1070-4272/02/7506-0935 $27.00 C 2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 6, 2002, pp. 935!938. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 6, 2002,
Original Russian Text Copyright + 2002 by Ivanova, Boldyrev, Ivanov, Sokol’skii, Makeeva.
AND CORROSION PROTECTION OF METALS
Comparative Characteristics of Chemical Power Cells Based on
!Zn Systems with Various Manganese Dioxide Samples
N. D. Ivanova, E. I. Boldyrev, S. V. Ivanov, G. V. Sokol’skii, and I. S. Makeeva
Vernadskii Institute of General and Inorganic Chemistry, National Academy of Sciences of Ukraine, Kiev, Ukraine
National University of Aviation, Kiev, Ukraine
Received September 4, 2001; in final form, February 2002
Abstract-The relationship between the catalytic activity of various manganese dioxide samples and the
electrical characteristics of chemical power cells with cathode materials on their base was studied.
Chemical power cells (CPC) with cathode mass
based on manganese dioxide find widest application.
About 70380% of the total amount of power cells
manufactured are CPCs with manganese dioxide. This
can be attributed to the fact that CPCs of this kind
have an almost horizontal discharge curve, are effi-
cient in a wide temperature range, and their cathode
material is less expensive as compared with other oxide
materials. In addition, manganese dioxide is stable in
aqueous and organic electrolytes, i.e., the 1.533.0-V
electrochemical systems operate on its basis.
CPCs predominantly employ electrolytic g-man-
ganese dioxide (EMD-2), since it is more active as
compared with other modifications .
The wide use of this compound in CPCs brings
forth the problem of raising its activity, in particular,
via directional disordering of the manganese dioxide
structure. All other conditions being the same, the
most active compounds are those whose structure is
characterized by a larger number of defects ,
nonstoichiometric compounds among them, e.g., MnO
(1.7 < x < 2) .
The aim of this study was to determine how the
electrical characteristics of CPCs depend on the cat-
alytic activity of various samples of manganese diox-
ide. In this connection, we studied various samples
of this compound, differing in the preparation proce-
dures, for the electrochemical system manganese di-
We studied the following manganese dioxide
samples: synthesized electrochemically: no. 1, from
fluorine-containing electrolytes (EMD
) ; no. 2,
from sulfate electrolyte (EMD-2), Georgia, OST
(All-Union Standard) 6-22-34376; and chemically:
no. 3 (CMD
) at Pridneprovskii chemical plant, TU
(Technical Specifications) 14312708, 174394; and
no.4 (CMD) of special-purity grade.
Chemical analysis was carried out by the known
procedures. The total manganese was determined in
the samples by redox titration with KMnO
. The per-
centage of Mn
was estimated using oxalic acid.
The content of manganese(II) was determined by the
procedure given in . The difference between the
total manganese and the content of manganese (IV)
[after correction for content of manganese(II)] corre-
sponded to the experimental content of manganese(III)
ions . The data on the content of manganese ions
were given in terms of MnO
, and MnO;
the x value was calculated for all the samples from
the content of differently charged manganese ions in
a sample under study :
x = ÄÄÄÄÄÄ , R = ÄÄÄÄÄÄ .
2 + 1.5R
We carried out electrochemical studies in 9 N aque-
ous solutions of analytically pure KOH at 18320oC.
Pellets of diameter 4 mm served as working electrodes.
The weighed portions for preparing cathode sam-
ples were chosen in such a way that the sample thick-
ness was almost the same (0.55 + 0.02 mm). The elec-
tric contact with the pellets was effected by pressing
In terms of Mn