Boosting reversible anionic redox reaction with Li/Cu dual honeycomb centers

• DOI: 10.1016/j.esci.2023.100159
• Publication Date: 2023-07-12T06:31:38Z
• Authors: Xiaohui Rong; Dongdong Xiao; Qinghao Li; Yaoshen Niu; Feixiang Ding; Xueyan Hou; Qiyu Wang; Juping Xu; Chenglong Zhao; Dong Zhou; Ruijuan Xiao; Xiqian Yu; Wen Yin; Lin Gu; Hong Li; Xuejie Huang; Liquan Chen; Yong-Sheng Hu
• Keywords: Cationic polymerization

The anionic redox reaction (ARR) is a promising charge contributor to improve the reversible capacity of layered-oxide cathodes for Na-ion batteries; however, some practical bottlenecks still need be eliminated, including low retention, large voltage hysteresis, and rate capability. Herein, we proposed high-Na content honeycomb-ordered cathode, P2-Na5/6[Li1/6Cu1/6Mn2/3]O2 (P2-NLCMO), with combined cationic/anionic redox. Neutron powder diffraction X-ray P2-NLCMO suggested P2-type stacking rarely found P6322 symmetry. In addition, advanced spectroscopy techniques density functional theory calculations confirmed synergistic stabilizing relationship between Li/Cu dual honeycomb centers, achieving fully active Cu3+/Cu2+ stabilized ARR interactively suppressed local distortion. With meticulously regulated charge/discharge protocol, both cycling capability were significantly improved, demonstrating reasonable eliminating hysteresis. Overall, this work contributes well-defined layered oxide cathode towards rational designing batteries.