A newly designed paraffin@VO2 phase change material with the combination of high latent heat and large thermal conductivity

The paraffin is the widely used solid-liquid phase change material (PCM) with large fusion latent heat in thermal management, and vanadium dioxide (VO2) is a promising reversible solid-solid PCM with a near-ambient phase transition temperature (Tc = ~68 °C). In the real applications, the paraffin is always wrapped with inorganic or organic shells to stabilize the shape during the fusion/solidification with compromising large amounts of latent heat. Herein, we proposed the [email protected]2 PCM structure for the first time, which combines the solid-liquid paraffin PCM core and the solid-solid VO2 PCM shell. The [email protected]2 PCM structure is synthesized via an emulsion method starting with the Te/W-codoped VO2 microparticles and the paraffin wax (C26H54). This developed PCM structure shows a suitable Tc = 58.2 °C (ΔTc = 5.5 °C), a decent fusion latent heat 163 J/g and a largely enhanced thermal conductivity 1.53 W/mK, which should be promising for the high-efficient thermal management applications.