Affiliation:
1. Centre for Nano and Soft Matter Sciences Arkavathi Campus Bengaluru 562162 India
2. Manipal Academy of Higher Education Manipal 576104 India
3. Chemistry and Physics of Materials Unit Jawaharlal Nehru Centre for Advanced Scientific Research Rachenahalli Lake Rd Jakkur Bengaluru Karnataka 560064 India
4. Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
Abstract
AbstractExcessive electricity usage in buildings, notably for heating and cooling, accounts for over 30% of energy consumption, creating a pressing need for energy‐saving solutions. Electrochromic Smart Windows (ECSW) aims to reduce energy use while maintaining comfort but faces high costs due to materials like tin‐doped indium oxide (ITO) and thick electrochromic films. Moreover, achieving full opacity in the colored state of ECSW is a bottleneck for the industry to overcome privacy concerns. Herein, efforts are directed toward finding cost‐efficient alternatives, with all‐tungsten‐based mesh networks showing promise due to enhanced stability. This newly developed ITO‐free, all‐tungsten ECSW displays minimal transmittance (≈3%) in the colored state using only 260 nm thick sub‐stoichiometric tungsten oxide (WO3‐x) film within a lithium‐ion‐based electrolyte. The ECSW device of size (25 cm2) also demonstrates areal capacitance of ≈13 mF cm−2 to power a liquid crystal display (LCD) for ≈25 min, showcasing its energy storage capabilities. Additionally, to confirm scalability and cost‐effectiveness, a larger 15 × 15 cm2 ECSW utilized a single hybrid electrode, highlighting the potential for reducing costs when scaling up production processes. This advancement represents a significant stride toward accessible and energy‐efficient smart window technology, offering broader applicability within modern architectural practices.