Dielectric composite films and uses in thin film capacitors

The invention relates to the technical field of dielectric composite films, in particular to a dielectric composite film and application of the dielectric composite film in a thin-film capacitor, the dielectric composite film comprises a base film, and the base film comprises the following components in percentage by mass: 40-60% of polyvinylidene fluoride and not less than 20% of polypropylene; the upper surface and the lower surface of the base film are coated with polypropylene layers, and the polypropylene layers comprise not less than 70% by mass of polypropylene. The maximum energy storage density of the dielectric composite film is 6.4 J/cm < 3 >, the charge-discharge efficiency is close to that of a pure polypropylene film, and industrial requirements can be met. 本发明涉及介电复合膜技术领域，具体涉及一种介电复合膜及在薄膜电容器中的用途，介电复合膜包括基膜，所述基膜的组分中包含质量分数40-60%的聚偏氟乙烯，以及质量分数不少于20%的聚丙烯；所述基膜的上表面和下表面覆有聚丙烯层，所述聚丙烯层的组分中包含质量分数不少于70%的聚丙烯。介电复合膜的储能密度最高至6.4J/cm3、充放电效率与纯聚丙烯薄膜接近，能够满足工业需求。