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701 results on '"Ehrenberg, Helmut"'

1. Tailoring superstructure units for improved oxygen redox activity in Li-rich layered oxide battery’s positive electrodes

Author

Liu, Hao, Hua, Weibo, Kunz, Sylvia, Bianchini, Matteo, Li, Hang, Peng, Jiali, Lin, Jing, Dolotko, Oleksandr, Bergfeldt, Thomas, Wang, Kai, Kübel, Christian, Nagel, Peter, Schuppler, Stefan, Merz, Michael, Ying, Bixian, Kleiner, Karin, Mangold, Stefan, Wong, Deniz, Baran, Volodymyr, Knapp, Michael, Ehrenberg, Helmut, and Indris, Sylvio

Published
2024
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26. Revealing the disrupted Li/vacancy structure in Co, Mg, and Al co-doped ultra-high Ni-rich cathodes.

Author

Li, Hang, Hua, Weibo, Missyul, Alexander, Bergfeldt, Thomas, Knapp, Michael, Ehrenberg, Helmut, Pan, Feng, and Indris, Sylvio

Abstract

Li atoms are believed to rearrange during Li insertion/removal in LiNiO2 cathodes in lithium-ion batteries, forming certain Li/vacancy ordering structures. Substitution of Ni by dopants is considered to hinder such orderings, which is related to a quasi-solid-solution behavior in phase transitions and improved battery cyclability. Previous studies investigate the disruptions by theoretical calculations, however, direct experimental evidence is missing. Herein, the disturbed Li/vacancy structures are first observed based on the ex situ6Li nuclear magnetic resonance measurement. [ABSTRACT FROM AUTHOR]

Published
2024
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34. Influence of oxygen distribution on the Li-ion conductivity in oxy-sulfide glasses – taking a closer look.

Author

Zimmermanns, Ramon, Luo, Xianlin, Hansen, Anna-Lena, Sadowski, Marcel, Fu, Qiang, Albe, Karsten, Indris, Sylvio, Knapp, Michael, and Ehrenberg, Helmut

Subjects
IONIC conductivity, SOLID electrolytes, THIOPHOSPHATES, GLASS structure, BALL mills
Abstract

Lithium thiophosphates are a promising class of solid electrolyte (SE) materials for all-solid-state batteries (ASSBs) due to their high Li-ion conductivity. Yet, the practical application of lithium thiophosphates is hindered by their chemical instability, which remains a prevalent challenge in the field. Oxygen substitution has been discussed in the literature as a promising strategy to enhance stability. Nevertheless, the lack of understanding of the role of synthesis strategy on the resulting structure–property relationship makes it difficult to predict and control the material's behaviour, limiting our ability to fully utilize oxygen substitution as a viable solution. Here, we show that not only the total oxygen content but also the oxygen distribution within the material affects the ion conductivity. By carefully analysing the local structure of oxy-sulfide glasses, we find that few highly oxygenated structural units like [PO4]3− and [PO3S]3− are more detrimental to the ionic conductivity than a larger amount of less substituted units like [POS3]3−. Further, we demonstrate how the oxygen distribution is connected to the synthesis in high-energy ball milling by comparing two different sets of precursor materials. The results may explain the deviations in the past literature. The findings should be transferable to other Li-thiophosphate materials and enable more directed design of new materials. [ABSTRACT FROM AUTHOR]

Published
2024
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35. Probing Particle‐Carbon/Binder Degradation Behavior in Fatigued Layered Cathode Materials through Machine Learning Aided Diffraction Tomography.

Author

Hua, Weibo, Chen, Jinniu, Ferreira Sanchez, Dario, Schwarz, Björn, Yang, Yang, Senyshyn, Anatoliy, Wu, Zhenguo, Shen, Chong‐Heng, Knapp, Michael, Ehrenberg, Helmut, Indris, Sylvio, Guo, Xiaodong, and Ouyang, Xiaoping

Subjects
MACHINING, MACHINE learning, TOMOGRAPHY, CATHODES, COMPOSITE construction, ELECTROCHEMICAL electrodes
Abstract

Understanding how reaction heterogeneity impacts cathode materials during Li‐ion battery (LIB) electrochemical cycling is pivotal for unraveling their electrochemical performance. Yet, experimentally verifying these reactions has proven to be a challenge. To address this, we employed scanning μ‐XRD computed tomography to scrutinize Ni‐rich layered LiNi0.6Co0.2Mn0.2O2 (NCM622) and Li‐rich layered Li[Li0.2Ni0.2Mn0.6]O2 (LLNMO). By harnessing machine learning (ML) techniques, we scrutinized an extensive dataset of μ‐XRD patterns, about 100,000 patterns per slice, to unveil the spatial distribution of crystalline structure and microstrain. Our experimental findings unequivocally reveal the distinct behavior of these materials. NCM622 exhibits structural degradation and lattice strain intricately linked to the size of secondary particles. Smaller particles and the surface of larger particles in contact with the carbon/binder matrix experience intensified structural fatigue after long‐term cycling. Conversely, both the surface and bulk of LLNMO particles endure severe strain‐induced structural degradation during high‐voltage cycling, resulting in significant voltage decay and capacity fade. This work holds the potential to fine‐tune the microstructure of advanced layered materials and manipulate composite electrode construction in order to enhance the performance of LIBs and beyond. [ABSTRACT FROM AUTHOR]

Published
2024
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37. Electrochemical Testing and Benchmarking of Compositionally Complex Lithium Argyrodite Electrolytes for All‐Solid‐State Battery Application.

Author

Du, Jianxuan, Lin, Jing, Zhang, Ruizhuo, Wang, Shuo, Indris, Sylvio, Ehrenberg, Helmut, Kondrakov, Aleksandr, Brezesinski, Torsten, and Strauss, Florian

Subjects
LITHIUM cells, LITHIUM, ELECTROLYTES, CHEMICAL stability, IONIC conductivity, SOLID electrolytes
Abstract

Ceramic ion conductors play a pivotal role as electrolytes in solid‐state batteries (SSBs). Aside from the ionic conductivity, their (electro)chemical stability has a profound effect on the performance. Lithium thiophosphates represent a widely used class of superionic materials, yet they suffer from limited stability and are known to undergo interfacial degradation upon battery cycling. Knowledge of composition‐dependent properties is essential to improving upon the stability of thiophosphate solid electrolytes (SEs). In recent years, compositionally complex (multicomponent) and high‐entropy lithium argyrodite SEs have been reported, having room‐temperature ionic conductivities of σion>10 mS cm−1. In this work, various multi‐cationic and ‐anionic substituted argyrodite SEs are electrochemically tested via cyclic voltammetry and impedance spectroscopy, as well as under operating conditions in SSB cells with layered Ni‐rich oxide cathode and indium‐lithium anode. Cation substitution is found to negatively affect the electrochemical stability, while anion substitution (introducing Cl−/Br− and increasing halide content) has a beneficial effect on the cyclability, especially at high current rates. [ABSTRACT FROM AUTHOR]

Published
2024
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45. Constructing Hollow Microcubes SnS2 as Negative Electrode for Sodium‐ion and Potassium‐ion Batteries.

Author

Li, Chengping, Yu, Hongrui, Dong, Peng, Wang, Ding, Zeng, Xiaoyuan, Wang, Jinsong, Zhang, Zhengfu, Zhang, Yingjie, Sarapulova, Angelina, Luo, Xianlin, Pfeifer, Kristina, Ehrenberg, Helmut, and Dsoke, Sonia

Subjects
NEGATIVE electrode, LITHIUM sulfur batteries, LITHIUM-ion batteries, SODIUM ions, ENERGY storage, POWER density, STORAGE batteries, NANOSTRUCTURED materials
Abstract

Sodium/potassium‐ion batteries (NIBs and KIBs) are considered the most promising candidates for lithium‐ion batteries in energy storage fields. Tin sulfide (SnS2) is regarded as an attractive negative candidate for NIBs and KIBs thanks to its superior power density, high‐rate performance and natural richness. Nevertheless, the slow dynamics, the enormous volume change and the decomposition of polysulfide intermediates limit its practical application. Herein, microcubes SnS2 were prepared through sacrificial MnCO3 template‐assisted and a facile solvothermal reaction strategy and their performance was investigated in Na and K‐based cells. The unique hollow cubic structure and well‐confined SnS2 nanosheets play an important role in Na+/K+ rapid kinetic and alleviating volume change. The effect of the carbon additives (Super P/C65) on the electrochemical properties were investigated thoroughly. The in operando and ex‐situ characterization provide a piece of direct evidence to clarify the storage mechanism of such conversion‐alloying type negative electrode materials. [ABSTRACT FROM AUTHOR]

Published
2024
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46. Modification of Al Surface via Acidic Treatment and its Impact on Plating and Stripping.

Author

Rahide, Fatemehsadat, Palanisamy, Krishnaveni, Flowers, Jackson K., Hao, Junjie, Stein, Helge S., Kranz, Christine, Ehrenberg, Helmut, and Dsoke, Sonia

Subjects
SURFACE properties, METALLIC oxides, SURFACE roughness, ALUMINUM oxide films, ALUMINUM batteries, METALLIC films
Abstract

Amorphous Al2O3 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 Al2O3 film induces different surface properties (roughness and microstructure) on the metal. Al foils present two optically different sides (shiny and non‐shiny), but their surface properties and influence on plating and stripping have not been studied so far. Compared to the shiny side, the non‐shiny one has a higher (~28 %) surface roughness, and its greater concentration of active sites (for Al plating and stripping) yields higher current densities. Immersion pretreatments in Ionic‐Liquid/AlCl3‐based electrolyte with various durations modify the surface properties of each side, forming an electrode‐electrolyte interphase layer rich in Al, Cl, and N. The created interphase layer provides more tunneling paths for better Al diffusion upon plating and stripping. After 500 cycles, dendritic Al deposition, generated active sites, and the continuous removal of the Al metal and oxide cause accelerated local corrosion and electrode pulverization. We highlight the mechanical surface properties of cycled Al foil, considering the role of immersion pretreatment and the differences between the two sides. [ABSTRACT FROM AUTHOR]

Published
2024
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47. Thermal Structural Behavior of ElectrochemicallyLithiated Graphite (LixC6) Anodes in Li‐ion Batteries.

Author

Hölderle, Tobias, Monchak, Mykhailo, Baran, Volodymyr, Kriele, Armin, Mühlbauer, Martin J., Dyadkin, Vadim, Rabenbauer, Alfred, Schökel, Alexander, Ehrenberg, Helmut, Müller‐Buschbaum, Peter, and Senyshyn, Anatoliy

Subjects
LITHIUM-ion batteries, EXOTHERMIC reactions, NEUTRON diffraction, ANODES, LITHIUM ions, SOLID electrolytes
Abstract

A full series of variously lithiated graphite anodes material LixC6 (0

Published
2024
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