Enhancement of Y5−xPrxSb3−yMy (M = Sn, Pb) Electrodes for Lithium- and Sodium-Ion Batteries by Structure Disordering and CNTs Additives

The maximally disordered (MD) phases with the general formula Y5−xPrxSb3−yMy (M = Sn, Pb) are formed with partial substitution of Y by Pr and Sb by Sn or Pb in the binary Y5Sb3 compound. During the electrochemical lithiation and sodiation, the formation of Y5-xPrxSb3-yMyLiz and Y5−xPrxSb3−yMyNaz maximally disordered–high entropy intermetallic phases (MD-HEIP), as the result of insertion of Li/Na into octahedral voids, were observed. Carbon nanotubes (CNT) are an effective additive to improve the cycle stability of the Y5−xPrxSb3−yMy (M = Sn, Pb) anodes for lithium-ion (LIBs) and sodium-ion batteries (SIBs). Modification of Y5−xPrxSb3−ySny alloys by carbon nanotubes allowed us to significantly increase the discharge capacity of both types of batteries, which reaches 280 mAh · g−1 (for LIBs) and 160 mAh · g−1 (for SIBs), respectively. For Y5−xPrxSb3−yPby alloys in which antimony is replaced by lead, these capacities are slightly smaller and are 270 mAh · g−1 (for LIBs) and 155 mAh · g−1 (for SIBs), respectively. Results show that structure disordering and CNT additives could increase the electrode capacities up to 30% for LIBs and up to 25% for SIBs.

Synthesis, properties, and activity of MoVTeNbO catalysts modified by zirconia-pillared clays in oxidative dehydrogenation of ethane

Composites comprising MoVTeNbO mixed oxide and zirconia-pillared montmorillonite clays (PilCs) were prepared. XRD and TEM with EDX studies confirmed the preservation of M1 MoVTeNbO phase in these composites responsible for high activity and selectivity in ethane oxidative dehydrogenation into ethylene. For composites with PilC content of 10 wt%, the best ethylene yield exceeding that of bulk MoVTeNbO oxide was demonstrated for clays with zirconia pillars doped with Ce and Al possessing the highest specific surface area. This is explained by optimized chemical interaction of these clays with MoVTeNbO mixed oxide improving its bulk oxygen mobility and reactivity by structure disordering while blocking surface sites responsible for combustion due to the stabilization of the reactive terminal oxygen species.

Natural magmatic granite as matrix for immobilizing simulated An4+ waste

In nature, many rocks contain radionuclides, and returning radioactive waste to nature is an environmentally friendly way. In this work, a natural magmatic granite rock has been studied as a host matrix for simulated An4+ waste disposal. The blank granite, in the form of powder, was firstly treated by muffle furnace heating in the temperature range of 800 °C to 1400 °C. It was found that the lowest crystallinity of the samples was obtained at 1300 °C. Moreover, 8 wt.% of simulated tetravalent actinides (CeO2) could be successfully immobilized in the natural granite at 1300 °C for 60 min. Raman results show the structure disordering in samples tends to increase with the increased amount of CeO2. SEM-EDS observation shows that the distribution of Ce was relatively uniform in the matrix. Moreover, the hardness of solidified body is comparable to traditional glasses and it decreases with the increase of CeO2 content.

Capacity degradation of Li4Ti5O12 during long-term cycling in terms of composition and structure

The performance decay of Li4Ti5O12 (LTO) associates with the ever-increasing residual Li+ and Ti3+ in the delithiated LTO, structure disordering, gradually reduced conductivities, and escalated polarization besides the electrolyte decomposition.

JPD-analysis as a new approach for studying the zircon texture with micron spatial resolution with application to geochronology

The polygenic and polychronous character of zircon texture is the key source of information on the conditions of its growth and secondary alterations. In this research the JPD method of processing of the BSE and CL images including plotting of JPD histograms and JPD maps of grains was developed and applied for quantitative study of the internal texture of zircon grains with micron spatial resolution and for its use in geochronometry. The nomenclature for distinguished zones on the generalized diagram (BSE vs. CL) is suggested for zircons of a wide range of the conditions of its formation, age, size, texture types, and degrees of structure disordering. The JPD-analysis of zircon internal texture is applied for interpretation of the nature of variations in the BSE and CL intensities within an individual heterogeneous grain (on the quantitative level) and between different grains (on the qualitative level). The approach is suggested as the preliminary stage during geochronological studies increasing the reliability of the local electron microprobe and mass spectrometry isotope dating of the mineral.

Lithium storage in disordered graphitic materials: a semi-quantitative study of the relationship between structure disordering and capacity

Disordered graphite can store more Li ions in a battery but acts as a supercapacitor.