Origin of fast ion diffusion in super-ionic conductors.
Origin of fast ion diffusion in super-ionic conductors.
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DOI：
10.1038/ncomms15893
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发表时间：
2017-06-21
影响因子：
16.6
通讯作者：
Mo Y
中科院分区：
文献类型：
--
作者：
He X;Zhu Y;Mo Y
超离子导体材料在能量存储和转换方面具有巨大的潜力。然而，目前尚不清楚为什么只有少数材料可以提供比典型固体更高的离子电导率，或者如何根据简单的原理设计快速离子导体。使用从头算模型，我们发现超离子导体中的快速扩散不是通过固体中典型的孤立离子跳跃发生的，而是通过具有低能垒的多个离子的协同迁移进行的。此外，我们阐明了协同离子扩散的低能垒是超离子导体中独特的移动离子构型和强移动离子相互作用的结果。我们的研究结果为设计具有快速离子扩散的固体材料提供了一个总体框架和通用策略。从头算原子模型揭示了超离子导体中离子的快速扩散是由多个离子的协同迁移介导的。在此基础上，提出并论证了一种设计快速离子导体的通用策略。
Super-ionic conductor materials have great potential to enable novel technologies in energy storage and conversion. However, it is not yet understood why only a few materials can deliver exceptionally higher ionic conductivity than typical solids or how one can design fast ion conductors following simple principles. Using ab initio modelling, here we show that fast diffusion in super-ionic conductors does not occur through isolated ion hopping as is typical in solids, but instead proceeds through concerted migrations of multiple ions with low energy barriers. Furthermore, we elucidate that the low energy barriers of the concerted ionic diffusion are a result of unique mobile ion configurations and strong mobile ion interactions in super-ionic conductors. Our results provide a general framework and universal strategy to design solid materials with fast ionic diffusion. Ab initio atomistic modelling reveals that fast ion diffusion in super-ionic conductors is mediated by concerted migration of multiple ions. On the basis of this understanding, a universal strategy for designing fast ion conductors is proposed and demonstrated.