J. Mater. Sci. Technol. ›› 2025, Vol. 215: 157-166.DOI: 10.1016/j.jmst.2024.05.083

• Research Article • Previous Articles     Next Articles

Nitrogen-based redox couple regulated anionic redox to long-term cycling stability of Li and Mn-rich layered oxide cathode for Li-ion batteries

Zhijun Wua,1, Chenchen Lia,1, Panyu Gaob, Xin Zhangc, Yue Lind, Xuebin Yub, Yongfeng Liuc,*, Wenping Sunc, Yinzhu Jiangc, Mingxia Gaoc, Hongge Pana,c,*, Yaxiong Yanga,*   

  1. aInstitute of Science and Technology for New Energy, Xi'an Technological University, Xi'an 710021, China;
    bDepartment of Materials Science, Fudan University, Shanghai 200433, China;
    cState Key Laboratory of Silicon and Advanced Semiconductor Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China;
    dHefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
  • Received:2024-03-27 Revised:2024-05-16 Accepted:2024-05-18 Published:2025-04-20 Online:2024-07-14
  • Contact: *E-mail addresses: mselyf@zju.edu.cn (Y. Liu), honggepan@zju.edu.cn, hgpan@zju.edu.cn (H. Pan), yangyaxiong@xatu.edu.cn (Y. Yang)
  • About author:1These authors contributed equally to this work.

Abstract: Lithium and manganese-rich layered oxides (LMROs) have attracted extensive attention and are promising cathode materials for next-generation lithium ion batteries due to their high capacities and high energy densities. However, LMRO cathode suffers from severe capacity and voltage fading originating from irreversible surface oxygen evolution. Herein, we propose a facile redox couple strategy by introducing nitroxyl radicals species to regulate the surface anionic redox reaction of LMRO cathode. Differential electrochemical mass spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses demonstrate that during charge process, the peroxide ion O22- on the surface generated from the oxidation of lattice O2- could be reduced back to stable O2- by redox couple in time, thus avoiding oxygen evolution and structure degradation, as well as enhancing bulk oxygen redox activity. The enhanced LMRO electrode delivers a high capacity of 220.3 mAh g-1 at 1 C. An excellent cycling stability with a capacity retention of 94.4 % is achieved after 500 cycles, as well as a suppressed voltage decay with only 1.12 mV per cycle.

Key words: Nitroxyl radicals, Redox couple, 2,2,6,6-tetramethylpiperidinooxy, Cycling stability, Li and Mn-rich layered oxides