Computational and Experimental investigation of Nalipoite-Li2APO4 (A = Na, K) electrolytes for Li-ion batteries

2015 ◽  
Vol 1740 ◽  
Author(s):  
G. F. Ortiz ◽  
M C. López ◽  
M.E. Arroyo-de Dompablo ◽  
José L. Tirado
Keyword(s):  
Energy Barrier ◽  
Density Functional ◽  
Ionic Mobility ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Ionic Conductors ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Li Ion ◽  
Calculated Energy Barrier

ABSTRACTThe potential ionic conductors Li2APO4 (A = Na, K) are investigated combining experiments and first principles calculations at the Density Functional Theory level. A high ionic conductivity of 6.5 x10−6 and 1.5 x10−5 S cm−1 at 25 and 70°C, respectively, is found in Nalipoite-Li2NaPO4. For this mixed phosphate the energy barriers to Li motion are calculated. The lower energy barrier (0.7 eV) implies the inter-chain diffusion of Li in the b-c plane. We predict that ionic mobility is enhanced in the isostructural Li2KPO4, with the lowest calculated energy barrier being 0.4 eV.

scholarly journals First-Principles Study of the Structural Stability and Dynamic Properties of Li2MSiO4 (M = Mn, Co, Ni) Polymorphs

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Ponniah Vajeeston ◽  
Federico Bianchini ◽  
Helmer Fjellvåg
Keyword(s):  
Structural Stability ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Li Ion

In recent years, the scientific community has shown an increasing interest in regards to the investigation of novel materials for the intercalation of lithium atoms, suitable for application as cathodes in the new generations of Li-ion batteries. Within this framework, we have computed the relative structural stability, the electronic structure, the elastic and dynamic properties of Li2MSiO4 compounds (M = Mn, Co, Ni) by means of first-principles calculations based on density functional theory. The so-obtained structural parameters of the examined phases are in agreement with previous reports. The energy differences between different polymorphs are found to be small, and most of these structures are dynamically stable. The band structures and density of states are computed to analyse the electronic properties and characterise the chemical bonding. The single crystal elastic constants are calculated for all the examined modifications, proving their mechanical stability. These Li2MSiO4 materials are found to present a ductile behaviour upon deformation. The diffusion coefficients of Li ions, calculated at room temperature for all the examined modifications, reveal a poor conductivity for this class of materials.

A DFT study on the mechanism of reaction between 2, 4-diisocyanatotolune and cellulose

2016 ◽  
Vol 15 (02) ◽  
pp. 1650012 ◽  
Author(s):  
Jiping Cao ◽  
Yali Liu ◽  
Aijuan Shi ◽  
Yuan Yuan ◽  
Mingliang Wang
Keyword(s):  
Reaction Mechanisms ◽  
Energy Barrier ◽  
Density Functional ◽  
Membered Ring ◽  
Functional Theory ◽  
Mechanism Of Reaction ◽  
The Density Functional Theory ◽  
Good Accordance ◽  
Experimental Activation Energy ◽  
Ring Transition State

The reaction mechanisms between 2, 4-Diisocyanatotolune (2, 4-TDI) and cellulose have been investigated using the density functional theory at the B3LYP/6-31[Formula: see text]G (d, p) level. The calculations show that the direct addition of 2, 4-TDI and cellulose possesses an unrealistically high barrier of 32–34[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. With a neighboring [Formula: see text]-d-glucose serving as a proton transporter by forming a flexible six-membered ring transition state, the energy barrier of the reaction is significantly reduced to 16–18 kcal[Formula: see text]mol[Formula: see text], which is in a good accordance with the experimental activation energy of 13.9–16.7[Formula: see text]kcal[Formula: see text]mol[Formula: see text]. It is indicated that the reaction between 2, 4-TDI and cellulose is auto-catalyzed with a neighboring [Formula: see text]-d-glucose acting as a reactive catalyst.

scholarly journals Electronic, optical and thermoelectric properties of Fe2ZrP compound determined via first-principles calculations

RSC Advances ◽  
2019 ◽  
Vol 9 (44) ◽  
pp. 25900-25911 ◽  
Author(s):  
Esmaeil Pakizeh ◽  
Jaafar Jalilian ◽  
Mahnaz Mohammadi
Keyword(s):  
Density Functional Theory ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Density Functional ◽  
Transport Theory ◽  
First Principles Calculations ◽  
Boltzmann Transport ◽  
Functional Theory ◽  
Boltzmann Transport Theory ◽  
The Density Functional Theory

In this study, based on the density functional theory and semi-classical Boltzmann transport theory, we investigated the structural, thermoelectric, optical and phononic properties of the Fe2ZrP compound.

scholarly journals Effect of Defects on Spontaneous Polarization in Pure and Doped LiNbO3: First-Principles Calculations

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 100 ◽  
Author(s):  
Weiwei Wang ◽  
Dahuai Zheng ◽  
Mengyuan Hu ◽  
Shahzad Saeed ◽  
Hongde Liu ◽  
...  
Keyword(s):  
Spontaneous Polarization ◽  
First Principles ◽  
Density Functional ◽  
Lattice Distortion ◽  
Stable Structure ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Specific Configuration ◽  
The Relationship

Numerous studies have indicated that intrinsic defects in lithium niobate (LN) dominate its physical properties. In an Nb-rich environment, the structure that consists of a niobium anti-site with four lithium vacancies is considered the most stable structure. Based on the density functional theory (DFT), the specific configuration of the four lithium vacancies of LN were explored. The results indicated the most stable structure consisted of two lithium vacancies as the first neighbors and the other two as the second nearest neighbors of Nb anti-site in pure LN, and a similar stable structure was found in the doped LN. We found that the defects dipole moment has no direct contribution to the crystal polarization. Spontaneous polarization is more likely due to the lattice distortion of the crystal. This was verified in the defects structure of Mg2+, Sc3+, and Zr4+ doped LN. The conclusion provides a new understanding about the relationship between defect clusters and crystal polarization.

scholarly journals Ab initio study of optical and bulk properties of cesium lead halide perovskite solid solutions

2019 ◽  
Vol 33 (31) ◽  
pp. 1950386
Author(s):  
Vladimir Saleev ◽  
Alexandra Shipilova
Keyword(s):  
Solid Solutions ◽  
First Principles ◽  
Disordered Systems ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Bulk Properties ◽  
The Density Functional Theory ◽  
Halide Perovskite ◽  
Lead Halide

The first-principles calculations of band gaps and bulk moduli of cesium lead halide perovskite solid solutions, [Formula: see text] and [Formula: see text], are performed at the level of general gradient approximation of the density functional theory. We use supercell approach for computational modeling of disordered systems, which gives a description of the properties of the structure baasing on the average over a set of multiple configurations, namely distributions of different species over a given set of atomic positions. The calculations were performed with the CRYSTAL14 program package. The dependence of the band gap and bulk modulus on the content [Formula: see text] are investigated over the whole range [Formula: see text].

scholarly journals Application of DFT-based machine learning for developing molecular electrode materials in Li-ion batteries

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39414-39420 ◽  
Author(s):  
Omar Allam ◽  
Byung Woo Cho ◽  
Ki Chul Kim ◽  
Seung Soon Jang
Keyword(s):  
Machine Learning ◽  
Density Functional Theory ◽  
High Throughput Screening ◽  
Density Functional ◽  
Electrode Materials ◽  
Screening Method ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Learning Framework ◽  
Li Ion

In this study, we utilize a density functional theory-machine learning framework to develop a high-throughput screening method for designing new molecular electrode materials.

First Principles Calculations of Electronic Structure and Optical Properties of Cu-Doped SnS2

2013 ◽  
Vol 373-375 ◽  
pp. 1965-1969
Author(s):  
Kun Nan Qin ◽  
Ling Zhi Zhao ◽  
Yong Mei Liu ◽  
Fang Fang Li ◽  
Chao Yang Cui
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Optical Absorption Coefficient ◽  
Impurity Level ◽  
First Principles Calculations ◽  
Absorption Region ◽  
Functional Theory ◽  
The Density Functional Theory

The electronic structure and optical properties of Cu-doped SnS2with Sn-substituted content of 0, 12.5 and 37.5 at.% were successfully calculated by the first principles plane-wave pseudopotentials based on the density functional theory. It is found that the intermediate belts appear near the Fermi level and the energy band gap becomes narrower after the doping of the Cu atoms. The absorption peaks show a remarkable redshift and the absorption region broadens relatively after introducing acceptor impurity level. When Sn atoms of 37.5 at% were substituted by Cu, the optical absorption coefficient is significantly improved in the frequency range below 5.58 eV and over 8.13 eV.

Pressure-Induced Tunable Magnetism and Half-Metallic Stability in Co2FeGa Heusler Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1303-1306
Author(s):  
Qin Xiang Gao
Keyword(s):  
Fermi Level ◽  
First Principles ◽  
Density Functional ◽  
High Energy ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
The Density Functional Theory

Using the first-principles calculations within the density functional theory (DFT), we have investigated the structure, magnetism and half-metallic stability of Co2FeGa Heusler compound under pressure from 0 to 50GPa. The results revel that the lattice constant is gradually shrank and total magnetic moment in per unit slightly decreased with increasing pressure, respectively. Moreover, with the increase of the pressure, the Fermi level will move towards high-energy orientation. When the pressure reaches at 30GPa the most stable half-metallicity is observed which the Fermi level is located at the middle of the spin-minority gap.

FIRST-PRINCIPLES STUDY OF Ni ADSORPTION ON Mo(110)

2008 ◽  
Vol 15 (05) ◽  
pp. 661-668
Author(s):  
Y. G. ZHOU ◽  
X. T. ZU ◽  
J. L. NIE ◽  
H. Y. XIAO
Keyword(s):  
First Principles ◽  
Energy Barrier ◽  
Density Functional ◽  
Geometric Analysis ◽  
Alloy Layer ◽  
Layer By Layer ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Low Coverage ◽  
Theory Framework

The adsorption of Ni atom on the Mo (110) surface has been studied within the density functional theory framework. It turned out that Ni–Mo surface alloy was formed with Ni atoms substituting Mo atom in the outermost layer. The subsurface site adsorption was found to be not preferred. Geometric analysis showed that the rumpling between substitutional Ni and Mo in the first alloy layer was about 0.108 Å at medium and low coverage (Θ). In addition, the diffusion of Ni on bare and Ni -substitutional Mo (110) surface has been investigated. It was shown that the diffusion energy barrier was reduced as the increase of coverage on bare Mo (110) surface, which supports the switch of growth mode layer-by-layer to Stranski–Krastanov as the function of coverage. Substitutional Ni atom only slightly increases the energy barrier for Ni diffusion on Mo (110) surface.

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