Acid-treated carbon nanotubes form a dual-continuous “electron-ion” transport network to enhance the remarkable dynamic thermal regulation properties of polyaniline

Polyaniline (PANI)-based infrared electrochromic devices (IR-ECD) typically offer advantages such as a broad spectral response and multi-state tunability. However, PANI prepared using conventional solution processing methods suffers from limited infrared radiation modulation capability, poor mechanical stability, and low scalability, significantly hindering its practical application. This paper introduces a scalable fabrication strategy centered on a dual-continuous “electron-ion” transport network. Specifically, templated PANI growth on acidified carbon nanotubes (CNTs) achieves interfacial molecular ordering, with CNTs serving as efficient charge transport pathways and proton reservoirs for PANI. Research confirms that incorporating CNTs significantly enhances carrier mobility and the utilization efficiency of polarons/bipolarons, thereby substantially boosting the device's infrared radiation modulation capability. Simultaneously, CNTs function as proton reservoirs, providing continuous protons, effectively suppressing deprotonation while delivering high redox activity and excellent reversibility. The resulting IR-ECD achieves 0.398 emissivity modulation (2.5–25 µm) and 0.452 (8–14 µm), with no degradation after 2000 cycles. Scalable fabrication of the solution-processable functional layer via ultrasonic spraying technology extends applications from wearable devices to large-area thermal radiation control. This study provides a generalizable and scalable solution for constructing next-generation PANI-based IR-ECD, demonstrating outstanding modulation capability, durability, and application adaptability in advanced thermal management systems.