CMC取代度对负极浆料流变性及分散稳定性的影响  

Effect of CMC on Rheological Properties and Dispersion Stability of Anode Slurry

作　　者：席孝敏 景希玮 徐健 公维光 郑柏存 XI Xiaomin;JING Xiwei;XU Jian;GONG Weiguang;ZHENG Baicun(School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China;Shanghai Sunrise Polymer Material Co.Ltd,Shanghai 200237,China;Shanghai Nanotechnology Promotion Center,Shanghai 200237,China)

机构地区：[1]华东理工大学材料科学与工程学院,上海200237 [2]上海三瑞高分子材料股份有限公司,上海200237 [3]上海市纳米科技与产业发展促进中心,上海200237

出　　处：《华东理工大学学报（自然科学版）》2019年第5期742-749,共8页Journal of East China University of Science and Technology

摘　　要：以羧甲基纤维素钠(CMC)为锂离子电池负极黏结剂,研究了CMC取代度(DS)对石墨负极浆料流变性、分散性以及稳定性的影响。结果表明,随着DS的增加,浆料的表观黏度逐渐增加,石墨颗粒表面Zeta电位逐渐增大,浆料分散性及稳定性逐渐增强。同时发现CMC掺量对负极浆料同样具有显著影响,当负极浆料中CMC(DS=1.2)掺量(质量分数)为1.5%时,浆料分散性最好,浆料稳定性趋于不变,制备的极片电阻率最小。Lithium ion batteries have been widely used in many fields such as electronic products,electric vehicles and large-scale energy storage materials due to their excellent performances.Binder directly affects the electrochemical properties of the battery,including the rate capacity,charge and discharge cycle stability and so on.Compared with the PVDF binder,the aqueous binder,sodium carboxymethyl cellulose (CMC),has a better dispersion stabilizing effect on the graphite anode slurry,which could be ascribed to the presence of carboxyl group and hydroxyl group on its molecular chain.The electrostatic repulsion generated by the hydroxyl groups on CMC chains make the graphite disperse homogenously.Accordingly,the substitution degree (DS) which is closely related to the content of carboxyl and hydroxyl groups may have remarkable influences on the dispersion of graphite.The influences of substitution degree of CMC on the rheological properties,dispersion and stability of graphite anode slurry,as well as the pole piece electrical resistivity,were studied in this paper.The mechanism of CMC on graphite slurry was also analyzed by scanning electron microscope (SEM) and Zeta potential.The results showed that the viscosity and stability of graphite slurry were enhanced,while the pole piece electrical resistivity was decreased with the gradual increase in the CMC substitution degree,which could be explained by the stronger electrostatic repulsions as measured by Zeta potential tests.Meanwhile,the content of CMC had significant effects on the rheological properties,stability and the pole piece electrical resistivity of the graphite slurry.The slurry showed the best stability and dispersion,also the pole piece displayed the lowest electrical resistivity in case the dosage of CMC was 1.5%.

关 键 词：羧甲基纤维素钠 取代度 流变 分散 稳定 

分 类 号：TM921.9[电气工程—电力电子与电力传动]