Scalable, Patternable Glass‐Infiltrated Ceramic Radiative Coolers for Energy‐Saving Architectural Applications

Abstract

Abstract A huge concern on global climate/energy crises has triggered intense development of radiative coolers (RCs), which are promising green‐cooling technologies. The continuous efforts on RCs have fast‐tracked notable energy‐savings by minimizing solar absorption and maximizing thermal emission. Recently, in addition to spectral optimization, ceramic‐based thermally insulative RCs are reported to improve thermoregulation by suppressing heat gain from the surroundings. However, a high temperature co‐firing process of ceramic‐based thick film inevitably results in a large mismatch of structural parameters between designed and fabricated components, thereby breaking spectral optimization. Here, this article proposes a scalable, non‐shrinkable, patternable, and thermally insulative ceramic RC (SNPT‐RC) using a roll‐to‐roll process, which can fill a vital niche in the field of radiative cooling. A stand‐alone SNPT‐RC exhibits excellent thermal insulation (≈0.251 W m−1 K−1) with flame‐resistivity and high solar reflectance/long‐wave emissivity (≈96% and 92%, respectively). Alternate stacks of intermediate porous alumina/borosilicate (Al2O3‐BS) layers not only result in outstanding thermal and spectral characteristics, causing excellent sub‐ambient cooling (i.e., 7.05 °C cooling), but also non‐shrinkable feature. Moreover, a perforated SNPT‐RC demonstrates its versatility as a breathable radiative cooling shade and as a semi‐transparent window, making it a highly promising technology for practical deployment in energy‐saving architecture.

Keywords

• glass infiltration
• multi‐layer
• non‐shrinkable ceramics
• passive radiative cooling
• thermal management