锂离子电池浆料高效循环制备工艺

High efficiency circular pulping process of Li-ion battery

近两年,有别于传统搅拌机及双螺杆的锂离子电池高效循环制浆系统出现。为了解适用于高效匀浆系统的工艺流程,采用干法和湿法工艺,制备固含量为62%的磷酸铁锂浆料和52%的石墨浆料。相较于干法,采用湿法工艺能解决胶粉在短时间内溶解和各组分均匀混合的问题。湿法工艺的正极浆料,黏度比干法低10300 mPa·s,高速剪切后10 s的反弹率比干法高3.6%,细度比干法更小,四探针电阻率比干法低0.0410Ω·cm,极片黏结力比干法高76.46%。负极浆料,高速剪切后10 s的反弹率比干法高2.2%,触变环的面积比干法低45.5%。SEM分析表明,干法浆料比湿法浆料团聚严重,进一步说明无论是正极还是负极,湿法制浆工艺更适合高效循环制浆系统。

In the past two years,a high-efficiency circulating slurry system for Li-ion battery has emerged,which is different from traditional mixers and twin screws pulping.To understand the suitable process flow for efficient homogenization systems,lithium iron phosphate slurry with a solid content of 62%and graphite slurry with a solid content of 52%are prepared using dry and wet processes.Compared to the dry process,using the wet process can solve the problem of short-term dissolution of rubber powder and uniform mixing of various components.The viscosity of the cathode slurry in the wet process is 10300 mPa·s lower than that of the dry method.The rebound rate after 10 s of high-speed shear is 3.6%higher than that of the dry method,the fineness is smaller than that of the dry method.The internal resistance of the four probes is 0.0410Ω·cm lower than that of the dry method,the electrode bonding force is 76.46%higher than that of the dry method.The rebound rate of the anode slurry after high-speed shear for 10 s is 2.2%higher than that of the dry method,the area of the thixotropic ring is 45.5%lower than that of the dry method.According to SEM analysis,the agglomeration of dry process slurry is more severe than that of wet process slurry,further revealing that wet process slurry is more suitable for efficient circulating pulping systems,regardless of the cathode or anode.