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AbstractLayered transition-metal oxide materials are ideal cathode candidates for sodium-ion batteries due to high specific energy, yet suffer severe interfacial instability and capacity fading owing to strongly nucleophilic surface. In this work, the interfacial stability of layered NaNi1/3Fe1/3Mn1/3O2 cathode was effectively enhanced by electrolyte optimization. And the interfacial chemistry between the cathode and four widely used electrolytes (EC/DMC, EC/EMC, EC/DEC and EC/PC) was elucidated through experiments and theoretical calculations. The Na+ solvation structures at cathode-electrolyte interface in all four electrolytes exhibited enhanced coordination due to high electron density and strong nucleophilicity of oxide surface, which promoted the electrolytes' decomposition with decreased oxidation stability. Among them, the EC/DMC electrolyte showed the tightest solvation structure due to smaller molecular chains and stable electrochemistry, which derived an even and robust cathode electrolyte interphase. It effectively protected the cathode and facilitated the reversible Na+ transport during long cycles, enabling the batteries with a high capacity retention of 83.3% after 300 cycles. This work provides new insights into the role of electrode surface characteristics in interface chemistry that can guide the design of advanced electrode and electrolyte materials for rechargeable batteries.

We have computationally investigated the structure and stability of B-DNA. To this end, we have analyzed the bonding in a series of 47 stacks consisting of two base pairs, in which the base pairs cover the full range of natural Watson-Crick pairs, mismatched pairs, and artificial DNA base pairs. Our analyses provide detailed insight into the role and relative importance of the various types of interactions, such as, hydrogen bonding, π-π stacking interactions, and solvation/desolvation. Furthermore, we have analyzed the functionality of the twist-angle on the stability of the structure. Interestingly, we can show that all stacked base pairs benefit from a stabilization by 6 to 12 kcal mol-1 if stacked base pairs are twisted from 0° to 36°, that is, if they are mutually rotated from a congruent superposition to the mutually twisted stacking configuration that occurs in B-DNA. This holds especially for stacked AT pairs but also for other stacked base pairs, including GC. The electronic mechanism behind this preference for a twisted arrangement depends on the base pairs involved. We also show that so-called "diagonal interactions" (or cross terms) in the stacked base pairs are crucial for understanding the stability of B-DNA, in particular, in GC-rich sequences ; We thank the following organizations for financial support: the HPC-Europa2 Transnational Access program of the European Union, the Netherlands Organization for Scientific Research (NWO), the Ministerio de Ciencia e Innovacion (MICINN, project number CTQ2011-25086), the DIUE of the Generalitat de Catalunya (project number 2009SGR528), the Netherlands National Research School Combination - Catalysis (NRSC-C), and the European Fund for Regional Development (FEDER, grant UNGI08-4E-003)

We have computationally investigated the structure and stability of B-DNA. To this end, we have analyzed the bonding in a series of 47 stacks consisting of two base pairs, in which the base pairs cover the full range of natural Watson-Crick pairs, mismatched pairs, and artificial DNA base pairs. Our analyses provide detailed insight into the role and relative importance of the various types of interactions, such as, hydrogen bonding, π-π stacking interactions, and solvation/desolvation. Furthermore, we have analyzed the functionality of the twist-angle on the stability of the structure. Interestingly, we can show that all stacked base pairs benefit from a stabilization by 6 to 12 kcal mol-1 if stacked base pairs are twisted from 0° to 36°, that is, if they are mutually rotated from a congruent superposition to the mutually twisted stacking configuration that occurs in B-DNA. This holds especially for stacked AT pairs but also for other stacked base pairs, including GC. The electronic mechanism behind this preference for a twisted arrangement depends on the base pairs involved. We also show that so-called "diagonal interactions" (or cross terms) in the stacked base pairs are crucial for understanding the stability of B-DNA, in particular, in GC-rich sequences ; We thank the following organizations for financial support: the HPC-Europa2 Transnational Access program of the European Union, the Netherlands Organization for Scientific Research (NWO), the Ministerio de Ciencia e Innovacion (MICINN, project number CTQ2011-25086), the DIUE of the Generalitat de Catalunya (project number 2009SGR528), the Netherlands National Research School Combination - Catalysis (NRSC-C), and the European Fund for Regional Development (FEDER, grant UNGI08-4E-003)

We have computationally investigated the structure and stability of B-DNA. To this end, we have analyzed the bonding in a series of 47 stacks consisting of two base pairs, in which the base pairs cover the full range of natural Watson-Crick pairs, mismatched pairs, and artificial DNA base pairs. Our analyses provide detailed insight into the role and relative importance of the various types of interactions, such as, hydrogen bonding, π-π stacking interactions, and solvation/desolvation. Furthermore, we have analyzed the functionality of the twist-angle on the stability of the structure. Interestingly, we can show that all stacked base pairs benefit from a stabilization by 6 to 12 kcal mol-1 if stacked base pairs are twisted from 0° to 36°, that is, if they are mutually rotated from a congruent superposition to the mutually twisted stacking configuration that occurs in B-DNA. This holds especially for stacked AT pairs but also for other stacked base pairs, including GC. The electronic mechanism behind this preference for a twisted arrangement depends on the base pairs involved. We also show that so-called "diagonal interactions" (or cross terms) in the stacked base pairs are crucial for understanding the stability of B-DNA, in particular, in GC-rich sequences ; We thank the following organizations for financial support: the HPC-Europa2 Transnational Access program of the European Union, the Netherlands Organization for Scientific Research (NWO), the Ministerio de Ciencia e Innovacion (MICINN, project number CTQ2011-25086), the DIUE of the Generalitat de Catalunya (project number 2009SGR528), the Netherlands National Research School Combination - Catalysis (NRSC-C), and the European Fund for Regional Development (FEDER, grant UNGI08-4E-003)

AbstractHigh energy density lithium metal batteries (LMBs) have garnered significant research interests in the past decades. However, the growth of lithium dendrites and the low Coulombic efficiency (CE) of Li metal anode pose significant challenges for the development of LMBs. Herein, we report a triethyl orthoformate (TEOF)-based localized high-concentration electrolyte (LHCE) that facilitates a highly reversible Li metal anode with dendrite-free deposition morphologies and an average Coulombic efficiency of 99.1% for 450 cycles. Mechanistic study reveal that the steric hindrance caused by the terminal ethyl groups in the TEOF solvent molecule results in a weak solvating ability, leading to the formation of anion-dominant solvation structures. The anion-dominant solvation sheaths play an essential role in the formation of a LiF-rich solid-electrolyte interphase (SEI), which effectively suppresses the growth of Li dendrites. Furthermore, the TEOF-based electrolyte demonstrates the stable cycling of high-voltage Li||NMC811 cells. These results provide insights into understanding of steric hindrance effect on electrolyte solvation structure and offer valuable guidance for the design of electrolyte solvents in the development of lithium metal batteries.

Publisher's version (útgefin grein) ; Metal oxide nanoparticles (NPs) are regarded as good candidates for many technological applications, where their functional environment is often an aqueous solution. The correct description of metal oxide electronic structure is still a challenge for local and semilocal density functionals, whereas hybrid functional methods provide an improved description, and local atomic function-based codes such as CRYSTAL17 outperform plane wave codes when it comes to hybrid functional calculations. However, the computational cost of hybrids are still prohibitive for systems of real sizes, in a real environment. Therefore, we here present and critically assess the accuracy of our electrostatic embedding quantum mechanical/molecular mechanical (QM/MM) coupling between CRYSTAL17 and AMBER16, and demonstrate some of its capabilities via the case study of TiO2 NPs in water. First, we produced new Lennard–Jones (LJ) parameters that improve the accuracy of water–water interactions in the B3LYP/TIP3P coupling. We found that optimizing LJ parameters based on water tri- to deca-mer clusters provides a less overstructured QM/MM liquid water description than when fitting LJ parameters only based on the water dimer. Then, we applied our QM/MM coupling methodology to describe the interaction of a 1 nm wide multilayer of water surrounding a spherical TiO2 nanoparticle (NP). Optimizing the QM/MM water–water parameters was found to have little to no effect on the local NP properties, which provide insights into the range of influence that can be attributed to the LJ term in the QM/MM coupling. The effect of adding additional water in an MM fashion on the geometry optimized nanoparticle structure is small, but more evident effects are seen in its electronic properties. We also show that there is good transferability of existing QM/MM LJ parameters for organic molecules–water interactions to our QM/MM implementation, even though these parameters were obtained with a different QM code and QM/MM implementation, but with the same functional. ; National Council for Eurasian and East European Research. Funding: This research was funded by the Icelandic Research Fund (grant 174244-051) and VILLUM FONDEN, the European Research Council (ERC) under the European Union's HORIZON2020 research and innovation programme (ERC Grant Agreement No [647020]). Acknowledgments: A.O.D. Would like to thank Jónsson, H. for discussions about fitting strategies. C.D.V. is grateful to Lara Ferrighi, Massimo Olivucci, and Stefano Motta for fruitful discussions. A.O.D. Acknowledges funding from the Icelandic Research Fund (grant 174244-051) and VILLUM FONDEN. The project has received funding from the European Research Council (ERC) under the European Union's HORIZON2020 research and innovation programme (ERC Grant Agreement No [647020]). ; Peer Reviewed

To achieve climate protection goals set out by national governments and the United Nations, it is paramount to reduce society's dependence on fossil fuels and to introduce more sustainable energy solutions. Furthermore, to not only protect our climate but the natural environment in general, it is necessary to reduce humanity's waste production and to turn waste into a resource wherever possible. The solutions to both of these ambitions will heavily rely on new chemical processes being discovered and upscaled. Thus, with catalysis and photochemistry at its heart, the challenge to build a greener and more sustainable future is largely a materials discovery and design problem. In this work, I introduce a new way of aligning the electronic energy levels of semiconductors with respect to redox potentials which might facilitate in silico screening studies of materials suitable for photoelectrochemistry. In particular, I demonstrate how continuum solvation models can be used to replace computationally expensive atomistic descriptions of water when describing an electrode-electrolyte interface. I tested this approach on rutile (TiO2) showing that, when combined with a description of rutile's electronic structure within many-body perturbation theory, the proposed alignment procedure yields the correct positioning of rutile's band edges on the standard hydrogen electrode scale. My investigation surfaced and explained important differences between atomistic and continuum solvation models when describing the electric potential across interfaces. Furthermore, I present a detailed study of the electronic structure of osmium dioxide (OsO2) near its Fermi level. OsO2 is closely related to important catalysts such as IrO2 and RuO2, which also crystallise in the rutile structure. Specifically, by collaborating with colleagues specialised in experimental photoelectron spectroscopy (PES), we highlight the importance of computational insights for the correct interpretation of PES spectra. By going beyond a simple comparison between the experimentally measured PES spectrum and the computed single-particle electronic density of states, we reveal that the spectrum of OsO2 features a rare low-energy bulk plasmon satellite. ; Open Access

As for other multivalent systems, the interface between the calcium (Ca) metal anode and the electrolyte is of paramount importance for reversible plating/stripping. Here, we combined experimental and theoretical approaches to unveil the potential solid electrolyte interphase (SEI) components enabling facile Ca plating. Borates compounds, in the form of cross-linked polymers are suggested as divalent conducting component. A pre-passivation protocol with such SEI is demonstrated and allows to broaden the possibility for electrolyte formulation. We also demonstrated a 10-fold increase in Ca plating kinetics by tuning the cation solvation structure in the electrolyte limiting the degree of contact ion pair. ; Funding from the European Union's Horizon 2020 research and innovation program H2020 is acknowledged: European Research Council (ERC-2016-STG, CAMBAT grant agreement no. 715087) and H2020-MSCA-COFUND-2016 (DOC-FAM, grant agreement no. 754397). A. Ponrouch is grateful to the Spanish Ministry for Economy, Industry and Competitiveness Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2015-0496) and to Prof. D. Lemordant (Tours University, France) for stimulating discussions. P. Canepa acknowledges funding from the National Research Foundation under his NRFF NRFF12-2020-0012 and the ANR-NRF NRF2019-NRF-ANR073 Na-MASTER. P. Canepa acknowledges the National Supercomputing Centre, Singapore (https://www.nscc.sg). This work has been done in the frame of the Doctoral Degree Program in Materials Science by the Universitat Autònoma de Barcelona. The FTIR experiments were performed at MIRAS beamline at ALBA Synchrotron with the collaboration of ALBA staff. ; Peer reviewed

This presentation will bring the reader on a journey across the microscopic world of water clusters. After a brief introduction about molecular spectroscopy, I will show how the semiclassical approximation to quantum molecular dynamics allows for accurate full-dimensional quantum simulations of water cluster vibrational spectra, differently from classical molecular dynamics approaches. I will employ the semiclassical spectroscopy tool to determine the minimal network of surrounding water molecules needed to make the central one display the same vibrational features of liquid water. Remarkably, the minimal surrounding structure eventually responsible for proper solvation is made of just a few water molecules and includes two complete solvation shells.