Coating slurries for making anodes and cathodes of lithium batteries contain a large percentage of solid particles of different chemicals, sizes and shapes in highly viscous media. A thorough mixing of these slurries poses a major challenge in the battery manufacturing process. Several types of mixing devices and mixing methods were examined. The conventional turbine stirrers or ball mill mixers could be adequately used for the preparation of anode slurries, but not suitable for cathode slurries. In this study, a newly three-dimensional mixer, in conjunction with a multi-stage mixing sequence was proposed. The mixing effectiveness was examined by means of rheological measurements and flow visualization techniques. Preliminary electrical performance results indicated that the battery obtained using the 3D mixing device with a multi-stage mixing sequence was more efficient to those obtained from conventional methods.

The cathode and anode electrodes in lithium‐ion batteries typically contain a significant proportion of particles and binders. During the electrode drying process, high temperature will lead to the binder migration phenomenon. Uneven particle/binder distribution can cause poor adhesion between coating and substrate, disruption of conductive paths, and decrease in electrode performance. In this study, a two‐layered cathode was designed by using separate compositions of slurry ingredients in each layer, as produced by means of a simultaneous multilayer coating method. The two‐layered cathode with the top layer containing less binder than the bottom layer yielded a better particle/binder distribution in the final structure under high‐temperature drying. A battery made with the two‐layered cathode appeared to give a better overall performance.

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