The revival of the Na‐ion battery concept has prompted intense research activities toward new sustainable Na‐based insertion compounds and their implementation in full Na‐ion cells. Efforts are parted between Na‐based polyanionic and layered compounds. For the latter, there has been a specific focus on Na‐deficient layered phases that show cationic and anionic redox activity similar to a Na_0.67Mn_0.72Mg_0.28O₂ phase. Herein, a new alkali‐deficient P2‐Na_2/3Mn_7/9Zn_2/9O₂ phase using a more electronegative element (Zn) than Mg is reported. Like its Mg counterpart, this phase shows anionic redox activity and no O₂ release despite evidence of cationic migration. Density functional theory (DFT) calculations show that it is the presence of an oxygen nonbonding state that triggers the anionic redox activity in this material. The phase delivers a reversible capacity of 200 mAh g⁻¹ in Na‐half cells with such a value be reduced to 140 mAh g⁻¹ in full Na‐ion cells which additionally shows capacity decay upon cycling. These findings establish Na‐deficient layered oxides as a promising platform to further explore the underlying science behind O₂ release in insertion compounds based on anionic redox activity.

中文翻译：

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新掺杂锌的钠氧化物P2-Na2 / 3Mn1-yZnyO2中的阴离子氧化还原活性（0 <y <0.23）

钠离子电池概念的复兴促使人们对新型可持续的基于钠的插入化合物及其在完整的钠离子电池中的应用进行了广泛的研究活动。在基于钠的聚阴离子和层状化合物之间进行了努力。对于后者，一直特别关注Na不足的层状相，这些相表现出类似于Na _0.67 Mn _0.72 Mg _0.28 O ₂相的阳离子和阴离子氧化还原活性。本文报道了一种新的碱缺乏型P2-Na _2/3 Mn _7/9 Zn _2/9 O ₂相，其使用的负电性元素（Zn）比Mg多。像它的Mg对应物一样，该相显示出阴离子氧化还原活性并且没有O ₂释放，尽管有阳离子迁移的迹象。密度泛函理论（DFT）计算表明，正是氧非键态的存在触发了该材料中的阴离子氧化还原活性。在Na-半电池中，该相提供了200 mAh g ^-1的可逆容量，在完整的Na-离子电池中，该值降低到140 mAh g ^-1，这在循环时还会显示容量衰减。这些发现将钠缺乏的层状氧化物建立为一个有前途的平台，可以进一步探索基于阴离子氧化还原活性的插入化合物中O ₂释放背后的基础科学。