Harnessing Outer Space for Improved Electrocaloric Cooling

Abstract Solid‐state refrigeration based on the electrocaloric (EC) effect has recently been applied to thermal management for humans and electronics due to its low power consumption, zero carbon emissions, and compact size. However, the temperature span of the EC device is limited by the adiabatic temperature change ( ΔT ad ) of the caloric materials. Moreover, significant ΔT ad performance in high‐temperature environments, such as strong sunlight or parasitic heat sources, has yet to be demonstrated. In this study, a novel radiative heat sink/source‐integrated electrocaloric ( R ‐iEC) thermal regulation system is presented that overcomes the inherent heat dissipation limitations of the EC devices by using outer space as a reliable and sustainable heat sink. To effectively dissipate parasitic heat, a nonmetallic thermally conductive radiative cooler (TCRC) is implemented with a high thermal conductivity of 1.1 W mK −1 and exceptional spectral features, including solar reflectivity of ≈96% and emissivity of ≈95% in the atmospheric window region. The R ‐iEC system fortified with TCRC demonstrates superior heat dissipation compared to conventional radiative coolers, providing an additional cooling heat flux of 87 W m −2 . Under high‐temperature conditions with heat fluxes exceeding 770 W m −2 , this improvement results in a maximum heat dissipation performance of 240 W m −2 , surpassing that of conventional metal heat sinks.