Oxygen Vacancies Boosted Fast Mg2+ Migration in Solids at Room Temperature
Oxygen Vacancies Boosted Fast Mg2+ Migration in Solids at Room Temperature
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DOI：
10.1016/j.ensm.2022.07.012
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发表时间：
2022-07
影响因子：
20.4
通讯作者：
Qian Wang;Hongjiao Li;Ruixue Zhang;Zhenzhen Liu;Hanyu Deng;Wanglai Cen;Yigang Yan;Yun-gui Chen
中科院分区：
文献类型：
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作者：
Qian Wang;Hongjiao Li;Ruixue Zhang;Zhenzhen Liu;Hanyu Deng;Wanglai Cen;Yigang Yan;Yun-gui Chen
镁（Mg）电池由于其高的理论容量和丰富的天然丰度的Mg而被有希望的锂离子电池的候选者。然而，镁金属电池的发展，特别是在一个有吸引力的固态配置，阻碍了缓慢的Mg 2+迁移。在这里，我们发现，通过在金属氧化物纳米粉末的表面上引入氧空位，在Mg（BH 4）2·1.5NH3中室温下的Mg 2+离子电导率（σi）显著提高到10 - 4S cm-1的数量级，例如，2.96× 10−4S cm−1，通过添加60 wt.%二氧化钛理论模拟表明，高σ i是由于界面处的“配位解锁”现象，即Mg（BH 4）2·1. 5 NH3的配位鞘层被氧空位解锁，缺配位Mg通过与氧位的相互作用在表面转移.该策略包括氧空位的辅助，可以为设计新的二价阳离子导体创造一条新的途径。
Magnesium (Mg) batteries are promising candidates for lithium-ion batteries owing to their high theoretical capacity and the rich natural abundance of Mg. However, the development of Mg metal batteries, especially in an attractive solid-state configuration, is hampered by sluggish Mg2+migration. Here, we discover that by incorporating oxygen vacancies on the surface of metal oxide nanopowders, the Mg2+ion conductivity (σi) at room temperature in Mg(BH4)2·1.5NH3is dramatically improved on the order of 10−4S cm−1,e.g.,2.96 × 10−4S cm−1, by the addition of 60 wt.% TiO2. Theoretical simulations indicate that the high σiis due to the “coordination-unlock” phenomenon at the interface, where the coordination sheath of Mg(BH4)2·1.5NH3is unlocked by oxygen vacancies and coordination-deficient Mg transfers on the surface through interactions with oxygen sites. The strategy involving the assistance of oxygen vacancies could create a new path for designing new divalent cation conductors.