为了高效合成分散性良好的纳米球形氧化铈(CeO2)抛光粉,采用室温固相合成工艺制备了CeO2 抛光粉,探究了原料配比、分散剂种类及含量对CeO2 成相温度和微观形貌的影响,并将CeO2抛光粉配制成抛光液,通过抛光液的沉降效果研究分散剂对抛光液分散稳定性的影响.研究表明,当Ce(NO3)3·6H2O与Na2CO3摩尔比为 1 ∶ 2.5,分散剂吐温-80 质量分数为 20%,煅烧温度为700℃时,CeO2抛光粉呈现出粒径约75 nm的高分散球形结构,此外采用吐温-80 做分散剂配制的抛光液稳定性最佳.

High-performance solid oxide fuel cell (SOFC) is in urgent need of high-quality electrolyte powders with high reactivity and chemical uniformity. Here, 8 mol% Y2O3 doped ZrO2 (YSZ) nano-powders were synthesized by an improved solid-state reaction method at ambient temperature, and were applied to the fabrication of SOFC electrolytes. YSZ nano-powders show average grain sizes of similar to 20 nm and high dispersibility, which is comparable with or even better than some other chemical methods. Benefitting from their high reactivity, dense YSZ electrolytes (relative density of 97.9%) can be obtained at a relatively low sintering temperature of 1400 degrees C. The optimized electrical conductivity reaches up to a high value of 0.034 S/cm at 800 degrees C in air. The anode supported single cell with the construction of Ni-YSZ/YSZ/Sm0.2Ce0.8O2-delta(SDC)/La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) exhibits the peak power density of 0.827 W/cm(2) at 800 degrees C while taking wet H-2 as fuels and ambient air as oxidants. (c) 2022 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Er0.2Bi0.8O1.5 (ESB), the oxide with the best oxygen conduction ability, is introduced to modify the electrical performance of Y0.16Zr0.84O1.92 (YSZ) electrolytes for solid oxide fuel cells, and the electrical property and grain boundary conduction mechanism of xESB-YSZ (x = 0, 5, 10, 15, and 20 mol.%) are investigated. The introduction of ESB effectively promotes densification during sintering and improves the electrical performance of YSZ. At the addition of 20 mol.% ESB (20ESB-YSZ), the electrolyte allows a decrease of 500 degrees C for sintering temperature due to the low melting point of ESB, and-4 times higher electrical conductivity (0.093 S cm- 1 at 750 degrees C) than that of YSZ (0.021 S cm- 1 at 750 degrees C) without extra electronic conduction. Basing on the Motte-Schottky model, the enhance electrical performance is mainly attribute to two aspects. One is the lower space charge potential (0.014 V for 20ESB-YSZ, 0.207 V for YSZ), and the other is the higher impurity blocking term (0.97 for 20ESB-YSZ, 0.928 for YSZ). X-ray photoelectron spectroscopy analysis of composite electrolytes reveals that the oxygen vacancies content increase with the increased addition amount of ESB. The 20ESB-YSZ electrolyte-supported single cell with Ag-Sm0.2Ce0.8O1.9 as electrodes exhibits a power density of 0.572 W cm-2 at 750 degrees C.

As a promising electrolyte material for solid oxide fuel cells (SOFCs), BaZr0.1Ce0.7Y0.1Yb0.1O3-delta (BZCYYb) often surfers from its high sintering temperature, which causes Ba evaporation and sluggish grain growth, thus reducing the electrical conductivity. In this work, densified BZCYYb electrolytes were fabricated at temperatures as low as 1400 degrees C using the microwave sintering technique. Comparing with the conventional sintered ones, a temperature decrease of 150 degrees C is achieved. The Ba evaporation is effectively suppressed, and large grain sizes of similar to 4 mu m are obtained. The total conductivity for microwave sintered symmetric cell measured in wet air at 700 degrees C is 3.8 x 10(-2) S cm(-1), benefiting from both enhanced bulk conductivities by 1-2 times and grain boundary conductivities by 50 times. With the microwave sintered BZCYYb as electrolyte, an anode-supported cell reaches a maximum power density of 0.64 W cm(-2) at 700 degrees C. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.