Papers by Keyword: Electrochemical Cell

Abstract: Inkjet printing (IJP) has emerged as a promising additive manufacturing technique for fabrication of electrodes and sensors due to its cost-effectiveness compared to the traditional techniques, such as screen-printing. In this work, we present a planar, three-electrode system fabricated by inkjet printing on a polyethylene naphthalate (PEN) flexible substrate for rapid voltametric electrochemical analysis. An in-house formulation of aqueous-based gold ink with low temperature-sintering was used in printing the working and counter electrodes. The reference electrode was also inkjet-printed using a commercial silver ink and chlorinated to form an AgCl layer. Cyclic voltammetry studies using the ferri/ferrocyanide redox couple showed that the inkjet-printed electrode system has a comparable electrochemical performance to a commercial screen-printed electrode. Fabrication of a single inkjet-printed electrochemical 3-electrode platform consumes only about 0.5 mg Au and 0.2 mg Ag loading of ink with minimal waste during fabrication because of the additive nature of the printing technique. The 3-electrode platform operates with a microliter sample volume for analysis and can be used in aqueous media without delamination.

Abstract: Moderately thermophilic bioleaching of a pyritic chalcopyrite concentrate was mimicked in an electrochemical vessel. The bioleaching was carried out for 28 days at 45°C with 2.5% (wt/vol) solid content at pH 1.5. Data from the redox potential development was used to program a redox potential controller in an electrochemical vessel to reproduce the same leaching conditions in the absence of microorganisms. Despite precipitation of iron as jarosite and formation of elemental sulphur in the electrochemical experiment, the copper recoveries were almost the same in both experiments.

Abstract: Hexanoyl chitosan that exhibited solubility in THF was prepared by acyl modification of chitosan. Films of hexanoyl chitosan-based polymer electrolyte were prepared by the technique of solution casting. The effect of plasticizers on the electrical properties of hexanoyl chitosan: LiCF3SO3 electrolytes have been investigated. The plasticizers used were EC, PC and a mixture of EC and PC. The highest room temperature conductivity of about 1.1 x 10-4 S cm-1 was achieved for electrolyte with composition of 50:50 (wt.%) mixture of PC: EC. The variations in conductivity have been explained using the Rice and Roth model from which the numbers of free ions per unit volume, mobility and diffusion coefficient of free ions were obtained. Electrochemical cells based on LiCoO2/MCMB couple were assembled using the electrolyte that exhibited the highest ionic conductivity. The performance of the cells have been studied and discussed in this paper.

Abstract: A series of experiment has been carried out to study the electrochemical performances of lithium primary cells using different cathode materials. The cathode material was made of metal oxide, electrolyte, activated carbon, and PVdF with a wt. ratio of 60: 20:10:10. PVdF was added as a binder. The metal oxides used are MnO2 and V2O5. The anode was made up of lithium metal and LiI-Li2WO4-Li3PO4 compound is used as an electrolyte. In this work the open circuit voltage (OCV) of Li/MnO2 and Li/V2O5 obtained is about 3.0 V and 3.2 V respectively. This shows that LiI-Li2WO4-Li3PO4 compound is lithium ion conductor. Lithium cell showed better performance at 100º C than at room temperature. Among these two types of cells investigated, cell Li/V2O5 worked better than the Li/MnO2 cell at room temperature and at 100°C as this cell exhibits the longest continuous discharge time and the highest OCV.