探索化物替代,结构障碍和在阿吉罗底石 (Li6-PS5-Br1+) 中的分布之间的关系
Ajay Gautam1, Hanan Al-Kutubi1, Theodosios Famprikis1
1Storage of Electrochemical Energy, Department of Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands.
Chemistry of materials : a publication of the American Chemical Society
|October 16, 2023
概括
在 argyrodite固体电解质中的化物替代增强了离子导电性,增加了结构障碍并创造了新的离子通路. 这种优化对于设计先进的全固态电池至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 固态化学 固态化学
背景情况:
- argyrodite超离子导体是所有固态电池的有希望的固体电解质,由于其高离子导电性和可加工性.
- 在Li6-xPS5-y中化物替代 (Cl, Br) 影响的分布和结构障碍,影响离子导电性.
- 化物替代,乱和离子运输之间的确切关系仍然不完全理解,这阻碍了材料优化.
研究的目的:
- 为了研究化物替代对 argyrodite (Li6-xPS5-xBrx) 性能的影响.
- 通过合成协议设计结构障碍,以了解其对离子导电性的影响.
- 阐明基结构,结构障碍和离子运输机制之间的相关性.
主要方法:
- 合成具有不同化物含量 (0.0 ≤ x ≤ 0.5) 的 argyrodite.
- 通过中子衍射分析晶体结构和分布.
- 固态核磁共振 (NMR) 光谱检测基结构.
- 电化学阻抗光谱 (EIS) 用于测量离子导电.
主要成果:
- 较高的离子导电性与4d位点上较低的平均负电荷相关,这是由于S2-被Br-取代.
- 这种电荷降低削弱了Li+子相互作用,增强了Li-ion扩散性.
- 确定了一个额外的T4Li+站点,使得一个低能量的T5-T4-T5跳跃路线成为可能.
- 灭Li5.5PS4.5Br1.5的最大离子导电率为8.55mS/cm,比缓慢冷却的样品提高了11倍.
结论:
- 结构障碍和化物替代显著影响基结构和 argyrodites中的运输特性.
- 优化合成方法和组合有效调整这些属性,以提高性能.
- 这项工作为设计优质固体电解质提供了对结构-运输相关性的关键见解.
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