功能化PVDF粘结剂的制备及在锂电池正极中的应用  

Preparation of Functionalized Binder and Application to NCM811 Lithium Cathode Battery System

作　　者：石元昊 李智琪 付玉林 桂雪峰 许凯[1,2] SHI Yuanhao;LI Zhiqi;FU Yunlin;GUI Xuefeng;XU Kai(Guangzhou Institute of Chemistry,Chinese Academy of Sciences,Guangzhou 510650,China;University of Chinese Academy of Sciences,Beijing 100049,China;CAS Engineering Laboratory for Special Fine Chemicals,Guangzhou 510650,China;CASH GCC Shaoguan Research Institute of Advanced Materials,Shaoguan 512400,China;CASH GCC Fine Chemicals Incubator(Nanxiong)Co.,Ltd,Nanxiong 512400,China)

机构地区：[1]中国科学院广州化学研究所,广东广州510650 [2]中国科学院大学,北京101408 [3]中国科学院新型特种精细化学品工程实验室,广东广州510650 [4]国科广化韶关新材料研究院,广东韶关512400 [5]国科广化(南雄)新材料研究院有限公司,广东南雄512400

出　　处：《广州化学》2024年第6期7-11,I0001,共6页Guangzhou Chemistry

基　　金：中国科学院科技服务网络计划(No.20211600200052)。

摘　　要：以N-三氟甲磺酰基对苯乙烯磺酰亚胺锂(LiSTSI)为接枝单体,通过紫外对聚(偏二氟乙烯-co-六氟丙烯)(PVDF)进行接枝功能化改性,引入了具有良好锂离子传导性的阴离子聚合物,将其作为聚电解质型粘结剂STSI,应用于三元正极LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)体系中。利用核磁共振氢谱(^(1)H-NMR)和氟谱(^(7)F-NMR)表征了STSI粘结剂的结构,利用180°剥离实验和接触角实验测试了STSI粘结剂的物理性能,采用倍率测试和长循环测试评价了SISI粘结剂的电化学性能。结果表明,这种功能性阴离子支链的引入可以有效地提高PVDF粘结剂的粘结强度,并且在正极中形成锂离子传导路径改善正极电化学反应,在0.2C倍率下经过100圈的循环,基于STSI粘结剂的电池依然保持着177.2mAh/g比容量,并且在循环过程中保持着平均99.1%的效率。Lithium N-trifluoromethanesulfonyl p-styrenesulfonimide(LiSTSI)was used as a grafting monomer,and an anionic polymer with good lithium ion conductivity was introduced by UV graft-functionalized modification of poly(vinylidene difluoride-co-hexafluoropropylene)(PVDF)as a polyelectrolyte-type binder STSI,and was applied in a ternary cathode LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)system.The structure of the STSI binder was characterized using nuclear magnetic resonance hydrogen spectroscopy(^(1)H-NMR)and fluorine spectroscopy(^(7)F-NMR),the physical properties of the STSI binder were tested using 180°stripping experiment and contact angle experiment,and the electrochemical properties of the SISI binder were evaluated using multiplicity test and long cycle test.The results show that the introduction of this functional anionic branched chain can effectively improve the bond strength of the PVDF binder and form a lithium-ion conduction path in the cathode to improve the cathode electrochemical reaction,and after 100 cycles at a multiplicity of 0.2 C,the battery based on the STSI binder still maintains a specific capacity of 177.2 mAh/g,and maintains an average of 99.1%during the cycling process.

关 键 词：PVDF N-三氟甲磺酰基对苯乙烯磺酰亚胺锂(LiSTSI) 正极粘结剂 锂电池正极材料 高离子电导性 

分 类 号：TQ314[化学工程—高聚物工业]