinel (LiM2O4, M – transition metal) or rock-salt derivatives (LiMO2) has already been widely commercialised. However, the potential to further improve the performance of these materials is almost exhausted. The compounds, containing lithium and transition metal cations together with different polyanions (XmOn)p- (X=B, P, S, Si), are now considered as the most promising cathode materials for the next generation of the Li-ion batteries. Covalently-bonded structural frameworks in these compounds offer long-term structural stability, which is essential for good cyclability and safety. Further advantages are expected from combining different anions (such as (XO4)p- and F- ) in the anion sublattice, with the hope to enhance the specific energy and power of these materials. Various fluoride-phosphates and fluoride-sulphates have been recently discovered, and some of them exhibit attractive electrochemical performance. An overview of the research on the cathode materials for the Li-ion batteries will be presented with special emphasis on crystallography as a guide towards improved properties important for practical applications.

scholarly journals A First-Principles Study on Titanium-Decorated Adsorbent for Hydrogen Storage

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6845
Author(s):  
Kai Ma ◽  
Erfei Lv ◽  
Di Zheng ◽  
Weichun Cui ◽  
Shuai Dong ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Density Functional Theory Calculation ◽  
Partial Density ◽  
Ambient Conditions ◽  
Functional Theory ◽  
Hydrogen Molecules ◽  
Theory Calculation ◽  
Hydrogen Storage Medium

Based on density functional theory calculation, we screened suitable Ti-decorated carbon-based hydrogen adsorbent structures. The adsorption characteristics and adsorption mechanism of hydrogen molecules on the adsorbent were also discussed. The results indicated that Ti-decorated double vacancy (2 × 2) graphene cells seem to be an efficient material for hydrogen storage. Ti atoms are stably embedded on the double vacancy sites above and below the graphene plane, with binding energy higher than the cohesive energy of Ti. For both sides of Ti-decorated double vacancy graphene, up to six H2 molecules can be adsorbed around each Ti atom when the adsorption energy per molecule is −0.25 eV/H2, and the gravimetric hydrogen storage capacity is 6.67 wt.%. Partial density of states (PDOS) analysis showed that orbital hybridization occurs between the d orbital of the adsorbed Ti atom and p orbital of C atom in the graphene layer, while the bonding process is not obvious during hydrogen adsorption. We expect that Ti-decorated double vacancy graphene can be considered as a potential hydrogen storage medium under ambient conditions.

Lithium Decorated Borane Clusters (BnHnLi6, n=5-7) as Promising Materials for Hydrogen Storage: A Computational Study

2021 ◽  
Author(s):  
Shakti S Ray ◽  
Sridhar Sahu
Keyword(s):  
Hydrogen Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Computational Study ◽  
Density Functional Theory Calculations ◽  
Md Simulations ◽  
Department Of Energy ◽  
Hydrogen Molecules ◽  
The Stability ◽  
Almost All

Abstract In this study, we have investigated the hydrogen adsorption potential of lithium decorated borane clusters (BnHnLi6, n = 5–7) using density functional theory calculations. The principle of maximum hardness and minimum electrophilicity confirmed the stability of the hydrogen adsorbed complexes. The outcomes of the study reveals that, the hydrogen molecules are adsorbed in a quasi-molecular fashion via Niu-Rao-Jena type of interaction with average adsorption energy falling in the range of 0.10-0.11eV/H2and average Li-H2 bond length is in the range of 2.436–2.550Å. It was found that the hydrogen molecules are physiosorbed at the host clusters at low temperature range 0K- 77K with gravimetric density up to 26.4 wt% which was well above target set by U.S. Department of Energy (US-DOE). ADMP-MD simulations showed that almost all the H2 molecules are desorbed at higher temperature form 373K-473K without distorting the host clusters which indicates the studied clusters can be promoted as promising reversible hydrogen storage

MOLECULAR SIMULATION OF HYDROGEN ADSORPTION IN ALUMINUM ORGANIC FRAMEWORK

2013 ◽  
Vol 27 (13) ◽  
pp. 1350095 ◽  
Author(s):  
WEI DAI ◽  
RUI LI ◽  
HAIQIN JIN ◽  
SHIFANG WANG
Keyword(s):  
Hydrogen Storage ◽  
Storage Capacity ◽  
Hydrogen Adsorption ◽  
Grand Canonical Monte Carlo ◽  
Hydrogen Storage Capacity ◽  
Weight Density ◽  
Hydrogen Molecules ◽  
Preferential Adsorption ◽  
Grand Canonical ◽  
Organic Framework

With the aid of molecular simulations, a new aluminum organic framework structure is designed, and the hydrogen storage capability of the designed structure is studied using grand canonical Monte Carlo technique. Results show that the hydrogen storage capacity of aluminum organic framework at 77 K and 1 MPa is about 430 hydrogen molecules per unit cell, the corresponding weight density be equivalent to 17.45 wt.%. The preferential adsorption site is located at the aluminum–oxygen cluster. Hydrogen molecules are preferentially distributed on the surface of Al ions. The complexation of organic linkers with Al ions is found to be in favor of the adsorption of hydrogen.

Correction to “Influence of Graphene Curvature on Hydrogen Adsorption: Toward Hydrogen Storage Devices”

2013 ◽  
Vol 117 (39) ◽  
pp. 20377-20377
Author(s):  
Sarah Goler ◽  
Camilla Coletti ◽  
Valentina Tozzini ◽  
Vincenzo Piazza ◽  
Torge Mashoff ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Adsorption ◽  
Storage Devices

A simulation study on the hydrogen storage properties of fullerene family molecules Cx(x = 56,60,70) and their hydrides

2016 ◽  
Vol 30 (22) ◽  
pp. 1650303
Author(s):  
Wei Dai ◽  
Ming Xiao ◽  
Mu-Qing Chen ◽  
Jia-Jing Xu ◽  
Yong-Jian Tang
Keyword(s):  
Hydrogen Storage ◽  
Energy Barrier ◽  
Hydrogen Adsorption ◽  
High Energy ◽  
Hydrogen Energy ◽  
Carbon Cage ◽  
First Principle Calculation ◽  
Hydrogen Storage Properties ◽  
Hydrogen Molecules ◽  
Storage Properties

Hydrogen storage is a key factor for the application of hydrogen energy. From first principle calculation, we have acquired the energy barrier for hydrogen molecules to pass through the hexagonal rings and pentagonal rings of the fullerene. Then the absorption energy and energy barrier are used to analyze the hydrogen adsorption capacity of the fullerene family and their hydrides. We have also studied the hydrogen storage properties of the fullerene family and their hydrides by grand canonical Monte Carlo method. It is found that the weight density of hydrogen storage at ambient temperature and pressure can reach 7.71 wt.%. The results show that it is difficult for hydrogen to get into the carbon cage of the fullerene because of the high energy barrier, while it is beneficial to destroy the fullerene structure for the processes of absorption and desorption. Meanwhile, fullerene hydrogenation is an effective method to improve the hydrogen storage properties. Our study facilitates the design and synthesis of hydrogen storage materials, and provides theoretical support to improve the hydrogen storage capability for materials.

FIRST-PRINCIPLES STUDY OF Ti-CATALYZED HYDROGEN ADSORPTION ON LiB (001) SURFACE

2013 ◽  
Vol 12 (07) ◽  
pp. 1350065 ◽  
Author(s):  
WEIBIN ZHANG ◽  
AILING WU ◽  
YIDING LIU ◽  
SHAOLIN ZHANG ◽  
JIANHONG GONG ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
First Principles ◽  
Electronic Structures ◽  
Hydrogen Adsorption ◽  
Department Of Energy ◽  
Hydrogen Storage Material ◽  
Ambient Conditions ◽  
Storage Material ◽  
Practical Applications ◽  
Temperature And Pressure

Ti -doped LiB (001) is a promising material for hydrogen storage. The adsorption of H 2 is greatly enhanced by doping Ti into LiB (001), change the electronic structures of the surface Li , B atoms. After H 2 is adsorbed on the surface, the E ad of the ( H 2)n@ Ti / LiB (001) system is considered. It is around -0.22 eV/ H 2 to -0.31 eV/ H 2, which is close to the target specified by U.S. Department of Energy. The nature of the bonding between Ti and H 2 is due to the H 1s, Ti 4s and B 2s orbital hybridization. In addition, Ti 3d orbital is hybridized strongly with B -2p orbital, resulting in more stable Ti / LiB (001) system. These results are verified by the electron density distribution intuitively. It is found that the system can adsorb up to four H 2 at ambient temperature and pressure. Therefore, the Ti -doped LiB (001) would be a promising hydrogen storage material. Such optimal molecular hydrogen adsorption system makes H 2 adsorption feasible at ambient conditions, which is critical for practical applications.

High Capacity Hydrogen Storage in Li Decorated Octagraphene - A First Principles Study

2017 ◽  
Vol 17 ◽  
pp. 131-139 ◽  
Author(s):  
B. Rekha ◽  
S. Seenithurai ◽  
R. Kodi Pandyan ◽  
S. Vinodh Kumar ◽  
Manickam Mahendran
Keyword(s):  
Binding Energy ◽  
Hydrogen Storage ◽  
First Principles ◽  
Density Functional ◽  
Storage Capacity ◽  
Hydrogen Adsorption ◽  
Pristine Graphene ◽  
Carbon Allotrope ◽  
Average Binding Energy ◽  
Hydrogen Molecules

From first principles density functional theory, Li-decorated octagraphene and its usage as a hydrogen storage media is theoretically investigated. Octagraphene is a versatile structure with periodic sp2 – bonded carbon atomic planar sheet. This carbon allotrope consists of carbon octagons and rectangular lattices with two bond lengths. The Li binding energy in octagraphene is 2.5 eV, which is much higher than that of pristine graphene. Maximum of four hydrogen molecules can be adsorbed on Li decorated on one side of octagraphene and this leads to a gravimetric storage capacity of 2.4 wt% with an average adsorption binding energy of 0.35eV/H2. Li decorated on both sides of octagraphene, attains a gravimetric storage capacity of 8.1 wt% with an average binding energy of 0.23 eV/ H2. Thus, the structure investigated here is flattering for the reversible hydrogen adsorption/ desorption at the room temperature.

scholarly journals Influence of Graphene Curvature on Hydrogen Adsorption: Toward Hydrogen Storage Devices

2013 ◽  
Vol 117 (22) ◽  
pp. 11506-11513 ◽  
Author(s):  
Sarah Goler ◽  
Camilla Coletti ◽  
Valentina Tozzini ◽  
Vincenzo Piazza ◽  
Torge Mashoff ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Adsorption ◽  
Storage Devices

scholarly journals High-Pressure Hydrogen Adsorption in the Zeolites: A Grand Canonical Monte Carlo Study

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Xiuying Liu ◽  
Jie He ◽  
Rui Li
Keyword(s):  
Monte Carlo ◽  
Hydrogen Storage ◽  
High Pressures ◽  
Storage Capacity ◽  
Hydrogen Adsorption ◽  
Monte Carlo Study ◽  
Grand Canonical Monte Carlo ◽  
Hydrogen Molecules ◽  
Different Temperatures ◽  
Grand Canonical

The adsorption of hydrogen molecules on different zeolites at near room temperature and extremely high pressures has been simulated employing Grand Canonical Monte Carlo (GCMC) method. Some important physical amounts under different temperatures and pressures, such as adsorption isotherms, adsorption amounts, and isosteric heats were studied. We predict the storage capacity of hydrogen in ZON and CHA zeolites at different conditions. The results show that the hydrogen storage capacity of CHA is superior to that of ZON. The different hydrogen adsorption behavior between them is explained by the isosteric heats of adsorption at different temperatures. These results may help us to understand different hydrogen adsorption properties of these two zeolites, thus facilitate exploring new hydrogen storage candidates experimentally.

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