Abstract

Irreversible phase transformation of layered structure into spinel structure is considered detrimental for most of the layered structure cathode materials. Here we report that this presumably irreversible phase transformation can be rendered to be reversible in sodium birnessite (NaxMnO2·yH2O) as a basic structural unit. This layered structure contains crystal water, which facilitates the formation of a metastable spinel-like phase and the unusual reversal back to layered structure. The mechanism of this phase reversibility was elucidated by combined soft and hard X-ray absorption spectroscopy with X-ray diffraction, corroborated by first-principle calculations and kinetics investigation. These results show that the reversibility, modulated by the crystal water content between the layered and spinel-like phases during the electrochemical reaction, could activate new cation sites, enhance ion diffusion kinetics and improve its structural stability. This work thus provides in-depth insights into the intercalating materials capable of reversible framework changes, thereby setting the precedent for alternative approaches to the development of cathode materials for next-generation rechargeable batteries.

Details

Title
Triggered reversible phase transformation between layered and spinel structure in manganese-based layered compounds
Author
Mi, Ru Jo 1 ; Kim, Yunok 2 ; Yang, Junghoon 1 ; Jeong, Mihee 2   VIAFID ORCID Logo  ; Song, Kyeongse 1 ; Yong-Il, Kim 3 ; Jin-Myoung Lim 4   VIAFID ORCID Logo  ; Cho, Maenghyo 4 ; Jae-Hyun Shim 5 ; Young-Min, Kim 6 ; Yoon, Won-Sub 2   VIAFID ORCID Logo  ; Yong-Mook, Kang 7 

 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul, Republic of Korea 
 Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea 
 Korea Research Institute of Standards and Science (KRISS), Daejeon, Republic of Korea 
 Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea 
 Department of Advanced Materials and Energy Engineering, Dongshin University, Naju, Republic of Korea 
 Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea; Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon, Republic of Korea 
 Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul, Republic of Korea; Department of Materials Science and Engineering, Korea University, Seoul, Republic of Korea 
Pages
1-9
Publication year
2019
Publication date
Sep 2019
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2283281450
Copyright
© 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.