Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (12): 3733-3740.doi: 10.19799/j.cnki.2095-4239.2022.0382

• Energy Storage Materials and Devices • Previous Articles     Next Articles

Effect of anionic redox reaction on lithium-rich manganese-based materials and its modification strategy

Junfei ZHOU1(), Xingpeng CAI1, Hao DING1, Xiaoling CUI1,2()   

  1. 1.College of Petrochemical Technology, Lanzhou University of Technology
    2.Gansu Key Laboratory of Low Carbon Energy and Chemical Engineering, Lanzhou 730050, Gansu, China
  • Received:2022-07-07 Revised:2022-08-06 Online:2022-12-05 Published:2022-12-29
  • Contact: Xiaoling CUI E-mail:zjf20001018@163.com;xlcuilw@163.com

Abstract:

Cathode materials with high energy density, high power density, and long cycle life are the focus of current research on battery energy storage materials and are also in high demand in the energy storage market. Lithium-rich manganese-based oxide (LRMO) cathode materials are some of the most promising cathode materials owing to their high discharge specific capacity (≥250 mAh/g), high operating voltage (4.2~4.5 V vs. Li/Li+), low cost, and environmental friendliness. Although the sequential or simultaneous redox of cations and anions of LRMO materials results in their enhanced capacity compared with other conventional layered oxides, several problems such as high irreversible capacity for the first cycle and poor cycling and rate performance hinder their engineering applications, which are closely related to the anionic redox reactions in the materials. This paper introduces the crystal structure of LRMO materials and then reviews the relationship between the energy band structure of LRMO materials and anionic redox reactions based on molecular orbital theory. In addition, the effects of anionic redox reactions on LRMO cathode materials, including high capacity, irreversible oxygen loss, and transition metal ion migration, are summarized. Moreover, recent modification strategies for mitigating the negative effects of anionic redox reactions are summarized from three perspectives: transition metal ratio adjustment, surface modification, and ion doping. Finally, the paper discusses the future theoretical and application direction of LRMO materials.

Key words: lithium-ion batteries, lithium-rich manganese based, cathode material, anionic redox, modification strategy

CLC Number: