Papers by Keyword: Electrolyte Concentration

Abstract: The effects of temperature and electrolyte concentration on the reaction of graphite electrodes in propylene carbonate (PC)-based solutions were investigated. In the case of natural graphite, it was confirmed that the reaction leading to the insertion of lithium ions into the graphite, which does not proceed at 25°C in a solution with a concentration of 0.85 mol kg^–1, proceeds by lowering the reaction temperature to –15°C. The temperature at which lithium ions were inserted increased as the concentration increased. That is, lithium ions were electrochemically inserted into the interior of the natural graphite at 5°C in a solution of 1.63 mol kg^–1 and at 15°C in a solution of 2.45 mol kg^–1, indicating that the temperature and the electrolyte concentration greatly affect the properties of the solid electrolyte interphase produced by the decomposition of the PC-based electrolyte. Similar and slightly different electrochemical behavior was observed for synthetic graphite in terms of changes in temperature and the electrolyte concentration factor. In synthetic graphite, the temperature at which lithium ions were inserted was lower than in natural graphite: –25°C and 5°C in solutions of 0.85 mol kg^–1 and 2.45 mol kg^–1, respectively.

Abstract: In this paper, we report a simple method to fabricate lead oxide nanostructure by electrochemical deposition. In our experiment, the electrolyte was lead nitrate aqueous solution containing some drops of concentrated hydrochloric acid. ITO was employed as both cathode and substrate. The controlled current that was supplied by a direct current power supply passed through the electrolyte to deposit the PbO nanostructure on the surface of ITO at room temperature. The morphology of lead oxide was affected by the concentration of electrolyte. So the impact of the electrolyte concentration on the synthesis of PbO nanostructure was discussed. The as-synthesized products were characterized by scanning electron microscopy and X-ray diffraction. Our results indicate that different PbO nanostructure could be formatted with different electrolyte concentration at current densities in the range of 5-10mA/cm2.

Abstract: A mathematical model for the transport in cathode of a lithium-ion cell is developed and analytical solutions to the model equations are obtained. The derived equation is tested by fitting it to published experimental discharge characteristics. Wherever possible, the values of the relevant parameters are obtained from the same literature from which the discharge characteristics were obtained. The agreement between the predicted and the experimental discharge curves are measured statistically using t-test. Since the discharge characteristics are usually plotted as voltage versus time or capacity or even state-of-discharge, hence the expression for the cell voltage has been derived.