石墨化中间相炭微球作为锂离子电池负极材料性能的研究

Performance of Graphitized MCMB as Anode Material for lithium Ion Batteries

研究了石墨化中间相炭微球(MCMB)及其粒径分布对锂离子电池电化学性能的影响。采用激光粒度分析仪、扫描电子显微镜、X射线衍射仪和半电池组装对MCMB进行了物理结构表征和电化学性能测试。结果表明,MCMB均具有良好的表面层状堆积结构和石墨化结构;电极材料的首次充放电容量与MCMB的粒径大小呈正相关性,当MCMB的粒径(d_(50))从6.9μm递增到14.2μm时,负极材料的首次充电容量相应从319.0 mAh/g增加到346.3 mAh/g,首次库伦效率>80%,并表现出优异的循环充放电稳定性;粒径大的MCMB在循环充放电过程中,维持了较高充放电容量,d50为14.2μm的MCMB负极材料经100次循环充放电后,其容量保持为329.0 mAh/g,表现出优异的电化学性能。

The effect of graphitized MCMB and its particle size on the performance of lithium-ion battery was studied. The physical structure and electro-chemical properties of MCMB were characterized by laser particle size analyzer, scanning electron microscope, X-ray diffractometer and half-cell assembly. The results showed that MCMB with different particle size has good surface layered stacking and graphitization structure. The electrochemical properties showed that the first charge and discharge capacity are proportional to the particle size of MCMB. When the D50 of MCMB increases from 6.9 μm to 14.2 μm, the first discharge capacity of anode material increases from 319.0 mAh/g to 346.3 mAh/g, and the first coulomb efficiency reaches above 80%. MCMB with large particle size maintained a high charge discharge capacity during the cycle process. After 100 cycles of charge discharge, the capacity of MCMB with D_(50) of 14.2 μm was 329.0 mAh/g, displaying excellent electrochemical performance.