Improving the Cycling Stability of LiNi0.8Co0.1Mn0.1O2 by Enhancing the Structural Integrity via Synchronous Li2SiO3 Coating

The strain variation of LiNi0.8Co0.1Mn0.1O2 (NCM) during cycling deteriorates its structural integrity and causes microcracks, resulting in a quick capacity decay. Enhancing NCM's structural integrity can suppress microcrack occurrence, thereby increasing its capacity retention. Here, we experimentally realize the microcrack suppression in NCM by enhancing its structural stability via the synchronous Li2SiO3 coating. The Li2SiO3-coated NCM (NCM@LSO) is prepared by the precoating and solid-state lithiation methods. NCM@LSO exhibits good structural integrity with a high capacity retention of 97% after 500 cycles at 0.5 C, while NCM suffers serious microcracks with only 79% capacity retention after 450 cycles at 0.5 C. The microscopies and elemental analysis support that Li2SiO3 coating not only stabilizes NCM's structural integrity by increasing its strain tolerance and avoiding microcrack occurrence but also affects the formation and distribution of a cathode electrolyte interphase on NCM. These effects result in the improved cycling stability of NCM@LSO. The work developed here sheds light on the development of high-performance NCM.