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The recent development of lithium rechargeable batteries results from the use of carbon materials as lithium reservoir at the negative electrode. Carbon anodes for Liion cells have been prepared by the polymerization of polysaccharides, in the channels of a clay mineral. Sepiolite is a microfibrous magnesium silicate, Si12O30Mg8(OH,F)4(H2O)4⋅8H2O, with large specific surface area and then the ability to adsorbe large quantities of water, which is related to the presence of pores of different sizes that allow the molecular and polymeric species inclusion. A mixture of sepiolite and sucrose is mixed with water and heated for several minutes. The sucrose is caramelized into the mineral surface and forms homogeneous nanocomposite materials. The Pyrolysis of this nanocomposite was performed at 700 and 800°C for different times. The precursors and final materials were characterized by XRD, FTIR, SEM, TEM and Van Der Pauw conductivity measurement. [ABSTRACT FROM AUTHOR]

This paper presents the reactions of precipitation of cobalt (III) oxide, substance which is employed in the nickel industry and the purification of the industrial liquors. For doing this research the air is employed as oxidant agent, regulating environmental pH with hydroxide of sodium, carbonate of sodium and the mixture of both, doing the thermodynamic analysis for determining its spontaneity in the interval of temperatures from 303 to 353 K. The values were calculated in the variation of free energy and the constants of equilibrium to the given, according to the method proposed by Criss and Cobble. In each proposed reactions are studied the behavior of pH is the course of time and it is determined the percentage of the product submission obtained. The percentage of total cobalt in form cobalt (III) are determine. Those solids were characterized by diffraction of X rays. From the studied reactions only is possible to reach the derived product in that one that is used hydroxide of sodium as basic reagent (reaction I), obtaining a percentage of submission higher than 93 %. [ABSTRACT FROM AUTHOR]