Thermo-Optically Engineered Radiative Cooling Materials With Tailored Thermal Conduction.

Abstract

Radiative cooling, featuring zero-energy operation and compatibility with global decarbonization, is a promising route for passive thermal management. Despite major progress over the past few years, advances in radiative cooling have mainly focused on spectral modulation, while the role of thermal conduction in determining practical cooling performance remains far less systematically understood. In fact, different thermal conduction modes can influence radiative cooling in distinct ways by either limiting parasitic heat gain from the environment or enabling heat dissipation from internal sources. Accordingly, radiative cooling materials need to be systematically examined through the lens of tailored thermal conduction. Here, we first analyze the coupling mechanisms between radiative cooling and three different thermal-conduction modes, namely thermal insulation, enhanced heat conduction, and thermal rectification, and further quantitatively clarify the effects of thermal conduction under different operating conditions, together with the distinct roles of in-plane and through-plane thermal transport and system-level thermal resistance. Building on these mechanisms, we survey recent developments in thermo-optically engineered radiative cooling materials and their implementation. We further discuss the potential of these different coupling mechanisms in diverse applications. Finally, we identify unresolved challenges and promising research directions for advancing radiative cooling technologies with tailored thermal conduction.