Silver decorated γ-manganese dioxide nanorods for alkaline battery cathode

gamma-Manganese dioxide nanorods were prepared using a simple hydrothermal method based on redox reactions between S2O82- and Mn2+ and decoration of silver nanoparticles was performed by a wet impregnation method. The as-prepared materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Electrochemical discharging capacity of Ag/MnO2, MnO2/multi-walled carbon nanotubes (MWNTs), and Ag/MnO2/MWNTs electrodes were determined at 0.1 C discharging rate. The results showed that utility efficiency of MnO2 was greatly enhanced when silver particles were introduced and there was strong interaction between silver nanoparticles and bulk MnO2 materials. Electrochemical impedance spectroscopy (EIS) measurements were performed to investigate the discharging mechanism of the Ag/MnO2/MWNTs electrodes. Silver nanoparticles not only enhanced electronic conductivity of the network, but also improved proton diffusion process. (c) 2008 Elsevier B.V. All rights reserved.