Long-Cycle-Life Calcium Battery with a High-Capacity Conversion Cathode Enabled by a Ca/Li Hybrid Electrolyte.

Calcium (Ca) batteries represent an attractive option for electrochemical energy storage due to physicochemical and economic reasons. The standard reduction potential of Ca (-2.87 V) is close to Li and promises a wide voltage window for Ca full batteries, while the high abundance of Ca in the earth's crust implicates low material costs.

Molecular Engineering of Metalloporphyrins for High-Performance Energy Storage: Central Metal Matters.

Porphyrin derivatives represent an emerging class of redox-active materials for sustainable electrochemical energy storage. However, their structure-performance relationship is poorly understood, which confines their rational design and thus limits access to their full potential. To gain such understanding, we here focus on the role of the metal ion within porphyrin molecules.

Durable Nickel-Iron (Oxy)hydroxide Oxygen Evolution Electrocatalysts through Surface Functionalization with Tetraphenylporphyrin.

NiFe-based oxides are one of the best-known active oxygen evolution electrocatalysts. Unfortunately, they rapidly lost performance in Fe-purified KOH during the reaction. Herein, tetraphenylporphyrin (TPP) was loaded on a catalyst/electrolyte interface to alleviate the destabilization of NiFe (oxy)hydroxide.

Potential-Dependent Pt(111)/Water Interface: Tackling the Challenge of a Consistent Treatment of Electrochemical Interfaces.

The interface between an electrode and an electrolyte is where electrochemical processes take place for countless technologically important applications. Despite its high relevance and intense efforts to elucidate it, a description of the interfacial structure and, in particular, the dynamics of the electric double layer at the atomic level is still lacking. Here we present reactive force-field molecular dynamics simulations of electrified Pt(111)/water interfaces, shedding light on the orientation of water molecules in the vicinity of the Pt(111) surface, taking into account the influence of potential, adsorbates, and ions simultaneously.

Enabling High-Stability of Aqueous-Processed Nickel-Rich Positive Electrodes in Lithium Metal Batteries.

Lithium batteries occupy the large-scale electric mobility market raising concerns about the environmental impact of cell production, especially regarding the use of poly(vinylidene difluoride) (teratogenic) and N-methyl-2-pyrrolidone (NMP, harmful). To avoid their use, an aqueous electrode processing route is utilized in which a water-soluble hybrid acrylic-fluoropolymer together with sodium carboxymethyl cellulose is used as binder, and a thin phosphate coating layer is in situ formed on the surface of the nickel-rich cathode during electrode processing. The resulting electrodes achieve a comparable performance to that of NMP-based electrodes in conventional organic carbonate-based electrolyte (LP30).

Calcium-tin alloys as anodes for rechargeable non-aqueous calcium-ion batteries at room temperature.

Rechargeable calcium batteries possess attractive features for sustainable energy-storage solutions owing to their high theoretical energy densities, safety aspects and abundant natural resources. However, divalent Ca-ions and reactive Ca metal strongly interact with cathode materials and non-aqueous electrolyte solutions, leading to high charge-transfer barriers at the electrode-electrolyte interface and consequently low electrochemical performance. Here, we demonstrate the feasibility and elucidate the electrochemical properties of calcium-tin (Ca-Sn) alloy anodes for Ca-ion chemistries.

Micron-sized single-crystal cathodes for sodium-ion batteries.

Confining the particle-electrolyte interactions to the particle surface in electrode materials is vital to develop sustainable and safe batteries. Micron-sized single-crystal particles offer such opportunities. Owing to the reduced surface area and grain boundary-free core, particle-electrolyte interactions in micron-sized single-crystal particles will be confined to the particle surface.

First-Principles Studies on the Atomistic Properties of Metallic Magnesium as Anode Material in Magnesium-Ion Batteries.

Rechargeable magnesium-ion batteries (MIBs) are a promising alternative to commercial lithium-ion batteries (LIBs). They are safer to handle, environmentally more friendly, and provide a five-time higher volumetric capacity (3832 mAh cm ) than commercialized LIBs. However, the formation of a passivation layer on metallic Mg electrodes is still a major challenge towards their commercialization.

Valence energy correction for electron reactive force field.

Reactive force fields (ReaxFF) are a classical method to describe material properties based on a bond-order formalism, that allows bond dissociation and consequently investigations of reactive systems. Semiclassical treatment of electrons was introduced within ReaxFF simulations, better known as electron reactive force fields (eReaxFF), to explicitly treat electrons as spherical Gaussian waves. In the original version of eReaxFF, the electrons and electron-holes can lead to changes in both the bond energy and the Coulomb energy of the system.

Dual Role of Mo S in Polysulfide Conversion and Shuttle for Mg-S Batteries.

Magnesium-Sulfur batteries are one of most appealing options among the post-lithium battery systems due to its potentially high energy density, safe and sustainable electrode materials. The major practical challenges are originated from the soluble magnesium polysulfide intermediates and their shuttling between the electrodes, which cause high overpotentials, low sulfur utilization, and poor Coulombic efficiency. Herein, a functional Mo S modified separator is designed to effectively address these issues.

First-principles study of -dodecaborates MBH (M = Li, Na, K) as solid-state electrolyte materials.

-dodecaborates MBH are considered among the potential candidates for solid-state electrolyte materials due to their high ionic conductivities. It has been demonstrated that the reorientation of the icosahedral anion BH plays a key role in high cation motion. However, this category of BH materials is still not well established with respect to their structural, thermodynamic and diffusion properties.

Spike residue 403 affects binding of coronavirus spikes to human ACE2.

The bat sarbecovirus RaTG13 is a close relative of SARS-CoV-2, the cause of the COVID-19 pandemic. However, this bat virus was most likely unable to directly infect humans since its Spike (S) protein does not interact efficiently with the human ACE2 receptor. Here, we show that a single T403R mutation increases binding of RaTG13 S to human ACE2 and allows VSV pseudoparticle infection of human lung cells and intestinal organoids.

Atomistic Studies on Water-Induced Lithium Corrosion.

It is well known that lithium reacts violently with water under the release of molecular hydrogen and the formation of lithium hydroxide. In this work, the initial mechanisms for the surface reactions of metallic lithium with water from the gas phase were investigated by means of periodic density functional theory calculations. For this purpose, adsorption/absorption structures and diffusion and dissociation processes of hydrogen, OH, and H O on low-index metallic lithium surfaces were investigated.

Cation Overcrowding Effect on the Oxygen Evolution Reaction.

The influence of electrolyte ions on the catalytic activity of electrode/electrolyte interfaces is a controversial topic for many electrocatalytic reactions. Herein, we focus on an effect that is usually neglected, namely, how the local reaction conditions are shaped by nonspecifically adsorbed cations. We scrutinize the oxygen evolution reaction (OER) at nickel (oxy)hydroxide catalysts, using a physicochemical model that integrates density functional theory calculations, a microkinetic submodel, and a mean-field submodel of the electric double layer.

Multifunctional Polyoxometalate Platforms for Supramolecular Light-Driven Hydrogen Evolution*.

Multifunctional supramolecular systems are a central research topic in light-driven solar energy conversion. Here, we report a polyoxometalate (POM)-based supramolecular dyad, where two platinum-complex hydrogen evolution catalysts are covalently anchored to an Anderson polyoxomolybdate anion. Supramolecular electrostatic coupling of the system to an iridium photosensitizer enables visible light-driven hydrogen evolution.

Assessment of the Accuracy of Density Functionals for Calculating Oxygen Reduction Reaction on Nitrogen-Doped Graphene.

Experimental studies of the oxygen reduction reaction (ORR) at nitrogen-doped graphene electrodes have reported a remarkably low overpotential, on the order of 0.5 V, similar to Pt-based electrodes. Theoretical calculations using density functional theory have lent support to this claim.

Elastic Collision Based Dynamic Partitioning Scheme for Hybrid Simulations.

In hybrid simulations, such as the QM/MM approach, the system is partitioned into regions that are treated at different levels of theory. The key question then becomes how to evaluate the interactions between particles on opposite sides of the boundary. One approach is to place the boundary in such a way that particles near the boundary on both sides are of the same type, thus simplifying the evaluation of the interactions.

Surface Engineering of a Mg Electrode via a New Additive to Reduce Overpotential.

In nonaqueous Mg batteries, inactive adsorbed species and the passivation layer formed from the reactive Mg with impurities in the electrolyte seriously affect the Mg metal/electrolyte interface. These adlayers can impede the passage of Mg ions, leading to a high Mg plating/stripping overpotential. Herein, we report the properties of a new additive, bismuth triflate (Bi(OTf)), for synthesizing a chlorine-free Mg electrolyte to enhance Mg plating/stripping from initial cycles.

Establishing a Stable Anode-Electrolyte Interface in Mg Batteries by Electrolyte Additive.

Simple magnesium salts with high electrochemical and chemical stability and adequate ionic conductivity represent a new-generation electrolyte for magnesium (Mg) batteries. Similar to other Mg electrolytes, the simple-salt electrolyte also suffers from high charge-transfer resistance on the Mg surface due to the adsorbed species in the solution. In the current study, we built a model Mg cell system with the Mg[B(hfip)]/DME electrolyte and Chevrel phase MoS cathode, to demonstrate the effect of such anode-electrolyte interfacial properties on the full-cell performance.

Density Functional Theory Studies on Sulfur-Polyacrylonitrile as a Cathode Host Material for Lithium-Sulfur Batteries.

Cyclized polyacrylonitrile, which can be obtained by vulcanization of polyacrylonitrile with sulfur, is an electron-conductive polymer that can be used as a host material in lithium-sulfur batteries. Using density functional theory, we investigated the interaction between a surrounding electrolyte and the polymeric sulfur-polyacrylonitrile (SPAN) electrode. In particular, we focused on different configurations, where the system contains 1,3-dioxane as a solvent and can have (i) polysulfide (PS) solvated in the electrolyte, (ii) a PS attached to the polymer backbone, (iii) lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as a salt dissolved in the electrolyte, and (iv) both PS and LiTFSI dissolved in the electrolyte.

Highly conductive anion exchange membranes based on polymer networks containing imidazolium functionalised side chains.

Two novel types of anion exchange membranes (AEMs) having imidazolium-type functionalised nanofibrous substrates were prepared using the facile and potentially scalable method. The membranes' precursors were prepared by graft copolymerization of vinylbenzyl chloride (VBC) onto syndiotactic polypropylene (syn-PP) and polyamide-66 (PA-66) nanofibrous networks followed by crosslinking with 1,8-octanediamine, thermal treatment and subsequent functionalisation of imidazolium groups. The obtained membranes displayed an ion exchange capacity (IEC) close to 1.

CO Oxidation on Planar Au/TiO Model Catalysts under Realistic Conditions: A Combined Kinetic and IR Study.

The oxidation of CO on planar Au/TiO model catalysts was investigated under pressure and temperature conditions similar to those for experiments with more realistic Au/TiO powder catalysts. The effects of a change of temperature, pressure, and gold coverage on the CO oxidation activity were studied. Additionally, the reasons for the deactivation of the catalysts were examined in long-term experiments.

Rapid Surface Modification of Ultrafiltration Membranes for Enhanced Antifouling Properties.

In this work, several ultrafiltration (UF) membranes with enhanced antifouling properties were fabricated using a rapid and green surface modification method that was based on the plasma-enhanced chemical vapor deposition (PECVD). Two types of hydrophilic monomers-acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) were, respectively, deposited on the surface of a commercial UF membrane and the effects of plasma deposition time (i.e.

Cathode-Electrolyte Interphase in a LiTFSI/Tetraglyme Electrolyte Promoting the Cyclability of VO.

VO, one of the earliest intercalation-type cathode materials investigated as a Li host, is characterized by an extremely high theoretical capacity (441 mAh g). However, the fast capacity fading upon cycling in conventional carbonate-based electrolytes is an unresolved issue. Herein, we show that using a LiTFSI/tetraglyme (1:1 in mole ratio) electrolyte yields a highly enhanced cycling ability of VO (from 20% capacity retention to 80% after 100 cycles at 50 mA g within 1.