Electric and dielectric behavior of carbonate intercalated CoAl-Layered Double Hydroxide (LDH) investigated by impedance spectroscopy

Abstract

Cobalt-based layered double hydroxides (LDH) have invoked a great deal of interest in the field of energy storage due to their unique properties and low cost. Herein, carbonate intercalated CoAl-LDH was prepared in order to investigate the electrical and dielectric properties of this material. This polycrystalline sample was synthesized by the conventional co-precipitation method, characterized by PXRD, FT-IR and TGA, and analyzed by ICP. Ac impedance was measured by the complex impedance spectroscopy (CIS) method using pressed pellet sample over a frequency range of (1Hz-1MHz) and room temperature, to separate contribution of grains and grain boundaries to capacitance, resistance and conductivity of the sample. The adjustment of conductivity parameters by the double power law allowed the determination of σ dc. The relaxation mechanism is dominated by long range movement of charge carriers: carbonate ions and H+ protons of water molecules in the interlayer space. This material exhibits high dielectric constant values and a low loss factor at high frequencies which makes the valorization of this material may be interesting in the area of dielectrics.