ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 4, pp. 547−566. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © A.G. Morachevskii, A.I. Demidov, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 4, pp. 513−533.
Lithium–Silicon Alloys: Phase Diagram, Electrochemical Studies,
Thermodynamic Properties, Application
in Chemical Power Cells
A. G. Morachevskii and A. I. Demidov
St. Petersburg State Polytechnic University, ul. Politekhnicheskaya 29/1, St. Petersburg, 194064 Russia
Received March 16, 2015
Abstract—Review summarizes and analyzes data on the phase diagram, electrochemical behavior in molten
media, and thermodynamic properties of alloys in the lithium–silicon system in the solid and liquid states. The
use of Li–Si alloys in medium-temperature chemical power cells and prospects for application of silicon and
silicon-containing components as the anode material in lithium-ion batteries are discussed.
Lithium is one of the most important metals pres-
ently determining the scientiﬁ c-technological progress.
The metal itself and its alloys and compounds ﬁ nd use
in various industries: light alloys, chemical power cells,
nuclear technologies, and nonferrous metallurgy [1–11].
The world’s production of lithium steadily grows, data
on lithium resources, their geographical distribution,
and application ﬁ elds of lithium-containing products as
of the year of 2006 can be found in . Silicon is the
most widely occurring semiconductor; its annual world’s
production constitutes thousands of tons and continues
In the present review, the main attention is focused
on studies concerned with the phase diagram and, es-
pecially, thermodynamic properties of solid alloys in
the Li–Si system. The application of these alloys in
medium-temperature power cells for various purposes
is considered [10, 13–15].
In the XXI century, particular attention is given to
prospects for application of silicon in one form or another
as the anode material in new-generation lithium-ion
batteries. In the last 15 years, this problem has been the
subject of a large number of studies carried out in quite a
number of countries. We also made an attempt to reﬂ ect
the main areas of research in this ﬁ eld in the concluding
part of the review.
Lithium has the lowest, among metals, electrochemical
equivalent (0.259 g A
) and the most negative value
of the electrode potential (–3.045 V on the hydrogen
scale). Doping of lithium with aluminum or silicon
markedly facilitates the design of chemical power cells
with molten electrolytes. The thermodynamic properties
and electrochemical behavior of alloys in the Li–Al
system in molten media have been considered in detail
Phase diagram of the lithium–silicon system. First
studies of the phase diagram of the Li–Si system,
mostly carried out by the thermal analysis method,
were reported in [17, 18]. According to these data, only
two compounds are formed in the system, congruently
Si and Li
Si melting with decomposition.
However, significant changes were introduced in
later studies into the number and composition of the
compounds being formed. In , the electromotive
force of the following circuit was measured in the
temperature range 377–452°C:
(–)Li(l) | (LiCl, KCl)eut(l) | Li,Si (s) (+). (1)