Fabrication and structural characterization of self-supporting electrolyte membranes for a micro solid-oxide fuel cell
Fabrication and structural characterization of self-supporting electrolyte membranes for a micro solid-oxide fuel cell
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DOI：
10.1557/jmr.2004.0350
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发表时间：
2004-09-01
影响因子：
2.7
通讯作者：
Schmidt, MA
中科院分区：
文献类型：
--
作者：
Baertsch, CD;Jensen, KF;Schmidt, MA
微机械燃料电池是一类正在开发用于便携式发电的微型设备。在本文中，我们报告的加工和几何设计标准的微型固体氧化物燃料电池的独立电解质膜的制造。采用电子束蒸发和溅射沉积法在氮化硅薄膜上制备了亚微米、致密的纳米晶氧化钇稳定氧化锆（YSZ）和掺钆氧化铈（GDC）薄膜。选择性的氮化硅去除导致独立的，正方形的，电解质膜的侧面尺寸为1025 μ m的YSZ和525 μ m的GDC，与高的YSZ的加工产量大。在沉积态蒸镀膜和溅射膜中，残余应力分别为拉伸应力（+85至+235 MPa）和压缩应力（-865至-155 MPa）。拉伸蒸发膜失败，通过脆性断裂在退火过程中在低于773 K的温度下，热限制取决于膜厚度膜尺寸的纵横比。溅射薄膜的压缩残余应力表现出上级的机械和热稳定性比蒸发薄膜。溅射的1025 μ m膜在773 K下退火后存活，这导致在升高的温度（923 K）下产生拉伸应力和脆性断裂。
Micromachined fuel cells are among a class of microscale devices being explored for portable power generation. In this paper, we report processing and geometric design criteria for the fabrication of free-standing electrolyte membranes for microscale solid-oxide fuel cells. Submicron, dense, nanocrystalline yttria-stabilized zirconia (YSZ) and gadolinium-doped ceria (GDC) films were deposited onto silicon nitride membranes using electron-beam evaporation and sputter deposition. Selective silicon nitride removal leads to free-standing, square, electrolyte membranes with side dimensions as large as 1025 mum for YSZ and 525 mum for GDC, with high processing yields for YSZ. Residual stresses are tensile (+85 to +235 MPa) and compressive (-865 to -155 MPa) in as-deposited evaporated and sputtered films, respectively. Tensile evaporated films fail via brittle fracture during annealing at temperatures below 773 K; thermal limitations are dependent on the film thickness to membrane size aspect ratio. Sputtered films with compressive residual stresses show superior mechanical and thermal stability than evaporated films. Sputtered 1025-mum membranes survive annealing at 773 K, which leads to the generation of tensile stresses and brittle fracture at elevated temperatures (923 K).