State-of-Health of Li-ion Battery Estimation Based on the Efficiency of the Charge Transfer Extracted from Impedance Spectra

Several studies show that impedance spectroscopy is a suitable method for online battery diagnosis and State-of-Health (SoH) estimation. However, the most common method is to model the acquired impedance spectrum with equivalent circuits and focus on the most sensitive parameters, namely the charge-transfer resistance. This paper introduces first a detailed model of a battery cell, which is then simplified and adapted to the observable spectrum behavior. Based on the physical meaning of the model parameters, we propose a novel approach for SoH assessment combining parameters of the impedance spectrum by building the ratio of the solid electrolyte interphase (SEI) resistance to the total resistance of SEI and the charge transfer. This ratio characterizes the charge-transfer efficiency at the electrodes’ surfaces and should decrease systematically with SoH. Four different cells of the same type were cycled 400 times for the method validation, and impedance spectroscopy was performed at every 50th cycle. The results show a systematic correlation between the proposed ratio and the number of cycles on individual cell parameters, which build the basis of a novel online method of SoH assessment.

Synthesis, Structure and Magnetic Properties of NiFe3O5

A new CaFe3O5-type phase NiFe3O5 (orthorhombic Cmcm symmetry, cell parameters a = 2.89126(7), b = 9.71988(21) and c = 12.52694(27) Å) has been synthesised under pressures of 12-13 GPa at 1200 °C. NiFe3O5 has an inverse cation site distribution and reveals an interesting evolution from M2+(Fe3+ )2Fe2+O5 to Fe2+(M2+ 0.5Fe3+ 0.5)2Fe3+O5 distributions over three distinct cation sites as M2+ cation size decreases from Ca to Ni. Magnetic susceptibility measurements show successive transitions at 275, ~150, and ~20 K and neutron diffraction data reveal a series of at least three spin-ordered phases with evolving propagation vectors k = [0 0 0] [0 ky 0]  [½ ½ 0] on cooling. The rich variety of magnetically ordered phases in NiFe3O5 likely results from frustration of Goodenough-Kanamori exchange interactions between the three spin sublattices, and further interesting magnetic materials are expected to be accessible within the CaFe3O5-type family.

Novel Fluoridoaluminates from Ammonothermal Synthesis: Two Modifications of K2AlF5 and the Elpasolite Rb2KAlF6

Two new modifications of the pentafluoridoaluminate K2AlF5 were obtained from ammonothermal synthesis at 753 K, 224 MPa and 773 K, 220 MPa, respectively. Both crystallize in the orthorhombic space group type Pbcn, with close metric relations and feature kinked chains of cis-vertex-connected AlF6 octahedra resulting in the Niggli formula ∞1{[AlF2/2eF4/1t]2−}. The differences lie in the number of octahedra necessary for repetition within the chains, which for K2AlF5-2 is realized after four and for K2AlF5-3 after eight octahedra. As a result, the orthorhombic unit cell for K2AlF5-3 is doubled in chain prolongation direction [001] as compared to K2AlF5-2 (1971.18(4) pm versus 988.45(3) pm, respectively), while the unit cell parameters within the other two directions are virtually identical. Moreover, the new elpasolite Rb2KAlF6 is reported, crystallizing in the cubic space group Fm3¯m with a = 868.9(1) pm and obtained under ammonothermal conditions at 723 K and 152 MPa.

Interactions in ternary bismuth-containing molybdate systems M2MoO4-Bi2(MoO4)3-Zr(MoO4)2 in the subsolidus region

A fundamental problem in materials science consists in establishing a relationship between the chemical composition, structure, and properties of materials. This issue can be solved through the study of multicomponent systems and the directed synthesis of promising compounds. Of practical interest here are active dielectrics that are based on complex oxide compounds, specifically molybdates. Among complex molybdates and tungstates, ternary caged molybdates of the following structural types are of greatest importance: nasicon, perovskite, langbeinite, etc. Due to their widely varying elemental and quantitative compositions, such molybdates are convenient models for structural and chemical design, as well as the establishment of “composition–structure– properties” genetic relationships. Bismuth-containing complex molybdate systems exhibit the formation of phases having ferro-piezoelectric, ionic, and other properties. In this work, the Rb2MoO4–Bi2(MoO4)3–Zr(MoO4)2 ter nary salt system was studied for the first time using the method of intersecting sections in the subsolidus region (450–650 ℃). To this end, quasibinary sections were identified; triangulation was performed. Ternary molybdates Rb5BiZr(MoO4)6 and Rb2BiZr2(MoO4)6,5 were formed in the system using a ceramic technology. These compounds are isostructural to the previously obtained REE molybdates (M5LnZr(MoO4)6) but contain trivalent bismuth instead of rare earth elements. The structure of Rb5BiZr(MoO4)6 was adjusted via the Rietveld refinement technique using the TOPAS 4.2 software package. The ternary molybdate crystallizes in a trigonal system, with the following unit cell parameters of the R`3c space group: a = 10.7756(2) and c = 39.0464(7) Å. According to the studies of thermal properties exhibited by M5BiZr(MoO4)6, these ternary molybdates undergo the first-order phase transition in the temperature range of 450–600 ºC. The IR and Raman spectra of M5BiZr(MoO4)6 reveal the crystallization of ternary molybdates in the R`3c space group. The conducted comparative characterization of M2MoO4–Bi2(MoO4)3–Zr(MoO4)2 phase diagrams suggests that the phase equilibria of these systems depend on the nature of molybdates of monovalent elements.

Method of calculating the coherent scattering power of crystals with unknown atomic arrangements and its application in the quantitative phase analysis

Quantitative phase analysis is one of the major applications of X-ray powder diffraction. The essential principle of quantitative phase analysis is that the diffraction intensity of a component phase in a mixture is proportional to its abundance. Nevertheless, the diffraction intensities of the component phases cannot be compared with each other directly since the coherent scattering power per unit cell (or chemical formula) of each component phase is usually different. The coherent scattering power per unit cell of a crystal is well represented by the sum of the squared structure factors, which cannot be calculated directly when the crystal structure data is unavailable. Presented here is a way to approximate the coherent scattering power per unit cell based solely on the unit cell parameters and the chemical contents. This approximation is useful when the atomic coordinates for one or more of the phases in a sample are unavailable. An assessment of the accuracy of the approximation is presented. This assessment indicates that the approximation will likely be within 10% when X-ray powder diffraction data is collected over a sufficient portion of the measurable pattern.

Pulsed Electric Fields Alter Expression of NF-κB Promoter-Controlled Gene

The possibility to artificially adjust and fine-tune gene expression is one of the key milestones in bioengineering, synthetic biology, and advanced medicine. Since the effects of proteins or other transgene products depend on the dosage, controlled gene expression is required for any applications, where even slight fluctuations of the transgene product impact its function or other critical cell parameters. In this context, physical techniques demonstrate optimistic perspectives, and pulsed electric field technology is a potential candidate for a noninvasive, biophysical gene regulator, exploiting an easily adjustable pulse generating device. We exposed mammalian cells, transfected with a NF-κB pathway-controlled transcription system, to a range of microsecond-duration pulsed electric field parameters. To prevent toxicity, we used protocols that would generate relatively mild physical stimulation. The present study, for the first time, proves the principle that microsecond-duration pulsed electric fields can alter single-gene expression in plasmid context in mammalian cells without significant damage to cell integrity or viability. Gene expression might be upregulated or downregulated depending on the cell line and parameters applied. This noninvasive, ligand-, cofactor-, nanoparticle-free approach enables easily controlled direct electrostimulation of the construct carrying the gene of interest; the discovery may contribute towards the path of simplification of the complexity of physical systems in gene regulation and create further synergies between electronics, synthetic biology, and medicine.

Thyroid Dysfunction and its Effect on Red Blood Cell Parameters

Background: Thyroid hormones are necessary for the growth and development, cellular differentiation, physiological function and metabolic regulation of almost all tissues in our body. Thyroid disorders are accompanied by alteration in hematological profile. This study aims to evaluate the effect of thyroid dysfunction on red blood cell parameters. Materials and Methods: This case-control observational study was conducted in the Department of Clinical Biochemistry, KIST Medical College and Teaching Hospital (KISTMCTH), Lalitpur, Nepal from January 2021 to June 2021.Total number of recruited subjects was 248, out of which 67 were labeled as hypothyroid, 7 were hyperthyroid and 174 were euthyroid as control. Subjects for all three groups were between 16-93 years old. Thyroid hormone profile of patients was determined by Siemens ADVIA Centaur CP immunoassay analyzer and hematological parameters by automated hematology analyzer Sysmex XN-550. Results were analyzed by SPSS 21 software and a chi-square test was applied to see significant differences among the groups. Results: The mean age of all study participants was 42.08±17.27 years and female constituted 74.6% of total subjects. Analysis of the data obtained a statistically significant difference in the mean hemoglobin (p<0.001) between hypothyroid and euthyroid groups. The difference was not significant for hemoglobin (p=0.252) among hyperthyroid and euthyroid groups. There was no statistical significant difference between thyroid cases and control for MCV, MCH and MCHC. Conclusion: The current study concluded that thyroid dysfunction have a significant effect on red blood cell parameters. Hematological parameters should be evaluated in patient with thyroid dysfunction.