Redox Potential Based Self‐Powered Electrochromic Devices for Smart Windows

Abstract

AbstractEnergy‐efficient glass windows are pivotal in modern infrastructure striving toward the “Zero energy” concept. Electrochromic (EC) energy storage devices emerge as a promising alternative to conventional glass, yet their widespread commercialization is impeded by high costs and dependence on external power sources. Addressing this, redox potential‐based self‐powered electrochromic (RP‐SPEC) devices are introduced leveraging established EC materials like tungsten oxide (WO3) and vanadium‐doped nickel oxide (V‐NiO) along with aluminum (Al) as an anode. These devices produce open circuit voltages (OCV) exceeding ±0.3 V, enabling autonomous operation for multiple cycles. The WO3 film exhibits 1% transmission and 88% modulation in the colored state at 550 nm with a mere 260 nm thickness. The redox interactions facilitate coloring and bleaching cycles without external power, while photo‐charging rejuvenates the system. Notably, the inherent voltages of the RP‐SPEC device offer dual functionality, powering electronic devices for up to 81 h. Large‐area (≈28 cm2) device feasibility is demonstrated, paving the way for industrial adoption. The RP‐SPEC device promises to revolutionize smart window technology by offering both energy efficiency and autonomous operation, thus advancing sustainable infrastructure.