Experimental investigation of form-stable phase change material with enhanced thermal conductivity and thermal-induced flexibility for thermal management

Form-stable phase change material (PCM) has become the preferred material in the field of thermal management. However, the practical application of form-stable PCM is restricted by low thermal conductivity, strong rigidity, and complicated production. In this work, a facile strategy is successfully proposed to prepare a novel form-stable PCM, which is composed of paraffin (PA), styrene-ethylene-propylene-styrene (SEPS), and expanded graphite (EG). Here, SEPS acted as supporting material not only prevents leakage of liquid PA but also provides thermal-induced flexibility property. Moreover, EG takes a positive part in improving heat transfer and shape stability. The thermal conductivity and enthalpy of PA/SEPS/EG composite are measured as high as 1.340 W m⁻¹ K⁻¹ and 207.02 kJ kg⁻¹, respectively. Simultaneously, the composite PCM performs excellent leakage-proof and realizes good flexibility under external force without fracture. It is worth mentioning that the flexible PCM can reduce thermal contact resistance between battery and PCM under steady state. As a result, the battery temperature could be maintained about 43 °C by PA/SEPS/EG composite in the form of interference fit. Therefore, these results imply that the flexible composite PCM with excellent integrated properties has promising prospects for applications in thermal management.