中文摘要：

制备了4种不同分子量的α相聚偏氟乙烯（PVDF）膜,研究了PVDF分子量对其介电性能与储能特性的影响。研究结果表明,低分子量PVDF膜具有更窄的电滞回线,其充放电效率达到了73.05%,是高分子量薄膜的2.27倍。进一步的研究发现,在1 000kV/cm电场下,低分子量PVDF膜的漏导电流为0.07175μA,远低于高分子量PVDF膜,并体现出较高的电阻率（22.7TΩ·m）,更适合作为储能电容器的电介质材料。

英文摘要：

The molecular weight shows great influence on dielectric and energy storage performance of poly（vinylidene fluoride）（PVDF）films and related devices.In this letter,four kinds of PVDF with different molecular weight and corresponding films with predominantαphase were fabricated and the influences of molecular weight on the dielectric and energy storage properties of these PVDF films were studied.It has been found that the lowmolecular-weight PVDF film presents a much slimmer polarization-electric field hysteresis loops,higher discharge energy storage efficiency（73.05%）,lower leakage current（0.07175μA）and higher resistivity（22.7TΩ·m）.Under a 1 000kV/cm electric field,the discharge energy storage efficiency and resistivity of the low-molecular-weight PVDF film are 2.27 and 18.92 times as much as which of the high-molecular-weight PVDF film respectively,while the leakage current of the former is less than 6% of the latter,which means the low-molecular-weight PVDF film is more desirable and promising for high performance pulse discharge capacitor application.