储能科学与技术 ›› 2022, Vol. 11 ›› Issue (12): 3733-3740.doi: 10.19799/j.cnki.2095-4239.2022.0382

• 储能材料与器件 • 上一篇    下一篇

阴离子氧化还原反应对富锂锰基正极材料的影响及其改性策略

周俊飞1(), 蔡星鹏1, 丁浩1, 崔孝玲1,2()   

  1. 1.兰州理工大学石油化工学院
    2.甘肃省低碳能源化工重点实验室,甘肃 兰州 730050
  • 收稿日期:2022-07-07 修回日期:2022-08-06 出版日期:2022-12-05 发布日期:2022-12-29
  • 通讯作者: 崔孝玲 E-mail:zjf20001018@163.com;xlcuilw@163.com
  • 作者简介:周俊飞(2000—),男,硕士研究生,研究方向为锂离子电池正极材料,E-mail:zjf20001018@163.com
  • 基金资助:
    甘肃省产业支撑计划项目(2021CYZC-18);甘肃省重点研发项目(21YF5GA079)

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

摘要:

兼具高能量密度、高功率密度、长循环寿命性能的正极材料是当下电池储能材料研究的重点,也是储能市场的重要需求。富锂锰基正极材料(LRMO)因其极高的放电比容量(≥250 mAh/g)、较高的工作电压(4.2~4.5 V vs. Li/Li+)、低成本且环境友好等优点成为当下最具应用前景的正极材料之一。虽然金属阳离子和阴离子依次或同时进行的氧化还原反应使LRMO材料的容量超过了传统层状氧化物,但首次不可逆容量高、循环和倍率性能较差等一系列的问题阻碍了其工程化应用,这与材料中阴离子氧化还原反应紧密相关。本文首先介绍了LRMO材料的晶体结构,然后基于分子轨道理论,回顾了LRMO材料的能带结构与阴阳离子氧化还原反应的联系,总结了阴离子氧化还原反应对富锂锰基正极材料的影响,包括高容量、不可逆的氧流失、过渡金属离子迁移。同时,分别从过渡金属比例调节、表面修饰、离子掺杂三个方面总结了近些年国内外研究人员针对阴离子氧化还原反应造成的负面影响设计的改性策略。最后展望了LRMO材料理论研究与应用研究的大致方向。

关键词: 锂离子电池, 富锂锰基, 正极材料, 阴离子氧化还原, 改性策略

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

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