热处理石油焦用作锂离子蓄电池碳负极的研究

Investigation of heat-treated petroleum cokes as negative electrode for lithium ion batteries

研究了经不同温度热处理后石油焦在 1mol/LLiClO4/EC +DEC(1∶1)溶液体系中作为锂离子电池负极的充放电性能 ,分析了热处理后石油焦的结构与其充放电性能之间的关系 ,借助傅里叶红外光谱 (FTIR)推断了初次充电时形成固体电解质中间相膜 (SEI膜 )的反应机理 ,并利用原位X射线衍射法 (In situXRD)观察了充放电过程中锂离子插入、脱出碳电极石墨层间形成Li C石墨层间化合物 (Li GIC)所出现的阶转变。实验表明 ,经 30 0 0℃热处理后的抚顺石油焦具有 2 50mAh/ g的容量和超过 50 0次的循环寿命 (循环伏安法 ) 。

Electrochemical performance of one kind of petroleum cokes prepared at different heat treatment temperature (HTT) as a negative electrode for lithium ion batteries with LiClO 4 in a mixture electrolyte (1∶1) of ethylene carbonate (EC) and diethyl carbonate (DEC) were investigated. The relationship between structure and charge/discharge performance of the petroleum coke was analyzed and the structure transition of the lithium graphite intercalation compound was determined by in situ X ray diffraction (in situ XRD). The reaction mechanism of forming solid electrolyte interphase film (SEI) was concluded by FTIR spectrum measurement. The results show that the petroleum coke being heat treated at 3000 ℃ becomes an excellent negative electrode material for lithium ion batteries for its advantages of high capacity, high cycling efficiency and long cycle life.