Whole-Voltage-Range Oxygen Redox in P2-Layered Cathode Materials for Sodium-Ion Batteries

Whole-Voltage-Range Oxygen Redox in P2-Layered Cathode Materials for Sodium-Ion Batteries

© 2021 Wiley-VCH GmbH.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 33(2021), 13 vom: 01. Apr., Seite e2008194
1. Verfasser: Li, Xun-Lu (VerfasserIn)
Weitere Verfasser: Wang, Tian, Yuan, Yifei, Yue, Xin-Yang, Wang, Qin-Chao, Wang, Jun-Yang, Zhong, Jun, Lin, Ruo-Qian, Yao, Yuan, Wu, Xiao-Jing, Yu, Xi-Qian, Fu, Zheng-Wen, Xia, Yong-Yao, Yang, Xiao-Qing, Liu, Tongchao, Amine, Khalil, Shadike, Zulipiya, Zhou, Yong-Ning, Lu, Jun
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2021
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article Mg substitution Na-ion batteries cathode materials layered structures oxygen redox
Beschreibung
Zusammenfassung:© 2021 Wiley-VCH GmbH.
Oxygen-redox of layer-structured metal-oxide cathodes has drawn great attention as an effective approach to break through the bottleneck of their capacity limit. However, reversible oxygen-redox can only be obtained in the high-voltage region (usually over 3.5 V) in current metal-oxide cathodes. Here, we realize reversible oxygen-redox in a wide voltage range of 1.5-4.5 V in a P2-layered Na0.7 Mg0.2 [Fe0.2 Mn0.6 □0.2 ]O2 cathode material, where intrinsic vacancies are located in transition-metal (TM) sites and Mg-ions are located in Na sites. Mg-ions in the Na layer serve as "pillars" to stabilize the layered structure during electrochemical cycling, especially in the high-voltage region. Intrinsic vacancies in the TM layer create the local configurations of "□-O-□", "Na-O-□" and "Mg-O-□" to trigger oxygen-redox in the whole voltage range of charge-discharge. Time-resolved techniques demonstrate that the P2 phase is well maintained in a wide potential window range of 1.5-4.5 V even at 10 C. It is revealed that charge compensation from Mn- and O-ions contributes to the whole voltage range of 1.5-4.5 V, while the redox of Fe-ions only contributes to the high-voltage region of 3.0-4.5 V. The orphaned electrons in the nonbonding 2p orbitals of O that point toward TM-vacancy sites are responsible for reversible oxygen-redox, and Mg-ions in Na sites suppress oxygen release effectively
Beschreibung:Date Revised 02.04.2021
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202008194