Probing Phase Formation and Structural Transformations in Sodium Extraction and Insertion of NaFeMnPO through First-Principles Calculations.

Manganese (Mn) substitution is a widely explored strategy aimed at sustainably enhancing the energy density of iron (Fe)-based electrode materials by taking advantage of the higher redox potential of the former. However, excessive Mn content can lead to detrimental effects, offsetting the expected improvements. In experimental studies, triphylite NaFeMnPO has been identified as an optimal composition with enhanced electrochemical performance compared to that of its parent phase NaFePO.

Role of the voltage window on the capacity retention of P2-Na[FeMn]O cathode material for rechargeable sodium-ion batteries.

P2-Na[FeMn]O layered oxide is a promising high energy density cathode material for sodium-ion batteries. However, one of its drawbacks is the poor long-term stability in the operating voltage window of 1.5-4.

Suppressed Mobility of Negative Charges in Polymer Electrolytes with an Ether-Functionalized Anion.

Suppressing the mobility of anionic species in polymer electrolytes (PEs) is essential for mitigating the concentration gradient and internal cell polarization, and thereby improving the stability and cycle life of rechargeable alkali metal batteries. Now, an ether-functionalized anion (EFA) is used as a counter-charge in a lithium salt. As the salt component in PEs, it achieves low anionic diffusivity but sufficient Li-ion conductivity.

Searching for Hidden Descriptors in the Metal-Ligand Bond through Statistical Analysis of Density Functional Theory (DFT) Results.

A statistical treatment of the DFT-computed heterolytic bond dissociation energies (BDE) between a diverse variety of metal fragments and ligands leads to the identification of five hidden descriptors that best characterize the bonding ability per moiety, and of a simple mathematical formula able to obtain from these hidden descriptors a BDE estimation within a few kcal/mol from the DFT value. A simple extension of this treatment beyond the original set of metal fragments and ligands is also presented. The first two hidden descriptors can be associated with the well-known concepts of σ-donation and π-effects, with the next two associated with cis influence and degree of covalency.

A computational study of radical initiated protein backbone homolytic dissociation on all natural amino acids.

Hydroxyl radical (˙OH) is known to be one of the most reactive species. In this work, the hydrogen abstraction by ˙OH from C and C atoms of all amino acids is studied in the framework of density functional theory as this is the most favorable reaction mechanism when this kind of radical attacks a protein. From the myriad routes that the oxidation of a protein by a ˙OH radical may follow, fragmentation of the protein is one of the most damaging ones as it hampers the normal function of the protein.

Quantum chemical study of the reactions between Pd+/Pt+ and H2O/H2S.

The study of the reactions of water and hydrogen sulfide with palladium and platinum cations has been completed in this work, in both low- and high-spin states. Our calculations predict that only the formation of platinum sulfide is exothermic (in both spin states), whereas for the remaining species the oxides and sulfides are found to be more reactive than their corresponding bare metal cations. An in-depth analysis of the reaction paths leading to metal oxide and sulfide species is given, including various minima, and several important transition states.

Quantum chemical study of the reaction between Ni+ and H2S.

The reaction between the Ni(+) cation and H(2)S is studied by considering both the doublet ground state and the lowest-lying quartet state. For the doublet state the reaction is endothermic, whereas it is exothermic for the quartet state. Both CCSD(T)//B3LYP and B3LYP levels of theory, combined with the triple-zeta quality TZVP++G(3df,2p), predict that there are three spin crossings along the characterized reaction path.