用超声/电声谱监测锂电池正极浆料的合浆及包覆质量  

Monitoring particle mixing and coating of LFP slurry of lithium battery by ultrasonic/electro acoustic spectroscopy

作　　者：杨正红 李萍 王莘泉 刘春燕 YANG Zhenghong;LI Ping;WANG Xinquan;LIU Chunyan(Insearch Technology Development Beijing Co.,Ltd.,Beijing 100096,China;China Aviation Lithium Battery(Luoyang)Co.,Ltd.,Luoyang Henan 471031,China)

机构地区：[1]仪思奇(北京)科技发展有限公司,北京100096 [2]中航锂电(洛阳)有限公司研究院,河南洛阳471031

出　　处：《电源技术》2024年第2期284-288,共5页Chinese Journal of Power Sources

摘　　要：在前期工作的基础上,利用超声/电声学方法对锂电池浆料合浆工艺的质量控制参数进行了探索,对不同来源和不同批次的N-甲基吡咯烷酮(NMP)体系磷酸铁锂电池(LFP)浆料进行了粒度、zeta电位及其微观电学参数的测定。结果显示,对于分散较好的合格样品,浆料的粒度、zeta电位、表面电荷密度可基本重现;而对于原料粒度检测不合格的样品,不仅浆料粒度分布呈现双峰,zeta电位有较大的波动,且表面电荷密度降低,批次间不稳定。研究表明,超声法直接测定锂电池合浆过程中的原浓浆料粒度直观有效,对于工艺质控非常重要;在合浆过程中,因导电添加剂团聚的存在,很难均匀包覆在LFP颗粒上。因此,zeta电位和双电层厚度可以成为导电剂是否分散和包覆均匀的关键质量控制参数。On the basis of previous work,the quality control parameters of the slurry mixing process of lithium battery slurry were explored by ultrasonic/electroacoustic methods,and the particle size,zeta potential and micro electrical parameters of lithium iron phosphate(LFP)slurry with NMP system from different sources and batches were measured.The results show that the particle size,zeta potential and surface charge density of the slurry can be basically reproduced for the qualified samples with good dispersion;for the samples with unqualified raw material on particle size,the size distribution of the slurry shows double peaks,the zeta potential fluctuates greatly,and the surface charge density decreases with poor reproducibility between the batches.The results imply that it is very important to determine directly the particle size of the concentrated slurry during the slurry mixing by ultrasonic method for the process quality control.In the process of slurry mixing,LFP particles are difficult to be coated uniformly by the conductive additive due to its agglomeration.Therefore,the zeta potential and the double layer thickness can be the key quality control parameters characterized for the additive dispersion and coating uniformity.

关 键 词：超声法 锂电池 合浆 粒度分布 ZETA电位 表面电荷 双电层厚度 颗粒包覆 

分 类 号：TM912.9[电气工程—电力电子与电力传动]