Correction: Mechanisms of Electronic and Ionic Transport during Mg Intercalation in Mg-S Cathode Materials and Their Decomposition Products.

[This corrects the article DOI: 10.1021/acs.chemmater.2c03784.].

High-throughput Compositional Screening of PdxTi1-xHy and PdxNb1-xHy Hydrides for CO2 Reduction.

Electrochemical experiments and theoretical calculations have shown that Pd-based metal hydrides can perform well for the CO2 reduction reaction (CO2RR). Our previous work on doped-PdH showed that doping Ti and Nb into PdH can improve the CO2RR activity, suggesting that the Pd alloy hydrides with better performance are likely to be found in the PdxTi1-xHy and PdxNb1-xHy phase space. However, the vast compositional and structural space with different alloy hydride compositions and surface adsorbates, makes it intractable to screen out the stable and active PdxM1-xHy catalysts using density functional theory calculations. Herein, an active learning cluster expansion (ALCE) surrogate model equipped with Monte Carlo simulated annealing (MCSA), a CO* binding energy filter and a kinetic model are used to identify promising PdxTi1-xHy and PdxNb1-xHy catalysts with high stability and superior activity. Using our approach, we identify 24 stable and active candidates of PdxTi1-xHy and 5 active candidates of PdxNb1-xHy. Among these candidates, the Pd0.23Ti0.77H, Pd0.19Ti0.81H0.94, and Pd0.17Nb0.83H0.25 are predicted to display current densities of approximately 5.1, 5.1 and 4.6 µA cm-2 at -0.5 V overpotential, respectively, which are significantly higher than that of PdH at 3.7 µA cm-2.

Electrolytes for Zn Batteries: Deep Eutectic Solvents in Polymer Gels.

Gel polymer electrolytes composed of deep eutectic solvent acetamide4 :Zn(TFSI)2 and poly(ethylene oxide) (PEO) are prepared by using a fast, solvent-free procedure. The effect of the PEO molecular weight and its concentration on the physicochemical and electrochemical properties of the electrolytes are studied. Gels prepared with ultrahigh molecular-weight PEO present pseudo-solid behavior and ionic conductivity even higher than that of the original liquid electrolyte. A decrease in the dendritic growth in soft gels with PEO contents up to 1 wt % is demonstrated. The changes in the chemical structure of the electrolyte produced by the strong interactions between ethylene oxide units and Zn2+ have also been studied. The addition of PEO takes the electrolyte out of its original eutectic composition, producing blend crystallization. However, it is possible to retain the eutectic point of the electrolyte in a gel form if the addition of PEO is accompanied by the reduction of acetamide.

Phase-Field Investigation of Lithium Electrodeposition at Different Applied Overpotentials and Operating Temperatures.

Li metal is an exciting anode for high-energy Li-ion batteries and other future battery technologies due to its high energy density and low redox potential. Despite their high promise, the commercialization of Li-metal-based batteries has been hampered due to the formation of dendrites that lead to mechanical instability, energy loss, and eventual internal short circuits. In recent years, the mechanism of dendrite formation and the strategies to suppress their growth have been studied intensely. However, the effect of applied overpotential and operating temperature on dendrite formation and their growth rate remains to be fully understood. Here, we elucidate the correlation between the applied overpotential and operating temperature to the dendrite height and tortuosity of the Li-metal surface during electrodeposition using phase-field model simulations. We identify an optimal operating temperature of a half-cell consisting of a Li metal anode and 1 M LiPF6 in EC/DMC (1/1), which increases gradually as the magnitude of the overpotential increases. The investigation reveals that the temperature dependence identified in the simulations and experiments often disagree because they are primarily conducted under galvanostatic and potentiostatic conditions, respectively. The temperature increase under potentiostatic conditions increases the induced current while it decreases the induced overpotential under galvanostatic conditions. Therefore, the analysis and comparison of temperature-dependent characteristics must be carried out with care.

Density functional theory study of superoxide ions as impurities in alkali halides.

The orientation of diatomic molecular impurities in crystals is a classic problem in physics, whose analysis started in the early 1930s with Pauling's pioneering studies and has extended to the present day. In the present work, we investigate the orientation of a superoxide ion (O2-), which is known to be oriented in the 1 1 0 direction when replacing a halide ion in alkali halide rock salt lattices. The unpaired electron of the superoxide, whose ground state is degenerate (2Πg), is oriented in the 0 0 1 direction for sodium halides while it is oriented in the 1 1[combining macron] 0 direction for potassium and rubidium halides. We performed density functional theory (DFT) calculations to describe the full adiabatic potential energy surface (APES) of this complex system for the first time with ab initio methods. We are focused on four alkali halide lattices, namely NaCl, NaBr, KCl, and KBr. We show that DFT, at the generalized gradient approximation (GGA) and meta-GGA levels, is able to reproduce all the experimental features for potassium halides. However, for sodium halides, although the DFT predicts the correct unpaired electron orientation, the forecasted APES energy minimum for the molecular orientation is found to be close to the 1 1 3/4 orientation, in contrast to the experimental 1 1 0 orientation. The difference in energy between the 1 1 3/4 and 1 1 0 orientation is less than 10 meV, which points out the subtleness of the considered problem. In addition to assessing the DFT accuracy and limitations to treat these systems, we also paid special attention to analyze the geometry distortions of the host lattice for the high symmetry orientations of the superoxide ion, i.e., 1 0 0, 1 1 0 and 1 1 1. In the case of the 1 1 0 molecular orientation, we find a strong dependence on the distance between the alkali ions in the 0 0 1 direction and the superoxide ion upon the unpaired electron orientation. This fact explains why the orientation of the unpaired electron is different in sodium vs. potassium halides. In the case of the 1 0 0 and 1 1 1 molecular orientations, we analyze the Jahn-Teller vibronic coupling to find an unusually large vibronic centrifugal term in the latter.

Correction: Density functional theory study of superoxide ions as impurities in alkali halides.

Correction for 'Density functional theory study of superoxide ions as impurities in alkali halides' by Alexander S. Tygesen et al., Phys. Chem. Chem. Phys., 2020, DOI: 10.1039/d0cp00719f.

A Protocol for Fast Prediction of Electronic and Optical Properties of Donor-Acceptor Polymers Using Density Functional Theory and the Tight-Binding Method.

The ability of donor-acceptor (D-A) type polymers to control the positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals makes them a popular choice for organic solar cell applications. The alternating D-A pattern in a monomer leads to a weak electronic coupling between the constituent monomers within the polymer chain. Exploiting the weak electronic coupling characteristics, we developed a method to efficiently calculate (1) the electronic properties and (2) the optical gap of such polymer chains. The electronic properties (HOMO and LUMO energies, ionization potential, electron affinity, and quasiparticle gap of an oligomer of any length up to an infinitely long polymer) of the D-A polymers are predicted by combining density functional theory calculation results and a tight-binding model. The weak electronic coupling implies that the optical gap of the polymer is size-independent, and thus, it can be calculated using a monomer. We validated the methods using a set of 104 polymers by checking the consistency where the electronic gap of a polymer is larger than the optical gap. Furthermore, we establish relationships between the results obtained from more accurate, yet slower methods (i.e., B3LYP functional, singlet-ΔSCF) with those obtained from the faster counterparts (i.e., BLYP functional, triplet-ΔSCF). Leveraging the found relationships, we propose a way in which the electronic and optical properties of the polymers can be calculated efficiently while retaining high accuracy. The use of the tight-binding model combined with the approach to estimate more accurate results based on less expensive simulations is crucial in the applications where a large volume of computations needs to be carried out efficiently with sufficiently high accuracy, such as high-throughput computational screening or training a machine-learning model.

CLEASE: a versatile and user-friendly implementation of cluster expansion method.

Materials exhibiting a substitutional disorder such as multicomponent alloys and mixed metal oxides/oxyfluorides are of great importance in many scientific and technological sectors. Disordered materials constitute an overwhelmingly large configurational space, which makes it practically impossible to be explored manually using first-principles calculations such as density functional theory due to the high computational costs. Consequently, the use of methods such as cluster expansion (CE) is vital in enhancing our understanding of the disordered materials. CE dramatically reduces the computational cost by mapping the first-principles calculation results on to a Hamiltonian which is much faster to evaluate. In this work, we present our implementation of the CE method, which is integrated as a part of the atomic simulation environment (ASE) open-source package. The versatile and user-friendly code automates the complex set up and construction procedure of CE while giving the users the flexibility to tweak the settings and to import their own structures and previous calculation results. Recent advancements such as regularization techniques from machine learning are implemented in the developed code. The code allows the users to construct CE on any bulk lattice structure, which makes it useful for a wide range of applications involving complex materials. We demonstrate the capabilities of our implementation by analyzing the two example materials with varying complexities: a binary metal alloy and a disordered lithium chromium oxyfluoride.

Interaction of H2O and H2S with Cu(111) and the impact of the electric field: the rotating & translating adsorbate, and the rippled surface.

The interactions of H2O and H2S monomers with Cu(111) in the absence and presence of an external electric field are studied using density functional theory. It is found that the adsorption is accompanied by a rippled pattern of the surface Cu atoms and electron accumulation on the surface Cu atoms surrounding the adsorption site. The response of the H2O/Cu(111) and H2S/Cu(111) interfaces to the external electric field is computed up to the field magnitude of 10(10) V m(-1). The results show that H2O rotates and translates much more with an electric field than H2S does. The extent of the surface deformation changes considerably with the applied electric field, which influences the translation pattern of the adsorbates. On the other hand, the rotation of the adsorbates is correlated to the dipole moment of the molecules and their adsorption energies.