scholarly journals Atomistic Modeling of Various Doped Mg2NiH4 as Conversion Electrode Materials for Lithium Storage

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 254 ◽  
Author(s):  
Zhao Qian ◽  
Guanzhong Jiang ◽  
Yingying Ren ◽  
Xi Nie ◽  
Rajeev Ahuja
Keyword(s):  
Density Functional ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Density Functional Theory Calculations ◽  
Lithium Storage ◽  
Pure Material ◽  
Computational Screening ◽  
Electrochemical Capacity ◽  
Ti Doping

In this work, we have compared the potential applications of nine different elements doped Mg2NiH4 as conversion-type electrode materials in Li-ion batteries by means of state-of-the-art Density functional theory calculations. The electrochemical properties, such as specific capacity, volume change and average voltage, as well as the atomic and electronic structures of different doped systems have been investigated. The Na doping can improve the electrochemical capacity of the pristine material. Si and Ti doping can reduce the band gap and benefit the electronic conductivity of electrode materials. All of the nine doping elements can help to reduce the average voltage of negative electrodes and lead to reasonable volume changes. According to the computational screening, the Na, Si and Ti doping elements are thought to be promising to enhance the comprehensive properties of pure material. This theoretical study is proposed to encourage and expedite the development of metal-hydrides based lithium-storage materials.

scholarly journals Encapsulating Metal-Organic-Foam Derived Nanocages into a Microcapsule for Shuttle Effect-Suppressive Lithium-Sulfur Batteries

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 236
Author(s):  
Jinyun Liu ◽  
Yajun Zhu ◽  
Junfei Cai ◽  
Yan Zhong ◽  
Tianli Han ◽  
...  
Keyword(s):  
Density Functional ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Density Functional Theory Calculations ◽  
Binding Energies ◽  
High Rate ◽  
Lithium Storage ◽  
Shuttle Effect ◽  
Metal Organic ◽  
High And Low Temperatures

Long-term stable secondary batteries are highly required. Here, we report a unique microcapsule encapsulated with metal organic foams (MOFs)-derived Co3O4 nanocages for a Li-S battery, which displays good lithium-storage properties. ZIF-67 dodecahedra are prepared at room temperature then converted to porous Co3O4 nanocages, which are infilled into microcapsules through a microfluidic technique. After loading sulfur, the Co3O4/S-infilled microcapsules are obtained, which display a specific capacity of 935 mAh g−1 after 200 cycles at 0.5C in Li-S batteries. A Coulombic efficiency of about 100% is achieved. The constructed Li-S battery possesses a high rate-performance during three rounds of cycling. Moreover, stable performance is verified under both high and low temperatures of 50 °C and −10 °C. Density functional theory calculations show that the Co3O4 dodecahedra display large binding energies with polysulfides, which are able to suppress shuttle effect of polysulfides and enable a stable electrochemical performance.

scholarly journals Ab Initio Screening of Doped Mg(AlH4)2 Systems for Conversion-Type Lithium Storage

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2599 ◽  
Author(s):  
Zhao Qian ◽  
Hongni Zhang ◽  
Guanzhong Jiang ◽  
Yanwen Bai ◽  
Yingying Ren ◽  
...  
Keyword(s):  
Volume Change ◽  
Density Functional ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Theoretical Research ◽  
Li Ion Battery ◽  
Lithium Storage ◽  
Pure System ◽  
Li Ion ◽  
Conversion Electrode

In this work, we have explored the potential applications of pure and various doped Mg(AlH4)2 as Li-ion battery conversion electrode materials using density functional theory (DFT) calculations. Through the comparisons of the electrochemical specific capacity, the volume change, the average voltage, and the electronic bandgap, the Li-doped material is found to have a smaller bandgap and lower average voltage than the pure system. The theoretical specific capacity of the Li-doped material is 2547.64 mAhg−1 with a volume change of 3.76% involving the electrode conversion reaction. The underlying reason for property improvement has been analyzed by calculating the electronic structures. The strong hybridization between Lis-state with H s-state influences the performance of the doped material. This theoretical research is proposed to help the design and modification of better light-metal hydride materials for Li-ion battery conversion electrode applications.

scholarly journals Interface Engineering of CoS/CoO@N-Doped Graphene Nanocomposite for High-Performance Rechargeable Zn–Air Batteries

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Yuhui Tian ◽  
Li Xu ◽  
Meng Li ◽  
Ding Yuan ◽  
Xianhu Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Large Scale ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Density Functional Theory Calculations ◽  
Interfacial Structure ◽  
Catalyst Stability ◽  
Bifunctional Electrocatalyst ◽  
Doped Graphene

Abstract Low cost and green fabrication of high-performance electrocatalysts with earth-abundant resources for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for the large-scale application of rechargeable Zn–air batteries (ZABs). In this work, our density functional theory calculations on the electrocatalyst suggest that the rational construction of interfacial structure can induce local charge redistribution, improve the electronic conductivity and enhance the catalyst stability. In order to realize such a structure, we spatially immobilize heterogeneous CoS/CoO nanocrystals onto N-doped graphene to synthesize a bifunctional electrocatalyst (CoS/CoO@NGNs). The optimization of the composition, interfacial structure and conductivity of the electrocatalyst is conducted to achieve bifunctional catalytic activity and deliver outstanding efficiency and stability for both ORR and OER. The aqueous ZAB with the as-prepared CoS/CoO@NGNs cathode displays a high maximum power density of 137.8 mW cm−2, a specific capacity of 723.9 mAh g−1 and excellent cycling stability (continuous operating for 100 h) with a high round-trip efficiency. In addition, the assembled quasi-solid-state ZAB also exhibits outstanding mechanical flexibility besides high battery performances, showing great potential for applications in flexible and wearable electronic devices.

Field Effect Modulation of Electrocatalytic Hydrogen Evolution at Back-Gated Two-Dimensional MoS2 Electrodes

2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie
Keyword(s):  
Electric Field ◽  
Hydrogen Evolution ◽  
Active Sites ◽  
Density Functional ◽  
Electrode Materials ◽  
Density Functional Theory Calculations ◽  
Electronic Charge ◽  
Back Side ◽  
Gate Electrode ◽  
Conventional Manner

<div> <div> <div> <p> </p><div> <div> <div> <p>Electrocatalytic activity for hydrogen evolution at monolayer MoS2 electrodes can be enhanced by the application of an electric field normal to the electrode plane. The electric field is produced by a gate electrode lying underneath the MoS2 and separated from it by a dielectric. Application of a voltage to the back-side gate electrode while sweeping the MoS2 electrochemical potential in a conventional manner in 0.5 M H2SO4 results in up to a 140-mV reduction in overpotential for hydrogen evolution at current densities of 50 mA/cm2. Tafel analysis indicates that the exchange current density is correspondingly improved by a factor of 4 to 0.1 mA/cm2 as gate voltage is increased. Density functional theory calculations support a mechanism in which the higher hydrogen evolution activity is caused by gate-induced electronic charge on Mo metal centers adjacent the S vacancies (the active sites), leading to enhanced Mo-H bond strengths. Overall, our findings indicate that the back-gated working electrode architecture is a convenient and versatile platform for investigating the connection between tunable electronic charge at active sites and overpotential for electrocatalytic processes on ultrathin electrode materials.</p></div></div></div><br><p></p></div></div></div>

scholarly journals Nanobelts-constructed Porous TiO2-B@SnS2 Heterostructure Hybrids for Enhance Lithium Storage Performance

2021 ◽  
Author(s):  
Chao Cai ◽  
Meiyu Song ◽  
Qixiang Ou ◽  
Jianmei Li ◽  
changsheng an
Keyword(s):  
Active Sites ◽  
Electrode Materials ◽  
Theoretical Calculations ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Electrode Structure ◽  
Lithium Storage ◽  
Volume Collapse ◽  
Alloy Type

Abstract Alloy-type anodes materials possess broad prospects for excellent electrochemical property lithium-ion batteries owing to its high theoretical capacity and excellent electronic conductivity. However, this type electrode materials experience poor kinetics and tremendous volume collapse during the repeated lithiation-delithiation process. Herein, an efficient method to provide a fast transmission channel and suppress the volume collapse during the discharge/charge process by constructing the heterostructure between porous TiO2-B nanoblets and few-layer SnS2 nanosheets interface, which provides high-active sites for the nucleation and growth of SnS2 nanosheets, and inhibits the agglomeration of SnS2 nanosheets. Both experimental results and theoretical calculations definite that porous TiO2 nanobelts provides more chemical active sites for the adsorption and transmission of lithium ion and then effectively improve the stability the electrode structure. As a result, TiO2-B@SnS2 hybrid exhibits excellent rate and cycle performance. This work paves a way to design and construction of high performance alloy-type anode materials.

High-Capacity Derivatives Produced from Hydrolytic Lignin as Electrode Materials for Energy Storage and Conversion

2018 ◽  
Vol 386 ◽  
pp. 359-364
Author(s):  
Yury M. Nikolenko ◽  
Denis P. Opra ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
Valery G. Kuryavyi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Energy Storage ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Energy Storage And Conversion ◽  
Operating Voltage ◽  
X Ray ◽  
Thermally Activated ◽  
Hydrolytic Lignin

The hydrolytic lignin derivatives have been prepared via its physical activation (high-temperature heating in vacuum) followed by chemical modification (fluorination). The obtained products were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that the graphitized product of thermal activation up to 1000 °C at a low rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes its potentially useful as sorbent, catalytic substrate or electrode material. To clarify the potentialities of hydrolytic lignin derivatives for energy storage and conversion, the electrochemical system with metallic lithium anode was applied. The galvanostatic discharge of battery at a current density of 100 μA/cm2between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The improve of the electrochemical performance of product originates from its graphitization, increasing electronic conductivity, and, possibly, enhanced ability to adsorb of oxygen. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process.

Constructing zigzag-like hollow mesoporous nanospheres MoO2/C with superior lithium storage performance

2021 ◽  
Author(s):  
Wencai Zhao ◽  
Y.F. Yuan ◽  
S.M. Yin ◽  
Gaoshen Cai ◽  
S.Y. Guo
Keyword(s):  
Reaction Kinetics ◽  
Discharge Capacity ◽  
Amorphous Carbon ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Structure Design ◽  
Structure Stability ◽  
Lithium Storage

Abstract Hollow mesoporous nanospheres MoO2/C are successfully constructed through metal chelating reaction between molybdenum acetylacetone and glycerol as well as the Kirkendall effect induced by diammonium hydrogen phosphate. MoO2 nanoparticles coupled by amorphous carbon are assembled to unique zigzag-like hollow mesoporous nanosphere with large specific surface area of 147.7 m2 g-1 and main pore size of 8.7 nm. The content of carbon is 9.1%. As anode material for lithium-ion batteries, the composite shows high specific capacity and excellent cycling performance. At 0.2 A g-1, average discharge capacity stabilizes at 1092 mAh g-1. At 1 A g-1 after 700 cycles, the discharge capacity still reaches 512 mAh g-1. Impressively, the composite preserves intact after 700 cycles. Even at 5 A g-1, the discharge capacity can reach 321 mAh g-1, exhibiting superior rate capability. Various kinetics analyses demonstrate that in electrochemical reaction, the proportion of the surface capacitive effect is higher, and the composite has relatively high diffusion coefficient of Li ions and fast faradic reaction kinetics. Excellent lithium storge performance is attributed to the synergistic effect of zigzag-like hollow mesoporous nanosphere and amorphous carbon, which improves reaction kinetics, structure stability and electronic conductivity of MoO2. The present work provides a new useful structure design strategy for advanced energy storage application of MoO2.

Theoretical study of SnS2 encapsulated in Graphene as a promising anode material for K−ion batteries

2021 ◽  
Author(s):  
Xuxin Kang ◽  
Wei Xu ◽  
Xiangmei Duan
Keyword(s):  
Anode Material ◽  
Density Functional ◽  
Open Circuit Voltage ◽  
Electronic Conductivity ◽  
Density Functional Theory Calculations ◽  
Rechargeable Batteries ◽  
Open Circuit ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Low K

Abstract Rechargeable batteries with superior electronic conductivity, large capacity, low diffusion barriers and moderate open circuit voltage have attracted amount attention. Due to abundant resources and safety, as well as the high voltage and energy density, potassium ion batteries (KIBs) could be an ideal alternative to next−generation of rechargeable batteries. Based on the density functional theory calculations, we find that the SnS2 monolayer expands greatly during the potassiumization, which limits its practical application. The construction of graphene/SnS2/graphene (G/SnS2/G) heterojunction effectively prevents SnS2 sheet from deformation, and enhances the electronic conductivity. Moreover, the G/SnS2/G has not only a high theoretical special capacity of 680 mAh/g, but an ultra−low K diffusion barrier (0.08 eV) and an average open circuit voltage (0.22 V). Our results predict that the G/SnS2/G heterostructure could be used as a promising anode material for KIBs.

scholarly journals Nitrogen-rich covalent organic frameworks with multiple carbonyls for high-performance sodium batteries

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ruijuan Shi ◽  
Luojia Liu ◽  
Yong Lu ◽  
Chenchen Wang ◽  
Yixin Li ◽  
...  
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Specific Capacity ◽  
Density Functional Theory Calculations ◽  
Rechargeable Batteries ◽  
High Rate ◽  
Ex Situ ◽  
Covalent Organic Frameworks ◽  
Rate Performance ◽  
Practical Applications

AbstractCovalent organic frameworks with designable periodic skeletons and ordered nanopores have attracted increasing attention as promising cathode materials for rechargeable batteries. However, the reported cathodes are plagued by limited capacity and unsatisfying rate performance. Here we report a honeycomb-like nitrogen-rich covalent organic framework with multiple carbonyls. The sodium storage ability of pyrazines and carbonyls and the up-to twelve sodium-ion redox chemistry mechanism for each repetitive unit have been demonstrated by in/ex-situ Fourier transform infrared spectra and density functional theory calculations. The insoluble electrode exhibits a remarkably high specific capacity of 452.0 mAh g−1, excellent cycling stability (~96% capacity retention after 1000 cycles) and high rate performance (134.3 mAh g−1 at 10.0 A g−1). Furthermore, a pouch-type battery is assembled, displaying the gravimetric and volumetric energy density of 101.1 Wh kg−1cell and 78.5 Wh L−1cell, respectively, indicating potentially practical applications of conjugated polymers in rechargeable batteries.

Lithiation mechanisms and lithium storage capacity of reduced graphene oxide nanoribbons: a first-principles study

2017 ◽  
Vol 5 (10) ◽  
pp. 4912-4922 ◽  
Author(s):  
Kun-Han Lin ◽  
Chin-Lung Kuo
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Storage Capacity ◽  
Density Functional Theory Calculations ◽  
Lithium Storage ◽  
Functional Theory ◽  
Capacity Limits ◽  
Graphene Oxide Nanoribbons ◽  
New Findings ◽  
Reduced Graphene

New findings on the lithiation mechanisms and the achievable Li capacity limits of various types of functional groups on the basal plane and those terminating the edge sites of graphene nanomaterials based on first-principles density functional theory calculations.

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