Layered Cathode Materials: Precursors, Synthesis, Microstructure, Electrochemical Properties, and Battery Performance

The exploitation of clean energy promotes the exploration of next‐generation lithium‐ion batteries (LIBs) with high energy‐density, long life, high safety, and low cost. Ni‐rich layered cathode materials are one of the most promising candidates for next‐generation LIBs. Numerous studies focusing on the synthesis and modifications of the layered cathode materials are published every year. Many physical features of precursors, such as density, morphology, size distribution, and microstructure of primary particles pass to the resulting cathode materials, thus significantly affecting their electrochemical properties and battery performance. This review focuses on the recent advances in the controlled synthesis of hydroxide precursors and the growth of particles. The essential parameters in controlled coprecipitation are discussed in detail. Some innovative technologies for precursor modifications and for the synthesis of novel precursors are highlighted. In addition, future perspectives of the development of hydroxide precursors are presented. The electrochemical performance of a layered cathode material in practical use largely depends on the precursor, since the former inherits the density and sphericity of the secondary particles as well as the arrangement, orientation, and exposed facets of the primary particles from the latter. Besides, modifications on a precursor can also endow the cathode with improved performance.