A high capacity cathode material-MnO2 doped with nano Ag4Bi2O5 for alkaline secondary batteries

In the present paper, we report a novel MnO2 cathode material doped with nano Ag4Bi2O5. The results of characteristic structure indicate that Ag4Bi2O5 is evenly distributed in the MnO2 material and affects the original structure of MnO2. The electrochemical performances of the doped electrode in the alkaline electrolyte are measured by galvanostatic method and cyclic voltammetry tests. Results show that the doped electrode has excellent electrochemical properties and its discharge voltage is 50-100 mV higher than that of the traditional MnO2 electrode. The doped electrode can offer a discharge specific capacity of 481 mAh g(-1) at 120 mA g(-1). The cycling life of the doped electrode reaches up to 115 cycles, which is 3.4 times longer than that of electrolytic MnO2 electrode at a high current density of 1000 mA g(-1). The effect of doping Ag4Bi2O5 is much better than that of doping Bi2O3 or Ag2O independently, which indicates that Ag4Bi2O5 shows more superior electrochemical performance with the assistance of both Ag and Bi cations. (C) 2011 Published by Elsevier B.V.