Elucidation of Active Oxygen Sites upon Delithiation of Li 3 IrO 4
Elucidation of Active Oxygen Sites upon Delithiation of Li 3 IrO 4
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Li 3 IrO 4 脱锂时活性氧位点的阐明
DOI：
10.1021/acsenergylett.0c02040
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发表时间：
2021
影响因子：
22
通讯作者：
Cabana, Jordi
中科院分区：
文献类型：
--
作者：
Li, Haifeng;Perez, Arnaud J.;Taudul, Beata;Boyko, Teak D.;Freeland, John W.;Doublet, Marie-Liesse;Tarascon, Jean-Marie;Cabana, Jordi
除了传统的过渡金属对之外，通过利用氧化物配体的氧化还原活性，可以实现电池阴极存储容量的转型增加。然而，控制这种晶格氧氧化还原（LOR）的关键特征尚未确定。Li 3 IrO 4具有最大的可逆LOR，使其成为一个独特的模型系统。在这里，X射线光谱和计算模拟表明，LOR在Li 3 IrO 4选择性地补偿通过O网站与三个孤对，这是激活Li/Ir无序。双电子LOR可以逆转以再生初始状态，而不会解锁在许多其他化合物中观察到的竞争性本体反应。我们发现了一个复杂的化学计量之间的相互作用，O协调，和非键合状态的LOR和精确的光谱特征。这种相互作用对于设计具有3D金属的材料是必不可少的，这些材料可以实现LOR的承诺，克服当前阴极的瓶颈，以便将来在实际电池中实现。
Transformational increases in the storage capacity of battery cathodes could be achieved by tapping into the redox activity at oxide ligands in addition to conventional transition metal couples. However, the key signatures that govern such lattice oxygen redox (LOR) have not been ascertained. Li3IrO4has the largest reversible LOR, rendering it a unique model system. Here, X-ray spectroscopy and computational simulations reveal that LOR in Li3IrO4is selectively compensated via O sites with three lone pairs, which are activated by Li/Ir disorder. The two-electron LOR can be reversed to regenerate the initial state without unlocking competing bulk reactions observed in many other compounds. We uncover an intricate interplay between stoichiometry, O coordination, and nonbonding states in LOR and pinpoint spectroscopic signatures. This interplay is indispensable for designing materials with 3d metals that fulfill the promise of LOR to overcome the bottlenecks of current cathodes for future implementation in practical batteries.