Superionic conductors with ionic conductivity on the order of mS cm-1 are expected to revolutionize the development of solid-state batteries (SSBs). However, currently available superionic conductors are limited to only a few structural families such as garnet oxides and sulfide-based glass/ceramic. Interfaces in composite systems such as alumina in lithium iodide have long been identified as a viable ionic conduction channel but practical superionic conductors employing the interfacial conduction mechanism are yet to be realized. Here we report a novel method that creates continuous interfaces in the bulk of composite thin films. Ions can conduct through the interface and consequently the inorganic phase can be ionically insu-lating in this type of bulk interface superionic conductors (BISCs). Ionic conductivities of lithium, sodium, and magnesium ion BISCs have reached 1.16 mS cm-1, 0.40 mS cm-1, and 0.23 mS cm-1 at 25 oC in 25 μm thick films, corresponding to areal conductance as high as 464 mS cm-2, 160 mS cm-2 and 92 mS cm-2, respectively. Ultralow over-potential and stable long-term cycling for up to 5000 hours was obtained for solid-state Li metal symmetric batteries employing Li ion BISCs. This work opens new structural space for superionic conductors and urges for future investigations on detailed conduction mech-anisms and material design principles.

中文翻译：

---

通过体界面传导的超离子导体

离子电导率约为 mS cm-1 的超离子导体有望彻底改变固态电池 (SSB) 的发展。然而，目前可用的超离子导体仅限于少数结构家族，如石榴石氧化物和硫化物基玻璃/陶瓷。复合系统中的界面，如碘化锂中的氧化铝，长期以来一直被认为是一种可行的离子传导通道，但采用界面传导机制的实用超离子导体尚未实现。在这里，我们报告了一种在大量复合薄膜中创建连续界面的新方法。离子可以通过界面传导，因此无机相可以在这种类型的体界面超离子导体 (BISC) 中进行离子绝缘。锂、钠的离子电导率，和镁离子 BISCs 在 25 oC 下在 25 μm 厚的薄膜中已达到 1.16 mS cm-1、0.40 mS cm-1 和 0.23 mS cm-1，对应的面积电导高达 464 mS cm-2、160 mS cm-分别为 2 和 92 mS cm-2。采用锂离子 BISC 的固态锂金属对称电池获得了超低过电位和长达 5000 小时的稳定长期循环。这项工作为超离子导体开辟了新的结构空间，并推动了未来对详细传导机制和材料设计原理的研究。采用锂离子 BISC 的固态锂金属对称电池获得了超低过电位和长达 5000 小时的稳定长期循环。这项工作为超离子导体开辟了新的结构空间，并推动了未来对详细传导机制和材料设计原理的研究。采用锂离子 BISC 的固态锂金属对称电池获得了超低过电位和长达 5000 小时的稳定长期循环。这项工作为超离子导体开辟了新的结构空间，并推动了未来对详细传导机制和材料设计原理的研究。