Electrochemical Energy Reviews ›› 2019, Vol. 2 ›› Issue (2): 277-311.doi: 10.1007/s41918-019-00032-8

Special Issue: Fundamental Electrochemistry

Previous Articles     Next Articles

Li-Rich Layered Oxides and Their Practical Challenges: Recent Progress and Perspectives

Sijiang Hu1,2, Anoop. S. Pillai1, Gemeng Liang1, Wei Kong Pang1, Hongqiang Wang3, Qingyu Li3, Zaiping Guo1   

  1. 1 Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Innovation Campus, North Wollongong, NSW 2500, Australia;
    2 Hubei Key Laboratory for Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, China;
    3 School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China
  • Received:2018-12-15 Revised:2019-02-07 Online:2019-06-20 Published:2019-06-28
  • Contact: Wei Kong Pang, Zaiping Guo E-mail:wkpang@uow.edu.au;zguo@uow.edu.au
  • Supported by:
    This review was conducted with the support of the Australian Research Council (ARC) through the Future Fellowship projects (FT150100109 and FT160100251) and funding from the NSFC (51474110), the Natural Science Foundation of Hubei Province (2018CFB192) and the CSC (201608420205). We would also like to thank Dr. Tania Silver for her critical review of the manuscript and her valuable feedback.

Abstract: Lithium-rich layered oxides (LLOs), also known as Li1+xM1-xO2 or xLi2MnO3-(1-x)LiMO2 (M=Ni, Co, Mn), have been regarded as some of the highest capacity lithium cathodes and have attracted increasing attention from battery researchers and engineers in recent years. This is because LLOs possess maximum possible capacities of~280 to 310 mAh g-1 with a high working potential of~3.7 V (vs. Li+/Li0) and an astounding energy density of~900 Wh kg-1. Despite these promising properties, these technologically important cathodes have not yet been successfully commercialized due to low initial Coulombic efciency, poor rate capabilities and gradual capacity/voltage fade during electrochemical cycling as well as further complications from continuous structural changes during cycling. Here, researchers have concluded that these issues mainly originate from the electrochemical activation of Li2MnO3 components, which, although it provides anomalously high capacity performances, also causes associated complex anionic redox activities of O and irreversible structural and phase transformations during charging at potentials greater than 4.5 V (vs. Li+/Li0). To provide perspectives, this review will summarize various attempts made towards addressing these issues and present the connections between electrochemical properties and structural change. In addition, this review will discuss redox chemistries and mechanistic behaviours during cycling and will provide future research directions to guide the commercialization of LLOs.

Full-text:https://link.springer.com/article/10.1007/s41918-019-00032-8/fulltext.html

Key words: Li-rich layered oxide, Surface coating, Voltage fade, Oxygen activities, Lithium-ion battery