甲基萘沥青基有序中孔炭的制备及电化学性能

以1-甲基萘热溴化/脱溴聚合沥青为前驱体, 中孔二氧化硅SBA-15为模板, 采用液相浸渍法合成有序中孔炭。通过不同测试手段对中孔炭的微观结构和电化学性能进行了研究。当模板剂和沥青质量比为1:1, 升温速率为 1 ℃·min^-1, 碳化温度为900 ℃时, 所制备的中孔炭性能最优, 具有高度有序的二维六方孔道结构, 比表面积为675 m²·g^-1, 孔容为1 cm³·g^-1, 孔径集中在3.84 nm左右。该中孔炭用于Li-S电池的正极载体材料表现出良好的电化学性能, 在0.2C(1C=1675 mA·g^-1)电流密度下经300次循环后放电比容量和容量保持率分别为688 mAh·g^-1和67.1%, 在3C电流密度下比容量可达556 mAh·g^-1。

Methylnaphthalene Pitch-based Ordered Mesoporous Carbon: Synthesis and Electrochemical Properties

Ordered mesoporous carbon was synthesized by liquid impregnation, using polymerized pitch prepared from 1-methylnaphthalene through thermal bromination with dehydrobromination as precursor and mesoporous silica SBA-15 as template. Microstructure and electrochemical properties of mesoporous carbon were characterized. It was found that the optimal preparation conditions were template/pitch mass ratio of 1:1, carbonization temperature of 900 ℃, and heating rate of 1 ℃·min^-1. The optimal sample exhibits highly ordered two-dimensional hexagonal channels, with specific surface area of 675 m²·g^-1, pore volume of 1 cm³·g^-1, and pore diameter concentrated at about 3.84 nm. The Li-S batteries with this mesoporous carbon as the sulfur host showed excellent electrochemical performance. After 300 cycles, the specific discharge capacity and capacity retention were 688 mAh·g^-1 and 67.1% at a current density of 0.2C (1C=1675 mA·g^-1), respectively, while the specific capacity could reach 556 mAh·g^-1 at a current density of 3C.