A Six‐Layer Cascaded Electrocaloric Cooling Device With Large Temperature Span

ABSTRACT Electrocaloric (EC) cooling technology offers advantages such as miniaturization, low energy consumption, and solid‐state operation. However, the temperature span (Δ T _span ) of EC devices remains limited and must be enhanced. Here, we construct a six‐layer cascade electrocaloric cooling device (SCECD) that achieves a large Δ T _span . The synergy of electrostatic actuation and self‐actuation ensures that electrostatic force and deformation force always act in the same direction on the EC stack, enhancing heat transfer efficiency in the SCECD. The copper (Cu) as the electrode is evaporated onto the EC stack to increase its stiffness and raise the critical voltage for instability, which typically manifests as localized wrinkling or dimpling. This enhancement improves the resistance of the EC stack to instability, thus ensuring uniform deformation under actuation conditions. As a result, the SCECD, which combines electrostatic actuation and self‐actuation, achieves a Δ T _span of 13.07 K and a cooling temperature change (Δ T _cooling ) of 6.45 K. The SCECD not only achieves an outstanding cooling performance within the field of polymer‐based EC devices, but also contributes to ongoing efforts in developing practical solid‐state cooling technologies.