One major challenge in the field of lithium-ion batteries is to understand the degradation mechanism of high-energy lithium- and manganese-rich layered cathode materials. Although they can deliver 30 ...% excess capacity compared with today's commercially- used cathodes, the so-called voltage decay has been restricting their practical application. In order to unravel the nature of this phenomenon, we have investigated systematically the structural and compositional dependence of manganese-rich lithium insertion compounds on the lithium content provided during synthesis. Structural, electronic and electrochemical characterizations of Li
Ni
Mn
O
with a wide range of lithium contents (0.00 ≤ x ≤ 1.52, 1.07 ≤ y < 2.4) and an analysis of the complexity in the synthesis pathways of monoclinic-layered LiLi
Ni
Mn
O
oxide provide insight into the underlying processes that cause voltage fading in these cathode materials, i.e. transformation of the lithium-rich layered phase to a lithium-poor spinel phase via an intermediate lithium-containing rock-salt phase with release of lithium/oxygen.
A crystalline LiNbO3 material was synthesized at 80 °C by an optimized sol–gel method using a double alkoxide alcoholic solution in the presence of hydrogen peroxide (H2O2) and strong acids. The same ...reaction in the presence of water or acetic acid resulted in amorphous powders with fewer impurities but which crystallized only at 450 °C and higher temperatures. The purity of the crystalline material obtained at 80 °C is strongly dependent on the Li/Nb molar ratio used for the reaction. It appears that the combination of strong acids with H2O2 in air generates perfect conditions for the synthesis of low-temperature crystalline lithium niobate oxide derivatives and can be extended to various other metal oxides. The developed synthetic method opens the potential for the coating of low-melting-point conductive polymer materials with LiNbO3 crystalline films.
LiNi0.5Mn1.5O4 (LNMO) cathode active materials for lithium‐ion batteries have been investigated for over 20 years. Despite all this effort, it has not been possible to transfer their favorable ...properties into applicable, stable battery cells. To make further progress, the research perspective on these spinel type materials needs to be updated and a number of persisting misconceptions on LNMO have to be overcome. Therefore, the current knowledge on LNMO is summarized and controversial points are addressed by detailed considerations on the composition and crystallography of LNMO. The findings are supported by an in‐situ high temperature X‐ray diffraction study and the investigation of four different types of LNMO materials, including Mn(III) rich ordered LNMO, and disordered LNMO with low Mn(III) content. It is shown that the importance of cation order is limited to a small composition range. Furthermore, new evidence contradicting the idea of oxygen defects in LNMO is presented and an enhanced classification of LNMO based on the Ni content of the spinel phase is proposed. Moreover, a balanced chemical equation for the formation of LNMO is presented, allowing for comprehensive calculations of key properties of LNMO materials. Finally, suitable target compositions and calcination programs are suggested to obtain better LNMO materials.
This study summarizes and extends the knowledge of the solid‐state chemistry of LiNi0.5Mn1.5O4 (LNMO) cathode active materials for lithium‐ion batteries. A balanced equation for the formation of LNMO is presented, allowing for comprehensive calculations of LNMO material properties. A coherent understanding of LNMO emerges, suggesting that Mn(III) rich disordered LNMO materials are not necessarily the best option for energy storage applications.
A crystalline LiNbO
material was synthesized at 80 °C by an optimized sol-gel method using a double alkoxide alcoholic solution in the presence of hydrogen peroxide (H
O
) and strong acids. The same ...reaction in the presence of water or acetic acid resulted in amorphous powders with fewer impurities but which crystallized only at 450 °C and higher temperatures. The purity of the crystalline material obtained at 80 °C is strongly dependent on the Li/Nb molar ratio used for the reaction. It appears that the combination of strong acids with H
O
in air generates perfect conditions for the synthesis of low-temperature crystalline lithium niobate oxide derivatives and can be extended to various other metal oxides. The developed synthetic method opens the potential for the coating of low-melting-point conductive polymer materials with LiNbO
crystalline films.
An innovative ceramic ink system for thin inkjet-printed dielectric layers is presented, with which it is possible to avoid undesired drying effects. This system contains surface-modified ...Ba0.6Sr0.4TiO3 (BST) particles, a cross-linking agent, and a thermal radical initiator. The polymerization starts immediately after the ink drop contacts the heated substrate and therefore leads to very homogeneous topographies. Since an organic/inorganic composite ink is used, no sintering is needed after printing and thus printing on flexible substrates is possible. A comparison of the printing and drying behavior between modified and nonmodified BST with the described ink system is performed. The successful surface modification is confirmed via X-ray photoelectron spectroscopy (XPS). Topographies of different printed structures are compared by white light interferometry, the occurring polymerization is confirmed by measurements with an oscillatory rheometer, layer thicknesses are determined by scanning electron microscopy (SEM) images, and the capacitance of a printed capacitor is measured via impedance spectroscopy. It is successfully shown that the developed ink system enables the production of thin ceramic layers (<1 μm) with very homogeneous topographies since undesired drying effects can be avoided. The printed dielectric layers on flexible substrates have a high ceramic content and a high permittivity of 40.
Sodium‐ion batteries (SIB) are considered as a promising alternative to overcome existing sustainability challenges related to Lithium‐ion batteries (LIB), such as the use of critical and expensive ...materials with high environmental impacts. In contrast to established LIBs, SIBs are an emerging technology in an early stage of development where a challenge is to identify the most promising and sustainable cathode active materials (CAM) for further research and potential commercialization. Thus, a comprehensive and flexible CAM screening method is developed, providing a fast and comprehensive overview of potential sustainability hotspots for supporting cathode material selection. 42 different SIB cathodes are screened and benchmarked against eight state‐of‐the‐art LIB‐cathodes. Potential impacts are quantified for the following categories: i) Cost as ten‐year average; ii) Criticality, based on existing raw material criticality indicators, and iii) the life cycle carbon footprint. The results reveal that energy density is one of the most important factors in all three categories, determining the overall material demand. Most SIB CAM shows a very promising performance, obtaining better results than the LIB benchmark. Especially the Prussian Blue derivatives and the manganese‐based layered oxides seem to be interesting candidates under the given prospective screening framework.
Sodium‐ion batteries (SIB) are a promising alternative regarding sustainability challenges related to Lithium‐ion batteries (LIB), such as carbon footprint, criticality, and cost. A screening method for supporting sustainable cathode material (CAM) selection is presented. SIB CAM show a very promising performance, obtaining better results than the LIB benchmark. Especially Prussian Blue derivatives and manganese‐based layered oxide CAM are good alternatives.
All-trans-retinoic acid (ATRA) is highly active in acute promyelocytic leukemia but not in other types of acute myeloid leukemia (AML). Previously, we showed that ATRA in combination with ...Lysine-specific demethylase 1 (LSD1) inhibition by tranylcypromine (TCP) can induce myeloid differentiation in AML blasts. This phase I/II clinical trial investigated the safety and efficacy of TCP/ATRA treatment as salvage therapy for relapsed/refractory (r/r) AML. The combination was evaluated in 18 patients, ineligible for intensive treatment. The overall response rate was 20%, including two complete remissions without hematological recovery and one partial response. We also observed myeloid differentiation upon TCP/ATRA treatment in patients who did not reach clinical remission. Median overall survival (OS) was 3.3 months, and one-year OS 22%. One patient developed an ATRA-induced differentiation syndrome. The most frequently reported adverse events were vertigo and hypotension. TCP plasma levels correlated with intracellular TCP concentration. Increased H3K4me1 and H3k4me2 levels were observed in AML blasts and white blood cells from some TCP/ATRA treated patients. Combined TCP/ATRA treatment can induce differentiation of AML blasts and lead to clinical response in heavily pretreated patients with r/r AML with acceptable toxicity. These findings emphasize the potential of LSD1 inhibition combined with ATRA for AML treatment.
Sodium‐ion‐batteries (SIB) are a low‐cost alternative to currently used lithium‐ion batteries (LIB) but suffer from poor cycling stability. Spray drying provides porous, hierarchically structured ...particles of cathode active material (CAM) in large amounts, suitable for up‐scaling. Changing the chemical composition of the Na0.6Al0.11 − xNi0.22 − yFex + yMn0.66O2 layered oxides under identical synthesis conditions lead to differences in particle morphology, conductivities, sodium vacancy ordering, and phase transition, therefore influencing the electrochemical performance via several mechanisms. Here, a broad overview on these changes for samples with variable nickel and iron content is presented. With increasing iron content, the particle porosity is reduced and lower initial capacity is received for most cycling windows. Substituting half of the original Ni amount with Fe still leads to high capacities and improved cycling stability. The influence of Al as electrochemically inactive element becomes visible in stabilized cycling stability as well.
The present publication describes this work with cathode materials for sodium ion batteries. Four different chemical compositions from the group of layered oxides are synthesized with the spray drying method to receive a hierarchical structure. Material properties and electrochemical cycling are investigated.
LiNi0.5Mn1.5O4 (LNMO) based spinel cathode materials for lithium-ion batteries are promising alternatives to widely used mixed transition-metal layered Li(Ni,Co,Mn)O2 (NCM) oxides. LNMO is cobalt ...free and thus cost efficient, while providing a high operating voltage of 4.7 V (vs. Li/Li+) and remarkable energy density of ∼650 W h kg−1. Commercialization and large-scale application however are still hindered, as short cycle life remains a main issue. To help overcome this problem, we present a comprehensive investigation into Fe–Ti doped LNMO materials with the formal composition LiNi0.5Mn1.37Fe0.1Ti0.03O3.95 (LNMFTO). Within this study, samples were calcined at temperatures between 460 °C and 940 °C and were cooled down to room temperatures rapidly or slowly. Small changes in the crystal structures were tracked by using a high-precision powder X-ray diffraction (PXRD) setup, while changes in cation order were investigated with Raman spectroscopy. It is shown that carefully elaborated calcination programs allow to maintain the optimized morphological features such as particle size, shape and specific surface, while crystallographic properties, such as the amounts of Mn(iii) or (partial) cation order, can be adjusted independently. We provide experimental evidence that calcination at high temperatures leads to nickel loss in the spinel phase, but not to the formation of additional oxygen defects. LNMFTO samples show good cycling stabilities and over 98% capacity retention after 100 cycles with capacities larger than 90 mA h g−1 at discharge rates of 10C when cycled vs. lithium metal. These results are almost fully transferable to cathodes with high active material loadings cycled vs. graphite anodes. A capacity retention of > 89% for 500 cycles and residual capacities of >100 mA h g−1 are observed, which makes LNMFTO a suitable candidate for industrial applications.
Laboratory X‐ray diffractometers are among the most widespread instruments in research laboratories around the world and are commercially available in different configurations and setups from various ...manufacturers. Advances in detector technology and X‐ray sources push the data quality of in‐house diffractometers and enable the collection of time‐resolved scattering data during operando experiments. Here, the design and installation of a custom‐built multipurpose laboratory diffractometer for the crystallographic characterization of battery materials are reported. The instrument is based on a Huber six‐circle diffractometer equipped with a molybdenum microfocus rotating anode with 2D collimated parallel‐beam X‐ray optics and an optional two‐bounce crystal monochromator. Scattered X‐rays are detected with a hybrid single‐photon‐counting area detector (PILATUS 300K‐W). An overview of the different diffraction setups together with the main features of the beam characteristics is given. Example case studies illustrate the flexibility of the research instrument for time‐resolved operando powder X‐ray diffraction experiments as well as the possibility to collect higher‐resolution data suitable for diffraction line‐profile analysis.
This paper describes the design and implementation of an in‐house laboratory powder X‐ray diffractometer tailored for structural investigations of energy materials. The performance characteristics of the diffractometer together with some example research applications are presented.
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