Coverage-dependent stability of RuSi on Ru(0001): a comparative DFT and XPS study.

This work investigates the interaction of silicon with ruthenium, extending from Si-defect centers in ruthenium bulk to the adsorption of Si on the Ru(0001) surface. Using density functional theory (DFT) we calculate the interaction energies of up to 2 monolayers (MLs) of Si with this surface, uncovering the initial formation of ruthenium silicide (RuSi). Our results demonstrate that Si readily forms substitutional defects (Si) in bulk ruthenium.

From Jekyll to Hyde and Beyond: Hydrogen's Multifaceted Role in Passivation, H-Induced Breakdown, and Charging of Amorphous Silicon Nitride.

In semiconductor devices, hydrogen has traditionally been viewed as a panacea for defects, being adept at neutralizing dangling bonds and consequently purging the related states from the band gap. With amorphous silicon nitride (a-SiN)─a material critical for electronic, optical, and mechanical applications─this belief holds true as hydrogen passivates both silicon and nitrogen dangling bonds. However, there is more to the story.

Stabilizing Cobalt-free Li-rich Layered Oxide Cathodes through Oxygen Lattice Regulation by Two-phase Ru Doping.

The application of Li-rich layered oxides is hindered by their dramatic capacity and voltage decay on cycling. This work comprehensively studies the mechanistic behaviour of cobalt-free Li Ni Mn O and demonstrates the positive impact of two-phase Ru doping. A mechanistic transition from the monoclinic to the hexagonal behaviour is found for the structural evolution of Li Ni Mn O and the improvement mechanism of Ru doping is understood using the combination of in operando and post-mortem synchrotron analyses.

Investigating the Role of Surface Roughness and Defects on EC Breakdown, as a Precursor to SEI Formation in Hard Carbon Sodium-Ion Battery Anodes.

Hard carbon (HC) anodes together with ethylene carbonate (EC)-based electrolytes have shown significant promise for high-performing sodium-ion batteries. However, questions remain in relation to the initial contact between the carbon surface and the EC molecules. The surface of the HC anode is complex and can contain both flat pristine carbon surfaces, curvature, nanoscale roughness, and heteroatom defects.

Introducing 4s-2p Orbital Hybridization to Stabilize Spinel Oxide Cathodes for Lithium-Ion Batteries.

Oxides composed of an oxygen framework and interstitial cations are promising cathode materials for lithium-ion batteries. However, the instability of the oxygen framework under harsh operating conditions results in fast battery capacity decay, due to the weak orbital interactions between cations and oxygen (mainly 3d-2p interaction). Here, a robust and endurable oxygen framework is created by introducing strong 4s-2p orbital hybridization into the structure using LiNi Mn O oxide as an example.

Xenon Ion Implantation Induced Surface Compressive Stress for Preventing Dendrite Penetration in Solid-State Electrolytes.

Solid-state electrolytes (SSEs) have been thrust into the limelight for the revival of energy-dense lithium metal batteries, but still face the challenge of failure caused by the dendrite penetration. Mounting evidence indicates that dendrite penetration is related to the mechanical failure in SSEs, which calls for mechanical engineering to tackle this problem. This work reports a proof of concept that ion implantation induced surface compressive stress enables resistance in the dendrite penetration.

Prediction of the Liquid-Liquid Extraction Properties of Imidazolium-Based Ionic Liquids for the Extraction of Aromatics from Aliphatics.

Liquid-liquid extraction (LLE) is an important technique to separate aromatics from aliphatics since these compounds have very similar boiling points and cannot be separated by distillation. Ionic liquids (ILs) are considered as potential extractants to extract aromatics from aliphatics. In this paper, molecular dynamics (MD) simulations were used to predict the extraction property (i.

Defects in Hard Carbon: Where Are They Located and How Does the Location Affect Alkaline Metal Storage?

Hard carbon anodes have shown significant promise for next-generation battery technologies. These nanoporous carbon materials are highly complex and vary in structure depending on synthesis method, precursors, and pyrolysis temperature. Structurally, hard carbons are shown to consist of disordered planar and curved motifs, which have a dramatic impact on anode performance.

Synthesis and Electrochemical Properties of BiMoO/Carbon Anode for Lithium-Ion Battery Application.

High capacity electrode materials are the key for high energy density Li-ion batteries (LIB) to meet the requirement of the increased driving range of electric vehicles. Here we report the synthesis of a novel anode material, BiMoO/palm-carbon composite, via a simple hydrothermal method. The composite shows higher reversible capacity and better cycling performance, compared to pure BiMoO.

Combined density functional theory and molecular dynamics study of SmACoMnO (A = Ca, Sr; x = 0.125, 0.25) cathode material for next generation solid oxide fuel cell.

One of the main challenges facing solid oxide fuel cell (SOFC) technology is the need to develop materials capable of functioning at intermediate temperatures (500-800 °C), thereby reducing the costs associated with SOFCs. Here, Sm0.75A0.

Modeling of Diffusion and Incorporation of Interstitial Oxygen Ions at the TiN/SiO Interface.

Silica-based resistive random access memory devices have become an active research area due to complementary metal-oxide-semiconductor compatibility and recent dramatic increases in their performance and endurance. In spite of both experimental and theoretical insights gained into the electroforming process, many atomistic aspects of the set and reset operation of these devices are still poorly understood. Recently a mechanism of electroforming process based on the formation of neutral oxygen vacancies (V) and interstitial O ions (O) facilitated by electron injection into the oxide has been proposed.

Computational study of the mixed B-site perovskite SmBCoO (B = Mn, Fe, Ni, Cu) for next generation solid oxide fuel cell cathodes.

SmCoO3 is a promising perovskite material for the next generation of intermediate temperature solid oxide fuel cells (SOFC), but its potential application is directly linked to, and dependent on, the presence of dopant ions. Doping on the Co-site is suggested to improve the catalytic and electronic properties of this cathode material. Fe, Mn, Ni, and Cu have been proposed as possible dopants and experimental studies have investigated and confirmed the potential of these materials.

Adsorption and migration of alkali metals (Li, Na, and K) on pristine and defective graphene surfaces.

In this paper, a computational study of Li, Na, and K adsorption and migration on pristine and defective graphene surfaces is conducted to gain insight into the metal storage and mobility in carbon-based anodes for alkali metal batteries. Atomic level studies of the metal adsorption and migration on the graphene surface can help address the challenges faced in the development of novel alkali metal battery technologies, as these systems act as convenient proxies of the crystalline carbon surface in carbon-based materials including graphite, hard carbons and graphene. The adsorption of Li and K ions on the pristine graphene surface is shown to be more energetically favourable than Na adsorption.

A computational study of the electronic properties, ionic conduction, and thermal expansion of SmACoO and SmACoO (A = Ba, Ca, Sr, and x = 0.25, 0.5) as intermediate temperature SOFC cathodes.

The substitutional doping of Ca, Sr, and Ba on the Sm-site in the cubic perovskite SmCoO is reported to improve both electronic and ionic conductivities for applications as solid oxide fuel cell (SOFC) cathodes. Hence, in this study we have used density functional theory (DFT) calculations to investigate dopant configurations at two different dopant concentrations: 25 and 50%. To preserve the electroneutrality of the system, we have studied two different charge compensation mechanisms: the creation of oxygen vacancies, and electronic holes.

Usability, Acceptability, and Adherence to an Electronic Self-Monitoring System in Patients With Major Depression Discharged From Inpatient Wards.

Background: Patients suffering from depression have a high risk of relapse and readmission in the weeks following discharge from inpatient wards. Electronic self-monitoring systems that offer patient-communication features are now available to offer daily support to patients, but the usability, acceptability, and adherence to these systems has only been sparsely investigated.

Objective: We aim to test the usability, acceptability, adherence, and clinical outcome of a newly developed computer-based electronic self-assessment system (the Daybuilder system) in patients suffering from depression, in the period from discharge until commencing outpatient treatment in the Intensive Outpatient Unit for Affective Disorders.

A DFT+U study of the structural, electronic, magnetic, and mechanical properties of cubic and orthorhombic SmCoO.

SmCoO is a perovskite material that has gained attention as a potential substitute for LaSrMnO as a solid oxide fuel cell cathode. However, a number of properties have remained unknown due to the complexity of the material. For example, we know from experimental evidence that this perovskite exists in two different crystal structures, cubic and orthorhombic, and that the cobalt ion changes its spin state at high temperatures, leading to a semiconductor-to-metal transition.

Ab initio study of vacancy formation in cubic LaMnO3 and SmCoO3 as cathode materials in solid oxide fuel cells.

Doped LaMnO3 and SmCoO3 are important solid oxide fuel cell cathode materials. The main difference between these two perovskites is that SmCoO3 has proven to be a more efficient cathode material than LaMnO3 at lower temperatures. In order to explain the difference in efficiency, we need to gain insight into the materials' properties at the atomic level.