M. Sima et al., A COMPARATIVE-STUDY OF ZINC-POLYANILINE ELECTROCHEMICAL-CELLS HAVING SULFATE AND CHLORIDE ELECTROLYTES, Journal of power sources, 56(2), 1995, pp. 133-136
Polyaniline (PANI) films were investigated at 20 degrees C as the posi
tive electrodes for Zn/PANI secondary cells containing either 1 M ZnCl
2, 0.5 M NH4Cl or 1 M ZnSO4, 0.18 M (NH4)(2)SO4 electrolytes, respecti
vely, at pH=4.5, Cyclic voltammograms showed similar behaviour for the
thin PANI films as those in highly acid media. From the discharge cur
ves specific capacities were calculated of 127-130 Ah kg(-1) for the Z
n/PANI, Cl- cell and 82-107 Ah kg(-1) for the Zn/PANI, SO42- cell. Cha
rging limit values of 1.48 V for the Zn/PANI, Cl- cell and 1.52 V for
the Zn/PANI SO42- cell were obtained in order to prevent the electroch
emical inactivation of the polymer. After 20 to 30 cycles the capacity
of both cells decreases rapidly and then levels off. The self-dischar
ge process is important only in the first approximately 80 h, after wh
ich the open-circuit voltage remains constant. Zn/PANI, Cl- cell showe
d better electrical characteristics for use as a secondary system.