Energy Saving Electrochromic Windows Based on Conjugated Polymers with Counter Electrode Modification

In the quest to reduce energy consumption, smart window devices present a core solution to reduce the massive energy loss through windows. Smart window devices can be designed on the basis of electrochromic (EC) principles, which offer simple integration mechanisms for color switching, optical sensing, and energy storage. An energy saving electrochromic window was explored based on charge-balancing concept and interfacial carrier transport control. A blue or black-to-transparent EC windows were achieved through the combination of EC polymers and a capacitive layer. A porous film was grown from aniline interfaced-graphene flakes, to provide a capacitive layer with a high surface area and electrical conductivity. As prepared EC windows afforded a highly transparent (>75%) and a large color-contrast EC window, which showed a high energy density enough to fuel an electronic clock and LED. A 10 × 10 cm2 size window was demonstrated, to feature the scalability of the electrochromic capacitive window. These electrochromic properties of CPs with counter electrode modification approaches make them very promising candidates for designing functional smart windows. Single cell type multi-functional windows have emerged based on CPs, to deliver electrochromic capacitive windows and photoelectrochromic windows. The progress of these efforts will be highlighted in this talk, along with guiding principles.