YDreams, Madan Parque-Sul, 2825-149 Caparica, Portugal.
ACS Appl Mater Interfaces. 2012 Oct 24;4(10):5266-75. doi: 10.1021/am301213b. Epub 2012 Oct 8.
Vanadium oxide gel was synthesized and formulated for the assembly of solid-state electrochromic cells on flexible and transparent electrodes using inkjet printing. FTIR, Raman, and X-ray diffraction spectroscopic measurements showed that the vanadium oxide gel here synthesized consisted of V(2)O(5)·6H(2)O, microstructures similar to orthorhombic V(2)O(5), while Raman spectroscopy also shows the presence of amorphous domains. Atomic force microscopy (AFM) images of the thin films printed using an inkjet shows a ribbonlike structure, which is in accordance with previous results of the vanadium oxide gels in solution. Solid-state electrochromic devices were assembled at room temperature using the inkjet printed films, without any sinterization step. The electrochemical properties of the vanadium oxide gel were characterized by cyclic voltammetry and spectroelectrochemistry by visible/NIR absorption spectroscopy (in both liquid and solid-state). Several redox steps are observed, which gives rise to a variety of color transitions as a function of the applied voltage. The different optical properties of the vanadium oxide gel are assigned to different intercalation steps of Li(+), leading to different crystalline phases of the gel. The final result is a solid-state electrochromic cell showing excellent contrast between the redox states, giving rise to colors such as yellow, green, or blue. Color space analysis was used to characterize the electrochromic transitions, and while absorption spectra showed rather long switching times (up to 100 s), in Lab* color space coordinates, the switching time is smaller than 30 s. These electrochromic cells also have an excellent cycling stability showing high reversibility and a cyclability up to more than 30,000 cycles with a degradation of 18%.
氧化钒凝胶被合成并配制用于在柔性透明电极上通过喷墨打印组装固态电致变色电池。傅里叶变换红外光谱（FTIR）、拉曼光谱和 X 射线衍射光谱测量表明，这里合成的氧化钒凝胶由 V(2)O(5)·6H(2)O 组成，具有类似于正交 V(2)O(5)的微观结构，而拉曼光谱也显示出非晶域的存在。使用喷墨打印的薄膜的原子力显微镜（AFM）图像显示出带状结构，这与溶液中氧化钒凝胶的先前结果一致。在室温下使用喷墨打印的薄膜组装了固态电致变色器件，无需任何烧结步骤。通过循环伏安法和可见/近红外吸收光谱（在液态和固态下）的光谱电化学对氧化钒凝胶的电化学性质进行了表征。观察到几个氧化还原步骤，这导致了各种颜色随着施加电压的变化而发生转变。氧化钒凝胶的不同光学性质归因于 Li(+)的不同嵌入步骤，导致凝胶的不同结晶相。最终的结果是一个固态电致变色电池，在氧化还原状态之间显示出极好的对比度，产生黄色、绿色或蓝色等颜色。颜色空间分析用于表征电致变色转变，虽然吸收光谱显示出相当长的开关时间（长达 100 秒），但在 Lab*颜色空间坐标中，开关时间小于 30 秒。这些电致变色电池还具有极好的循环稳定性，显示出高可逆性和可循环性，超过 30,000 次循环，降解率为 18%。
