Redox-Active Metaphosphate-Like Terminals Enable High-Capacity MXene Anodes for Ultrafast Na-Ion Storage

Bibliographische Detailangaben
Veröffentlicht in:	Advanced materials (Deerfield Beach, Fla.). - 1998. - 34(2022), 15 vom: 16. Apr., Seite e2108682
1. Verfasser:	Sun, Boya (VerfasserIn)
Weitere Verfasser:	Lu, Qiongqiong, Chen, Kaixuan, Zheng, Wenhao, Liao, Zhongquan, Lopatik, Nikolaj, Li, Dongqi, Hantusch, Martin, Zhou, Shengqiang, Wang, Hai I, Sofer, Zdeněk, Brunner, Eike, Zschech, Ehrenfried, Bonn, Mischa, Dronskowski, Richard, Mikhailova, Daria, Liu, Qinglei, Zhang, Di, Yu, Minghao, Feng, Xinliang
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2022
Zugriff auf das übergeordnete Werk:	Advanced materials (Deerfield Beach, Fla.)
Schlagworte:	Journal Article MXenes hybrid-ion capacitors redox-active terminals sodium-ion storage

Beschreibung
Zusammenfassung:	© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH. 2D transition metal carbides and/or nitrides, so-called MXenes, are noted as ideal fast-charging cation-intercalation electrode materials, which nevertheless suffer from limited specific capacities. Herein, it is reported that constructing redox-active phosphorus-oxygen terminals can be an attractive strategy for Nb4 C3 MXenes to remarkably boost their specific capacities for ultrafast Na+ storage. As revealed, redox-active terminals with a stoichiometric formula of PO2 - display a metaphosphate-like configuration with each P atom sustaining three PO bonds and one PO dangling bond. Compared with conventional O-terminals, metaphosphate-like terminals empower Nb4 C3 (denoted PO2 -Nb4 C3 ) with considerably enriched carrier density (fourfold), improved conductivity (12.3-fold at 300 K), additional redox-active sites, boosted Nb redox depth, nondeclined Na+ -diffusion capability, and buffered internal stress during Na+ intercalation/de-intercalation. Consequently, compared with O-terminated Nb4 C3 , PO2 -Nb4 C3 exhibits a doubled Na+ -storage capacity (221.0 mAh g-1 ), well-retained fast-charging capability (4.9 min at 80% capacity retention), significantly promoted cycle life (nondegraded capacity over 2000 cycles), and justified feasibility for assembling energy-power-balanced Na-ion capacitors. This study unveils that the molecular-level design of MXene terminals provides opportunities for developing simultaneously high-capacity and fast-charging electrodes, alleviating the energy-power tradeoff typical for energy-storage devices
Beschreibung:	Date Revised 14.04.2022 published: Print-Electronic Citation Status PubMed-not-MEDLINE
ISSN:	1521-4095
DOI:	10.1002/adma.202108682