posted on 2022-04-08, 16:08authored byYide Qiao, Ronghui Hao, Xiaowei Shi, Yingbo Li, Yaling Wang, Yan Zhang, Cheng Tang, Guohong Li, Guolong Wang, Jiamei Liu, Heguang Liu, Yuanzhen Chen, Qianqian Li, Lei Li
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.