中间相沥青碳微球的制备及其嵌锂行为的研究

Preparation of Mesocarbon Microbeads and Its Performance of Lithium Insertion

以含 0 .4 6 %～ 3.7% (质量分数 )吡啶不溶物 (PI)的宝钢煤焦油为原料 ,在 4 5 0℃下自升压热缩聚制备中间相碳微球 (MCMB) ,然后将其在 70 0℃下进行碳化。应用SEM、恒电流充放电等技术研究了所得MCMB的表面物理形态及充放电性能。研究发现 :随原料中一次PI含量的增加 ,MCMB的球径逐渐减小 ;首次电容量从 32 6mA·h·g- 1增至 4 2 5mA·h·g- 1,首次不可逆容量先增加而后减小 ,而首次充放电效率先减小而后增加。

Coal tars with different pyridine insoluble(PI) content (0.46～3.7wt%) were used as raw materials to prepare mesocarbon microbeads(MCMB) at 450℃ for 2 h under autoginous pressure. MCMB were then heat treated at 700℃ for 1 h. Surface morphology of the MCMB was investigated by SEM and constant current charge discharge properties were studied. It was found that, with the primary PI content increasing, the diameters of MCMB decreased,the first discharge capacity increased from 326 mA·h·g -1 to 425 mA·h·g -1 and the first coulombic efficiencies decreased at the beginning and then increased.