摘要
以间苯二酚和甲醛为原料,在催化剂和表面活性剂的作用下经溶胶-凝胶、超临界干燥、炭化等过程合成一种新型的炭气凝胶微球。采用扫描电镜(SEM)、X-射线衍射(XRD)、低温氮吸附(BET)和充放电测试等表征了炭气凝胶微球微观形貌、结构和电化学性能。结果表明:炭气凝胶微球具有纳米网络结构(孔径集中分布在3.5 nm左右),微球直径≤40μm,比表面积为555 m2/g。电化学性能表现出很大的首次不可逆容量损失,这主要与材料大的比表面积有关。但在首次循环后,具有良好的循环性能,循环20次后可逆充电容量为281 mAh/g,循环效率达到100%。
A micro-spherical carbon aerogel was synthesized by a series of steps such as involving a sol-gel process, supercritical drying and carbonization using resorcinol and formaldehyde as reagents in the presence of catalyst and surfactant. The micro-morphology, structure and electrochemical performance of the micro-spherical carbon aerogel were characterized by SEM, XRD, BET and charge-discharge measurements. It was found that the diameter of the micro-spherical carbon aerogel is below 40 μm with the pore size distributed around 3.5 nm and with a specific area of 555 m^2/g. As a consequence of the high surface area, a large initial capacity loss was observed. However, after the first cycle, the anode material showed excellent cyclability with a reversible charge capacity of 28l mAh/g after the 20 th cycle with the cycle efficiency approaching 100 %.
出处
《北京化工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第2期46-49,共4页
Journal of Beijing University of Chemical Technology(Natural Science Edition)
基金
北京市科技新星计划(2003B09)
北京化工大学青年教师基金(200405)
关键词
炭气凝胶
炭微球
中孔网络
锂离子电池
carbon aerogel
carbon microsphere
mesoporous network
lithium ion battery
