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Li-excess cathode materials with a disordered rock-salt structure (DRX) Li1.2Ti0.4Mn0.4O2 and Li1.3Nb0.3Mn0.4O2 were prepared by mechanochemically assisted solid-state synthesis at various synthesis conditions using different lithium sources (Li2O and LiOH). As-prepared samples were characterized by X-ray powder diffraction (XRD), thermal analysis in combination with mass spectrometry (DSC/TG/MS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), electron paramagnetic resonance spectroscopy (EPR), in situ time-resolved synchrotron powder X-ray diffraction (SPXRD) and galvanostatic cycling. The effects of different lithium sources and synthesis temperature on the crystal and local structure and the impact of additional thermal treatment (re-heating) on electrochemical performance of the DRX oxides were investigated. The results obtained show that the optimal synthesis temperature is 950 °C and the use of LiOH as a lithium source leads to the synthesis of the DRX oxides with a fully disordered structure, which is stable when re-heated at a temperature of 600 °C. In addition, re-heating leads to further optimization of the properties of the DRX oxides; this results in a significant improvement of their electrochemical properties. [ABSTRACT FROM AUTHOR]

Nano -and microcrystalline bismuth metal powders consisting of spherical particles with a size of 150-250 nm were obtained by reducing bismuth formates in an ethylene glycol medium. The phase composition and morphology of the obtained reaction products were studied by X-ray phase and thermal analysis, differential scanning calorimetry, scanning and transmission electron microscopy. Using Uv-vis, it was shown that a bismuth-ethylene glycol complex is formed with an absorption maximum at 249 nm and an extinction coefficient of 5.7×103 (L mol-1 cm-1) in a solution of chloric acid at 23°C. The concentration of bismuth enhances to 0.018 g L-1 in the ethylene glycol medium with a gradual increase in the temperature to 60°C of the reaction mixture. Thermolysis of bismuth glycolate with a composition of Bi2(OCH2CH2O)3 is accompanied by the formation of metallic bismuth at 190°C, which is oxidized to a monoclinic modification of bismuth oxide when the temperature increases in the air.

The hydrolytic processing of metallic bismuth to obtain compounds was investigated by methods of chemical, X-ray diffraction analyses, thermogravimetric analyzes, as well as electron microscopy. The conditions for obtaining bismuth nitrate pentahydrate composition Bi(NO3)3∙5H2O, oxide, citrate of bismuth of composition BiС6Н5O7, bismuth-potassium-ammonium citrate and oxohydroxotribromophenolate of bismuth of the pharmacopoeial composition [Bi6O6(OH)2](C6H2Br3O)4 Xeroform are presented.