Unwanted Processes Research Articles

Exploring the Impact of In Situ-Formed Solid-Electrolyte Interphase on the Cycling Performance of Aluminum Metal Anodes.

Unwanted processes in metal anode batteries, e.g., non-uniform metal electrodeposition, electrolyte decomposition, and/or short-circuiting, are not fully captured by the electrolyte bulk solvation structure but rather defined by the electrode-electrolyte interface and its changes induced by cycling conditions. Specifically, for aluminum-ion batteries (AIBs), the role of the solid-electrolyte interphase (SEI) on the Al0 electrodeposition mechanism and associated changes during resting or cycling remain unclear. Here, we investigated the current-dependent changes at the electrified aluminum anode/ionic liquid electrolyte interface to reveal the conditions of the SEI formation leading to irreversible cycling in the AIBs. We identified that the mechanism of anode failure depends on the nature of the counter electrode, where the areal capacity and cycling current for Al0 electrodeposition dictates the number of successful cycles. Notwithstanding the differences behind unstable aluminum anode cycling in symmetrical cells and AIBs, the uniform removal of electrochemically inactive SEI components, e.g., oxide-rich or solvent-derived organic-rich interphases, leads to more efficient cycling behavior. These understandings raise the importance of using specific conditioning protocols for efficient cycling of the aluminum anode in conjugation with different cathode materials.

Nanoparticle doping and molten-core methods towards highly thulium-doped silica fibers for 0.79 μm-pumped 2 μm fiber lasers – A fluorescence lifetime study

We study the fluorescence lifetime of Thulium-doped silica fibers for efficient laser operation in the 2 μm “eye-safe” wavelength range pumped by 0.79 μm radiation. A large set of optical fibers prepared by Modified Chemical Vapor Deposition combined with solution doping or nanoparticle doping, and Molten-core method is investigated in terms of fluorescence lifetimes of the 3F4 and 3H4 excited levels, which contain information about the Tm3+ ion environment, the rate of unwanted processes, such as concentration quenching or multiphonon relaxation, as well as the inter-ionic energy-transfer processes, including the cross-relaxation. Maximum evaluated lifetime values are 778 μs for the 3F4 level and 56 μs for the 3H4 level. From the lifetime study, we conclude that for Tm3+ concentrations above 10,000 ppm and enhanced aluminum concentrations above 5 mol. % Al2O3, the cross-relaxation efficiency is enhanced and multiphonon relaxation is remarkably reduced due to the lower phonon energy of the resulting alumino-silicate glass.

Charge Carrier Dynamics of the Mixed Conducting Interphase in All‐Solid‐State Batteries: Lithiated Li1.3Al0.3Ti1.7(PO4)3 as a Case Study

AbstractAll‐solid‐state batteries relying on Li metal as negative electrode material and a ceramic electrolyte may severely suffer from unwanted interfacial processes. Here, Li1.3Al0.3Ti1.7(PO4)3 (LATP) serve as a model electrolyte which is known to form an ionic‐electronic, that is, mixed conducting interphase (MCI) when in contact with metallic Li or any other Li source. Li1.3+xAl0.3Ti1.7(PO4)3 with x = 0.2, 0.6 and 1.3 is prepared via ex situ chemical lithiation to mimic the formation of MCIs taking place otherwise operando. The preparation of large amounts of lithiated LATP with controlled Li contents allowed us to use nuclear and electric techniques to study local structures and ionic/electronic dynamics in detail. The results point to the formation of a core‐shell two‐phase morphology with the Li‐rich Li3Al0.3Ti1.7(PO4)3 phase covering the nonlithiated Li‐poor regions. The originally poor electronic conductivity σeon of 6.5 × 10−12 S cm−1 (293 K) increases by ≈3 orders of magnitude, hence reaching the order of 6.6 × 10−9 S cm−1 for x = 0.6. At even higher loadings (x = 1.3), a decrease in conductivity is seen, i.e., not exceeding alarming values for σeon. Quantifying electronic and ionic transport processes will help assessing the extent of damage through MCI formation and discussing whether any strategies to mitigate such formation is necessary at all.

Calcium chloride declotted human platelet lysate promotes the expansion of mesenchymal stromal cells and allows manufacturing of immunomodulatory active extracellular vesicle products

BackgroundMesenchymal stromal cells (MSCs) exert immunomodulatory effects, primarily through released extracellular vesicles (EVs). For the clinical-grade manufacturing of MSC-EV products culture conditions need to support MSC expansion and allow the manufacturing of potent MSC-EV products. Traditionally, MSCs are expanded in fetal bovine serum-supplemented media. However, according to good manufacturing practice (GMP) guidelines the use of animal sera should be avoided. To this end, human platelet lysate (hPL) has been qualified as an animal serum replacement. Although hPL outcompetes animal sera in promoting MSC expansion, hPL typically contains components of the coagulation system that need to be inhibited or removed to avoid coagulation reactions in the cell culture. Commonly, heparin is utilized as an anticoagulant; however, higher concentrations of heparin can negatively impact MSC viability, and conventional concentrations alone do not sufficiently prevent clot formation in prepared media. MethodsTo circumvent unwanted coagulation processes, this study compared various clotting prevention strategies, including different anticoagulants and calcium chloride (CaCl2)-mediated declotting methods, which in combination with heparin addition was found effective. We evaluated the influence of the differently treated hPLs on the proliferation and phenotype of primary bone marrow-derived MSCs and identified the CaCl2-mediated declotting method as the most effective option. To determine whether CaCl2 declotted hPL allows the manufacturing of immunomodulatory MSC-EV products, EVs were prepared from conditioned media of MSCs expanded with either conventional or CaCl2 declotted hPL. In addition to metric analyses, the immunomodulatory potential of resulting MSC-EV products was assessed in a recently established multi-donor mixed lymphocyte reaction assay. Results and ConclusionsOur findings conclusively show that CaCl2-declotted hPLs support the production of immunomodulatory-active MSC-EV products.

Reversible Photoinduced Ligand Substitution in a Luminescent Chromium(0) Complex.

Light-triggered dissociation of ligands forms the basis for many compounds of interest for photoactivated chemotherapy (PACT), in which medicinally active substances are released or "uncaged" from metal complexes upon illumination. Photoinduced ligand dissociation is usually irreversible, and many recent studies performed in the context of PACT focused on ruthenium(II) polypyridines and related heavy metal complexes. Herein, we report a first-row transition metal complex, in which photoinduced dissociation and spontaneous recoordination of a ligand unit occurs. Two scorpionate-type tridentate chelates provide an overall six-coordinate arylisocyanide environment for chromium(0). Photoexcitation causes decoordination of one of these six ligating units and coordination of a solvent molecule, at least in tetrahydrofuran and 1,4-dioxane solvents, but far less in toluene, and below detection limit in cyclohexane. Transient UV-vis absorption spectroscopy and quantum chemical simulations point to photoinduced ligand dissociation directly from an excited metal-to-ligand charge-transfer state. Owing to the tridentate chelate design and the substitution lability of the first-row transition metal, recoordination of the photodissociated arylisocyanide ligand unit can occur spontaneously on a millisecond time scale. This work provides insight into possible self-healing mechanisms counteracting unwanted photodegradation processes and seems furthermore relevant in the contexts of photoswitching and (photo)chemical information storage.

Insights into the Interfacial Charge Transfer Dynamics in Semiconductor–Molecular Catalyst Assemblies for Photo–Induced CO2 Reduction

AbstractThis mini–review summarises examples of photo and photoelectrochemical CO2 reduction reactions (CO2RR) using semiconductor–molecular catalyst–based hybrid assemblies in which studies of charge transfer dynamics were also performed. In these catalysts, the grand challenges are controlling ultra–fast one–electron charge separation and simultaneously governing its impact on the efficiency and product selectivity in the multielectron and multi–proton–assisted CO2RR. In practice, several unwanted electron recombination processes occur in the femtosecond to millisecond timescale range impacting the overall catalysis efficiency. Titanium di‐oxide (TiO2) nanoparticle, mesoporous TiO2 film, copper indium sulphide (CuInS2) quantum dots were used as semiconductor materials, in turn rhenium (I) bipyridine, cobalt (II) terpyridine, cobaloxamine complex, and iron (III) porphyrins were investigated as molecular catalysts. The results of the charge transfer dynamic studies operating in such hybrid systems shed light on their charge accumulation processes, their rate constants for the intramolecular charge transfer processes and the decay lifetimes of the different excited state species that are produced. Moreover, a comprehensive understanding of the catalysts’ charge transfer dynamics is crucial to identifying detrimental charge recombination pathways. These undesired pathways can be used as rational basis for improving the design of future multi–redox–driven hybrid catalysts.

Assessing the rigidity of cubanes and bicyclo(1.1.1)pentanes as benzene bioisosteres

Aromatic rings are critical core substructures in the majority of pharmaceutical compounds. There is much recent interest in replacing aromatic structures with saturated bioisosteres of benzene, which are generally fused or bridged ring systems. These bioisosteres often show improved solubility properties compared to benzene, and may also undergo fewer unwanted metabolic processes. One key reason why aromatic rings have proven so successful in drug design is their rigidity. This paper uses molecular dynamics simulations supported by crystallographic data to assess the rigidity of bicyclopentane and cubane ring systems as two of the most common benzene bioisosteres and compares this to benzene. Whilst a benzene ring is shown to be more flexible than these two bioisosteres in terms of its dihedral ring flexibility, substituents around the ring tend to behave in a much more similar way in both benzene and the bioisosteric systems.

Interfacial Chemical Stability of Doped Li7-XLa3Zr2 -X(Nb/TaX)O12 with LiCoO2 Electrode Material

Garnet-type oxide solid state electrolytes (SEs) are promising candidates due to their potential high ionic conductivity and chemical stability with Li for the replacement of flammable liquid electrolytes used in the current Li-ion batteries. Intense research has been focused on optimising the interface of garnets with Li, with the positive side to be somehow neglected. A significant issue of oxide SEs, hurdling their industrial application, is their poor contact with positive materials due to their rigidity. Poor interfacial contact leads to the need of co-sintering at high temperatures (> 400 °C), which enables side reactions and unwanted processes like cation intermixing, diffusion of elements and formation of non-conductive secondary mixed phases.In this work the chemical stability of Ta and Nb doped LLZO garnet SE was tested in contact with LiCoO2, a common positive material used in the battery industry. Initially, mixed powders of SE and active material were heat treated and studied using Raman spectroscopy and scanning electron microscopy to observe side reactions. In order to improve contact between the two materials, instead of already synthesized crystalline powder, nitrate precursors were also used for in-situ synthesis of LiCoO2 material in contact with the garnet. Mixtures of the SE powder and nitrate precursors for LiCoO2 were also heat-treated at various temperatures for different time periods in different gas atmospheres. The heat-treated materials were then analysed extensively using scanning electron microscopy coupled with energy dispersive X-Ray element mapping and with Raman microscopy to prove the existence or absence of secondary mixed phases at given conditions. Additionally, the optimized heat-treatment conditions were adapted for layered garnet SE/LiCoO2 samples to study the actual electrolyte/electrode interface at the same conditions used for powder mixtures. Based on the results the symmetrical LiCoO2/garnet SE/LiCoO2 cells will be prepared and tested electrochemically.

Improvement in the sustainability and stability of acrylic protective coatings for outdoor bronze artworks

Outdoor bronze artworks are an entrenched part of our urban landscape. They are usually covered by a patina resulting from their exposition to the environment. This patina plays an important aesthetic role and may provide some passivation on the surface, nonetheless it does not prevent the degradation processes promoted by external factors such as pollution, light and humidity. One of the strategies to slow down these unwanted processes is the application of protective coatings. The products currently available have some limitations due to the loss of effectiveness over time and poor environmental sustainability. With the aim of proposing more performing alternatives, coatings based on Paraloid® B44 modified with corrosion inhibitors and light stabilizers were prepared and characterized. Two non-toxic corrosion inhibitors were studied, 5-mercapto-1-pheniltetrazole (MPT) and 5-ethyl-1,3,4-thiadiazol-2-amine (AEDTA), comparing them with the traditional benzotriazole (BTA). The approach used aimed to identify the blend providing the most stable coatings. The chemical and physical properties of the coatings, such as colour, solubility, glass transition and composition, were studied and monitored over time. All coatings have shown adequate visual properties; however, corrosion inhibitors degrade some other properties of the coatings and need to be used in conjunction with light stabilizers. The permanence of corrosion inhibitors in the coatings over time was also studied by investigating the role of the support. The establishment of specific interactions between inhibitors and the bronze surface lengthens their permanence in the coatings compared to what happens with inert supports. Especially for AEDTA, the inhibitor retention within the coating and at the coating-bronze interface is better than for BTA and MPT.The effect of each of the additives on the photooxidation stability of the coating was evaluated and the most promising inhibitor and stabilizer combination was identified.

Reduced female fertility due to sequestration of RNA Pol II by pervasive transcription in exosome RNase-depleted oocytes

Perturbing the transcriptome of mammalian oocytes results in meiotic failure. We previously reported that RNA-exosome-associated RNase, EXOSC10, degrades unwanted protein-coding RNA and processes ribosomal RNA to ensure proper oocyte maturation. Here, we establish oocyte-specific knockout mice of another RNA-exosome-associated RNase, DIS3. Mutant females (Dis3cKO) exhibit significantly reduced fertility because oocytes arrest after the growth phase. Single-oocyte RNA sequencing (RNA-seq) and CUT&Tag analyses show that DIS3 degrades intergenic RNA and mediates transcription silencing that is essential for chromatin condensation and resumption of meiosis. Dis3cKO oocytes exhibit elevated H3K27me3 in a pre-defined manner due to insufficient demethylation. During oocyte growth, EXOSC10 functions with DIS3 to degrade intergenic RNA. Double-knockout oocytes have earlier growth defects and more accumulated transcripts. We conclude that RNA exosomes synergistically degrade unwanted RNA and mediate transcription termination to ensure transcriptome integrity during oocyte development.

Nanoscale X-ray Imaging of Composition and Ferroelastic Domains in Heterostructured Perovskite Nanowires: Implications for Optoelectronic Devices.

Metal halide perovskites (MHPs) have garnered significant interest as promising candidates for nanoscale optoelectronic applications due to their excellent optical properties. Axially heterostructured CsPbBr3-CsPb(Br(1-x)Clx)3 nanowires can be produced by localized anion exchange of pregrown CsPbBr3 nanowires. However, characterizing such heterostructures with sufficient strain and real space resolution is challenging. Here, we use nanofocused scanning X-ray diffraction (XRD) and X-ray fluorescence (XRF) with a 60 nm beam to investigate a heterostructured MHP nanowire as well as a reference CsPbBr3 nanowire. The nano-XRD approach gives spatially resolved maps of composition, lattice spacing, and lattice tilt. Both the reference and exchanged nanowire show signs of diverse types of ferroelastic domains, as revealed by the tilt maps. The chlorinated segment shows an average Cl composition of x = 66 and x = 70% as measured by XRD and XRF, respectively. The XRD measurements give a much more consistent result than the XRF ones. These findings are consistent with photoluminescence measurements, showing x = 73%. The nominally unexchanged segment also has a small concentration of Cl, as observed with all three methods, which we attribute to diffusion after processing. These results highlight the need to prevent such unwanted processes in order to fabricate optoelectronic devices based on MHP heterostructures.

Vulnerability to Parameter Spread in Josephson Traveling-Wave Parametric Amplifiers

We analyze the effect of circuit parameter variation on the performance of Josephson traveling-wave parametric amplifiers (JTWPAs). Specifically, the JTWPA concept we investigate is using flux-biased nonhysteretic rf-SQUIDs in a transmission line configuration, which harnesses the three-wave mixing (3WM) regime. Dispersion engineering enables phase-matching to achieve power gain of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 20 dB, while suppressing the generation of unwanted mixing processes. Two dispersion engineering concepts using a 3WM-JTWPA circuit model, i.e., resonant phase-matching (RPM) and periodic capacitance modulation (PCM), are discussed, with results potentially also applicable to four-wave-mixing (4WM) JTWPAs. We propose suitable circuit parameter sets and evaluate amplifier performance with and without circuit parameter variance using transient circuit simulations. This approach inherently takes into account microwave reflections, unwanted mixing products, imperfect phase-matching, pump depletion, etc. In the case of RPM the resonance frequency spread is critical, while PCM is much less sensitive to parameter spread. We discuss degrees of freedom to make the JTWPA circuits more tolerant to parameter spread. Finally, our analysis shows that the flux-bias point where rf-SQUIDs exhibit Kerr-free nonlinearity is close to the sweet spot regarding critical current spread.

The influence of chitosan on the raspberry quality during the storage process

Raspberry is a perishable berry raw material with a high capacity for mechanical and microbiological damage, and therefore, after harvesting, it is necessary to use appropriate technologies to preserve its quality and extend the storage time. This work aimed to study the influence of different concentrations of chitosan solutions on the quality and duration of storage of raspberries under refrigerating conditions. Raspberries were picked at the consumer maturity stage in perforated plastic containers with a capacity of 500 grams. The berries were processed by spraying with 0.5%, 1.0%, and 2.0% chitosan solution, then removing residual moisture. The storage was carried out for twelve days in a refrigerating chamber at a temperature of 2 °С and relative humidity of 95%. The research was performed according to the physical, chemical, and organoleptic indicators, determining the changes in the mass fraction of ascorbic acid, the mass fraction of sugars during storage, taste, aroma, colour, etc. consistency and appearance at the end of storage. It was found that the loss of ascorbic acid in the processed berries was 1.5-3.9 times less than in the reference sample. A similar situation was observed with the mass fraction of sugars, which prevailed 0.9-2.5 times in the processed samples. According to the organoleptic indicators, the samples with a solution concentration of 1.0% and 2.0% were recognized as the best. According to the results of experimental investigations, it was established that pre-processing of berries with chitosan solutions is a promising method to slow down unwanted metabolic processes that take place after harvesting.

Suppression of Nonequilibrium Quasiparticle Transport in Flat-Band Superconductors.

We study nonequilibrium transport through a superconducting flat-band lattice in a two-terminal setup with the Schwinger-Keldysh method. We find that quasiparticle transport is suppressed and coherent pair transport dominates. For superconducting leads, the ac supercurrent overcomes the dc current, which relies on multiple Andreev reflections. With normal-normal and normal-superconducting leads, the Andreev reflection and normal currents vanish. Flat-band superconductivity is, thus, promising not only for high critical temperatures, but also for suppressing unwanted quasiparticle processes.

Energetically preferred Li+ ion jump processes in crystalline solids: Site-specific hopping in β-Li3VF6 as revealed by high-resolution 6Li 2D EXSY NMR

The visualization of atomic or ionic jump processes on the Ångström length scale is important to identify the preferred diffusion pathways in solid electrolytes for energy storage devices. Two-dimensional high-resolution 6Li nuclear magnetic resonance (NMR) spectroscopy is highly suited to yield unprecedented site-specific insights into local Li+ exchange processes within a single measurement. Here, the beta-modification of Li3VF6 is used as a model system for such an investigation as it provides a range of important Li+ geometric environments in one and the same crystal structure useful to elucidate qualitatively a ranking of energetic preferences of the Li+ exchange processes. In Li3VF6 the Li+ ions are subject to diffusive exchange processes among five crystallographically and magnetically inequivalent Li sites: LiFn (n = 6, 4). By using a sample with a natural concentration of the 6Li isotope, we suppressed unwanted spin-diffusion processes and visualized the various exchange processes on the ms time scale. We were able to verify the following ranking experimentally: Li+ ion jumps between face-shared polyhedra are preferred, followed by Li+ exchange between edge-shared configurations for which interstitial sites are needed to jump from site to site. Surprisingly, Li+ exchange between corner-shared polyhedra and Li+ hopping involving almost isolated LiF4 polyhedra do contribute to overall Li+ self-diffusion as well. In this sense, the current study experimentally verifies current predictions by theory but also extends our understanding of ion dynamics between corner-shared Li-bearing polyhedra.

Green Synthesis of Silver Nanoparticles via Cratoxylum glaucum Leaf Extract Loaded Polyvinyl Alcohol and Its Antibacterial Acitvity

&lt;p&gt;In this study, green synthesis of silver nanoparticles via &lt;em&gt;Cratoxylum glaucum &lt;/em&gt;leaf extracts loaded with polyvinyl alcohol and its bacterial activity were tested. Nanosilver from ‘Pucuk Idat’ leaves has a non-uniform size and tends to agglomerate, making the nanoparticle size unstable and challenging to apply further. Therefore, so that nanoparticles do not aggregate, efforts are made to add stabilizers. Polyvinyl alcohol (PVA) is a polymer that can be used as a stabilizer because it can prevent unwanted aggregation and oxidation processes. UV-Vis analysis results show that PVA as a stabilizer can avoid an increase in wavelength shift. Based on the results of this XRD analysis, it can be concluded that in this research sample, the silver nanoparticle is formed with a cubic crystal system, and it can be observed that the smallest average particle size is in the 0.75% Ag/PVA sample of 10.32 nm. Furthermore, based on the antibacterial test against E. coli and S. aureus, it can be explained that the 0.75% PVA-modified nanosilver sample showed weak to medium antibacterial activity.&lt;/p&gt;&lt;p&gt;. &lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;

The impact of free will beliefs on implicit learning

A growing number of studies demonstrate that belief in free will (FWB) is dynamic, and can be reduced experimentally. Most of these studies assume that doing so has beneficial effects on behavior, as FWBs are thought to subdue unwanted automatic processes (e.g. racial stereotypes). However, relying on automatic processes can sometimes be advantageous, for instance during implicit learning (e.g. detecting and exploiting statistical regularities in the environment). In this registered report, we tested whether experimentally reducing FWBs positively affected implicit motor learning. We hypothesized that reducing FWBs would lead to both faster and stronger implicit learning, as measured using the alternating serial reaction time (ASRT) task. While we did show a manipulation effect on free will beliefs, there was no detectable effect on implicit learning processes. This finding adds to the growing body of evidence that free will belief manipulations do not meaningfully affect downstream behavior.

Widely Tunable Single-Photon Frequency Conversion in a Nanomechanically Reconfigurable Si-Rich Nitride Waveguide

An on-demand single-photon source based on self-assembled semiconductor quantum dots (QDs) is a key building block for quantum communication and quantum information processing. To scale up, a challenge lies in frequency converting the emitted photons to the telecom wavelengths and eliminating the wavelength difference between multiple QDs. In this paper, we propose a novel nanomechanical silicon-rich nitride waveguide device, which can be reconfigured to realize efficient frequency conversion from the emission wavelength band of InAs/GaAs quantum dots at 900 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 950 nm to the telecom C-band around 1550 nm, by exploiting the Bragg scattering process in nonlinear four-wave mixing. Numerical results show that an optimal conversion efficiency over 99% and a signal-to-noise ratio up to 27 dB can be achieved when the waveguide loss is negligible, and the efficiency only reduces to 78% when a realistic loss of 1 dB/cm is considered. We conduct a detailed study on the unwanted noise processes, and provide design guidelines to improve the conversion efficiency and suppress the noises, e.g., by optimizing the power and wavelength of the pump laser.

Bacteriophages in wastewater treatment: can they be an approach to optimize biological treatment processes?

In this paper, we explore the applications of bacteriophages and the advantages of using these viruses to control undesirable organisms in wastewater treatment plants. Based on this, this paper reviewed the literature on the subject by performing a bibliometric and scientometric analysis of articles published in peer-reviewed journals through 2021. We obtained 806 publications, of which 40% were published in the last 5years, demonstrating an increase in interest in the subject. These articles analyzed, bacteriophages in treatment plants were strongly linked to bacteria such as Escherichia coli and related to disinfection, inactivation, sewage, and wastewater, in addition, biocontrol studies have gained prominence in recent years, particularly due to the resistance of microorganisms to antibiotics. Studies have shown that bacteriophages have great potential for application in treatment systems to control unwanted processes and act as valuable economic and environmental tools to improve the efficiency of various treatment technologies. Although these viruses have already been studied in various applications to optimize treatment plant processes, technology transfer remains a challenge due to the limitations of the technique-such as physicochemical factors related to the environment-and the complexity of biological systems. The research focusing on application strategies in conjunction with molecular biology techniques can expand this study area, enabling the discovery of new bacteriophages.

Borate‐Based Surface Coating of Li‐Rich Mn‐Based Disordered Rocksalt Cathode Materials

AbstractUpon cycling, Li‐rich Mn‐based disordered rocksalt (DRS) oxyfluoride cathode materials undergo unwanted degradation processes, which are triggered by chemical side reactions or irreversible oxygen redox activity, especially at high voltages and in contact with the electrolyte. A surface coating can be an effective strategy to mitigate these parasitic reactions. However, oxyfluorides generally experience limited stability, which makes the application of coatings requiring high temperatures challenging. For this purpose, this study is dealing with the implementation of a chemically inert and Li ion conducting borate‐based coating at mild‐temperature (300 °C), following a dry process on the Li2Mn2/3Ti1/3O2F particles. Electrochemical characterization, as function of the amount of coating, C‐rate and temperature, indicate that the coated samples possess considerably improved capacity retention and reduced Mn‐dissolution, however, at the cost of a measurable initial capacity loss. The authors further demonstrate that the presence of the coating reduces the interfacial resistance, which is beneficial for Li ion transfer. The 3 wt%‐coated sample loses only 27% of the capacity, where around 130 mAh g−1 after 100 cycles is retained. The utilization of surface modification can open up a path for further development of DRS cathode materials with high performance for Li‐ion batteries.