二次颗粒人造石墨负极材料的制备及储锂性能

以煤系针状焦生焦为原料、自制高性能煤沥青为黏结剂,对针状焦生焦进行造粒加工处理,制备了具有高能量密度和倍率性能的二次颗粒人造石墨负极材料,并研究了黏结剂沥青添加量分别为5%(质量分数,下同),8%和12%时二次颗粒人造石墨负极材料的理化指标和电化学性能。结果表明:当黏结剂沥青添加量为8%时,造粒工艺效果最为理想,形成的二次颗粒人造石墨负极材料大小较均匀,振实密度为1.10 g/cm³,在0.1 C电流密度下首次充电比容量为345.7 mAh/g,首次库伦效率为95.6%,高于其他黏结剂量下制备的二次颗粒人造石墨负极材料的首次充电比容量和首次库伦效率,在倍率性能测试方面也展现出优异的高倍率充放电能力。

Preparation and Lithium Storage Properties of Secondary-particles-based Artificial Graphite Anode Materials

The needle coke was granulated to prepare secondary-particles-based artificial graphite anode materials with high energy densities and excellent rate capabilities by using the coal-based green needle coke as the raw materials and the self-made coal pitch as the binder.The physical properties and electrochemical properties of the synthetic secondary graphite anode materials were studied when the binder pitch addition was 5%,8%and 12%,respectively.The results show that when the binder pitch addition is 8%,the granulation process shows the best performance.Under such condition,the particle size is relatively uniform,with the tap density of the secondary-particles-based artificial anode material reaching 1.10 g/cm³.In addition,the first charging specific capacity is 345.7 mAh/g at the current density of 0.1 C,and the first coulomb efficiency is 95.6%,which are higher than that of the secondary-particles-based artificial graphite anode materials prepared under other binder pitch addition conditions.Furthermore,the prepared materials also show high rate capabilities in the rate performance tests.