Yu Zhaoxin, Shang Shun-Li, Ahn Kiseuk, Marty Daniel T, Feng Ruozhu, Engelhard Mark H, Liu Zi-Kui, Lu Dongping
Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
ACS Appl Mater Interfaces. 2022 Jul 20;14(28):32035-32042. doi: 10.1021/acsami.2c07388. Epub 2022 Jul 11.
The all-solid-state battery (ASSB) is a promising next-generation energy storage technology for both consumer electronics and electric vehicles because of its high energy density and improved safety. Sulfide solid-state electrolytes (SSEs) have merits of low density, high ionic conductivity, and favorable mechanical properties compared to oxide ceramic and polymer materials. However, mass production and processing of sulfide SSEs remain a grand challenge because of their poor moisture stability. Here, we report a reversible surface coating strategy for enhancing the moisture stability of sulfide SSEs using amphipathic organic molecules. An ultrathin layer of 1-bromopentane is coated on the sulfide SSE surface (e.g., LiPSBrI) via Van der Waals force. 1-Bromopentane has more negative adsorption energy with SSEs than HO based on first-principles calculations, thereby enhancing the moisture stability of SSEs because the hydrophobic long-chain alkyl tail of 1-bromopentane repels water molecules. Moreover, this amphipathic molecular layer has a negligible effect on ionic conductivity and can be removed reversibly by heating at low temperatures (e.g., 160 °C). This finding opens a new pathway for the surface engineering of moisture-sensitive SSEs and other energy materials, thereby speeding up their deployment in ASSBs.
全固态电池（ASSB）因其高能量密度和更高的安全性，对于消费电子产品和电动汽车而言都是一种很有前景的下一代储能技术。与氧化物陶瓷和聚合物材料相比，硫化物固态电解质（SSE）具有低密度、高离子电导率和良好机械性能的优点。然而，由于硫化物SSE的水分稳定性较差，其大规模生产和加工仍然是一个巨大的挑战。在此，我们报道了一种使用两亲性有机分子增强硫化物SSE水分稳定性的可逆表面涂层策略。通过范德华力在硫化物SSE表面（例如LiPSBrI）涂覆一层超薄的1-溴戊烷。基于第一性原理计算，1-溴戊烷与SSE的吸附能比HO更负，从而提高了SSE的水分稳定性，因为1-溴戊烷的疏水长链烷基尾部排斥水分子。此外，这种两亲性分子层对离子电导率的影响可忽略不计，并且可以通过在低温（例如160°C）下加热可逆地去除。这一发现为对水分敏感的SSE和其他能量材料的表面工程开辟了一条新途径，从而加速它们在全固态电池中的应用。
