Currently, lithium-ion batteries are the leading technology for energy storage, finding application in electric devices and vehicles, medical equipment and intermittent energy storage systems. This extensive use, however, also requires a high throughput of material resources, and extending lithium-ion battery lifetimes would alleviate the strain on the supply chain. X-ray spectroscopy and scattering methods are ideal for probing through an outer surface at the micrometer length scale, allowing one to observe chemical processes and structural changes within the electrode. In this work, we perform in-house operando X-ray diffraction with novel 3D-printable cells, achieving an increase in signal intensity compared to standard setups by using aluminized Kapton current collectors. The increased resolution helps to clearly identify asymmetric changes in lattice parameters during charging and discharging, signifying for the first time a discrepancy in lithium migration kinetics during cycling of an NMC battery. This behavior is also confirmed by impedance spectroscopic cycling data, reiterating that the delithiation step is more abrupt than the lithiation. Ultimately, the significantly larger local structural changes that occur during delithiation emphasize that the charge step, specifically, should be investigated as a more likely source for critical lattice defects.

Abstract Ni-rich layered NMCs are a very promising class of cathode materials for commercial lithium-ion batteries with high energy and power densities, finding application in many portable devices and electric vehicles. However, upon extended cycling and deep-charging of the cathodes, they undergo irreversible capacity losses, severely limiting battery lifetime. Understanding interfacial and bulk processes behind cathode degradation can provide insight into necessary material enhancements. In this work, we performed operando and ex situ near-edge X-ray absorption fine structure (NEXAFS) of oxygen, fluorine, cobalt, and nickel in NMC811∥Li batteries as a function of cathode lithiation. We find that one of the driving forces for cathode degradation is the oxygen 2p─nickel 3d charge transfer at high states-of-charge (SoC), due to the increased Ni–O covalency beyond Ni3+. In the bulk, this leads to reversible formation of nickel peroxide species, while at the interface, irreversible phase change toward a rocksalt structure occurs. This causes local oxygen reduction into reactive 1O2, concomitant with the reduction of present transition metals, forming an irreversible, redox-inactive surface layer that grows over the course of battery cycling. These results expand the current knowledge of NMC battery degradation and pave the way for designing stable, high capacity cathodes in contemporary lithium-ion batteries.

A potent squaramide-based anion transporter was used to evaluate how vesicles prepared with tailored lipid compositions, which mimic organelle membranes, can impact transmembrane transport. Using HPTS and ISE assays, we show that the lipid environment and POPE flip-flop dynamics significantly influence transport efficiency.

Mixed-phase copper niobate anodes for lithium-ion batteries consisting of various phases work synergistically to deliver high electrochemical capacities at exceptional cycling rates.

Fe(V)O species can be generated by the heterolytic cleavage of the O-O bond of corresponding Fe(III)-OOH species. In haem complexes the redox non-innocence of the ligand facilitates such heterolytic cleavage, however non-haem iron complexes generally show homolytic cleavage to form an Fe(IV)O species and a hydroxyl radical. The hydroxyl radical formed is undesirable due to its non-selective reactivity. Here we show that the redox non-innocence of a phenolato ligand moiety in the complex [LFe(III)(μ-O)Fe(III)L]2+, where L is 2-(((di(pyridin-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)phenolate, facilitates heterolytic O-O bond cleavage, similar in manner to that observed with haem Fe(III)-OOH species, to yield a formal Fe(V)O intermediate. Although not observed directly, the intermediacy of an Fe(V)O species is manifested in the immediate appearance of a doubly oxidised bis-phenolato bridged complex observed by time resolved UV/vis absorption and resonance Raman spectroscopy. This complex is formed by C-C coupling at the para position of the phenolato moiety of the ligand. The pathways to form the final complex via various Fe(IV)O and Fe(V)O intermediates are investigated by DFT methods, which indicate that the impact of the phenolato moiety is due to its redox non-innocence primarily. The ability of the phenolato moiety to transfer charge and spin density induces a switch in the mechanism of O-O bond cleavage from homolytic to heterolytic manifested in the radical character at the para-position needed for C-C bond formation and the high oxidation state of the first observed product.

Self-assembled monolayers (SAMs), especially those based on thiol containing compounds on gold, are of both practical and fundamental interest. Thiols and thiolates can bind to gold in several ways due to the presence of holes and edges on the surfaces. The variety of binding motifs is increased by the presence of adatoms, i.e. gold atoms present on the surface, that sit between the thiolate and the surface. Although these motifs bind strongly to gold surfaces, they are sufficiently mobile to allow for self-assembly of thiols, either by movement across the surface or by desorption/re-adsorption. The motifs have been investigated primarily in the context of high surface coverage, with some attention given to the mobility of these motifs. Here we focus on the binding in the low-coverage regime, i.e. the initial stage of SAM formation, using theoretical methods. We determine the relative stability of the motifs formed with methane thiolate in the low-coverage regime, and rationalize their relative mobilities. Methane thiolate is used to minimize contributions of intermolecular interactions. Competition between the rates of adsorption, movement, and formation of the motifs can influence the formation of SAMs. In this work we expand the understanding of the early stages of monolayer formation and conclude that the type of motif formed initially depends strongly on the availability of gold adatoms and defects (edges and holes) on the surface at the point of adsorption.

Despite lithium-ion batteries (LIBs) being state-of-the-art commercial rechargeable batteries, there are still significant challenges. For example, heat generation during cycling can lead to performance degradation and safety issues 1-2 . During the process of charging and discharging, the heat that is generated from the chemical reactions taking placing is ideally distributed uniformly in space, to dissipate out the cell easily. However, in practice, heat generation tends to be heterogeneous throughout the battery, leading to localized overheating 3 . This phenomenon can result in e.g. decomposition of the solid-state electrolyte interphase (SEI) layer, triggering electrode reactions with the electrolyte and degradation of the electrolyte (producing combustible gases) and even melting of the separator 4 . Hence, comprehending the origins of temperature generation and its heterogeneity is crucial. To address this challenge, operando X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are applied to monitor the structural changes in the electrode materials during charge and discharge, while simultaneous temperature measurements are conducted using a thermal camera, as such obtaining spatial resolved structure/temperature/performance relationships. We have focused on state-of-the-art nickel rich NMC (Nickel Manganese Cobalt Oxide) versus graphite batteries and by comparing the structural changes of the electrode materials during cycling in ‘hot’ versus ‘cool’ areas of the electrode and battery, we were able to establish a structure-temperature relationships, on top of the electrochemical structure-performance relationships and as such unravel “heat-generation” process and reactions. The real-time temperature distribution was compared to the computational models using COMSOL, and insights in thermal processes and their possible control measures could be obtained. References Lain, M. & Kendrick, E. Understanding the limitations of lithium-ion batteries at high rates. Journal of Power Sources. Volume 493, 229690 (2021). Ma, S., et al. Temperature effect and thermal impact in lithium-ion batteries: A review. Progress in Natural Science: Materials International. Volume 28, Issue 6, Pages 653-666 (2018). Rafael, M., et al. Operando Radiography and Multimodal Analysis of Lithium–Sulfur Pouch Cells—Electrolyte Dependent Morphology Evolution at the Cathode. Adv. Energy Mater. 2103432 (2022). Joris, J., et al. A comprehensive review of future thermal management systems for battery electrified vehicles. Journal of Energy Storage 31, 101551(2020).

Nickel‐catalyzed cross‐coupling reactions have become a powerful methodology to construct C‐heteroatom bonds. However, many protocols suffer from competitive off‐cycle reaction pathways and require non‐equimolar amounts of coupling partners to suppress them. Here, we report on mechanistic examination of carboxylate O ‐arylation under thermal conditions, in both the presence and absence of an exogeneous bipyridine‐ligand. Furthermore, spectroscopic studies of the novel ligand‐free carboxylate O ‐arylation reaction unveiled the resting state of the nickel catalyst, the crucial role of the alkylamine base and the formation of an off‐cycle Ni I −Ni II dimer upon reduction. This study provides insights into the competition between productive catalysis and deleterious pathways (comproportionation and protodehalogenation) in the commonly proposed self‐sustained Ni I /Ni III catalytic cycle. Thereby we show that for productive nickel‐catalyzed carboxylate O ‐arylation a choice must be made between either mild conditions or equimolar ratios of substrates.

Several gold +I and +III complexes are investigated computationally and spectroscopically, focusing on the d-configuration and physical oxidation state of the metal center. Density functional theory calculations reveal the non-negligible electron-sharing covalent character of the metal-to-ligand σ-bonding framework. The bonding of gold(III) is shown to be isoelectronic to the formal CuIII complex [Cu(CF3 )4 ]1- , in which the metal center tries to populate its formally unoccupied 3dx2-y2 orbital via σ-bonding, leading to a reduced d10 CuI description. However, Au L3 -edge X-ray absorption spectroscopy reveals excitation into the d-orbital of the AuIII species is still possible, showing that a genuine d10 configuration is not achieved. We also find an increased electron-sharing nature of the σ-bonds in the AuI species, relative to their AgI and CuI analogues, due to the low-lying 6s orbital. We propose that gold +I and +III complexes form similar bonds with substrates, owing primarily to participation of the 5dx2-y2 or 6s orbital, respectively, in bonding, indicating why AuI and AuIII complexes often have similar reactivity.

The Cover Feature shows the novel exogeneous ligand-free nickel-catalyzed coupling of aryl halides and carboxylic acids. In their Research Article, J. N. H. Reek, M. Tromp, T. J. Korstanje and co-workers provide insight into the competition between productive catalysis and deleterious pathways in the commonly proposed self-sustained NiI/NiIII catalytic cycle. Spectroscopic studies of the exogeneous ligand-free carboxylate O-arylation reaction unveiled the resting state of the nickel catalyst, the crucial role of the alkylamine base and the formation of an off-cycle NiINiII dimer upon reduction. More information can be found in the Research Article by J. N. H. Reek, M. Tromp, T. J. Korstanje and co-workers.

The purpose of this study was to evaluate the impact of virtual reality on undergraduate students' self-efficacy, self-concept, interest, and laboratory anxiety in an introductory chemistry course. We used a mixed-methods approach to improve our understanding of how these factors mediate student learning. The findings showed that (i) the use of the virtual reality application had an overall positive impact on students' self-efficacy, self-concept, interest, and anxiety; and (ii) students who expressed some anxiety about doing the lab prior to the course reported the use of the virtual reality application decreased their levels of anxiety at the end of the lab. The implications of these findings speak to the potential value of the use of virtual reality applications in higher education and especially in situations when distance learning is the only option as well as in situations where the costs of real laboratories cannot be afforded.

Kinetic analysis of polyesterification reactions using Lewis-acidic metal catalysts have been performed. While Sn-based catalysts are superior to Ti-based catalysts under neat polycondensation conditions (high [H2O]), the result is inverted under azeotropic conditions (low [H2O]). These findings show that the catalytic activity is crucially determined by the robustness of the catalyst against hydrolytic degradation.

The influence of the support-oxygen groups and Pt particle size on the catalytic performance of Pt/AC for the aerobic oxidation of alpha-D-glucose to gluconic acid (glycolate) was studied. Surface-oxygen groups were introduced by treating the activated carbon support with diluted HNO3 without significantly affecting the support porosity. The platinum particle size could be decreased on both the treated and untreated support by adding an additional calcination step to the synthesis. The presence of oxygen-containing groups is shown to be highly beneficial (similar to 4 fold increase in the turnover frequency) only for the smallest Pt particle size (1.8-2.5 nm, determined by TEM). For the catalyst with the larger Pt size (3.4-3.6 nm), the presence of additional oxygen-contacting groups does not significantly enhance the activity. Since the size of the smaller Pt particles is close to the product/substrate molecular diameter (glucose/gluconic acid, similar to 0.9 nm) the observed effect can be attributed to the effective repulsion by the negatively charged oxygen groups in close proximity to the glycolate reaction product. The increase in activity originates from the resulting enhanced desorption of glycolate by alleviating the product inhibition presence due to the strong interaction of glycolate with Pt.

Nickel-catalyzed cross-coupling reactions have become a powerful methodology to construct C–heteroatom bonds. How-ever, many protocols suffer from competitive off-cycle reaction pathways and require non-equimolar amounts of cou-pling partners to suppress them. Here, we report on mechanistic examination of carboxylate O-arylation under thermal conditions, in both the presence and absence of an exogeneous bipyridine-ligand. Furthermore, spectroscopic studies of the novel ligand-free carboxylate O-arylation reaction unveiled the resting state of the nickel catalyst, the crucial role of the alkylamine base and the formation of a catalytically relevant NiI–NiII dimer upon reduction. This study provides in-sights into the competition between productive catalysis and deleterious pathways (comproportionation and pro-todehalogenation) that exist for all elementary steps in the commonly proposed self-sustained NiI/NiIII catalytic cycle. Thereby we show that for productive nickel-catalyzed carboxylate O-arylation a choice must be made between either mild conditions or equimolar ratios of substrates.

In recent years there have been regular reports about a new generation of batteries in which the liquid electrolyte is replaced by a solid material: the solid-state batteries. With a higher energy density and a better safety than current batteries, solid-state batteries potentially would boost electric mobility by enhancing the driving distance of e-cars and prevent extreme battery fires. Why are they not yet implemented in the latest generation of e-cars?

An important element in the reduction of CO2 is the change of vehicles with internal combustion engines to electric battery powered vehicles.The as such produced renewable energy can be used for individual mobility as well as for a temporary intermediate storage of excess energy.A viable electric mobility concept requires however stable cycle batteries with high specific energy (minimising weight, maximising driving range).Li ion batteries are widely used in applications such as mobile phones and laptops and will likely be key to future electromobility.An alternative promising battery is the lithium sulfur battery with a potential twofold energy density increase.The requirements for such batteries present major challenges, e.g.energy capacity, deactivation/stability and safety.A detailed understanding of the charge, discharge and deactivation mechanisms are thus required, preferably quantitative and spatially resolved.X-ray absorption spectroscopy (XAS) is a characterisation technique which provides detailed electronic and structural information on the material under investigation, in a time-and spatially resolved manner.Here, I will explain the strengths and limitations of XAS for battery research.A novel operando XAS cell design will be described [1], including the challenges to perform reliable experiments (electrochemically and spectroscopically).The cell allows time and spatial resolved XAS, providing insights in the type, location and reversibility of the intermediates formed in electrodes and electrolyte separately.Obtained insights in cycling and deactiviation mechanisms for the different battery types will be discussed [1-6] and future research directions described.

Monoalkyltin(IV) complexes are well-known catalysts for esterification reactions and polyester formation, yet the mode of operation of these Lewis acidic complexes is still unknown. Here, we report on mechanistic studies of n-butylstannoic acid in stoichiometric and catalytic reactions, analyzed by NMR, IR and MS techniques. While the chemistry of n-butyltin(IV) carboxylates is dominated by formation of multinuclear tin assemblies, we found that under catalytically relevant conditions only monomeric n-BuSn(OAc)(3) and dimeric (n-BuSnOAc2OEt)(2) are present. Density functional theory (DFT) calculations provide support for a mononuclear mechanism, where n-BuSn(OAc)(3) and dimeric (n-BuSnOAc2OEt)(2) are regarded as off-cycle species, and suggest that carbon-oxygen bond breaking is the rate-determining step.

MAX phases are layered ternary carbides or nitrides that are attractive for catalysis applications due to their unusual set of properties. They show high thermal stability like ceramics, but they are also tough, ductile, and good conductors of heat and electricity like metals. Here, we study the potential of the Ti3AlC2 MAX phase as a support for molybdenum oxide for the reverse water–gas shift (RWGS) reaction, comparing this new catalyst to more traditional materials. The catalyst showed higher turnover frequency values than MoO3/TiO2 and MoO3/Al2O3 catalysts, due to the outstanding electronic properties of the Ti3AlC2 support. We observed a charge transfer effect from the electronically rich Ti3AlC2 MAX phase to the catalyst surface, which in turn enhances the reducibility of MoO3 species during reaction. The redox properties of the MoO3/Ti3AlC2 catalyst improve its RWGS intrinsic activity compared to TiO2- and Al2O3-based catalysts.

X-ray spectroscopy is an important tool for scientific analysis. While the earliest demonstration experiments were realised in the laboratory, with the advent of synchrotron light sources most of the experiments shifted to large scale synchrotron facilities. In the recent past there is an increased interest to perform X-ray experiments also with in-house laboratory sources, to simplify access to X-ray absorption and X-ray emission spectroscopy, in particular for routine measurements. Here we summarise the recent developments and comment on the most representative example experiments in the field of in-house laboratory X-ray spectroscopy. We first give an introduction and some historic background on X-ray spectroscopy. This is followed by an overview of the detection techniques used for X-ray absorption and X-ray emission measurements. A short paragraph also puts related high energy resolution and resonant techniques into context, though they are not yet feasible in the laboratory. At the end of this section the opportunities using wavelength dispersive X-ray spectroscopy in the laboratory are discussed. Then we summarise the relevant details of the recent experimental laboratory setups split into two separate sections, one for the recent von Hamos setups, and one for the recent Johann/Johansson type setups. Following that, focussing on chemistry and catalysis, we then summarise some of the notable X-ray absorption and X-ray emission experiments and the results accomplished with in-house setups. In a third part we then discuss some applications of laboratory X-ray spectroscopy with a particular focus on chemistry and catalysis. (C) 2020 The Authors. Published by Elsevier B.V.