Effects of drying rate and slurry microstructure on the formation process of LiB cathode and electrochemical properties

The drying process of electrode slurry for LiB should be crucial to obtain higher electrochemical performance, but it has been a black box. Furthermore, the lack of sufficient information on slurry microstructure complicates solving this issue. In this study, the cathode slurries having different internal structures are prepared and characterized by rheological properties. The drying process of the coating layer is evaluated in terms of film shrinkage. When the coarse particles of active material and the network structure of acetylene-black particles are uniformly mixed, a low drying rate results in extensive particle segregation and poor cycle performance. On the other hand, it is found that insufficient dispersion of active materials causes poor rate performance. Under the optimal drying condition, the slurry microstructure is found not to affect battery performance. However, the optimization of drying conditions requires consideration of material mobility during drying.