柔性电致变色器件具有体积小、重量轻、可弯曲等优点，在可穿戴设备、曲面显示器、节能及自适应伪装等领域具有潜在应用前景。本工作以铁氰化钾、氯化钾、无水氯化铁为原料，采用电沉积方法在ITO-PET柔性基底上沉积普鲁士蓝(PB)制得PB/ITO-PET电致变色薄膜，并利用扫描电子显微镜、紫外光谱仪、电化学工作站对PB/ITO-PET电致变色薄膜微观结构和电化学性能进行分析表征。结果表明，电沉积时间为200 s时得到的PB/ITO-PET电致变色薄膜在700 nm波长处光吸收率达到0.755，且PB/ITO-PET电致变色薄膜可在较低电压(0.6 V/-0.3 V)下实现着色和褪色。其光调制范围为68%，着色/褪色响应时间分别为9 s/8 s，着色效率为108 cm2/C。PB/ITO-PET电致变色薄膜经1000次着色-褪色循环后光调制范围为68%，着色效率为100.3 cm2/C。PB/ITO-PET电致变色薄膜500次弯曲，着色效率为105.5 cm2/C，并经1000次着色-褪色循环后着色效率为91 cm2/C，光调制范围为65%。利用ITO-PET为离子存储层(对电极)、凝胶电解质和PB/ITO-PET为工作电极组装得到柔性电致变色器件，其光调制范围为53%，着色/褪色响应时间分别为13 s/18 s。

Due to the advantages of small volume, light weight and flexibility, flexible electrochromic (EC) devices have drawn much attention in various fields, such as flexible display screens, smart windows, information storage, electronic paper and energy-saving bracelets, etc. EC materials can be classified into two categories: inorganic and organic systems. Compared with organic EC materials, inorganic EC materials display good stability and reliability. Prussian blue and transition metal oxides are the two major classes of inorganic EC materials. Up to now, most reported EC devices in literatures are deposited on rigid substrates. It is still a major challenge to realize excellent EC devices on flexible substrates. Combining EC materials with flexible substrates is expected to have great application prospects in future smart clothes and implantable displays. In this work, potassium ferricyanide, potassium chloride and anhydrous ferric chloride were used as precursor. Prussian blue (PB) was deposited on ITO-PET flexible substrate by electrodeposition method to prepare PB/ITO-PET EC film. Scanning electron microscope, ultraviolet spectrometer and electrochemical workstation were used to characterize its microstructure and electrochemical performance. The experimental results showed that the light absorption rate of PB/ITO-PET EC film with the electrodeposition time of 200 s was 0.755 at the wavelength (λ) of 700 nm. The PB/ITO-PET EC film was colored and faded at low voltage (0.6 V/-0.3 V). The light modulation range, coloring/fading response time, coloring efficiency were 68%, 9 s/8 s and 108 cm2/C, respectively. The light modulation range and coloring efficiency of PB/ITO-PET EC film after 1000 coloring-fading cycles were 68% and 100.3 cm2/C. The coloring efficiency was 105.5 cm2/C after 500 bending, and the coloring efficiency and light modulation range of PB/ITO-PET electrochromic film were 91 cm2/C and 65% after 500 bending and 1000 coloring-fading cycles. Finally, a flexible EC device was assembled using ITO-PET as ion storage layer (counter electrode), gel electrolyte and PB/ITO-PET as working electrode, and its light modulation range and coloring/fading response time were 53% and 13 s/18 s, respectively.