Research Progress on Coating and Doping Modification of Nickel Rich Ternary Cathode Materials

Abstract

In recent years, the development of new energy vehicles industry is accelerating. Lithium nickel cobalt manganese/aluminum oxide ternary cathode materials (NCM/NCA), especially with the nickel content ≥50%, has aroused great interest in both academia and industry. This is mainly due to the fact that the aggregative parameters of performance and cost of NCM/NCA are superior to those of traditional cathode materials, such as LiCoO 2 and LiFePO 4. However, the application of NCM/NCA is affected by a number of drawbacks, including poor safety and insufficient cycle stability and so on, which are mainly attributed to its crystal and surface structure. Researchers have carried out various efforts to solve these problems and further improve the performance of NCM/NCA. Some remarkable results have been achieved in the past few years. In this review, the latest research progress on coating and doping of Ni-rich ternary cathode materials is summarized from the view on the mechanism of structural and electrochemical improvement of NCM/NCA. Finally, the perspective for the development of NCM/NCA cathode materials is also prospected.

Scalable Advanced Li(Ni0.8Co0.1Mn0.1)O2 Cathode Materials from a Slug Flow Continuous Process

“…However, during the continuous charge–discharge cycling, the transformation of Ni 4+ into the lower valent nickel oxides causes an abrupt phase change from layered to rocksalt structure. , The change in crystal structure facilitates the consumption of exposed active Li + by electrolyte leading to the formation of cathode electrolyte interface (CEI), resulting in the reduction of discharge capacity of the active material . Besides this, the corrosion of cathode material by HF, cation mixing, and the formation of an inert layer of Li 2 CO 3 /LiOH on the surface of active material are a few of the standing issues with the layered NCM811, which are required to be addressed. − Various modification techniques, including coating, doping, morphology design, and regulating the crystal structure, are already reported in the literature to overcome the aforementioned limitations. − …”

“… 16 Besides this, the corrosion of cathode material by HF, cation mixing, and the formation of an inert layer of Li 2 CO 3 /LiOH on the surface of active material are a few of the standing issues with the layered NCM811, which are required to be addressed. 18 − 22 Various modification techniques, including coating, doping, morphology design, and regulating the crystal structure, are already reported in the literature to overcome the aforementioned limitations. 23 − 25 …”