Wang Qing, Mariyappan Sathiya, Rousse Gwenaëlle, Morozov Anatolii V, Porcheron Benjamin, Dedryvère Rémi, Wu Jinpeng, Yang Wanli, Zhang Leiting, Chakir Mohamed, Avdeev Maxim, Deschamps Michaël, Yu Young-Sang, Cabana Jordi, Doublet Marie-Liesse, Abakumov Artem M, Tarascon Jean-Marie
Chimie du Solide-Energie, UMR 8260, Collège de France, Paris, France.
Sorbonne Université, Paris, France.
Nat Mater. 2021 Mar;20(3):353-361. doi: 10.1038/s41563-020-00870-8. Epub 2021 Jan 11.
Sodium ion batteries, because of their sustainability attributes, could be an attractive alternative to Li-ion technology for specific applications. However, it remains challenging to design high energy density and moisture stable Na-based positive electrodes. Here, we report an O3-type NaLiMnO phase showing anionic redox activity, obtained through a ceramic process by carefully adjusting synthesis conditions and stoichiometry. This phase shows a sustained reversible capacity of 190 mAh g that is rooted in cumulative oxygen and manganese redox processes as deduced by combined spectroscopy techniques. Unlike many other anionic redox layered oxides so far reported, O3-NaLiMnO electrodes do not show discernible voltage fade on cycling. This finding, rationalized by density functional theory, sheds light on the role of inter- versus intralayer 3d cationic migration in ruling voltage fade in anionic redox electrodes. Another practical asset of this material stems from its moisture stability, hence facilitating its handling and electrode processing. Overall, this work offers future directions towards designing highly performing sodium electrodes for advanced Na-ion batteries.
钠离子电池因其可持续性属性，对于特定应用而言可能是锂离子技术颇具吸引力的替代方案。然而，设计高能量密度且对水分稳定的钠基正极仍然具有挑战性。在此，我们报道了一种通过陶瓷工艺，经仔细调整合成条件和化学计量比而获得的具有阴离子氧化还原活性的O3型NaLiMnO相。该相展现出190 mAh g的持续可逆容量，这源于通过联合光谱技术推断出的累积氧和锰的氧化还原过程。与迄今为止报道的许多其他阴离子氧化还原层状氧化物不同，O3-NaLiMnO电极在循环过程中未表现出明显的电压衰减。这一发现经密度泛函理论合理化，揭示了层间与层内3d阳离子迁移在控制阴离子氧化还原电极电压衰减中的作用。这种材料的另一个实际优势源于其对水分的稳定性，从而便于其处理和电极加工。总体而言，这项工作为设计用于先进钠离子电池的高性能钠电极提供了未来方向。
