Preparation and Performance of Carbon-Coated Hollow SiOx Anode Materials
With tetraethyl orthosilicate as silicon source and cetyltrimethylammonium bromide(CTAB)as a surfactant and pore-forming agent,a carbon-coated mesoporous hollow silicon oxide as anode material was synthesized by adopting the modified stöber method and carbonthermal reduction.The results show that different volume ratio of ethanol to water can bring important impact to the particle size,morphology and performance of SiO nanospheres.With ethanol and water in a low volume ratio,the obtained nanomaterial has a low sphericity and becomes oval;as the ratio increases,the nanomaterial becomes larger in size;with ethanol and water in a ratio of 0.45,the obtained SiOx nanospheres are around 300 mm in size.The button batteries assembled with such nanospheres deliver a reversible specific capacity of 813 mAh/g after 200 cycles at a current density of 100 mA/g,and 704 mAh/g after 1 200 cycles at 500 mA/g,retaining 82％of this capacity,with a capacity attenuation rate of 0.015％after each cycle.
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维普
