Enkhtsetseg Dashjav

As an alternative way to separation of biological molecules, silica coated magnetite ore particles were prepared through two step synthetic method including ball milling of iron ore powder followed by silica coating with Stöber method. As synthesized silica coated magnetic ore particles were composed mainly of magnetite and other accompanying minerals such as hematite and Al2O3, ZrO2. The particles were irregular in shape, with average size of 0.4 ± 0.3 µm as demonstrated with SEM. Field dependent magnetization showed that silica-coated magnetite ore particles are soft ferromagnet with coercivity of 320Oe and remanent magnetization of 2.26 emu/g. Using these particles, genomic DNA was successfully separated from E. coli with sufficient yield and purity comparable to those obtained with a commercial magnetic separation kit, demonstrating their potential for bioseparation from diverse biological sources.

This study explores multi-component garnet-based materials as solid electrolytes for all-solid-state lithium batteries. Through a combination of computational and experimental approaches, we investigate the thermodynamic and structural properties of lithium lanthanum zirconium oxide garnets doped with various elements. Applying density functional theory, the influence of dopants on the thermodynamic stability of these garnets was studied. Probable atomic configurations and their impact on materials’ properties were investigated with the focus on understanding the influence of these configurations on structural stability, phase preference, and ionic conductivity. In addition to the computational study, series of cubic-phase garnet compounds were synthesized and their electrochemical performance was evaluated experimentally. Our findings reveal that the stability of cubic phase in doped Li-garnets is primarily governed by enthalpy, with configurational entropy playing a secondary role. Moreover, we establish that the increased number of doping elements significantly enhances the cubic phase’s stability. This in-depth understanding of materials’ properties at atomic level establishes the basis for optimizing high-entropy ceramics, contributing significantly to the advancement of solid-state lithium batteries and other applications requiring innovative material solutions.

The phosphate lithium-ion conductor Li_1.5Al_0.5Ti_1.5(PO₄)₃ (LATP) is an economically attractive solid electrolyte for the fabrication of safe and robust solid-state batteries, but high sintering temperatures pose a material engineering challenge for the fabrication of cell components. In particular, the high surface roughness of composite cathodes resulting from enhanced crystal growth is detrimental to their integration into cells with practical energy density. In this work, we demonstrate that efficient free-standing ceramic cathodes of LATP and LiFePO₄ (LFP) can be produced by using a scalable tape casting process. This is achieved by adding 5 wt % of Li₂WO₄ (LWO) to the casting slurry and optimizing the fabrication process. LWO lowers the sintering temperature without affecting the phase composition of the materials, resulting in mechanically stable, electronically conductive, and free-standing cathodes with a smooth, homogeneous surface. The optimized cathode microstructure enables the deposition of a thin polymer separator attached to the Li metal anode to produce a cell with good volumetric and gravimetric energy densities of 289 Wh dm^-3 and 180 Wh kg^-1, respectively, on the cell level and Coulombic efficiency above 99% after 30 cycles at 30 °C.

Invited for this month's cover picture is the group of Prof. Fattakhova‐Rohlfing from Forschungszentrum Jülich (IEK‐1). The cover picture shows LATP powder and a dense LATP pellet obtained after powder sintering, which typically requires high temperatures. With only a small weight fraction of Li₂WO₄, a significant reduction in sintering temperature and increase in ionic conductivity can be achieved. Processing and performance improvements render Li₂WO₄ a very promising sintering aid for the development of LATP‐based solid‐state batteries like the pouch cell also shown in the cover picture. Read the full text of the Research Article at 10.1002/celc.202101366.