High dielectric constant polymer composites have considerable potentials in energy storage and dielectric applications because of simple fabrication process, facile processability, light-weight, excellent thermal stability and mechanical properties. Perovskite (CsPbBr₃)/polyimide (PI) composites were successfully prepared via an in-situ polymerization from CsPbBr₃ precursor in polyamic acid, followed by thermal imidization. The dielectric properties of polyimide composites were controlled by adjusting the content of CsPbBr₃ nanocrystals. The obtained CsPbBr₃/PI composites not only possess a high dielectric constant of up to 25.5 but also exhibit low dielectric loss below 0.25. The maximal discharging energy density reached up to 3.10 J cm⁻³ with 10% CsPbBr_3, which is almost 3 times greater than pure PI under the same conditions. In addtiton, outstanding thermal properties of 5% decomposition temperature beyond 530 °C and good mechanical properties. The CsPbBr₃/PI composites can be prepared facilely and rapidly on a large scale, which will be a outstanding dielectric material for high temperature polymer film capacitors.

高介电常数聚合物复合材料由于制造工艺简单、加工容易、重量轻、热稳定性和机械性能优异，在储能和介电应用中具有相当大的潜力。钙钛矿（CsPbBr ₃被成功地制备的）/聚酰亚胺（PI）的复合材料通过一原位从CsPbBr聚合₃在聚酰胺酸前体，然后通过热酰亚胺化。通过调节CsPbBr ₃纳米晶的含量来控制聚酰亚胺复合材料的介电性能。得到的CsPbBr ₃/PI 复合材料不仅具有高达 25.5 的高介电常数，而且还表现出低于 0.25 的低介电损耗。10% CsPbBr ₃的最大放电能量密度达到3.10 J cm ^-3，在相同条件下几乎是纯PI的3倍。此外，530°C以上分解温度5%的优异热性能和良好的机械性能。CsPbBr ₃ /PI复合材料可以方便、快速地大规模制备，将成为一种优异的高温聚合物薄膜电容器介电材料。