1. Unexpected Elevated Working Voltage by Na+/Vacancy Ordering and Stabilized Sodium‐Ion Storage by Transition‐Metal Honeycomb Ordering.
- Author
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Wang, Yao, Jin, Junteng, Zhao, Xudong, Shen, Qiuyu, Qu, Xuanhui, Jiao, Lifang, and Liu, Yongchang
- Subjects
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ENERGY density , *DIFFUSION kinetics , *STRUCTURAL stability , *HONEYCOMB structures , *CATHODES - Abstract
Na+/vacancy ordering in sodium‐ion layered oxide cathodes is widely believed to deteriorate the structural stability and retard the Na+ diffusion kinetics, but its unexplored potential advantages remain elusive. Herein, we prepared a P2‐Na0.8Cu0.22Li0.08Mn0.67O2 (NCLMO‐12 h) material featuring moderate Na+/vacancy and transition‐metal (TM) honeycomb orderings. The appropriate Na+/vacancy ordering significantly enhances the operating voltage and the TM honeycomb ordering effectively strengthens the layered framework. Compared with the disordered material, the well‐balanced dual‐ordering NCLMO‐12 h cathode affords a boosted working voltage from 2.85 to 3.51 V, a remarkable ~20 % enhancement in energy density, and a superior cycling stability (capacity retention of 86.5 % after 500 cycles). The solid‐solution reaction with a nearly "zero‐strain" character, the charge compensation mechanisms, and the reversible inter‐layer Li migration upon sodiation/desodiation are unraveled by systematic in situ/ex situ characterizations. This study breaks the stereotype surrounding Na+/vacancy ordering and provides a new avenue for developing high‐energy and long‐durability sodium layered oxide cathodes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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