Controlling the Electrochemical Properties of Spinel Intercalation Compounds
Controlling the Electrochemical Properties of Spinel Intercalation Compounds
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DOI：
10.1021/acsaem.8b01080
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发表时间：
2018-10
影响因子：
6.4
通讯作者：
S. Kolli;A. Van der Ven
中科院分区：
文献类型：
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作者：
S. Kolli;A. Van der Ven
众所周知，尖晶石插层化合物有助于实现高倍率和高电压锂离子电池。然而，人们对用于钠离子和镁离子电池的尖晶石电极知之甚少。在这里，我们利用第一原理统计力学方法系统地研究了六种尖晶石化学性质，以确定尖晶石化合物的电化学性质如何受到（i）主体离子性、（ii）客体阳离子半径和（iii）客体阳离子氧化态的影响。作为模型系统，我们考虑尖晶石 CoO2 和 TiS2 作为主体，Li、Na 和 Mg 作为客体阳离子。尖晶石化合物的电化学性质很大程度上取决于客体阳离子位点的偏好。我们的研究表明，大的客体阳离子更喜欢八面体配位，而离子主体中的静电相互作用则有利于四面体配位的客体阳离子。这项研究的见解提出了简单的设计原则，可以用来开发新的尖晶石插层化合物，我们的预测表明过渡金属氧化物...
Spinel intercalation compounds are well-known to facilitate high rate and high voltage Li-ion batteries. Little is known, however, about spinel based electrodes for Na- and Mg-ion batteries. Here we systematically study six spinel chemistries with first-principles statistical mechanics approaches to determine how the electrochemical properties of spinel compounds are affected by (i) host ionicity, (ii) guest cation radius, and (iii) guest cation oxidation state. As model systems, we consider spinel CoO2 and TiS2 as hosts and Li, Na, and Mg as guest cations. Electrochemical properties of spinel compounds are strongly dependent on guest cation site preferences. Our study shows that large guest cations prefer octahedral coordination, while the electrostatic interactions in ionic hosts favor tetrahedrally coordinated guest cations. The insights of this study suggest simple design principles with which new spinel intercalation compounds can be developed, with our predictions indicating that transition metal ox...