关键词: 重芳烃, 聚合, 制备, 改性剂, 二次颗粒：负极材料, 电化学

Abstract:

The modification agents for the current commercial anode material are mainly made of refined bitumen of coal and petroleum, while the quality is remarkably different and the cost is always high. To address these problems it was proposed to use low-cost coal-based heavy aromatic hydrocarbons as the precursor to prepare the modification agent through purification and polymerization processes. The modification was firstly ground and coated on the needle coke, and then the anode was obtained by a subsequent granulation process with a pyrolysis process. The rheological properties and thermogravimetric properties of the modifier were analyzed by rotational rheometer and thermogravimetric analyzer. The apparent morphology, pore structure, layer spacing, crystallinity and electrochemical properties of the modified samples were characterized by scanning electron microscope, gas adsorption apparatus, X-ray diffractometer, laser Raman spectrometer and a battery test system. The electrochemical test showed that the reversible capacity of the modified negative electrode increased from 333.02mAh/g before modification to 356.34mAh/g and 359.67mAh/g, and the initial coulombic efficiency increases by 1.72% and 1.31%. The retention rate of 98.87% over 100 cycles at 30mA/g can be obtained. The reversible capacity increased from 95.27mAh/g before modification to 147.52mAh/g and 187.30mAh/g at 300mA/g. The results indicated that the anode material prepared by adding modifier exhibited excellent specific capacity, rate performance and cycle stability. Simultaneously, the cost was low and the industrialization of preparation process was feasible.

Key words: heavy aromatic hydrocarbons, polymerization, preparation, modifier, secondary particles, anode materials, electrochemistry