Surface degradation of Ni-enriched layered cathode material Li[Ni_0.6Mn_0.2Co_0.2]O₂ (NMC622) is the main reason that leads to large capacity decay during long-term cycling. In the frame of this research, an amorphous SiO₂ coating was applied onto the surface of the commercially available NMC622 powder by a wet coating process, through the condensation reaction of tetraethyl orthosilicate. The chemical composition of the coating layer was analyzed by inductively-coupled plasma. The morphology was studied by scanning electron microscopy and transmission electron microscopy. Electrochemical properties, including cyclic voltammetry, galvanostatic cycling, and rate capability measurements in a half-cell configuration, were tested to compare the electrochemical behavior of the non-coated and coated NMC622 materials. It is shown that the rate performance of the NMC622 materials is not affected by the coating layer. After 700 cycles in the range of 3.0–4.3 V at 2 C discharge, the cells with SiO₂-coated NMC622 materials retained 80% of their initial capacity, which is higher than the uncoated ones (74%). Physicochemical characterizations, e.g., XRD and SEM, were performed post-mortem to reveal the stabilizing mechanism of the SiO₂-coated NMC622 electrodes after long-term cycling. Based on these results, this is due to the shielding effect of the coating between the NMC622 particle surface and the liquid electrolyte, along with its scavenging effect on HF. SiO₂ coating is therefore a facile surface modification method that results in potentially significant enhancement of the cyclic stability of Ni-rich NMC materials.

To improve interface adhesion between anode film and Cu foil, ultrafast laser structuring was implemented to construct dot patterns with a variety of perio

The yeast Candida albicans can mate. However, in the natural environment mating may generate progeny (fusants) fitter than clonal lineages too rarely to render mating biologically significant: C. albicans has never been observed to mate in its natural environment, the human host, and the population structure of the species is largely clonal. It seems incapable of meiosis, and most isolates are diploid and carry both mating-type-like (MTL) locus alleles, preventing mating. Only chromosome loss or localized loss of heterozygosity can generate mating-competent cells, and recombination of parental alleles is limited. To determine if mating is a biologically significant process, we investigated if mating is under selection. The ratio of non-synonymous to synonymous mutations in mating genes and the frequency of mutations abolishing mating indicated that mating is under selection. The MTL locus is located on chromosome 5, and when we induced chromosome 5 loss in 10 clinical isolates, most of the resulting MTL-homozygotes could mate with each other, producing fusants. In laboratory culture, a novel environment favoring novel genotypes, some fusants grew faster than their parents, in which loss of heterozygosity had reduced growth rates, and also faster than their MTL-heterozygous ancestors – albeit often only after serial propagation. In a small number of experiments in which coinoculation of an oral colonization model with MTL-homozygotes yielded small numbers of fusants, their numbers declined over time relative to that of the parents. Overall, our results indicate that mating generates genotypes superior to existing MTL-heterozygotes often enough to be under selection.

All-solid-state lithium-ion batteries with argyrodite solid electrolytes have been developed to attain high conductivities of 10⁻³ S cm⁻¹ in studies aiming at fast ionic conductivity of electrolytes. However, no matter how high the ionic conductivity of the electrolyte, the design of the cathode composite is often the bottleneck for high performance. Thus, optimization of the composite cathode formulation is of utmost importance. Unfortunately, many reports limit their studies to only a few parameters of the whole electrode formulation. In addition, different measurement setups and testing conditions employed for all-solid-state batteries make a comparison of results from mutually independent studies quite difficult. Therefore, a detailed investigation on different key parameters for preparation of cathodes employed in all-solid-state batteries is presented here. Employing a rational approach for optimization of composite cathodes using solid sulfide electrolytes elucidated the influence of different parameters on the cycling performance. First, powder electrodes made without binders are investigated to optimize several parameters, including the active materials’ particle morphology, the nature and amount of the conductive additive, the particle size of the solid electrolyte, as well as the active material-to-solid electrolyte ratio. Finally, cast electrodes are examined to determine the influence of a binder on cycling performance.