Micro-Nano Composite Structures: General Resolution for Transparent-to-Multicolored Electrochromic Supercapacitors...

With the objective to fully exploit the energy-saving advantages of the electrochromic (EC) phenomenon for potential applications in related fields such as smart windows and displays, while conferring integrated functionality to a single device, it is urgent to explore a commonly applicable device construction strategy. Herein, the typical high performance polymer (HPP) materials of poly-(arylsulfones) and poly-(aryl ketones), each capable of achieving transparent-to-multicolored variations, are taken as the breakthrough point, and ingeniously coupled with the conductive substrate modification layer (SnO₂) and the ion storage layer (V₂O₅), to construct electrochromic supercapacitors (ECSs) capable of fully unlocking the extraordinary intrinsic performances from the active substances. SnO₂ nanosheets were utilized to construct the microstructure of the active layers with uniform porosity with a view to improving the response speed of the system in response to the input electrical signals. Alternatively, modified V₂O₅ nanowires, which were highly compatible with the EC materials and did not interfere with their color-changing effect, were specially identified as the counter electrode materials to facilitate the specific function. Benefiting from the porous composite structure, the delicately matched poly-(bis-(4-(diphenylamino)-phenyl)-sulfone) (P-TST) device with P-TST@SnO₂/V₂O₅ structure boasted an optical contrast ratio of 68.07%, a reduction in coloring time by more than 2/3, and a near-doubling coloration efficiency. Additionally, the construction strategy is beneficial to the capacitive properties as well. There is a perfectly adequate compatibility between material variety and multi-functionality. Such an alternative and versatile construction strategy is justified to inject vitality into the development of electrochromism in multifunctional smart windows or displays.