In this study, composite pouch films incorporating ionite were fabricated, and their structural properties as well as temperature variations during charge–discharge cycles were evaluated to examine their applicability as heat-suppression pouch films for secondary batteries. The films were prepared using a film coater (Coretech, CT-AF300), with variations in ionite content and particle size. In addition, the effects of plasma treatment on the surface state of PET films were investigated to enhance coating adhesion, with the aim of determining the optimal fabrication conditions. Furthermore, an infrared thermal imaging camera and a custom-built test device were employed to measure the temperature differences with and without the pouch films during charge– discharge processes, thereby assessing the potential of developing next-generation high-performance pouch films.

This study aimed to grow single crystals with low dislocation density using a heat exchange method using room temperature water, and investigated the effect of the structure of the heat exchanger under the crucible on the defects and dislocation density of the single crystals and the shape of the solid-liquid interface of the crystals, and obtained the following conclusions. The dislocation density of sapphire single crystal grown at 2,200℃ for 30 min and a growth rate of 0.2℃/min was 0.92x103pcs/㎠. Mo guard was used to stabilize the solid-liquid interface grown from seeds, and sapphire single crystals with a diameter of 130㎜ and a height of 75㎜ were grown.