A5082918470- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Graphene research and applications
- Advanced Battery Technologies Research
- Electron and X-Ray Spectroscopy Techniques
- Molecular Junctions and Nanostructures
- Supercapacitor Materials and Fabrication
- 2D Materials and Applications
- MXene and MAX Phase Materials
- Electrocatalysts for Energy Conversion
- Electronic and Structural Properties of Oxides
- Transition Metal Oxide Nanomaterials
- Graphene and Nanomaterials Applications
- Surface Chemistry and Catalysis
- Copper-based nanomaterials and applications
- Diamond and Carbon-based Materials Research
- Mesenchymal stem cell research
- Advanced Condensed Matter Physics
- Carbon Nanotubes in Composites
- Chemical Synthesis and Characterization
- Surface and Thin Film Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Photocatalysis Techniques
- Topological Materials and Phenomena
- Extraction and Separation Processes
Helmholtz-Zentrum Berlin für Materialien und Energie
2024-2025
Friedrich-Alexander-Universität Erlangen-Nürnberg
2019-2022
Lomonosov Moscow State University
2013-2018
Unfortunately, the practical applications of Li-O2 batteries are impeded by poor rechargeability. Here, for first time we show that superoxide radicals generated at cathode during discharge react with carbon contains activated double bonds or aromatics to form epoxy groups and carbonates, which limits rechargeability cells. Carbon materials a low amount functional defects demonstrate better stability thus keeping will-o'-the-wisp lit lithium-air batteries.
It is crucial to understand at which potentials electrolyte decomposition reactions start and chemical species are present in the subsequently formed films, e.g., solid interphase (SEI). Herein, a new operando experimental approach introduced investigate such by employing hard X-ray photoelectron spectroscopy (HAXPES). This enables examination of SEI below thin metal film (e.g., 6 nm nickel) acting as working electrode an electrochemical cell with sulfide-based Li6PS5Cl electrolyte....
The implementation of future graphene-based electronics is essentially restricted by the absence a band gap in electronic structure graphene. Options how to create reproducible and processing compatible manner are very limited at moment. A promising approach for graphene engineering introduce large-scale sublattice asymmetry. Using photoelectron diffraction spectroscopy we have demonstrated selective incorporation boron impurities into only one two sublattices. We shown that well-oriented on...
Abstract The rising interest in complex oxides for energy storage applications calls the development of efficient computational schemes that enable exploring vast configurational space these materials to guide and complement experiments. In this work, we adopt a high-throughput screening method based on density-functional theory investigate electronic-structure fingerprints specific stoichiometry lithiated manganese-cobalt-nickel oxide, $$\hbox {LiNi}_{0.8}\hbox {Co}_{0.1}\hbox...
The investigation of a wide range energy materials under relevant operation conditions, allowing for real-time investigations the (electro)chemical mechanisms governing performance related applications, is enabled by new Operando Absorption and Emission Spectroscopy at EMIL (OÆSE) endstation in Energy Materials In-situ Laboratory Berlin (EMIL) BESSY II synchrotron facility Berlin, Germany. Currently primarily used X-ray absorption spectroscopy (XAS) studies, OÆSE utilizes undulator-based...
Within the past few years, topological insulators (TIs) have attracted a lot of interest due to their unique electronic structure with spin-polarized surface states (TSSs), which may pave way for these materials great potential in multiple applications. However, enable consideration TIs as building blocks novel devices, stability TSSs toward oxidation should be tested. Among family tetradymite structure, Sb2Te3 is p-type and appears least explored material since its TSS unoccupied ground...
Oxygen reduction reaction (ORR) plays a key role in lithium–air batteries (LABs) that attract great attention thanks to their high theoretical specific energy several times exceeding of lithium-ion batteries. Because surface area, electric conductivity, and low weight, various carbons are often materials choice for applications as the LAB cathode. Unfortunately, possibility practical application such is still under question sustainable operation LABs with carbon cathodes not demonstrated yet...
One of the key problems hindering practical implementation lithium–air batteries is caused by carbon cathode chemical instability leading to low energy efficiency and short cycle life. Titanium carbide (TiC) nanopowders are considered as an alternative material; however, they intrinsically reactive toward oxygen, its stability controlled totally a surface overlayers. Using photoemission spectroscopy, we show that battery discharge product, lithium peroxide (Li2O2), easily oxidizes clean TiC...
Using X-ray photoemission microscopy, we discovered that oxidation of commercial large-scale graphene on Cu foil, which typically has bilayer islands, by atomic oxygen proceeds with the formation specific structures: though relatively mobile epoxy groups are generated uniformly across surface single-layer graphene, their concentration is significantly lower for islands. More oxidized species like carbonyl and lactones preferably located at centers these Such structures randomly distributed...
In this paper we propose a new and simple method to tune the carbon nanowall microstructure by sharp variation of CH4/H2 plasma conditions. Using theoretical calculations demonstrated that gas pressure discharge current leads significant radical composition. some cases such perturbation creates necessary conditions for nucleation smaller secondary nanowalls on surface primary ones.
We convert polycrystalline graphene into monocrystalline graphene, and explore the kinetics of two-dimensional recrystallization as well underlying mechanism.
Most solid electrolytes (SEs) which are promising for all-solid-state battery (ASSB) applications known to have a narrow electrochemical stability window. Consequently, parasitic electrolyte reactions observed when high-energy-density electrode materials such as lithium and silicon employed, hindering their utilization in commercial systems. Therefore, it is crucial understand at potentials start, chemical species present the subsequently formed interphase (SEI). Herein, new operando...
Abstract Thin‐film growth of molecular systems is interest for many applications, such as instance organic electronics. In this study, we demonstrate how X‐ray photoelectron spectroscopy (XPS) can be used to study the behavior systems. XPS, coverages are often calculated assuming a uniform thickness across surface. This results in an error rough films, and magnitude depends on kinetic energy photoelectrons analyzed. We have kinetic‐energy dependency estimate roughnesses thin porphyrin films...
Using Raman and photoemission spectroscopy, we probe the atmospheric adsorption on pristine nitrogen p -doped graphene supported by SiO2/Si. Laser annealing in vacuum led to a pronounced change spectra parameters, corresponding decrease hole density due adsorbate removal from sample surface. We found that shift inversely correlates with degree of initial doping, thus less -type doping takes place higher charge carriers same sign. The amount required for absence was be noad = (3.87 ± 0.31) ×...
Abstract Cancer models mimicking the tumor microenvironment are necessary to successfully develop and predict responses of oncological drugs. In this study, electrospun polycaprolactone (PCL) matrices tested for development an in vitro breast cancer model. The effects fiber thickness plasma‐treatment on growth cancer‐associated cells, namely cells MDA‐MB‐231, primary adipose‐derived stem (ADSCs) endothelial progenitor (EPCs) evaluated. Surface treatment by air‐plasma leads increased...
Abstract Photoelectron spectroscopy (PES) studies of solid electrolyte interphases (SEI) cycled battery electrodes are mostly performed in half cell configurations (i.e., against metallic counter electrodes). In contrast to less reactive Li metal, problems arise post‐Li systems, like K‐ion cells, where crosstalk phenomena strongly interfere with the surface layer formation process. This raises question whether analysis data from experiments still representative and transferable corresponding...
Understanding the adsorption of organic molecules on surfaces is essential importance for many applications. Adsorption energies are typically measured using temperature-programmed desorption. However, large molecules, often only desorption multilayers possible, while bottom monolayer in direct contact to surface cannot be desorbed without decomposition. Nevertheless, these directly adsorbed ones most interest. We use a layer-exchange process investigated with X-ray photoelectron...