New composite cathode material for Zn//MnO2 cells obtained by electro-deposition of polybithiophene on manganese dioxide particles

We studied the blend formed by electrochemical polymerization of bithiophene monomer (BTh) on electrolytic manganese dioxide (gamma-MnO2). The composite material (PBTh/gamma-MnO2) has been synthesised in 0.01 M PBTh/0.1 M LiClO4/CH3CN by chronoamperometry test at oxidation potential 1.1 V vs. saturated calomel electrode during 20 min, and then characterized by different methods including cyclic voltammetry, impedance spectroscopy, FTIR spectroscopy, and magnetic measurements. These blends have been tested as positive electrode in Zn//gamma-MnO2 cells. Good discharge performance was obtained with the modified MnO2, which exhibits better active material: increasing cell capacity is observed. (C) 2011 Elsevier B.V. All rights reserved.