摘要:
采用水热法合成了六角形的NH4V3(OH)6(SO4)2前驱体,经退火得到六角形V2O3纳米颗粒,分别对前驱体和退火产物进行表征,并通过SEM表征了不同水热反应时间段前驱体产物的形貌,讨论了六角形纳米结构的形成机理。测试表明,前驱体整体尺寸约600 nm,单枝长度超过200 nm,宽度则小于100 nm,而退火后尺寸减小为约300 nm,单枝长度约100 nm,宽度不超过50 nm。进一步对六角形V2O3纳米颗粒进行锂离子电池充放电性能测试,结果表明,在50 mAh/g的电流密度、1.5~3V终止电压下首次放电比容量为77 mAh/g,20次循环后还有42 mAh/g。
Abstract:
Hexagram-shaped V2O3 nanoparticles were synthesized by annealing hexagram-shaped NH4V3(OH)6(SO4)2 precursor prepared through hydrothermal method.Both the precursor and annealed samples were characterized,and the formation mechanism of hexagram-shaped nanostructure NH4V3(OH)6(SO4)2 was investigated by SEM characterization at different periods during the reaction.The results show that the dimensions of precursor particles are about 600 nm in axial direction,more than 200 nm for each branch and less than 100 nm in the width,respectively.After annealing,the dimensions of V2O3 particles are below 300 nm in axial direction and about 100 nm for each branch and no more than 50 nm in the width,respectively.Electrochemical measurements show that the discharge specific capacity of hexagram-shaped V2O3 reaches 77 mAh/g at a current density of 50 mAh/g with the cutoff voltage range 3.0~1.5 V,and remains at 42 mAh/g after 20 cycles.
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