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As anode materials for lithium-ion batteries, SiO_2 is of great interest because of its high capacity, low cost and environmental affinity. A facile approach has been developed to fabricate SiO_2@C hollow spheres by hydrolysis of tetraethyl orthosilicate(TEOS) to form SiO_2 shells on organic sphere templates followed by calcinations in air to remove the templates, and then the SiO_2 shells are covered by carbon layers.Electron microscopy investigations confirm hollow structure of the SiO_2@C. The SiO_2@C hollow spheres with different SiO_2 contents display gradual increase in specific capacity with discharge/charge cycling,among which the SiO_2@C with SiO_2 content of 67 wt% exhibits discharge/charge capacities of 653.4/649.6 mAh g~(-1) over 160 cycles at current density of 0.11 mA cm~(-2). The impedance fitting of the electrochemical impedance spectroscopy shows that the SiO_2@C with SiO_2 content of 67 wt% has the lowest charge transfer resistance, which indicates that the SiO_2@C hollow spheres is promising anode candidate for lithium-ion batteries.
A facile approach has been developed to fabricate SiO_2 @ C hollow spheres by hydrolysis of tetraethyl orthosilicate (TEOS) to form SiO_2 shells on organic sphere templates followed by calcinations in air to remove the templates, and then the SiO 2 shells are covered by carbon layers. Electron microscopy investigations confirm hollow structure of the SiO 2 @ C. The SiO_2 @ C hollow spheres with different SiO_2 contents display gradual increase in specific capacity with discharge / charge cycling, among which the SiO_2 @ C with SiO_2 content of 67 wt% exhibits discharge / charge capacities of 653.4 / 649.6 mAh g ~ (-1) over 160 cycles at current density of 0.11 mA cm ~ (-2). The impedance fitting of the electrochemical impedance spectroscopy that that SiO 2 @ C with SiO 2 content of 67 wt% has the lowest charge transfer resistance, which indicates that the SiO_2 @ C ho llow spheres is promising anode candidate for lithium-ion batteries.