Browse

A new lithium diffusion model in layered oxides based on asymmetric but reversible transition metal migration

Cited 8 time in Web of Science Cited 10 time in Scopus
Authors
Ku, Kyojin; Kim, Byunghoon; Jung, Sung-Kyun; Gong, Yue; Eum, Donggun; Yoon, Gabin; Park, Kyu-Young; Hong, Jihyun; Cho, Sung-Pyo; Kim, Noon; Kim, Hyungsub; Jeong, Eunsuk; Gu, Lin; Kang, Kisuk
Issue Date
2020-04
Citation
Energy and Environmental Sciences, Vol.13 No.4, pp.1269-1278
Abstract
Lithium-rich layered oxides (LLOs) are considered promising cathode materials for lithium-ion batteries because of their high reversible capacity, which is attributed to the exploitation of the novel anionic redox in addition to the conventional cationic redox process. Transition metal (TM) migration, which is known to be the main cause of the voltage decay in LLOs, is now understood to also be the critical factor triggering anionic redox, although this origin is still under debate. A better understanding of the specific TM migration behavior and its effect during charge/discharge would thus enable further development of this class of materials. Herein, we demonstrate that the unique TM migration during charge/discharge significantly alters the lithium diffusion mechanism/kinetics of LLO cathodes. We present clear evidence of the much more sluggish lithium diffusion occurring during discharge (lithiation) than during charge (de-lithiation), which contrasts with the traditional lithium diffusion model based on simple topotactic lithium intercalation/deintercalation in the layered framework. The reversible but asymmetric TM migration in the structure, which originates from the non-equivalent local environments around the TM during the charge and discharge processes, is shown to affect the lithium mobility. This correlation between TM migration and lithium mobility led us to propose a new lithium diffusion model for layered structures and suggests the importance of considering TM migration in designing new LLO cathode materials.
ISSN
1754-5692
URI
https://hdl.handle.net/10371/171801
DOI
https://doi.org/10.1039/c9ee04123k
Files in This Item:
There are no files associated with this item.
Appears in Collections:
College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Material Science and Engineering (재료공학부) Journal Papers (저널논문_재료공학부)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse