Study of ion transport behavior in a mechanochemically synthesized silver halide mixed composite system: [0.75 AgI:0.25 AgCl]

Ion transport behavior in a mechanochemically synthesized silver halide mixed composite has been investigated. AgI and AgCl, in 75: 25 mol. wt. (%) ratio, has been prepared by high energy ball milling for different milling times viz. 5, 10, 20, 30, 40, and 50 h as well as by simple physical mixing (referred to as zero hour milling). The room temperature conductivity has been evaluated as a function of milling time. The conductivity increased initially with increasing milling time, then decreased. The increase in conductivity has been attributed to the increased degree of amorphosity in the sample as a consequence of high energy ball milling. The 30-hour milled sample exhibited highest conductivity with an enhancement of more an order of magnitude from that of zero hour milled sample. To explain the ion transport mechanism in the optimum conducting sample, other basic ionic parameters viz, ionic mobility (mu), mobile ion concentration (n), ionic transference number (t(ion)) etc. have also been determined. The materials and structural properties have been characterized using XRD, FTIR, and DSC techniques. Using the optimum conducting sample as electrolyte, all-solid-state battery has been fabricated having cell configuration: Ag (anode) // (0.75 AgI:0.25AgCl) // C +I-2+ Electrolyte (cathode), and the cell performance has been studied under varying load conditions. (C) 2011 Elsevier B.V. All rights reserved.