Ag-modification improving the electrochemical performance of ZnO anode for Ni/Zn secondary batteries

Ag-modified ZnO was prepared by a facile silver mirror reaction process. The average size of silver particles was about 45 nm and they were modified on the part surface of ZnO particles. The electrochemical performance of ZnO as active materials for Ni/Zn batteries was investigated by charge/discharge cycling test, slow rate cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The Ag-modified ZnO anode showed the better cycle stability than unmodified ZnO. The discharge capacity maintained 456 mAh g(-1) throughout 65 cycling tests, and the fading rate of the discharge capacity was only 0.89 mAh per cycle. At the same time, it also exhibited the higher midpoint discharge voltage and the lower midpoint charge voltage. The better cycle performance was ascribed to that Ag nanoparticles on the surface of ZnO improved the conductivity of the electrode and inhibited the dissolution of ZnO. (C) 2009 Elsevier B.V. All rights reserved.