New insight into lattice variations of Ni-rich NMC811 cathode induced by Li2ZrO3coating

Ni-rich layered cathode LiNi0.8Mn0.1Co0.1O2 (NMC811) have been facing serious structural issues including high degree of Li/Ni mixing and poor surface stability, which lead to poor electrochemical cycling performances compared to other layered cathode with lower Ni content. Various surface coatings have been investigated to enhance the electrochemical performances of Ni-rich cathode. While, most work focus on the materials and methods of coating, and few has explored the subtle structural variations of cathode particles after coating. In this work, Li2ZrO3 coating induced structural variations of NMC811 have been carefully investigated. Ordered occupancy of Ni in Li slab with reduced Li/Ni mixing degree is firstly discovered after Li2ZrO3 coating. Moreover, the O–O distance becomes longer with less active O on surface, which can greatly suppress surface side reactions at high potentials. The obtained large reversible capacity and excellent capacity retention can be ascribed to the subtle structural variations of NMC811 after Li2ZrO3 coating.