Journal of Applied Electrochemistry

, Volume 29, Issue 4, pp 463–471

Electrochemical impedance studies of a decade-aged magnesium/manganese dioxide primary cell

  • N. Munichandraiah
Article

DOI: 10.1023/A:1026463531195

Cite this article as:
Munichandraiah, N. Journal of Applied Electrochemistry (1999) 29: 463. doi:10.1023/A:1026463531195

Abstract

A Mg/MnO2 primary cell yields specific energy higher than a conventional Zn/MnO2 cell. Additionally, the shelf life of the Mg/MnO2 cell is extremely high. These cells, which were more than a decade old, were investigated for their discharge capacity, delay-time behaviour and impedance characteristics. The values of discharge capacity and the delay-time of an aged Mg/MnO2 cell were comparable to those of a fresh cell. The voltage dip on initiation of a galvanostatic current, however, was rather large. This was attributed to the presence of a thick, and highly resistive, surface passive film on theMg anode. The complex plane electrochemical impedance spectrum of a partially discharged cell consisted of two semicircles whose sizes decreased with decrease of state-of-charge of the cell. The a.c. frequency corresponding to the maximum value of the imaginary part of the high frequency semicircle was shown to be a useful parameter for estimation of the state-of-charge of the cell. The resistance parameters of a partially discharged Mg/MnO2 cell increased linearly with open circuit ageing time. This feature was attributed to growth of a passive surface layer on the Mg anode.

a.c. impedancedischarge delay-timeMg/MnO2 primary cellstate-of-chargesurface passive film on Mg

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • N. Munichandraiah
    • 1
  1. 1.Department of Inorganic and Physical ChemistryIndian Institute of ScienceBangaloreIndia (