The lithium-ion battery (LIB) has been widely regarded as the
most promising power source for the plug-in hybrid electric vehicle
(PHEV) and electric vehicle (EV). New-generation electrode
materials with high energy, high rate capability, and good safety
performance have been extensively studied to meet the challenging
requirements for PHEV and EV applications [1]. At the moment, the
state-of-the-art anode material for the LIB is graphite, which has a
theoretical capacity of 372 mAh g−1 [2]. However, tin-based oxides
have been considered as a potential substitute for graphite because
of their higher theoretical reversible capacity (e.g., 781 mAh g−1 for
SnO2) [3]. The practical application of SnO2, so far, is hampered by
poor cyclability arising from the large volume change after repetitive
charging and discharging, which causes mechanical failure and
the loss of electrical contact [4]. To overcome this problem, many
researchers are focusing on synthesis of SnO2 nanoparticles, which
are able to better accommodate the mechanical stress experienced
during volume changes [5]. Another approach is the use of carbon
as matrix support on which SnO2 nanoparticles are attached [6].
Among various kinds of carbon materials, the carbon nanotube is
attractive due to its high electrical conductivity, high aspect ratio,
remarkable thermal conductivity, and good mechanical properties,
which can improve the electrode’s reversible capacity and rate
capability