Enhanced Activity and Reversibility of Anionic Redox by Tuning Lithium Vacancies in Li-Rich Cathode Materials

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

View graph of relations

Author(s)

  • Shihao Li
  • Haiyan Zhang
  • Shuai Zhang
  • Bin Zhu
  • Sha Wang
  • Jingqiang Zheng
  • Fangyan Liu
  • Zhian Zhang
  • Yanqing Lai

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)39480–39490
Journal / PublicationACS Applied Materials and Interfaces
Volume13
Issue number33
Online published12 Aug 2021
Publication statusPublished - 25 Aug 2021

Abstract

Li-rich Mn-based layered oxide cathodes (LLOs) are considered to be the most promising cathode candidates for lithium-ion batteries owing to their high-voltage platform and ultrahigh specific capacity originating from anionic redox. However, anionic redox results in many problems including irreversible oxygen release, voltage hysteresis, and so on. Although many efforts have been made to regulate anionic redox, a fundamental issue, the effect of lithium vacancies on anionic redox, is still unclear. Herein, we synthesized a series of LLO materials with different lithium vacancy contents by controlling the amount of lithium salt. Specifically, lithium-vacancy-type LLOs Li1.11Ni0.18Co0.18Mn0.53O2 with a pompon morphology exhibit an ultrahigh specific capacity (293.9 mA h g-1 at 0.1 C), an outstanding long-term cycling stability (173.5 mA h g-1 after 300 cycles at 1 C), and an excellent rate performance (106 mA h g-1 at 10 C). It reveals that lithium vacancy is a key factor to enhance anionic redox activity and reversibility. Lithium vacancies exhibit different inductive effects on the structure of the surface and bulk. Abundant surface oxygen vacancies and a surface spinel phase layer induced by lithium vacancies suppress irreversible oxygen release, while the bulk phase transformation and cation disorder combined with sufficient lithium vacancies in the bulk stabilize structure and improve anionic redox kinetic. The findings offer a significant theoretical guidance for the practical application of LLO materials.

Research Area(s)

  • activity, anionic redox, Li-rich cathode, lithium vacancy, reversibility

Citation Format(s)

Enhanced Activity and Reversibility of Anionic Redox by Tuning Lithium Vacancies in Li-Rich Cathode Materials. / Li, Shihao; Zhang, Haiyan; Li, Huangxu; Zhang, Shuai; Zhu, Bin; Wang, Sha; Zheng, Jingqiang; Liu, Fangyan; Zhang, Zhian; Lai, Yanqing.

In: ACS Applied Materials and Interfaces, Vol. 13, No. 33, 25.08.2021, p. 39480–39490.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review