Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States.
ACS Nano. 2013 Mar 26;7(3):2186-91. doi: 10.1021/nn305122f. Epub 2013 Feb 15.
Ion conducting oxides are commonly used as electrolytes in electrochemical devices including solid oxide fuel cells and oxygen sensors. A typical issue with these oxide electrolytes is sluggish oxygen surface kinetics at the gas-electrolyte interface. An approach to overcome this sluggish kinetics is by engineering the oxide surface with a lower oxygen incorporation barrier. In this study, we engineered the surface doping concentration of a common oxide electrolyte, yttria-stabilized zirconia (YSZ), with the help of atomic layer deposition (ALD). On optimizing the dopant concentration at the surface of single-crystal YSZ, a 5-fold increase in the oxygen surface exchange coefficient of the electrolyte was observed using isotopic oxygen exchange experiments coupled with secondary ion mass spectrometer measurements. The results demonstrate that electrolyte surface engineering with ALD can have a meaningful impact on the performance of electrochemical devices.
离子导体氧化物通常用作电化学装置中的电解质，包括固体氧化物燃料电池和氧气传感器。这些氧化物电解质的一个典型问题是气体-电解质界面处氧表面动力学缓慢。克服这种缓慢动力学的一种方法是通过用较低的氧掺入势垒对氧化物表面进行工程设计。在这项研究中，我们借助原子层沉积 (ALD) 对常见氧化物电解质氧化钇稳定氧化锆 (YSZ) 的表面掺杂浓度进行了工程设计。通过优化单晶 YSZ 表面的掺杂浓度，我们在同位素氧交换实验和二次离子质谱测量的基础上，观察到电解质的氧表面交换系数增加了 5 倍。结果表明，用 ALD 进行电解质表面工程处理可以对电化学装置的性能产生有意义的影响。
