467 results match your criteria: "Helmholtz Institute Ulm HIU[Affiliation]"

P2-type cobalt-free MnNi-based layered oxides are promising cathode materials for sodium-ion batteries (SIBs) due to their high reversible capacity and well chemical stability. However, the phase transformations during repeated (dis)charge steps lead to rapid capacity decay and deteriorated Na diffusion kinetics. Moreover, the electrode manufacturing based on polyvinylidene difluoride (PVDF) binder system has been reported with severely defluorination issue as well as the energy intensive and expensive process due to the use of toxic and volatile N-methyl-2-pyrrolidone (NMP) solvent.

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Development of in situ high resolution NMR: Proof-of-principle for a new (spinning) cylindrical mini-pellet approach applied to a Lithium ion battery.

Solid State Nucl Magn Reson

February 2024

Laboratory of Spin Design, Institute of Cybernetics, Tallinn University of Technology, Ehitajate Tee 5, 19086, Tallinn, Estonia; Helmholtz-Institute Ulm for Electrochemical Energy Storage (HIU), Helmholtzstr. 11, 89081, Ulm, Germany; Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), POB 3640, 76021, Karlsruhe, Germany; Institute of Quantum Optics, University Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany. Electronic address:

Solid-state nuclear magnetic resonance (ssNMR) spectroscopy is a powerful technique for characterizing the local structure and dynamics of battery and other materials. It has been widely used to investigate bulk electrode compounds, electrolytes, and interfaces. Beside common ex situ investigations, in situ and operando techniques have gained considerable importance for understanding the reaction mechanisms and cell degradation of electrochemical cells.

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Metal-Ion Intercalation Mechanisms in Vanadium Pentoxide and Its New Perspectives.

Nanomaterials (Basel)

December 2023

Department of Electrical and Computer Engineering, School of Engineering, Hellenic Mediterranean University, 71410 Heraklion, Greece.

The investigation into intercalation mechanisms in vanadium pentoxide has garnered significant attention within the realm of research, primarily propelled by its remarkable theoretical capacity for energy storage. This comprehensive review delves into the latest advancements that have enriched our understanding of these intricate mechanisms. Notwithstanding its exceptional storage capacity, the compound grapples with challenges arising from inherent structural instability.

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The demand for high-performance lithium-ion batteries and thus efficient cathode materials is steadily increasing. In addition to a high energy density and long lifetime, these should also be cost-effective and environmentally benign. Manganese-based materials have particular potential because manganese is available in sufficient quantities and can be supplied at a comparatively low cost.

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Aluminum-sulfur (Al-S) batteries have attracted extensive interest due to their high theoretical energy density, inherent safety, and low cost. However, severe polarization and poor cycling performance significantly limit the development of Al-S batteries. Herein, three-dimensional (3D) nitrogen-doped carbonaceous networks anchored with cobalt (Co@C) is proposed as a separator modification layer to mitigate these issues, prepared via carbonizations of a mixture of ZIF-7, melamine, and CoCl.

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Entropy-Mediated Stable Structural Evolution of Prussian White Cathodes for Long-Life Na-Ion Batteries.

Angew Chem Int Ed Engl

February 2024

Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.

Article Synopsis
  • * A synthesized material with a complex composition of multiple metal species showed significantly better cyclability compared to lower-entropy and traditional single-metal PWs.
  • * The research introduces evidence that a high-symmetry crystal structure can improve the operational stability of high-entropy PWs, which is linked to a mechanism that prevents phase transitions and gas evolution during charging and discharging.
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EPI-X4, an endogenous peptide inhibitor, has exhibited potential as a blocker of CXCR4-a G protein-coupled receptor. This unique inhibitor demonstrates the ability to impede HIV-1 infection and halt CXCR4-dependent processes such as tumor cell migration and invagination. Despite its promising effects, a comprehensive understanding of the interaction between EPI-X4 and CXCR4 under natural conditions remains elusive due to experimental limitations.

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Pharmacological properties of Ensete glaucum seed extract: Novel insights for antidiabetic effects via modulation of oxidative stress, inflammation, apoptosis and MAPK signaling pathways.

J Ethnopharmacol

February 2024

National Institute of Medicinal Materials (NIMM), Hanoi, 100000, Viet Nam; Research Center of Ginseng and Medicinal Materials (CGMM), National Institute of Medicinal Materials, Ho Chi Minh City, 700000, Viet Nam. Electronic address:

Ethnophamacological Relevance: Medicinal plants are increasingly making important contributions to diabetic treatment. Ensete glaucum seeds have been widely used in folk medicine to treat diabetes.

Aim Of The Study: The study was aimed to investigate the protective effect and active mechanisms of E.

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Ultrafine metal nanoparticles (NPs) hold promise for applications in many fields, including catalysis. However, ultrasmall NPs are typically prone to aggregation, which often leads to performance losses, such as severe deactivation in catalysis. Conventional stabilization strategies (, immobilization, embedding, or surface modification by capping agents) are typically only partly effective and often lead to loss of catalytic activity.

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Lithium metal batteries (LMBs) with nickel-rich cathodes are promising candidates for next-generation high-energy-density batteries, but the lack of sufficiently protective electrode/electrolyte interphases (EEIs) limits their cyclability. Herein, trifluoromethoxybenzene is proposed as a cosolvent for locally concentrated ionic liquid electrolytes (LCILEs) to reinforce the EEIs. With a comparative study of a neat ionic liquid electrolyte (ILE) and three LCILEs employing fluorobenzene, trifluoromethylbenzene, or trifluoromethoxybenzene as cosolvents, it is revealed that the fluorinated groups tethered to the benzene ring of the cosolvents not only affect the electrolytes' ionic conductivity and fluidity, but also the EEIs' composition via adjusting the contribution of the 1-ethyl-3-methylimidazolium cation (Emim ) and bis(fluorosulfonyl)imide anion.

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Iron-based fluorophosphate NaFePOF as a cathode for aqueous zinc-ion batteries.

Chem Commun (Camb)

December 2023

Faraday Materials Laboratory (FaMaL), Materials Research Centre, Indian Institute of Science, Bangalore 560012, India.

Aqueous zinc-ion batteries form a key post-Li-ion batteries to cater the rising demand for grid storage. Fe-based compounds can be used as economical cathodes for zinc-ion batteries. Herein, we explored iron-based flourophosphate as a potential polyanionic cathode.

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Poor interfacial contact between solid-state electrolytes and electrodes limits high-voltage performance of solid-state lithium batteries. A new gel electrolyte is proposed via in-situ polymerization, incorporating fluoroethylene carbonate (FEC) solvent and ionic liquid1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide (PP TFSI). This combination synergistically enhances Li ion transport, achieving a transfer number of 0.

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Developing suitable electrolytes is crucial for the advancement of rechargeable magnesium batteries. Recently, metal-organic frameworks (MOFs) have shown a great interest in the field of solid electrolytes for metal ion batteries. However, the ionic conductivity as well as the electrolyte stability in the presence of Mg electrodes are shown to be strongly dependent on the guest solvent used to solvate Mg salts in MOFsSEs.

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Solid state NMR is widely used to study the orientation and other structural features of proteins and peptides in lipid bilayers. Using data obtained by PISEMA (Polarization Inversion Spin Exchange at Magic Angle) experiments, periodic spectral patterns arise from well-aligned α-helical molecules. Significant problems in the interpretation of PISEMA spectra may arise for systems that do not form perfectly defined secondary structures, like α-helices, or the signal pattern is disturbed by molecular motion.

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Modification of Al Surface via Acidic Treatment and its Impact on Plating and Stripping.

ChemSusChem

March 2024

Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.

Amorphous Al O film that naturally exists on any Al substrate is a critical bottleneck for the cyclic performance of metallic Al in rechargeable Al batteries. The so-called electron/ion insulator Al oxide slows down the anode's activation and hinders Al plating/stripping. The Al O film induces different surface properties (roughness and microstructure) on the metal.

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Poly(2,2,6,6-tetramethyl-1-piperidinyloxy methacrylate) (PTMA) is one of the most promising organic cathode materials thanks to its relatively high redox potential, good rate performance, and cycling stability. However, being a p-type material, PTMA-based batteries pose additional challenges compared to conventional lithium-ion systems due to the involvement of anions in the redox process. This study presents a comprehensive approach to optimize such batteries, addressing challenges in electrode design, scalability, and cost.

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Utilization of human ACE2 allowed several bat coronaviruses (CoVs), including the causative agent of COVID-19, to infect humans directly or via intermediate hosts. However, the determinants of species-specific differences in ACE2 usage and the frequency of the ability of animal CoVs to use human ACE2 are poorly understood. Here we applied VSV pseudoviruses to analyze the ability of Spike proteins from 26 human or animal CoVs to use ACE2 receptors across nine reservoir, potential intermediate and human hosts.

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Rechargeable magnesium batteries could provide future energy storage systems with high energy density. One remaining challenge is the development of electrolytes compatible with the negative Mg electrode, enabling uniform plating and stripping with high Coulombic efficiencies. Often improvements are hindered by a lack of fundamental understanding of processes occurring during cycling, as well as the existence and structure of a formed interphase layer at the electrode/electrolyte interface.

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The search for new redox-active organic materials (ROMs) is essential for the development of sustainable energy-storage solutions. In this study, we present a new class of cyclobuta[]quinoxaline-1,2-diones or squaric acid quinoxalines (SQXs) as highly promising candidates for ROMs featuring exceptional stability and high redox potentials. While simple 1,2- and 1,3-squaric acid amides (SQAs), initially reported by Hünig and coworkers decades ago, turned out to exhibit low stability in their radical cation oxidation states, we demonstrate that embedding the nitrogen atoms into a quinoxaline heterocycle leads to robust two-electron SQX redox systems.

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The increasing need for electrochemical energy storage drives the development of post-lithium battery systems. Among the most promising new battery types are sodium-based battery systems. However, like its lithium predecessor, sodium batteries suffer from various issues like parasitic side reactions, which lead to a loss of active sodium inventory, thus reducing the capacity over time.

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An effective model for sodium insertion in hard carbons.

Phys Chem Chem Phys

October 2023

Department of Electrochemistry, University of Ulm, Albert-Einstein-Allee 47, 89081 Ulm, Germany.

Sodium ion batteries (NIBs) are a potential alternative to Lithium ion batteries (LIBs) because of their lower cost and greater availability. As anodes, hard carbons (HCs) seem to be the most promising candidates for NIBs. Previous numerical theoretical research studies have focussed on the general conditions for Na insertion in HCs, while experiments have shown that the properties of Na insertion in HCs depend strongly on specific material properties of HCs.

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Boosting the Reversibility and Kinetics of Anionic Redox Chemistry in Sodium-Ion Oxide Cathodes via Reductive Coupling Mechanism.

J Am Chem Soc

October 2023

Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.

Activating anionic redox chemistry in layered oxide cathodes is a paradigmatic approach to devise high-energy sodium-ion batteries. Unfortunately, excessive oxygen redox usually induces irreversible lattice oxygen loss and cation migration, resulting in rapid capacity and voltage fading and sluggish reaction kinetics. Herein, the reductive coupling mechanism (RCM) of uncommon electron transfer from oxygen to copper ions is unraveled in a novel P2-NaCuLiMnO cathode for boosting the reversibility and kinetics of anionic redox reactions.

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Fluoroethylene carbonate (FEC) and vinylene carbonate (VC) are considered the most effective electrolyte additives for improving the solid electrolyte interphase (SEI) of Si-containing anodes while lithium difluorophosphate (LiDFP) is known to improve the interphases of cathode materials and graphite. Here, we combine VC, FEC, and different amounts of LiDFP in a highly-concentrated electrolyte to investigate the effect on Si-dominant anodes in detail. Cycle life tests, electrochemical impedance spectroscopy and rate tests with anode potential monitoring were conducted in Si/NCM pouch cells.

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Based on quantum chemical calculations, we predict strong solvatochromism in a light-driven molecular photocatalyst for hydrogen generation, that is we show that the electronic and optical properties of the photocatalyst strongly depend on the solvent it is dissolved in. Our calculations in particular indicate a solvent-dependent relocation of the highest occupied molecular orbital (HOMO). Ground-state density functional theory and linear response time-dependent density functional theory calculations were applied in order to investigate the influence of implicit solvents on the structural, electronic and optical properties of a molecular photocatalyst.

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Article Synopsis
  • Poly(ethylene oxide) (PEO) faces challenges like limited ionic conductivity and a narrow electrochemical window, which impacts its use in high-energy-density lithium metal batteries.
  • An innovative hybrid filler-enhanced solid polymer electrolyte (SPE) has been developed to improve electrochemical performance for lithium metal anodes and LiFePO cathodes, achieving high ionic conductivity and transference numbers.
  • The composite membrane shows impressive stability and performance, evidenced by 2000 hours of operation in symmetric cells and a high-capacity retention in batteries after 400 cycles, indicating that combining active and inactive fillers can boost solid-state battery performance.
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