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Dual Honeycomb‐Superlattice Enables Double‐High Activity and Reversibility of Anion Redox for Sodium‐Ion Battery Layered Cathodes
Anion redox contributes to the anomalous capacity exceeding the theoretical limit of layered oxides. However, double‐high activity and reversibility is challenging due to the structural rearrangement and potential oxygen loss. Here, we propose a strategy for constructing a dual honeycomb‐superlattic...
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Published in: | Angewandte Chemie International Edition 2022-08, Vol.61 (33), p.e202206625-n/a |
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Main Authors: | , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Anion redox contributes to the anomalous capacity exceeding the theoretical limit of layered oxides. However, double‐high activity and reversibility is challenging due to the structural rearrangement and potential oxygen loss. Here, we propose a strategy for constructing a dual honeycomb‐superlattice structure in Na2/3[Li1/7Mn5/14][Mg1/7Mn5/14]O2 to simultaneously realize high activity and reversibility of lattice O redox. Theoretical simulation and electrochemical tests show that [Li1/7Mn5/14] superlattice units remarkably trigger the anion redox activity and enable the delivery of a record capacity of 285.9 mA g−1 in layered sodium‐ion battery cathodes. Nuclear magnetic resonance and in situ X‐ray diffraction reveal that [Mg1/7Mn5/14] superlattice units are beneficial to the structure and anion redox reversibility, where Li+ reversibly shuttles between Na layers and transition‐metal slabs in contrast to the absence of [Mg1/7Mn5/14] units. Our findings underline the importance of multifunctional units and provide a path to advanced battery materials.
A well‐designed sodium‐ion battery layered cathode has been constructed via dual honeycomb‐superlattice regulation, and this displayed double‐high anion redox activity and reversibility. Experimental and theoretical studies are carried out to explore the mechanism. |
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ISSN: | 1433-7851 1521-3773 |
DOI: | 10.1002/anie.202206625 |