The formation mechanism and composition of the solid electrolyte interphase (SEI) in lithium ion batteries has been widely explored. However, relatively little is known about function SEI as a transport medium. Such critical information directly relevant to battery rate performance, power loss, capacity fading. To partially bridge this gap case inorganic compounds, we report herein results first-principles calculations on defect thermodynamics, dominant diffusion carriers, pathways...

The accurate description of interface characteristics between organic molecules and metal surfaces has long been debated in theoretical studies. A well-founded geometry adsorption energy is highly desirable for these hybrid inorganic/organic interfaces. Using first principles calculations with the inclusion five van der Waals functionals (vdW-DF family), benzene (C6H6) on seven transition studied to explore performance vdW under varying surface chemistry. Our results reveal that interactions...

To evaluate the possible utility of single layer graphene for applications in Li ion batteries, an extensive series periodic density functional theory (DFT) calculations are performed on sheets with both point and extended defects a wide range lithium coverages. Consistent recent reports, it is found that adsorption defect-free not thermodynamically favorable compared to bulk metallic Li. However, surfaces activated by generally bind more strongly, interaction strength sensitive nature their...

We report an electrochemically driven transformation of amorphous TiO2 nanotubes for Li-ion battery anodes into a face-centered-cubic crystalline phase that self-improves as the cycling proceeds. The intercalation/deintercalation processes Li ions in grown were studied by synchrotron X-ray diffraction and absorption spectroscopies along with advanced computational methods. These techniques confirm spontaneous development long-range order presence high concentration (>75%). adopted cubic...

The self‐assembly of cyano‐substituted triarylamine derivatives on Au(111) is studied with scanning tunneling microscopy and density functional theory calculations. Two different phases, each stabilized by at least two cyano bonding motifs are observed. In the first phase, molecule involved in dipolar coupling hydrogen bonding, while second coupling, metal‐ligand interactions present. Interestingly, metal–ligand bond already observed for deposition molecules sample kept room temperature...

This work is Part 1 in a two part series that investigates the interfacial decomposition chemistry of [pyr14][TFSI] and [EMIM][BF4] ionic liquids (IL) at Li metal interfaces. Here, probed primarily through ab initio molecular dynamics (AIMD) simulations. For single ion pairs adsorbed on Li(100) surface, hybrid states are found to emerge about Fermi level. Interestingly, these have significant contribution from both ions, which suggests cathodic (reductive) stability could be governed by...

Despite much progress in development of oxide-based resistive random-access memory (ReRAM) devices that have an inherent and advantages increased speed operation, higher density, nonvolatility, ease integration, low power, many challenges remain, particularly relating to conductive filament (CF) formation rupture associated device uniformity. Oxygen vacancies (Vos) play important role for both the valence change (VCM), based on Vo or oxygen ion-mediated CFs, electrochemical metallization...

We report the results of Olympicene radical (C19H11) adsorption characteristics on Cu(111) obtained within density functional framework with and without inclusion self-consistent van der Waals (vdW) interactions to evaluate their effects. Our calculations suggest that vdW enhance energies, degree enhancement strongly depends implementation. Among considered configurations, highest energy calculated using PBE is found be 0.24 eV, while those are 1.32 eV (rPW86), 1.91 (optPBE), 2.29 (optB88),...

Electrically switchable resistive random access memories have drawn much interest as nonvolatile memory device candidates based on metal–insulator–metal (MIM) structure concepts. However, atomic level mechanisms that lead to conductive filament (CF) formation in MIM structures are often lacking, such for the system with NiO oxide layer, which was found promising (RRAM) applications. In this work, using density functional theory a Hubbard-type on-site Coulomb correction, we carefully...

We present the results of density-functional-theory-based calculations for activation energies diffusion adatoms (Cu or Ag) on Cu(100) and Ag(100) with without steps. find that only Cu Ag(100), exchange is dominant mechanism terraces. On other hand, at step edges, except Ag Cu(100). This result also indicates incorporation atoms into edges costs 330 meV, while energy cost edge much higher (about 700 meV). hierarchy Ehrlich-Schwoebel barriers to be: 170 meV Cu(100); 60 20...

We report on the energetics and dynamics of Li diffusion in bulk anatase amorphous TiO2 using molecular (MD) simulations density functional theory (DFT) calculations. Using MD simulations, for both TiO2, characteristics are first studied an isolated ion, followed by concentrations ranging from 10% to 100% order explore concentration effect diffusivity. The mechanism, revealed occurs via zigzag hops between octahedral sites anatase. corresponding barrier this process obtained DFT-NEB...

In recent years, evaluating the effect of van der Waals (vdW) forces for many physical systems, including adsorption small organic molecules on metal surfaces, became possible thanks to continuous improvements in vdW density functional theory (DFT). this work, employing vdW-DF (revPBE-vdW), optimized (optB88-vdW, optPBE-vdW, optB86b-vdW), and vdW-DF2 (rPW86-vdW2) methods, we study benzene a range (110) transition surfaces. We evaluate performance functionals by examining equilibrium...

Abstract The self‐assembly of cyano‐functionalized triarylamine derivatives on Cu(111), Ag(111) and Au(111) was studied by means scanning tunnelling microscopy, low‐energy electron diffraction, X‐ray photoelectron spectroscopy density functional theory calculations. Different bonding motifs, such as antiparallel dipolar coupling, hydrogen metal coordination, were observed. Whereas only one hexagonally close‐packed pattern stabilized is observed, two different partially porous phases are...

We report developments of the kinetic Monte Carlo (KMC) method with improved accuracy and increased versatility for description atomic diffusivity on metal surfaces. The on-lattice constraint built into our recently proposed self-learning KMC (SLKMC) (Trushin et al 2005 Phys. Rev. B 72 115401) is released, leaving atoms free to occupy 'off-lattice' positions accommodate several processes responsible small-cluster diffusion, periphery atom motion heteroepitaxial growth. This technique...

Li transport characteristics are studied by means of density functional theory (DFT) and molecular dynamics (MD) simulations in order to investigate concentration effects on chemical diffusivity conductivity TiO2 rutile. Our MD predict one-dimensional diffusion ions via jumps between the octahedral sites along channels parallel c-axis. The barrier coefficient (at room temperature) for isolated Li, determined DFT calculations, correspond 60 meV 9.1 × 10−6 cm2 s−1, respectively. Such a small...

Despite rapidly growing interest in the application of graphene lithium ion batteries, interaction with ions and electrolyte species during electrochemical cycling is not fully understood. In this work, we use Raman spectroscopy a model system monolayer transferred on Si(111) substrate density functional theory (DFT) to investigate defect formation as function lithiation. This enables early stages be probed manner previously possible commonly used reduced oxide or multilayer substrates....

Electronic structures of the free-standing core–shell (Cu@Ag) AgnCu34–n (n = 0–34) nanoalloy family are studied as a function stoichiometry using ab initio total energy electronic structure calculations. Our calculations show that progressive alloying significantly alters coordination distribution, bond lengths, formation energies, and densities states. Changes in elemental environment reflected states, which broaden or narrow result hybridization between Cu Ag atoms. The states atoms...

This is Part 2 of a two part series papers on decomposition ionic liquids at lithium metal interfaces. In 1 this series, ab initio molecular dynamics (AIMD) simulations were used to examine the stability and (ILs), [pyr14][TFSI] [EMIM][BF4], Li anodes. Here in 2, density functional calculations ions ion pairs gas phase are coupled with model electrode surface effects provide an in-depth analysis results obtained from more computationally expensive AIMD electrolytes 1. The approach cathodic...

We report the results of first-principles density functional theory calculations for adsorption thiophene (C4H4S) on Cu(100) and Ni(100) surfaces. The properties these surfaces are evaluated several configurations, performed with inclusion van der Waals (vdW) interactions invoking optimized vdW (optB86b-vdW, optB88-vdW, optPBE-vdW) as well revPBE-vdW rPW86-vdW2 functionals. In agreement earlier reports, both surfaces, most stable configurations correspond to hollow-45 at which adsorbs...

We report on the results of van der Waals (vdW) inclusive density functional theory (DFT) calculations for adsorption characteristics olympicene radical (C19H11) Au(111) and Pt(111) surfaces. The nature bonding between surfaces is evaluated along with effects vdW interactions, chemical surfaces, adsorption. Our show a significant increase in energies inclusion largest enhancement obtained optimized exchange functionals, while smaller found using rPW86-vdW2 functional, agreement trends our...

Oxide conversion reactions are known to have substantially higher specific capacities than intercalation materials used in Li-ion batteries, but universally suffer from large overpotentials associated with the formation of interfaces between resulting nanoscale metal and Li2O products. Here we use interfacial sensitivity operando X-ray reflectivity visualize structural evolution ultrathin NiO electrodes their during conversion. We observe two additional prior well-known bulk,...