College of Chemistry and Chemical Engineering, Henan Polytechnic University
Henan Key Laboratory of Coal Green Conversion, Henan Polytechnic University
Ningbo Lüdong Fuel Cell Company Limited
Collaborative Innovation Center of Coal Safety Production and Clean and Efficient Utilization Jointly Built by the Ministry and the Province, Henan Polytechnic University

煤沥青是一种原料来源丰富且含碳量高的钠离子电池碳负极材料。以煤沥青为碳源,通过炭化法制得热解炭,利用XRD,SEM,Raman光谱等表征技术,系统研究了不同炭化温度(600℃~1400℃)对煤沥青热解炭微观结构的影响规律。利用恒流充放电等测试,探究热解炭作为钠离子电池负极材料时的电化学性能,阐明“温度—结构—储钠性能”间的构效关系。结果表明:1000℃是热解炭微观结构从无序向有序发展的转折点;当温度低于1000℃时,热解炭为不规则的块状结构且表面平整光滑,未出现石墨微晶,具有较大的层间距和较高的无序度;当温度为800℃时,热解炭具有最大的层间距(d002=0.3541nm)和最高的无序度(ID/IG=2.57),其作为钠离子电池负极材料时,0.05A/g电流密度下的可逆容量为177.0mAh/g,首次库伦效率为73.87%,具有较好的倍率性能;当温度高于1000℃时,石墨碳层生长和堆叠的速度迅速加快,石墨化程度增加,层间距减小,同时表面缺陷程度降低,Na+吸附位点减少,不利于储钠,热解炭具有较低的可逆容量(小于100mAh/g)。

Coal tar pitch is a carbon anode material for sodium-ion batteries with abun-dant raw material sources and high carbon content.Coal tar pitch was used as the carbon source to obtain pyrolytic carbon through carbonization. The influence of carbonization temperature (600 ℃-1 400 ℃) on the microstructure and sodium storage behavior of coal tar pitch-derived pyrolytic carbon was systematically investigated using several characterization techniques such as XRD, SEM, Raman spectroscopy. The electrochemical properties of pyrolytic carbon as an anode material for sodium-ion batteries was investigated by means of constant current charge/discharge tests and the constitutive relationship between temperature, structure and sodium storage capaci-ty was clarified. The results show that 1 000 ℃ serves as a turning point in the development of microstructure of pyrolytic carbon from disorder to order. When the temperature is less than 1 000 ℃, the pyrolytic carbon exhibits irregular bulk structure with smooth surface, no apparent graphite microcrystals. In this case, the material has a larger interlayer spacing and a higher de-fect concentration. Pyrolytic carbon obtained at 800 ℃ shows the maximum interlayer spacing (d002=0.354 1 nm) and the highest defect concentration (ID/IG=2.57). When used as anode material of sodium-ion batteries, it demonstrates a reversible capacity of 177 mAh/g at a current density of 0.05 A/g, with an initial coulombic efficiency of 73.87% and good rate performance. At temperatures above 1 000 ℃, the growth and stacking rate of the graphitic carbon layers ac-celerate rapidly, resulting in higher graphitization degree, reduced interlayer spacing, decreased surface defect concentration, fewer Na+ adsorption sites, which is not conducive to sodium stor-age. Therefore, samples have a low reversible capacity (<100 mAh/g).

国家自然科学基金项目(52074109)和河南省高校基本科研业务费专项资金项目(NSFRF220437).

陈 林,张兆华,康伟 伟,等.煤 沥 青 热 解 炭 的 制 备 及 储 钠 性 能 研 究 [J].煤 炭 转 化,2023,46(5):42-52

CHEN Lin,ZHANG Zhaohua,KANG Weiwei,et al.Preparation of coal tar pitch pyrolytic carbon and its sodium storage properties[J].Coal Conversion,2023,46(5):42-52