Zhu Yizhou, Mo Yifei
Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA.
Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60201, USA.
Angew Chem Int Ed Engl. 2020 Sep 28;59(40):17472-17476. doi: 10.1002/anie.202007621. Epub 2020 Aug 6.
Sulfide solid electrolytes are promising inorganic solid electrolytes for all-solid-state batteries. Despite their high ionic conductivity and desirable mechanical properties, many known sulfide solid electrolytes exhibit poor air stability. The spontaneous hydrolysis reactions of sulfides with moisture in air lead to the release of toxic hydrogen sulfide and materials degradation, hindering large-scale manufacturing and applications of sulfide-based solid-state batteries. In this work, we systematically investigate the hydrolysis and reduction reactions in Li- and Na-containing sulfides and chlorides by applying thermodynamic analyses based on a first principles computation database. We reveal the stability trends among different chemistries and identify the effect of cations, anions, and Li/Na content on moisture stability. Our results identify promising materials systems to simultaneously achieve desirable moisture stability and electrochemical stability, and provide the design principles for the development of air-stable solid electrolytes.
硫化物固体电解质是用于全固态电池的很有前景的无机固体电解质。尽管它们具有高离子电导率和理想的机械性能，但许多已知的硫化物固体电解质表现出较差的空气稳定性。硫化物与空气中的水分发生的自发水解反应会导致释放出有毒的硫化氢并使材料降解，这阻碍了硫化物基固态电池的大规模制造和应用。在这项工作中，我们通过基于第一性原理计算数据库进行热力学分析，系统地研究了含锂和钠的硫化物及氯化物中的水解和还原反应。我们揭示了不同化学组成之间的稳定性趋势，并确定了阳离子、阴离子以及锂/钠含量对水分稳定性的影响。我们的结果确定了有前景的材料体系，以同时实现理想的水分稳定性和电化学稳定性，并为开发空气稳定的固体电解质提供了设计原则。
