Experimental investigation on thermally induced aluminum nitride based flexible composite phase change material for battery thermal management

Phase change material (PCM) based battery thermal management (BTM) system is an effective cooling system depending on the absorption/release of the latent heat of PCM, which can benefit for thermal buffering and extending lifespan. In this paper, a novel thermal induced high thermal conductivity flexible composite PCM was proposed, which combined with Styrene butadiene styrene (SBS), paraffin (PA) and aluminium nitride (AlN). The effects of different AlN mass fractions associated with different phase change enthalpy and thermal conductivity are investigated, the results displayed that an optimal 15% AlN mass fraction is needed to achieve the optimum thermal performance, which as cooling system is recommended to apply in battery module. The structure and morphology properties of composites PCM were characterized via XRD, SEM and universal tension machine, which indicated that optimum composite was a well physicochemical compatibility among various components. In addition, flexible CPCMs embedded in battery module can decrease the thermal contact resistance, thereby improving the thermal control performance. Compared with air cooled system and CPCM with AlN cooling system, the flexible CPCM can control the maximum temperature (T_max) below 32.5 °C and maintain temperature difference (ΔT) within 0.9 °C at 1C discharge rate. Even after nine cycles at 1C discharge rate, the T_max and ΔT are still 40.5 °C and 7.6 °C, respectively. It should be noted that PA with large latent heat was performed as PCM, while SBS employed as the supporting material and AlN as the thermal conductivity additions to enhance the performance of materials. Thus, this study indicates the prepared flexible composite PCM with a huge potential application for thermal energy storage and other fields, which possesses important significance in both academic and industrial worlds.