Research progress in degradation mechanism and modifi cation of high nickel layered cathode materials
Among the existing commercial positive electrodes,nickel-rich layered positive electrodes are widely used because of their high energy densi-ty,good rate performance and reasonable cycle performance.At present,the price of Co is much higher than that of Ni and Mn,and the research of cath-ode materials is advancing towards the direction of high nickel"less cobalt"or even"cobalt-free".In this paper,the research progress of high nickel layered cathode materials in recent years is reviewed,in order to provide important clues for the design and development of high nickel cathode in the fu-ture,and to promote its practical application.In this paper,we first introduce the main degradation mechanisms of high nickel cathode materials,inclu-ding surface/interface degradation,cationic mixing,electrode-electrolyte spontaneous parasitic reaction,gas precipitation and intergranular/intrachrys-talline cracking.Secondly,the modification and relevant progress of high nickel materials in recent years in terms of bulk phase doping,surface coating,composition adjustment and morphology engineering are reviewed.Finally,the future research direction and current technical challenges of high nickel cathode materials are prospected.
lithium ion batterylayered cathode materialultra high nickeldegradationmodification