The Ångström Laboratory, Department of Engineering Sciences, Uppsala University, P.O. Box 534, SE-75121 Uppsala, Sweden.
ACS Appl Mater Interfaces. 2015 May 13;7(18):9319-22. doi: 10.1021/acsami.5b01715. Epub 2015 May 5.
Anodically colored nickel oxide (NiO) thin films are of much interest as counter electrodes in tungsten oxide based electrochromic devices such as "smart windows" for energy-efficient buildings. However, NiO films are prone to suffering severe charge density degradation upon prolonged electrochemical cycling, which can lead to insufficient device lifetime. Therefore, a means to improve the durability of NiO-based films is an important challenge at present. Here we report that the incorporation of a modest amount of iridium into NiO films [Ir/(Ir + Ni) = 7.6 atom %] leads to remarkable durability, exceeding 10000 cycles in a lithium-conducting electrolyte, along with significantly improved optical modulation during extended cycling. Structure characterization showed that the face-centered-cubic-type NiO structure remained after iridium addition. Moreover, the crystallinity of these films was enhanced upon electrochemical cycling.
作为基于氧化钨的电致变色器件（如用于节能建筑的“智能窗”）中的对电极，阳极着色氧化镍（NiO）薄膜引起了广泛关注。然而，NiO 薄膜在长时间电化学循环过程中容易遭受严重的电荷密度退化，从而导致器件寿命不足。因此，提高基于 NiO 的薄膜的耐久性是目前面临的一个重要挑战。在这里，我们报告在 NiO 薄膜中掺入适量的铱（Ir/(Ir + Ni) = 7.6 原子%）可以显著提高耐久性，在锂离子导电电解质中超过 10000 次循环，并且在长时间循环过程中显著改善了光学调制。结构表征表明，铱的加入后仍保留了面心立方型 NiO 结构。此外，这些薄膜的结晶度在电化学循环过程中得到了增强。
