LiCl Aq Research Articles

Controllable structure transitions of Mn3O4 nanomaterials and their effects on electrochemical properties.

Mn3O4 with purposely tuned different morphologies, crystal structures and sizes is synthesized using a hydrothermal method with varying processing temperatures, together with the help of a surfactant. Systematic investigations, both by experimental and computational studies, into these Mn3O4 nanomaterials were conducted in order to find the most suitable morphology and a compatible electrolyte for energy storage applications. The Mn3O4 nanofibers with a tunnel size of 1.83 Å in the crystal structure show much higher volumetric capacitance (188 F cm-3 at a scan rate of 1 mV s-1 of cyclic voltammetry test) than two other morphologies/crystal structures, when using 1 M LiCl aq. as the electrolyte. It is demonstrated in this work that crystal morphology and particle size play important roles in determining the capacitance of an electrode material. In addition, the detailed structures, especially the atomic arrangements within the crystalline structure, are crucial in order to choose the most suitable electrolyte.

Speciation of phytate ion in aqueous solution. Protonation in CsCl aq at different ionic strengths and mixing effects in LiCl aq + CsCl aq

This paper reports the results of an investigation (at t = 25 °C by potentiometry, ISE-H + glass electrode) of phytate acid–base properties both in simple CsCl aq solutions at different ionic strengths (0.1 ≤ I/mol L − 1 ≤ 1.75) and in LiCl aq−CsCl aq mixtures at I = 1.28 mol L − 1 and different Li +/Cs + mole fractions [ y = C Li/(C Li + C Cs)]. These last measurements allowed us to evaluate the mixing effects on phytate protonation, and the deviation from the ideal mixing (Young rule) has been interpreted by means of a Δ parameter that can be associated to the free energy of mixing (Δ G mix) or, alternatively, in terms of formation of simple and mixed metal complexes. Dependence of protonation constants on ionic strength in simple CsCl aq solutions has been taken into account by a Debye–Hückel type equation. Complex formation constants for Cs jH iPhy (12 − i − j)− species at different ionic strengths have been calculated too, and comparisons have been made with phytate acid base behavior in other alkali metal chloride aqueous media.