Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 7, pp. 1179−1187.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © S.P. Kuksenko, I.O. Konovalenko, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 7, pp. 1107−1115.
AND CORROSION PROTECTION OF METALS
Silicon Nanopowder as Active Material for Hybrid Electrodes
of Lithium-Ion Batteries
S. P. Kuksenko and I. O. Konovalenko
Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, Kiev, Ukraine
Received October 1, 2010
Abstract—Cycling parameters (reversible speciﬁ c capacity, ﬁ rst-cycle coulombic efﬁ ciency, accumulated
irreversible capacity, and reversible capacity retention) of hybrid electrodes based on mechanical mixtures of
a silicon nanopowder with KS6 and MAG-20 synthetic graphites and binders of varied nature were subjected to
an integrated analysis in comparison with graphite electrodes.
A vital necessity for modern informational mobile
society is to manufacture high-capacity, inexpensive, and
ecologically safe devices for accumulation of electric
power. Lithium-ion batteries (LIBs) are the most widely
used power sources among small-size batteries, owing
to their better parameters (speciﬁ c energy, cycling life,
self-discharge), compared with the conventional lead,
nickel-cadmium, and nickel-metal-hydride batteries.
Although LIBs have long been a successful commercial
product for feeding portable electronic devices, they
still remain an object of intensive research in order
to improve characteristics necessary for expanding
their application ﬁ eld, such as new-generation cell
phones (4G), uninterruptible power sources, hybrid
automobiles and electric vehicles, and stationary
batteries for storage of electric power obtained from
renewable sources [1–3].
The active macromaterials used in the conventional
LIB electrodes have nearly reached their limits and
cannot satisfy the growing demand. Therefore, research
aimed to develop effective electrode nanomaterials
becomes particularly topical and there is good reason
to believe that they will be playing an increasingly
important role in improvement of LIB parameters [4–8].
A close researchers’ attention is attracted by nanosilicon
It has been shown previously  that the reversible
speciﬁ c capacity C
of a hybrid LIB electrode (anode)
fabricated from synthetic graphite with addition of
3.5 wt % powdered microcrystalline silicon in the form
of a 7 : 3 silicon–graphite composite produced in a high-
speed vibration ball mill is 25–30% higher than that
of the graphite anode. The capacity is 440–445 mA h
(depending on the cycling mode) at a high (92.6%)
ﬁ rst-cycle coulombic efﬁ ciency E (E = C
are, respectively, the speciﬁ c discharge and
char capacities in a cycle), high reversible-capacity
retention [89.4% after 100 cycles in the mode with
constant current/constant voltage (cc/cv) (C/2, 0.005 V,
C/200) and constant current (cc) (C/2, 1.0 V)], and
comparatively low irreversible capacity (175 mA h g
after 102 cycles).
Some electrochemical parameters of hybrid electrodes
can be improved [e.g., with an ultrafast charging being
possible, reversible-capacity retention by nth cycle
) raised, and the related cycling life extended]
by making smaller the grain size of powdered crystalline
silicon to the point of transition to the nanosize range.
The improvement is enabled by the shorter diffusion
paths, high adhesion of silicon nanoparticles to the
surface of a distributed current lead, fast relaxation of
mechanical stresses upon structural and volume changes
(nanoparticles can free themselves of stresses without