A5002086034- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Magnetic and transport properties of perovskites and related materials
- Extraction and Separation Processes
- Supercapacitor Materials and Fabrication
- Advanced Condensed Matter Physics
- X-ray Diffraction in Crystallography
- Inorganic Chemistry and Materials
- Multiferroics and related materials
- Rare-earth and actinide compounds
- Crystal Structures and Properties
- Ferroelectric and Piezoelectric Materials
- Chemical Synthesis and Characterization
- Transition Metal Oxide Nanomaterials
- Magnetic Properties of Alloys
- Advanced battery technologies research
- Solid-state spectroscopy and crystallography
- Crystallization and Solubility Studies
- Catalysis and Oxidation Reactions
- Microwave Dielectric Ceramics Synthesis
- Thermal Expansion and Ionic Conductivity
- Inorganic Fluorides and Related Compounds
- Luminescence Properties of Advanced Materials
- Nuclear materials and radiation effects
Karlsruhe Institute of Technology
2016-2025
Applied Materials (Germany)
2013-2025
Helmholtz-Institute Ulm
2015-2024
Kerntechnische Entsorgung Karlsruhe (Germany)
2024
Institut für Klinische Forschung und Entwicklung
2023
Energy Storage Systems (United States)
2016-2021
Technical University of Darmstadt
2011-2020
Leibniz Institute for Solid State and Materials Research
2008-2018
Interface (United Kingdom)
2017
John Wiley & Sons (United States)
2017
Piezoelectric actuators convert electrical into mechanical energy and are implemented for many large-scale applications such as piezoinjectors ink jet printers. The performance of these devices is governed by the electric-field-induced strain. Here, authors describe development a class lead-free (0.94−x)Bi0.5Na0.5TiO3–0.06BaTiO3–xK0.5Na0.5NbO3 ceramics. These can deliver giant strain (0.45%) under both unipolar bipolar field loadings, which even higher than obtained with established...
The solid lithium-ion electrolyte "Li(7)La(3)Zr(2)O(12)" (LLZO) with a garnet-type structure has been prepared in the cubic and tetragonal modification following conventional ceramic syntheses routes. Without aluminium doping LLZO was obtained, which shows two orders of magnitude lower room temperature conductivity than modification. Small concentrations Al order 1 wt% were sufficient to stabilize phase, is known as fast conductor. ion dynamics Al-doped studied by impedance spectroscopy, dc...
This overview addresses the atomistic aspects of degradation layered LiMO2 (M = Ni, Co, Mn) oxide Li-ion battery cathode materials, aiming to shed light on fundamental mechanisms especially inside active materials and at their interfaces. It includes recent results obtained by novel in situ/in operando diffraction methods, modelling, quasi situ surface science analysis. Degradation material occurs upon overcharge, resulting from a positive potential shift anode. Oxygen loss eventual phase...
Accurate capacity estimation is crucial for the reliable and safe operation of lithium-ion batteries. In particular, exploiting relaxation voltage curve features could enable battery without additional cycling information. Here, we report study three datasets comprising 130 commercial cells cycled under various conditions to evaluate approach. One dataset collected model building from batteries with LiNi0.86Co0.11Al0.03O2-based positive electrodes. The other two datasets, used validation,...
Abstract One major challenge in the field of lithium-ion batteries is to understand degradation mechanism high-energy lithium- and manganese-rich layered cathode materials. Although they can deliver 30 % excess capacity compared with today’s commercially- used cathodes, so-called voltage decay has been restricting their practical application. In order unravel nature this phenomenon, we have investigated systematically structural compositional dependence lithium insertion compounds on content...
Abstract Sodium-ion batteries operating at ambient temperature hold great promise for use in grid energy storage owing to their significant cost advantages. However, challenges remain the development of suitable electrode materials enable long lifespan and high rate capability. Here we report a sodium super-ionic conductor structured electrode, vanadium titanium phosphate, which delivers specific capacity 147 mA h g −1 0.1 C excellent retentions rates. A symmetric sodium-ion full cell...
The Al-substituted LiTi2(PO4)3 powders Li1+xAlxTi2–x(PO4)3 (LATP) were successfully prepared by a water-based sol–gel process with subsequent calcination and sintering. crystal structure of obtained samples was characterized at different temperatures using high-resolution synchrotron-based X-ray neutron powder diffraction. Possible lithium diffusion pathways initially evaluated the difference bond-valence approach. Experimental 3D pathway in LATP extracted from negative nuclear density maps...
Abstract Conventional lithium-ion batteries embrace graphite anodes which operate at potential as low metallic lithium, subjected to poor rate capability and safety issues. Among possible alternatives, oxides based on titanium redox couple, such spinel Li 4 Ti 5 O 12 , have received renewed attention. Here we further expand the horizon include a perovskite structured titanate La 0.5 TiO 3 into this promising family of anode materials. With average around 1.0 V vs. + /Li, exhibits high...
High entropy oxides (HEOs) with chemically disordered multi-cation structure attract intensive interest as negative electrode materials for battery applications. The outstanding electrochemical performance has been attributed to the high-entropy stabilization and so-called 'cocktail effect'. However, configurational of HEO, which is thermodynamically only metastable at room-temperature, insufficient drive structural reversibility during conversion-type reaction, effect' not explained thus...
Abstract Solid‐state batteries (SSBs) currently attract great attention as a potentially safe electrochemical high‐energy storage concept. However, several issues still prevent SSBs from outperforming today's lithium‐ion based on liquid electrolytes. One major challenge is related to the design of cathode active materials (CAMs) that are compatible with superionic solid electrolytes (SEs) interest. This perspective, gives brief overview required properties and possible challenges for...
Abstract Herein, an eco‐friendly and high safety aqueous Mg‐ion electrolyte (AME) with a wide electrochemical stability window (ESW) ≈3.7 V, containing polyethylene glycol (PEG) low‐concentration salt (0.8 m Mg(TFSI) 2 ), is proposed by solvation structure reorganization of AME. The PEG agent significantly alters the Mg 2+ hydrogen bonds network AMEs forms direct coordination TFSI ‐ , thus enhancing physicochemical properties electrolytes. As exemplary material, V O 5 nanowires are tested in...
Ni-rich layered oxides are one of the most attractive cathode materials in high-energy-density lithium-ion batteries, their degradation mechanisms still not completely elucidated. Herein, we report a strong dependence pathways on long-range cationic disordering Co-free Li1-m (Ni0.94 Al0.06 )1+m O2 (NA). Interestingly, disordered phase with lattice mismatch can be easily formed near-surface region NA particles very low cation disorder (NA-LCD, m≤0.06) over electrochemical cycling, while...
Extended lifetime of lithium-ion batteries decreases economic costs and environmental burdens in achieving sustainable development. Cycle life tests are conducted on 18650-type commercial batteries, exhibiting nonlinear inconsistent degradation. The accelerated fade dispersion is proposed to be triggered by the evolution an additional potential anode during cycling as measured vs. Li+/Li. A method prolong battery cycle proposed, which lower cutoff voltage raised 3 V when reaches a capacity...
In situ synchrotron diffraction revealed a stepwise appearance of two new phases upon electrochemical lithium extraction from LiCoPO4. These were demonstrated to have the same olivine-like structure as pristine compound. The lithium-deficient proposed be Li0.7CoPO4 and CoPO4. completely delithiated phase appears unstable in air undergoes amorphization. transitions are reversible, but slow kinetics initial delithiation was identified by potentiostatic intermittent titration technique. We that...
The temperature dependence of the dielectric and ferroelectric properties lead-free piezoceramics composition (1−x−y)Bi0.5Na0.5TiO3–xBaTiO3–yK0.5Na0.5NbO3 (0.05⩽x⩽0.07, 0.01⩽y⩽0.03) was investigated. Measurements polarization strain hystereses indicate a transition to predominantly antiferroelectric order when heating from room 150°C, while for 150<T<200°C both remnant coercive field increase. Frequency-dependent susceptibility measurements show that is relaxorlike. For some...
The origin of the electric field-induced strain in polycrystalline ceramic 0.92Bi 1/2 Na TiO 3 –0.06BaTiO –0.02K NbO was investigated using situ high-resolution X-ray and neutron diffraction techniques. initially existing tetragonal phase with pseudocubic lattice undergoes a reversible transition to significantly distorted rhombohedral under field, accompanied by change oxygen octahedral tilting from 0 c + − angle. polarization values for phases were calculated based on structural...
LixCoO2 and LixNiO2 (0.5 < x 1) are used as prototype cathode materials in lithium ion batteries. Both systems show degradation fatigue when material during electrochemical cycling. In order to analyze the change of structure electronic a function Li content detail, we have performed X-ray diffraction studies, photoelectron spectroscopy (PES) investigations band calculations for series compounds Lix(Co,Ni)O2 (0 x⩽ 1). The calculated density states (DOS) weighted by theoretical...
The thermodynamic stability of Li2MnSiO4 polymorphs and their electrochemical properties as electrode for Li batteries are investigated combining experimental computational methods. Three possible forms have been considered crystallizing in Pmnb, Pmn21 (β-Li3PO4 derivatives) P21/n (γ-Li3PO4 derivative) space groups (S.G.). We first demonstrated that the relative β- γ-Li3PO4 is well-reproduced by density functional theory (DFT) methods (LDA, GGA). For Li2MnSiO4, Pmnb form predicted to be 2.4...
N-doped carbon materials are discussed as catalyst supports for the electrochemical oxygen reduction reaction (ORR) in fuel cells. This work deals with preparation of Pt nanoparticles (NPs) supported on nanofibers (N-CNF) from a polyaniline nanofiber (PANI NF) precursor, and investigates ORR activity produced materials. Initially, NPs deposited PANI NFs. The NF precursors characterized by near-edge X-ray absorption fine structure (NEXAFS) transmission electron microscopy (TEM) measurements....