硅-石墨/炭负极制备工艺对其性能的影响机制研究  

Study on influencing mechanism of preparation technology for Si-graphite/carbon cathode material on its performance

作　　者：羡小超[1] 向军[1] 张勇[1] 李立新[1] 孙雷明[1] 赵朔[1] 

机构地区：[1]重庆大学化学化工学院,重庆400030

出　　处：《化工新型材料》2015年第10期126-128,131,共4页New Chemical Materials

基　　金：国家自然科学基金(锂离子电池用具有空腔结构的Si/C复合负极材料的制备及储能机理研究;21203258);中央高校基本科研业务费项目(锂离子电池负极材料多孔Li4Ti5O12的制备及性能研究;CQDXWL-2013-018)

摘　　要：以马铃薯淀粉为炭源,制备硅-石墨/炭复合负极材料,研究复合材料中硅/石墨比例、负极片制备过程中粘结剂种类、调浆溶剂种类和pH值对材料电化学性能的影响,并对影响机理进行初步探讨,采用红外光谱法和扫描电镜分别对材料结构和形态进行表征,恒流充放电法测定材料的电化学性能。结果表明:当复合材料中硅/石墨比例为4∶8,羟甲基纤维素钠做粘结剂,pH=3的柠檬酸-氢氧化剂缓冲液做调浆溶剂时,复合材料经50次循环后可逆容量达到890mAh/g,容量保持率为95%,这是由于粘结剂和硅颗粒之间形成的酯键可使电极片在充放电过程中保持很好的完整性,从而显示出良好的电化学性能。Si-graphite/carbon cathode materials were prepared using potato starch as carbon resource.The effects of Si/graphite ratio,kinds of binder and solvent and pH of solvent on the electrochemical performance of composite were studied,and the influencing mechanism was investigated further.Fourier transform infrared spectrometer and scanning electron microscopy were used to characterize the structure and morphology of composite,respectively.Eelectrochemical performances were studied by galvanostatic charge-discharge method.The results indicated that a high capacity of 890mAh/g of the cathode materials was achieved after 50 cycles when Si/graphite ratio in composite was 4∶8,carboxymethyl cellulose（CMC）was as binder,and citric acid and KOH buffer solution at pH 3was as solvent.The ester bond formed between Si particles and CMC played an important role in maintained the integrity of electrode during charge and discharge.

关 键 词：锂离子电池 硅-石墨/炭负极材料 制备工艺 影响机制 

分 类 号：TB332[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]