Dual-band electrochromic energy-storage windows (D-EESWs) integrating solar-spectrum regulation with electrochemical energy storage offer a promising strategy for building energy conservation. Here, a multifunctional polyaniline (PANI) film with an interconnected network structure was fabricated on FTO glass via a simple one-step electrodeposition process. By regulating its oxidation and doping states, the PANI film enables independent visible (VIS)–near-infrared (NIR) modulation among “Bright-Warm”, “Bright-Cool”, and “Dark-Cool” modes. The film exhibits rapid switching, with coloration/bleaching times of 9.3/11 s at 700 nm and 7.0/7.6 s at 1200 nm, with coloration efficiencies of 385.6 cm²·C^-1 in the VIS region and over 1000 cm²·C^-1 in the NIR region. In situ spectroscopic analyses reveal that VIS modulation is associated with the reversible evolution of quinonoid structures and polarons, whereas NIR modulation is dominated by polaron-related absorption. Meanwhile, the PANI electrode achieves 28.1% energy recovery and 78.7% charge recovery during electrochromic operation. The assembled D-EESW achieves a maximum temperature difference of 11.5 ℃ under outdoor solar irradiation and delivers an output voltage of up to 2.56 V to power an LED. Moreover, its distinct multicolor states enable visual indication of the charge-storage state. These results demonstrate a simple and low-cost strategy for multifunctional smart windows integrating dual-band solar regulation, electrochemical energy storage and recovery, and visual energy-state indication.

 

Polyaniline,Dual-band electrochromism,Electrochromic energy storage,Smart windows