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 Nb4C3 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 Nb4C3 (denoted PO2-Nb4C3) 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 Nb4C3, PO2-Nb4C3 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.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:90389 |
| Date | 08 April 2024 |
| Creators | Sun, Boya, 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 |
| Publisher | Wiley-VCH |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1521-4095, 2108682, 10.1002/adma.202108682, info:eu-repo/grantAgreement/European Commission/H2020 | SGA-RIA/881603//Graphene Flagship Core Project 3/GrapheneCore3, info:eu-repo/grantAgreement/Deutsche Forschungsgemeinschaft/SFB 1415: Chemie der synthetischen zweidimensionalen Materialien/417590517/ |
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