Effects of Sodium Sources on Nonaqueous Precipitation Synthesis of β″-Al 2 O 3 and Formation Mechanism of Uniform Ionic Channels

作者：Xiaolong Huang, Guo Feng, Jun Mu, Yan Li, Weifeng Xie, Fang Wu, Zhiqi Guo, Yanqiao Xu, Zhongjie Wang, Feng Jiang · 发表于：Langmuir · 年份：2025 · DOI：10.1021/acs.langmuir.4c04641 · 被引用次数：31 · 研究领域：Advanced Battery Materials and Technologies、Thermal Expansion and Ionic Conductivity、Layered Double Hydroxides Synthesis and Applications

High-temperature and long-term sintering of β″-Al 2 O 3 solid electrolyte (Beta″ Alumina Solid Electrolyte, BASE) can easily cause Na 2 O volatilization. It reduces the solid electrolyte (SE) quality, resulting in low ion conductivity of the electrolyte. It is also difficult to form uniform ionic channels. This work designs a simple nonaqueous precipitation through de-etherification heterogeneous polymerization reaction between optimal sodium source sodium ethoxide and aluminum isopropoxide to synthesize highly active precursor powders with Na–O–Al as the skeleton, effectively reducing the synthesis and sintering temperatures of β″-Al 2 O 3 solid electrolyte and minimizing the Na 2 O volatilization. Importantly, residual organic groups and a low synthesis temperature of 1150 °C promote the formation of in situ carbon uniformly. In-situ carbon with a mass fraction of about 3.98% will form uniformly distributed ion transport channels with a diameter of 1–3 μm when sintering at 1580 °C. These channels ensure a migration rate of sodium ions and ion conductivity of β″-Al 2 O 3 solid electrolyte of 0.028 S/cm at 300 °C.