scholarly journals Delithiated states of layered cathode materials: doping and dispersion interaction effects on the structure

2018 ◽  
Vol 177 ◽  
pp. 02001 ◽  
Author(s):  
Roman Eremin ◽  
Pavel Zolotarev ◽  
Ivan Bobrikov
Keyword(s):  
Cathode Material ◽  
Cathode Materials ◽  
Density Functional ◽  
Interaction Effects ◽  
Dispersion Interaction ◽  
Functional Theory ◽  
Cathode Structure ◽  
Layered Cathode Materials ◽  
In Situ Neutron Diffraction

Here we present results of density functional theory (DFT) study of delithiated structures of layered LiNiO2 (LNO, Li12Ni12O24 model) cathode material and its doped analogue LiNi0.833Co0.083Al0.083O2 (N10C1A1, Li12Ni10CoAlO24 model). The paper is aimed at independent elucidation of doping and dispersion interaction effects on the structural stability of cathode materials studied. For this purpose, the LNO and N10C1A1 configurational spaces consisting of 87 and 4512 crystallographically independent configurations (obtained starting from 2×2×1 supercell of R-3m structure of LNO) are optimized within a number of DFT models. Based on a comparison of the calculated dependencies for the lattice parameters with the results of in situ neutron diffraction experiments, the most pronounced effect of cathode material stabilization is due to the dispersion interaction. In turn, the doping effect is found to affect cathode structure behavior at the latest stages of delithiation only.

Ab initio calculations of Na and Ni diffusion in NaNi1/2Mn1/2O2 and NaNi1/3Mn1/3Co1/3O2 for Na-ion batteries

2014 ◽  
Vol 28 (25) ◽  
pp. 1450202 ◽  
Author(s):  
J. J. Shi ◽  
G. Q. Yin ◽  
L. M. Jing ◽  
J. Guan ◽  
M. P. Wu ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Energy Barrier ◽  
Density Functional ◽  
Electrode Materials ◽  
Elastic Band ◽  
Nickel Ion ◽  
Functional Theory ◽  
Layered Cathode Materials ◽  
Band Method ◽  
Sodium Diffusion

In this paper, sodium and nickel ion dynamics in layered cathode materials of NaNi 1/2 Mn 1/2 O 2 and NaNi 1/3 Mn 1/3 Co 1/3 O 2 for Na -ion battery applications were investigated using first principles based on density functional theory. The diffusion pathways for sodium and nickel migration inside the layered cathode materials were optimized and their energy barriers were calculated based on the nudged elastic band method. The energy barrier of Na diffusion in NaNi 1/2 Mn 1/2 O 2 and NaNi 1/3 Mn 1/3 Co 1/3 O 2 is about 1.0 eV. However, when the Ni is located at the Na layer, i.e. occupying the Na position, the energy barrier for Ni diffusion inside the layered cathode materials is about 0.36 eV, which indicates that Ni will diffuse to the surface of electrode materials, thus will block or slow down the sodium diffusion, limiting the battery performance.

scholarly journals Measuring the structure and equation of state of polyethylene terephthalate at megabar pressures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Lütgert ◽  
J. Vorberger ◽  
N. J. Hartley ◽  
K. Voigt ◽  
M. Rödel ◽  
...  
Keyword(s):  
Equation Of State ◽  
Polyethylene Terephthalate ◽  
Density Functional ◽  
Equations Of State ◽  
Md Simulations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Shock Hugoniot ◽  
Highly Correlated

AbstractWe present structure and equation of state (EOS) measurements of biaxially orientated polyethylene terephthalate (PET, $$({\hbox {C}}_{10} {\hbox {H}}_8 {\hbox {O}}_4)_n$$ ( C 10 H 8 O 4 ) n , also called mylar) shock-compressed to ($$155 \pm 20$$ 155 ± 20 ) GPa and ($$6000 \pm 1000$$ 6000 ± 1000 ) K using in situ X-ray diffraction, Doppler velocimetry, and optical pyrometry. Comparing to density functional theory molecular dynamics (DFT-MD) simulations, we find a highly correlated liquid at conditions differing from predictions by some equations of state tables, which underlines the influence of complex chemical interactions in this regime. EOS calculations from ab initio DFT-MD simulations and shock Hugoniot measurements of density, pressure and temperature confirm the discrepancy to these tables and present an experimentally benchmarked correction to the description of PET as an exemplary material to represent the mixture of light elements at planetary interior conditions.

In Situ Exsolved Au Nanoparticles from Perovskite Oxide for Efficient Epoxidation of Styrene

2021 ◽  
Author(s):  
Yang Gao ◽  
Xing Chen ◽  
Shuqi Hu ◽  
Shiguo Zhang
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Analysis ◽  
Density Functional ◽  
Au Nanoparticles ◽  
Oxide Catalyst ◽  
Density Functional Theory Calculations ◽  
Average Diameter ◽  
Perovskite Oxide ◽  
Functional Theory

Au-doped SrTiO3 perovskite oxide catalyst (Sr0.995Au0.005TiO3-δ) has been designed and synthesized based on thermodynamic analysis and density functional theory calculations. During reduction, Au nanoparticles with an average diameter of 2...

The catalytic mechanism of the Au@TiO2−x/ZnO catalyst towards a low-temperature water-gas shift reaction

2020 ◽  
Vol 10 (3) ◽  
pp. 768-775
Author(s):  
Ning Liu ◽  
Pan Yin ◽  
Ming Xu ◽  
Yusen Yang ◽  
Shaomin Zhang ◽  
...  
Keyword(s):  
Density Functional ◽  
Catalytic Mechanism ◽  
Density Functional Theory Calculation ◽  
Water Gas Shift ◽  
Water Gas Shift Reaction ◽  
Functional Theory ◽  
Shift Reaction ◽  
Water Gas ◽  
Theory Calculation

A redox mechanism towards the water-gas shift reaction was certified based on in situ/operando experiments and density functional theory calculation studies.

A combined study of the equation of state of monazite-type lanthanum orthovanadate usingin situhigh-pressure diffraction andab initiocalculations

2014 ◽  
Vol 70 (3) ◽  
pp. 533-538 ◽  
Author(s):  
Olga Ermakova ◽  
Javier López-Solano ◽  
Roman Minikayev ◽  
Stefan Carlson ◽  
Agata Kamińska ◽  
...  
Keyword(s):  
Equation Of State ◽  
Density Functional ◽  
Room Temperature ◽  
Theoretical Data ◽  
Perfect Agreement ◽  
Functional Theory ◽  
Compression Direction ◽  
The Density Functional Theory ◽  
Murnaghan Equation

Lanthanum orthovanadate (LaVO4) is the only stable monazite-type rare-earth orthovanadate. In the present paper the equation of state of LaVO4is studied usingin situhigh-pressure powder diffraction at room temperature, andab initiocalculations within the framework of the density functional theory. The parameters of a second-order Birch–Murnaghan equation of state,i.e.those fitted to the experimental and theoretical data, are found to be in perfect agreement – in particular, the bulk moduli are almost identical, with values of 106 (1) and 105.8 (5) GPa, respectively. In agreement with recent reported experimental data, the compression is shown to be anisotropic. Its nature is comparable to that of some other monazite-type compounds. The softest compression direction is determined.

scholarly journals A density functional theory study of the carbon-coating effects on lithium iron borate battery electrodes

2017 ◽  
Vol 19 (3) ◽  
pp. 2087-2094 ◽  
Author(s):  
Simon Loftager ◽  
Juan María García-Lastra ◽  
Tejs Vegge
Keyword(s):  
Density Functional Theory ◽  
Cathode Material ◽  
Carbon Coating ◽  
Density Functional ◽  
Li Ion Battery ◽  
Density Functional Theory Study ◽  
Iron Borate ◽  
Functional Theory ◽  
Carbon Coatings ◽  
Li Ion

Density functional theory modelling shows that carbon coatings on a LiFeBO3 cathode material does not impede the Li transport in a Li-ion battery.

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