【摘要】 糠醛和混甲酚在正丙醇中进行溶胶-凝胶聚合反应形成气凝胶,在600～1000℃下炭化制备炭气凝胶。粉末X射线衍射(XRD)研究了其微观物理结构随热处理温度的变化;元素分析考察了其元素组成;恒电流充放电性能研究了其嵌锂性能。结果发现,随着热处理温度的升高,炭气凝胶的微晶结构逐渐变得规整、有序;碳元素百分含量逐渐增加,氢元素含量逐渐减少;首次充放电可逆容量逐渐下降;其中在600℃下炭化所制备的炭气凝胶,放电容量高达417mAh·g-1,超过了石墨的理论比容量(372mAh·g-1),这主要是由于其内部的微孔起到了锂离子储存“仓库”的作用。更多还原

【Abstract】 Sol gel polymerization between furfural and mix cresol was carried out in 1 propanol,leading to the formation of gels.The gels were dried in supercritical petroleum ether at 250 ℃ under 7 MPa for 1 hour and further heat treatment under nitrogen atmosphere at 600～1 000 ℃ to form carbon aerogels.Powder X ray diffraction pattern of carbon materials was studied.Elemental analysis of carbon aerogels were investigated.Electrochemical cells were made to study lithium insertion in carbon aerogels.Mechanism of lithium insertion was discussed.The results showed that,with increasing pyrolysis temperature,carbon aerogels became structurally order,carbon content increased,while hydrogen content,first reversible capacity and coulombic efficiencies decreased.It was found that carbon aerogels heat treated at 600 ℃ possessed a high reversible capacity of about 417 mAh·g 1,which was higher than graphite (372 mAh·g 1)did.The micropore in carbon aerogels seems to have some capacity for lithium ion storage.更多还原