Adv. Mater. | 通过NiMn₆超晶格拓扑结构实现层状氧化物正极中阳离子与阴离子氧化还原的高可逆性用于钠离子电池
时间: 2025-05-15 作者: 浏览次数: 291


题目:

Enabling High Reversibility of Both Cationic and Anionic Redox in Layered Oxide Cathodes via NiMn6 Superlattice Topology for Sodium-Ion Batteries

作者:

Zhonghan Wu1, Youxuan Ni1, Na Jiang1, Jinhan Li1, Limin Zhou2, Lunhua He3, Liang Zhang4*, Kai Zhang1*, Fangyi Cheng1*, and Jun Chen1

摘要:

High-voltage oxygen anionic redox provides a transformative opportunity to achieve high energy density of batteries. However, it is challenging to guarantee the reversibility of both cationic and anionic redox for layered transition metal (TM) oxide cathode materials due to the high oxygen-redox reactivity and the complex structural rearrangements. Herein, a honeycomb-layered Na0.78Ni0.12Li0.18Mn0.7O2 (NNLMO) cathode material with the NiMn6 and LiMn6 dual-topology superlattice is proposed for sodium-ion batteries. The theoretical and experimental studies demonstrate that the Ni2+ electronic configuration serves as a redox buffer to tune the cationic and anionic redox activity by enlarging the energy gap between O 2p and Mn 3d orbitals, while the NiMn6 topology renders the LiMn6 topology delocalized in the TM layers to reinforce the superstructure stability through suppressing the intralayer Mn migration and O2 formation. As a result, NNLMO delivers a highly reversible capacity of 224 mAh g−1 with the mitigated voltage hysteresis and exhibits remarkable capacity retention of 92.2% over 50 cycles within the wide voltage range of 1.5–4.5 V. The findings suggest a new insight into the topological superstructure design of high-energy oxide cathode materials for sustainable batteries.

影响因子:

27.4

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