Identifying and Addressing Critical Challenges of High-Voltage Layered Ternary Oxide Cathode Materials

Layered ternary oxide cathode materials LiNixMnyCo1–x–yO2 (NMC) and LiNixCoyAl1–x–yO2 (NCA) (referred to as ternary cathode materials, TCMs) with large reversible capacity, high operating voltage as well as low cost are considered as the most potential candidate materials for high energy density lithium ion batteries (LIBs) used in hybrid electric vehicles and electric vehicles (EVs). However, next-generation long-range EVs require an energy density of 800 W h kg–1 at the cathode level, which cannot be obtained using the commercially available TCMs. Developing high-voltage TCMs is a promising solution to enhance energy density of LIBs. Nonetheless, the capacity decay, poor long-term cycle life and microcrack at high operating voltage have limited their practical applications. In this paper, the development of the high-voltage TCMs is reviewed from degradation mechanism, cathode electrode modification, electrolyte design, solid state electrolytes and so on. The critical factors, recent progress and perspectives that improve the performance of TCMs with high-voltage operation are reviewed, which could provide important information and precautions to the practical use of these cathode materials under high operating voltage.