摘要
以油系针状焦为原料,在1 500~3 000℃范围内,探索不同石墨化温度对二次颗粒石墨微晶层间距d002、微晶堆砌厚度Lc和微晶基面宽度La等微观结构的演变,揭示了碳原子从二维无序到三维有序排列的规律。研究结果表明:随着石墨化温度的升高,石墨微晶层间距逐渐减小,晶粒尺寸变大,同时石墨微晶的d002与La的倒数具有一定的线性关系;同时研究了不同石墨化温度对二次颗粒电化学性能的影响,二次颗粒的首次比容量、首次效率及真密度随石墨化温度的升高而增加;温度在2500℃及以上时,充放电曲线呈U型且存在稳定的电压平台;石墨化温度在3 000℃时,油系针状焦的首次比容量和首次库伦效率分别可达343 mAh/g、94.7%。
The effects of different graphitization temperatures of 1 500~3 000 ℃ on the interlayer spacing,microcrystal stacking thickness(Lc) and microcrystal basal plane width(La) of secondary particle graphite using oil-based needle coke as raw material are investigated. The evolution regularity of carbon atom arrangement changing from two-dimensional disorder to three-dimensional order is revealed. The research results show that with the increase of graphitization temperature,the interlayer spacing of graphite microcrystals gradually decreases,and the grain size increases. At the same time,the interplanar spacing(d002) of crystallized graphite has a certain linear relationship with the reciprocal of the crystallite basal plane width(La).The effects of different graphitization temperatures on the electrochemical properties of the secondary particles are also studied. The primary specific capacity,first efficiency and true density of secondary particles increase with the increase of graphitization temperature. When the temperature is 2 500 ℃ and above,the charge-discharge curve is U-shaped plot and a stable voltage platform exists. When the graphitization temperature is 3 000 ℃,the first capacity and the first Coulomb efficiency of the artificial graphite from oil-based needle coke can reach 343 mAh/g and 94.7%,respectively.
作者
廖林
尹伟乐
叶昱昕
Liao lin;Yin Wei-le;Ye Yu-xin(Guangdong Kaijin New Energy Co.,Ltd.,Guangdong Dongguan 523430,China)
出处
《炭素技术》
CAS
北大核心
2023年第1期46-50,共5页
Carbon Techniques
基金
广东省省级科技计划项目(2019A050510012)。
关键词
油系针状焦
石墨微晶
微观结构
石墨化温度
Oil-based needle coke
crystallized graphite
microstructure
graphitization temperature
