Superior room-temperature cycling stability of fluoride-ion batteries enabled by solid electrolytes synthesized by the solid-state reaction
Superior room-temperature cycling stability of fluoride-ion batteries enabled by solid electrolytes synthesized by the solid-state reaction
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DOI：
10.1007/s40843-022-2146-2
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发表时间：
2022-08-23
影响因子：
8.1
通讯作者：
Ma, Cheng
中科院分区：
文献类型：
--
作者：
Wang, Jinzhu;Ma, Cheng
全固态氟离子电池（ASSFIBs）具有高达5000 W h L-1的理论能量密度，因此受到越来越多的关注。然而，由于难以确定合适的固体电解质，人们普遍认为ASSFIB在25 ℃下不能表现出令人满意的长期循环性能。最近，这种情况被CsPb0.9K0.1F2.9的发现所改变，其显示出高离子电导率和优异的电化学稳定性的罕见组合。在这里，我们发现通过简单地改变已报道的机械化学合成方法与固态反应可以进一步提高该材料的性能。所得到的材料显示出2.2 mS cm（-1）的室温电导率，优于迄今为止报道的最导电的F离子固体电解质（PbSnF 4，1.6 mS cm（-1））。更重要的是，它首次实现了ASSFIB在25摄氏度下稳定运行100次，最终容量（100次循环后为152.5 mA h g（-1））也超过了文献中所有其他室温块状ASSFIB（不超过20次循环后低于80 mA h g（-1））。
All-solid-state fluoride-ion batteries (ASSFIBs) exhibit ultrahigh theoretical energy densities up to 5000 W h L-1, and thus receive increasing attention. However, due to the difficulty of identifying appropriate solid electrolytes, it was commonly believed that ASSFIBs cannot exhibit satisfactory long-term cycling performance at 25 degrees C. Recently, this situation is changed by the discovery of CsPb0.9K0.1F2.9, which shows a rare combination of high ionic conductivity and excellent electrochemical stability. Here, we discover that the performance of this material can be further improved by simply altering the reported mechanochemical synthesis approach with the solid-state reaction. The resulting material shows a room-temperature conductivity of 2.2 mS cm(-1), outperforming the most conductive F-ion solid electrolyte reported so far (PbSnF4, 1.6 mS cm(-1)). More importantly, it enables 100 cycles of stable ASSFIB operation at 25 degrees C for the first time, with a final capacity (152.5 mA h g(-1) after 100 cycles) also surpassing all the other room-temperature bulk-type ASSFIBs in literature (below 80 mA h g(-1) after no more than 20 cycles).