Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 4, pp. 607−614.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © R.D. Apostolova, O.V. Kolomoets, M.E. Shembel, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 4, pp. 571−577.
AND CORROSION PROTECTION OF METALS
Electrolytic Composites of Iron Sulﬁ des with Graphite
in a Prototype Lithium Battery
R. D. Apostolova
, O. V. Kolomoets
, and M. E. Shembel
Ukrainian State University of Chemical Engineering, Dnepropetrovsk, Ukraine
Enerize Corporation, Coral Springs, Fl, USA
Received April 27, 2010
Abstract—Electrolytic composites of iron sulﬁ des FeS and Fe
with natural graphites of GAK and EUZ-3
brands and Chinese graphite were synthesized in thin layers and studied in a prototype lithium battery.
Metal sulﬁ des (M = Fe, Mo, Ni, Co) produced in thin
layers on an aluminum cathode in solutions containing
a metal sulfate and thiosulfate ions can be used in
positive electrodes of low-temperature lithium batteries
[1, 2]. It has also been shown that binary electrolytic
Co, Ni sulﬁ des deposited on stainless steel can be
employed in negative electrodes of lithium-ion power
cells . A 2-V lithium-ion system with electrolytic
iron sulﬁ de and LiCoO
has been suggested as negative
and positive electrodes, respectively ]. The discharge
capacity of such a prototype system reaches values of
350–400 mA h g
Fe sulﬁ de.
In the last case, application of an M-sulﬁ de material
is restricted by the decrease in its discharge capacity in
cycling because of the worsening adhesion of the deposit
to the substrate. To improve the stability of the exchange
capacity of an M-sulﬁ de compound and enable its more
effective use in negative electrodes of the lithium-ion
system, it has been suggested to synthesize an M-sulﬁ de/
graphite composite as a thin-layer compact deposit. The
problem is solved by additional introduction of graphite
into the electrolyte for synthesis of an M-sulﬁ de by the
method suggested in . Graphites of varied nature have
been used for co-deposition with the M-sulﬁ de.
In this study, we electrolytically synthesized
composites of iron sulﬁ de with natural graphites of
GAK and EUZ-M brands and that of and Chinese origin
and examined these composites in a prototype lithium
Thin-layer deposits of electrolytic iron sulﬁ de–
graphite composites (e-Fe
–Gr) with a mass of
2–6 mg cm
were produced by the method described
in  on 18N12Kh9T stainless steel substrates by
cathodic reduction from an aqueous solution of iron(II)
sulfate, which contained thiosulfate ions, graphite, and
The electrolyte was of composition (g l
5.0–5.5, graphite 1.5–2.0, sodium
lauryl sulfate 0.1–0.3, and H
25. The deposition
was performed at pH 2.8–3.2, T
= 20 ± 2°C, and i
2–3 mA cm
, with mechanical agitation of the solution.
We used graphite powders of GAK [GOST (State
Standard) 10273–73] and EUZ-M (GOST 10274–79)
brands, Chinese natural graphite with a grain size of
18 μm, and commercial reagents of analytically pure
and pure grades without additional puriﬁ cation.
The composition of the composites we synthesized
was determined by X-ray phase analysis, described in
more detail in , on a DRON-2 installation.
The electrochemical characteristics of the
composites were determined in a galvanostatic charge/