microspheres containing carbon have been synthesized viaa one-pot hydrothermal process using CTAB as the mesoporous template and nanoparticle stabilizer and Ti(SO
4
)
2
and sucrose as titanium and carbon precursors
respectively. Through well designed calcinations
TiO
2
microspheres with various amounts of carbon-residue
such as core/shell C@TiO
2
hollow neat H-TiO
2
and hollow C/TiO
2
composites
are obtained.When these microspheres are used as anode materials for lithium ion batteries
the lithium storage performance is significantly influenced by the structure and carbon-residue. With a thin shell of TiO
2
nanoparticles and carbon-residue
the capacity of hollow C/TiO
2
composites maintains at 143.3 mA·h·g
-1
at 0.5 C (83.5 mA·g
-1
) after 100 cycles. Moreover
after high rate charge/discharge cycles from 0.2 C to 20 C and back to 0.2 C again
the reversible capacity recovers atas high as 195.1 mA·h·g
-1
with respect to its initial value of 205.0 mA·h·g
-1
. The results of cycle voltammograms and electrochemical impedance spectroscopy further reveal that Li
+
insertion/extraction processes
are reversible
and the diffusion coefficient of Li
+
in the hollow C/TiO
2
composites is much higher than those of others
because the hollow structure can act as the ion-buffering reservoir and facilitate Li
+
transfer from both sides of the shell
and the carbon-residue in the shell improves the conductivity as well.
关键词
Keywords
references
The trial reading is over, you can activate your VIP account to continue reading.