10.1016/j.jelechem.2014.05.031
Low pressure preparation of spherical Si@C@CNT@C anode material for lithium-ion batteries

Spherical Si@C@CNT@C multiple composite was prepared from Si powder. Si powder was put in a chamber and vacuumed for 1 h. After that, 100 mL, 500 g L-1 glucose solution was added and the mixture was pyrolyzed at 650 degC for 5 h in an argon atmosphere. The obtained product was crushed to form Si@C composite and soaked in 0.5 mol L-1 Co(NO3)2 solution for 10 min. Then, the sample was filtrated and coated with CNT at 650 degC for 30 min by chemical vapor deposition (CVD) using acetylene as carbon source. The as-prepared Si@C@CNT was put in the vacuum chamber and vacuumed for 1 h. To form spherical Si@C@CNT@C multiple composite, 10 g pitch was acted as the carbon source for outer layer. The as-obtained sample was pyrolyzed at 800 degC for 5 h in an argon atmosphere and then crushed into smaller particles and granulated by ball-milling. The final product was obtained after a washing by water to remove the dust.
Si powder
vacuumed
1 h
h
glucose
added
100 mL
mL
glucose
added
500 g L-1
g L-1
mixture
pyrolyzed
650 degC
degC
mixture
pyrolyzed
5 h
h
Co(NO3)2 solution
0.5 mol L-1
mol L-1
Si@C composite
soaked
10 min
min
sample
coated
650 degC
degC
sample
coated
30 min
min
as-prepared Si@C@CNT
vacuumed
1 h
h
pitch
acted as the carbon source
10 g
g
sample
pyrolyzed
800 degC
degC
sample
pyrolyzed
5 h
h