Liu Shuangshuang, Zhang Jingde, Tian Yuhang, Sun Jian, Huang Panxin, Li Jianzhang, Han Guifang
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Material Science and Engineering, Shandong University, Jinan 250061, China.
Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Jinan 250100, China.
Materials (Basel). 2023 Jun 28;16(13):4673. doi: 10.3390/ma16134673.
BiO is a promising sintering additive for YSZ that not only decreases its sintering temperature but also increases its ionic conductivity. However, BiO preferably grows into large-sized rods. Moreover, the addition of BiO induces phase instability of YSZ and the precipitation of monoclinic ZrO, which is unfavorable for the electrical property. In order to precisely control the morphology and size of BiO, a microemulsion method was introduced. Spherical BiO nanoparticles were obtained from the formation of microemulsion bubbles at the water-oil interface due to the interaction between the two surfactants. Nanosized BiO-YSZ composite powders with good mixing uniformity dramatically decreased the sintering temperature of YSZ to 1000 °C. YO-stabilized BiO (YSB)-YSZ composite powders were also fabricated, which did not affect the phase of YSZ but decreased its sintering temperature. Meanwhile, the oxygen vacancy concentration further increased to 64.9% of the total oxygen with the addition of 5 mol% YSB. In addition, its ionic conductivity reached 0.027 S·cm at 800 °C, one order of magnitude higher than that of YSZ. This work provides a new strategy to simultaneously decrease the sintering temperature, stabilize the phase and increase the conductivity of YSZ electrolytes.
BiO是一种很有前景的用于YSZ的烧结添加剂，它不仅能降低YSZ的烧结温度，还能提高其离子电导率。然而，BiO倾向于生长成大尺寸的棒状。此外，BiO的添加会导致YSZ的相不稳定以及单斜ZrO的析出，这对电性能不利。为了精确控制BiO的形貌和尺寸，引入了微乳液法。由于两种表面活性剂之间的相互作用，在水油界面形成微乳液气泡从而获得了球形BiO纳米颗粒。具有良好混合均匀性的纳米级BiO-YSZ复合粉末显著降低了YSZ的烧结温度至1000°C。还制备了YO稳定的BiO（YSB）-YSZ复合粉末，其不影响YSZ的相但降低了其烧结温度。同时，添加5 mol% YSB后氧空位浓度进一步增加至总氧的64.9%。此外，其在800°C时的离子电导率达到0.027 S·cm，比YSZ高一个数量级。这项工作为同时降低YSZ电解质的烧结温度、稳定相和提高电导率提供了一种新策略。
