论文标题：Advanced sulfide solid electrolyte by core-shell structural design

期刊：Nature Communications

作者: Fan Wu, William Fitzhugh, Luhan Ye, Jiaxin Ning, Xin Li

发表时间：2018/10/02

数字识别码： 10.1038/s41467-018-06123-2

原文链接：https://www.nature.com/articles/s41467-018-06123-2?utm_source=Other_website&utm_medium=Website_links&utm_content=RenLi-MixedBrand-multijournal-Multidisciplinary-China&utm_campaign=ORG_USG_JRCN_RL_article_promotion_sciencenet_Oct_5th

固体电解质是实现具有高能量密度、高安全性能的下一代固态锂离子电池的关键。硫化物固体电解质具有如高离子导电性、低机械刚度等独特性质。

近日，在《自然-通讯》上发表的一篇研究Advanced sulfide solid electrolyte by core-shell structural design中，来自哈佛大学的Xin Li领导的团队发现，通过控制硫化物电解质的合成参数和相应的核壳微观结构组成，可以扩大其电化学稳定窗口。由此可使壳结构中具有高含量的硅的Li-Si-P-S硫化物电解质的稳定性窗口达到0.7-3.1 V，准稳定性窗口高达5 V，比过往预测的1.7-2.1 V的窗口值大得多。

作者利用理论和计算，从体积收缩的角度解释了这种电压窗口的优化，因为体积收缩可以抵抗固体电解质随膨胀而产生的分解。研究结果表明，在对电解质施加恒定体积约束的核壳形貌的限制情况下，稳定性窗口可以被进一步提升。作者在该研究基础上，还进一步讨论了如何设计下一代硫化物固体电解质的先进策略。

图1：Li9.54Si1.74P1.44S11.7Cl0.3 (LSPS-Cl)粉末在450，460，480，500摄氏度条件下进行退火后的显微结构及成分分析

摘要：Solid electrolyte is critical to next-generation solid-state lithium-ion batteries with high energy density and improved safety. Sulfide solid electrolytes show some unique properties, such as the high ionic conductivity and low mechanical stiffness. Here we show that the electrochemical stability window of sulfide electrolytes can be improved by controlling synthesis parameters and the consequent core-shell microstructural compositions. This results in a stability window of 0.7–3.1 V and quasi-stability window of up to 5 V for Li-Si-P-S sulfide electrolytes with high Si composition in the shell, a window much larger than the previously predicted one of 1.7–2.1 V. Theoretical and computational work explains this improved voltage window in terms of volume constriction, which resists the decomposition accompanying expansion of the solid electrolyte. It is shown that in the limiting case of a core-shell morphology that imposes a constant volume constraint on the electrolyte, the stability window can be further opened up. Advanced strategies to design the next-generation sulfide solid electrolytes are also discussed based on our understanding.

阅读论文全文请访问：https://www.nature.com/articles/s41467-018-06123-2?utm_source=Other_website&utm_medium=Website_links&utm_content=RenLi-MixedBrand-multijournal-Multidisciplinary-China&utm_campaign=ORG_USG_JRCN_RL_article_promotion_sciencenet_Oct_5th

期刊介绍：Nature Communications (https://www.nature.com/ncomms/) is an open access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.

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（来源：科学网）