Excess-Li Localization Triggers Chemical Irreversibility in Li- and Mn-Rich Layered Oxides
- Authors
- Hwang, Jaeseong; Myeong, Seungjun; Jin, Wooyoung; Jang, Haeseong; Nam, Gyutae; Yoon, Moonsu; Kim, Su Hwan; Joo, Se Hun; Kwak, Sang Kyu; Kim, Min Gyu; Cho, Jaephil
- Issue Date
- Aug-2020
- Publisher
- WILEY-V C H VERLAG GMBH
- Keywords
- chemical irreversibility; excess-Li localization; Li- and Mn-rich layered oxide; lithium-ion batteries; oxygen stability
- Citation
- ADVANCED MATERIALS, v.32, no.34
- Journal Title
- ADVANCED MATERIALS
- Volume
- 32
- Number
- 34
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/69299
- DOI
- 10.1002/adma.202001944
- ISSN
- 0935-9648
1521-4095
- Abstract
- Li- and Mn-rich layered oxides (LMRs) have emerged as practically feasible cathode materials for high-energy-density Li-ion batteries due to their extra anionic redox behavior and market competitiveness. However, sluggish kinetics regions (<3.5 V vs Li/Li+) associated with anionic redox chemistry engender LMRs with chemical irreversibility (first-cycle irreversibility, poor rate properties, voltage fading), which limits their practical use. Herein, the structural origin of this chemical irreversibility is revealed through a comparative study involving Li(1.15)Mn(0.51)Co(0.17)Ni(0.17)O(2)with relatively localized and delocalized excess-Li in its lattice system. Operando fine-interval X-ray absorption spectroscopy is used to simultaneously observe the interplay between transition-metal-oxygen (TM-O) redox chemistry and TM migration behavior in real time. Density functional theory calculations show that excess-Li localization in the LMR structure attenuates TM-O covalency and stability, leading to overall chemical irreversibility. Hence, the delocalized excess-Li system is proposed as an alternative design for practically feasible LMR cathodes with restrained TM migration and sustainable O-redox chemistry.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - ETC > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.