First principles studies of silicon as a negative electrode material for lithium-ion batteries

2009 ◽  
Vol 87 (6) ◽  
pp. 625-632 ◽  
Author(s):  
V. L. Chevrier ◽  
J. W. Zwanziger ◽  
J. R. Dahn
Keyword(s):  
Bulk Modulus ◽  
Density Functional ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Absolute Error ◽  
Average Absolute Error ◽  
Functional Theory ◽  
Composition Curve ◽  
Projector Augmented Wave ◽  
Negative Electrode Material

An investigation of Li–Si alloys using density functional theory is presented. Various calculation methods and pseudopotentials are analyzed to best reproduce the potential versus composition curve of a Li/LixSi electrochemical cell at high temperature using the experimentally observed Li–Si phases. Total energy calculations, structural optimizations, and bulk modulus estimations were completed for the Si, Li12Si7, Li7Si3, Li13Si4, Li15Si4, Li22Si5, and Li phases. The potential plateaus of the co-existing phase regions, obtained using the projector augmented wave (PAW) method, have an average absolute error of 31 mV with respect to experiment. The Li7Si3 and Li15Si4 compositions are discussed and the Li15Si4 phase is found to have a lower bulk modulus relative to the other phases.

Assessment of PBE0 Calculation of C-NO2 Bond Dissociation Energies for Nitroaromatic System

2014 ◽  
Vol 915-916 ◽  
pp. 675-678
Author(s):  
Xin Fang Su ◽  
Wei Huang ◽  
Hai Ying Wu
Keyword(s):  
Density Functional ◽  
Molecular System ◽  
Absolute Error ◽  
Basis Sets ◽  
Bond Dissociation Energies ◽  
Average Absolute Error ◽  
Functional Theory ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Experimental Values

Density functional theory (DFT) is used to calculate the C-NO2bond dissociation energies (BDEs) in nitrobenzene; 3-amino-nitrobenze; 4-amino-nitrobenze; 1,3-dinitrobenzene; 1,4-dinitrobenzene; 2-methyl-nitrobenzene; 4-methyl-nitrobenzene and 1,3,5-trinitrobenzene nitroaromatic molecular system. B3P86 and PBE0 methods in combination with 6-31G** and 6-311G** basis sets are employed. Comparison between the computational results and the experimental values reveals that the calculated C-NO2bond BDEs can be improved from B3P86 to PBE0 functional. Level of theory employing PBE0/6-311G** is found to be sufficiently reliable to compute BDEs of C-NO2bond for nitroaromatic molecules with an average absolute error of 0.98 kcal mol-1.

Benchmark of Simplified Time-Dependent Density Functional Theory for UV-Vis Spectral Properties of Porphyrinoids

2019 ◽  
Author(s):  
Kamal Batra ◽  
Stefan Zahn ◽  
Thomas Heine
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Large Scale ◽  
Absolute Error ◽  
Time Dependent ◽  
Basis Set ◽  
Basis Sets ◽  
Functional Theory ◽  
Framework Materials ◽  
Dependent Density

<p>We thoroughly benchmark time-dependent density- functional theory for the predictive calculation of UV/Vis spectra of porphyrin derivatives. With the aim to provide an approach that is computationally feasible for large-scale applications such as biological systems or molecular framework materials, albeit performing with high accuracy for the Q-bands, we compare the results given by various computational protocols, including basis sets, density-functionals (including gradient corrected local functionals, hybrids, double hybrids and range-separated functionals), and various variants of time-dependent density-functional theory, including the simplified Tamm-Dancoff approximation. An excellent choice for these calculations is the range-separated functional CAM-B3LYP in combination with the simplified Tamm-Dancoff approximation and a basis set of double-ζ quality def2-SVP (mean absolute error [MAE] of ~0.05 eV). This is not surpassed by more expensive approaches, not even by double hybrid functionals, and solely systematic excitation energy scaling slightly improves the results (MAE ~0.04 eV). </p>

scholarly journals Predicting the new carbon nanocages, fullerynes: a DFT study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Qasemnazhand ◽  
Farhad Khoeini ◽  
Farah Marsusi
Keyword(s):  
Density Functional Theory ◽  
Lithium Ion Batteries ◽  
Density Functional ◽  
Lithium Ion ◽  
The Other ◽  
Electron Affinities ◽  
Chemical Formula ◽  
Functional Theory ◽  
Triple Bonds ◽  
Structural And Electronic Properties

AbstractIn this study, based on density functional theory, we propose a new branch of pseudo-fullerenes which contain triple bonds with sp hybridization. We call these new nanostructures fullerynes, according to IUPAC. We present four samples with the chemical formula of C4nHn, and the structures derived from fulleranes. We compare the structural and electronic properties of these structures with those of two common fullerenes and fulleranes systems. The calculated electron affinities of the sampled fullerynes are negative, and much smaller than those of fullerenes, so they should be chemically more stable than fullerenes. Although fulleranes also exhibit higher chemical stability than fullerynes, but pentagon or hexagon of the fullerane structures cannot pass ions and molecules. Applications of fullerynes can be included in the storage of ions and gases at the nanoscale. On the other hand, they can also be used as cathode/anode electrodes in lithium-ion batteries.

First-principle investigations on structural, elastic, electronic and thermodynamic properties of ScX3(X = Ir,Pd,Pt and Rh) under high pressure

2015 ◽  
Vol 29 (32) ◽  
pp. 1550201 ◽  
Author(s):  
Bao Chen ◽  
Santao Qi ◽  
Hongquan Song ◽  
Chuanhui Zhang ◽  
Jiang Shen
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
External Pressure ◽  
First Principle ◽  
Zero Temperature ◽  
Functional Theory ◽  
Change Trend ◽  
Experimental Values

In this paper, the structural, elastic, electronic and thermodynamic properties of [Formula: see text] and [Formula: see text] intermetallic compound are investigated using pseudopotential method based on density functional theory (DFT) under pressure. In this work, the calculated lattice constant and bulk modulus are in accordance with experimental values at zero temperature and zero pressure. The bulk modulus [Formula: see text], shear modulus [Formula: see text] and Young’s modulus [Formula: see text] for [Formula: see text] and [Formula: see text] increase with the increasing external pressure. It is noted that [Formula: see text] of investigated compound has the largest [Formula: see text], [Formula: see text] and [Formula: see text]. The results of [Formula: see text] and [Formula: see text] have the same change trend, but [Formula: see text] presents an irregular change for [Formula: see text] and [Formula: see text]. The density of states for [Formula: see text] and [Formula: see text] are investigated at 0, 30 and 50 GPa. In addition, the thermodynamic properties as a function of temperature at different pressure are also studied.

Electrochemical Performance of Anode Materials for Lithium-Ion Power Batteries

2014 ◽  
Vol 1056 ◽  
pp. 3-7 ◽  
Author(s):  
Wan Hong Zhang ◽  
Kun Peng Wang
Keyword(s):  
Cyclic Voltammetry ◽  
Surface Morphology ◽  
Electrochemical Performance ◽  
Anode Materials ◽  
Coulombic Efficiency ◽  
Rate Capability ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Positive Influence ◽  
Negative Electrode Material

Graphite is widely used as the negative electrode material. To find out the influence of several different modified ways on the material's electrochemical performance, the electrochemical properties of 0318、0318-GLQ、MCMB22、AGP-3-2、AGP-3-2-1 and AGP-3-2-2 batteries were investigated by means of cyclic voltammetry (CV) experimental method. Results show that surface morphology, lithium intercalate/de-intercalate process, the first coulombic efficiency, reversibility and rate capability are all different for different material. Above all, AGP-3-2-2 has the best electrochemical performance, AGP-3-2 is worst, and the results prove that coating by pitch has a positive influence on the electrochemical performance of the material.

Carbon Materials and Their Modified Materials for Lithium Ion Battery Anodes : A Comprehensive Review

2021 ◽  
Author(s):  
Qiaoyu feng ◽  
Xueye Chen
Keyword(s):  
Electrical Conductivity ◽  
Carbon Materials ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Lithium Ions ◽  
New Type ◽  
Metal Materials ◽  
Negative Electrode Material ◽  
Poor Stability ◽  
Carbon Based

<p>As a negative electrode material for lithium ion batteries (LIBs), carbon has a higher cycle life and higher safety. However, it has poor electrical conductivity, low charging and discharging platform, and poor stability of layered structure. Some carbon materials are complicated to make such as synthetic graphene, and the shape is difficult to control. Metal materials have good electrical conductivity, but due to the rapid volume expansion of lithium ions during the cycle of insertion and extraction, the electrodes are extremely quickly crushed and accompanied by extremely rapid capacity decay. Scholars have combined the advantages of carbon and metal materials to create a new type of carbon-based composite material. This article outlines the use of carbon based composite materials as lithium-ion electrodes to improve battery performance.</p>

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