溶剂法处理锂电池黏结剂PVDF的试验研究  

Experimental Study on Solvent Treatment of Lithium Battery Binder PVDF

作　　者：周起帆 郑朝振 秦树辰 王子豪 王海北 ZHOU Qifan;ZHENG Zhaozhen;QIN Shuchen;WANG Zihao;WANG Haibei(BGRIMM Technology Group,Beijing 100160,China)

机构地区：[1]矿冶科技集团有限公司,北京100160

出　　处：《中国资源综合利用》2024年第9期20-23,27,共5页China Resources Comprehensive Utilization

基　　金：国家重点研发计划(2023YFC3905901)。

摘　　要：作为一种油性黏结剂,聚偏二氟乙烯(Polyvinylidene Fluoride,PVDF)在电池充放电的电势范围内具有化学惰性,不会与电解质或锂发生反应。因此,锂电池正极通常采用PVDF作为黏结剂。试验采用溶剂法处理锂电池黏结剂,以有机溶剂为载体,配制一定浓度梯度的PVDF溶液,通过黏度计测定溶液黏度,分析不同有机溶剂对PVDF的溶解性能。其中,单组分有机溶剂有6种,即N-甲基-2-吡咯烷酮、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺、二甲亚砜、甲基丙烯酸甲酯和四氢呋喃;双组分有机溶剂有1种,由N,N-二甲基甲酰胺和N,N-二甲基乙酰胺(体积比1∶1)配制而成;三组分有机溶剂有1种,由N-甲基-2-吡咯烷酮、N,N-二甲基甲酰胺和N,N-二甲基乙酰胺(体积比1∶2∶2)配制而成。试验结果表明,不同有机溶剂对PVDF的溶解效果存在差异,但多数溶剂配制的PVDF溶液黏度变化规律一致。随着浓度的增加,PVDF溶液的黏度一般呈指数型增长。相比单组分有机溶剂,多组分有机溶剂溶解PVDF时,PVDF溶液黏度的改善效果不佳。经综合比较,工业应用选择N,N-二甲基甲酰胺、N,N-二甲基乙酰胺作为最佳PVDF溶剂。As an oily binder,Polyvinylidene Fluoride (PVDF) exhibits chemical inertness within the potential range of battery charging and discharging,and does not react with electrolytes or lithium.Therefore,PVDF is usually used as a binder for the positive electrode of lithium batteries.In this experiment,the solvent method is used to treat lithium battery binder,and the organic solvents is taken as carriers to prepare a PVDF solution with a certain concentration gradient,and the viscosity of the solution is measured by a viscometer to analyze the solubility of PVDF in different organic solvents.Among them,there are six types of single component organic solvents,namely N-methyl-2-pyrrolidone,N,N-dimethylformamide,N,N-dimethylacetamide,dimethyl sulfoxide,methyl methacrylate,and tetrahydrofuran;there is one type of two-component organic solvent,which is prepared by mixing N,N-dimethylformamide and N,N-dimethylacetamide (volume ratio 1∶1);there is one type of three component organic solvent,which is prepared by mixing N-methyl-2-pyrrolidone,N,N-dimethylformamide,and N,N-dimethylacetamide (volume ratio 1∶2∶2).The experimental results show that there are differences in the dissolution effect of PVDF by different organic solvents,but the viscosity change pattern of PVDF solutions prepared with most solvents is consistent.As the concentration increases,the viscosity of PVDF solution generally increases exponentially.Compared to single component organic solvents,the improvement effect of viscosity of PVDF solution is not significant when dissolved in multi-component organic solvents.After comprehensive comparison,N,N-dimethylformamide and N,N-dimethylacetamide are selected as the best PVDF solvents for industrial applications.

关 键 词：溶剂法 锂电池 黏结剂 聚偏二氟乙烯(PVDF) 萃取 黏度 N N-二甲基甲酰胺 N N-二甲基乙酰胺 

分 类 号：X705[环境科学与工程—环境工程]