基于氢键相互作用构建三维网络型粘接剂及在锂电池中的应用  

Three-dimensional Network Binder via Hydrogen Bonding Interaction for Silicon Anode in Lithium Ion Batteries

作　　者：靳玲玲 郭盼龙 许钰婷 陈佳欣 马宇婷 李素丽 李真 Jin Lingling;Guo Panglong;Xu Yuting;Chen Jiaxin;Ma Yuting;Li Suli;Li Zhen(Zhuhai CosMX Power Battery Co.,Ltd.,Zhuhai 519600;Zhuhai CosMX Battery Co.,Ltd.,Zhuhai 519600;School of Materials and Environment,Beijing Institute of Technology,Zhuhai 519600,China)

机构地区：[1]珠海冠宇动力电池有限公司,广东珠海519600 [2]珠海冠宇电池股份有限公司,广东珠海519600 [3]北京理工大学珠海学院材料与环境学院,广东珠海519600

出　　处：《广东化工》2023年第19期10-12,共3页Guangdong Chemical Industry

基　　金：2023年北京理工大学珠海学院大学生创新创业项目资助(2023027DCXM)。

摘　　要：硅负极具有较高的理论克容量,利用硅负极替代石墨负极是提升锂离子电池容量最有效的方法。但硅负极充放电过程中存在体积膨胀变化大,容易造成粘接网络破损、极片脱模等问题,传统的PAA、PVA、PVDF、CMC等粘接剂无法很好地解决此问题。本文利用刚性聚丙烯酸和柔性聚环氧乙烷通过氢键结合,构建具有刚柔并济型的新型粘接剂网络,很好适应硅负极体积膨胀,提升硅负极循环容量保持率,降低电芯厚度增长率。本文通过核磁表征了粘接剂的结构,利用剥离力测试表征了极片粘接强度;并将该粘接剂组装成软包全电池,评估了电化学阻抗(EIS)和不同温度循环性能。结果显示,采用新型粘接剂电池的循环性能得到显著改善,与纯PAA相比,常温循环600 T,容量保持率由85.7%提升到90.2%;45℃循环600T,容量保持率由80.1%提升到85.2%。此外,采用PAA-PEO复合物粘接剂电芯的厚度显著下降,膨胀得到改善。Since silicon anode has a very high theoretical capacity,the use of silicon anode instead of graphite anode is the most effective way to improve the capacity of lithium-ion batteries.However,during the charging and discharging process of silicon anode,there are large changes in volume expansion,which is easy to cause problems such as bonding network damage and demolding of the electrode piece.Traditional Si anode binder such as PAA,PVDF,CMC and other binder cannot completely solve this problem.In this paper,rigid polyacrylic acid and flexible polyethylene oxide are used to construct a novel adhesive network with soft and hard phases by hydrogen bonding composite.The binder can be well adapted to the volume expansion of silicon anode,improves the retention rate of silicon anode cycle capacity,and reduces the growth rate of cell thickness.We characterized the structure of the adhesive by infrared and nuclear magnetism,and the bond strength of the pole piece by peeling force test.Assemble this adhesive into a pouch full battery.The performance of different temperature cycles discharge performance were further evaluated.The results show that the cycle performance of battery with new binder is significantly improved,and the capacity retention rate is increased from 85.7%to 90.2%compared with pure PAA with a room temperature cycle of 600 T.After cycling 600 T at 45℃,the capacity retention rate is increased from 80.1%to 85.2%.In addition,the thickness of the cells using the PAA-PEO composite adhesive is significantly reduced and the expansion is improved.

关 键 词：锂离子电池 硅负极 粘接剂 聚合物复合物 软硬段 

分 类 号：TQ[化学工程]