Sb@Ni6 Superstructure Units Stabilize Li-Rich Layered Cathode in the Wide Voltage Window

• DOI: 10.2139/ssrn.4157514
• Publication Date: 2022-07-10T10:59:12Z
• Authors: Bo Cao; Yiwei Li; Mingjian Zhang; Ningyan Cheng; Ming Shen; Bingwen Hu; Jianyuan Li; Zhibo Li; Shenyang Xu; Wenguang Zhao; Ni Yang; Junliang Sun; Shixue Dou; Yang Ren; Haibiao Chen; Liang Yin; Feng Pan
• Keywords: Superstructure

In the practical operations of Li-ion batteries, inevitable deep charge/discharge happens locally due to intrinsic (de)lithiation inhomogeneity at electrode and particle level, which would damage health batteries even cause safety concern. It is essential develop stable cathodes operating in a wide voltage window ensure batteries. Herein, we comprehensively investigate behaviors representative Li-rich cathode Li1.2Mn0.54Ni0.13Co0.13O2 1.0-4.8 V, reveal that, deep-lithiation drive violent TM migration severe Li/TM mixing, thereby leading irreversible structural transformation from layered spinel then rock salt, eventually causing fast decay electrochemical performance. Based on these understandings, novel Li[Li1/4Mn1/2Ni1/6Sb1/12]O2 successfully synthesized through introducing aromatic Sb@Ni6 superstructure units layers. The introduced can effectively tune local oxygen environment, suppress migration, stabilize framework under lithiation. Finally, achieved V. This work deepens understanding into stability window, benefits development high-energy-density safe cathodes.