AC conductivity studies of Lithium mixed layered Potassium tetraTitanates (K 1.9 Li 0.1 Ti 4 O 9 ) electrode materials for K ions batteries

Abstract

Lithium mixed Potassium Tetra Titanates with 0.1, molar percentage of Li 2 CO 3 (general formula K 2-X Li X Ti 4 O 9 ) have prepared by a high temperature solid-state reaction route. The XRD results indicate that Lithium ions enter the unit cell maintaining the layered structure of solid solution. The crystals are monoclinic for x= 0.1, 0.3 and 0.5. EPR analysis, high temperature range (373-798K) in frequency range 100kHz-1MHz ac conductivity measurements were carried out on prepared sample. The Lithium ions are accommodated with the Potassium ions in the interlayer space. The EPR spectra of Lithium mixed Potassium Tetra Titanates confirm
the partial reduction of Ti 4+ ions to Ti 3+ . Four distinct regions have identified in the LnσT vs 1000/T plots. Various conduction mechanisms, which dependence on concentration, frequency and temperature are reported in this paper.

Keywords: C. Structure and Characterization, D. Charge transport, D. AC Conductivity 71.20.Dg Alkali and alkaline earth metals, 72.15.-v Electronic conduction in metals and alloys, 72.60.+g Mixed conductivity and conductivity transitions.