Polypropylene diaphragm as well as preparation method and application thereof

The invention discloses a polypropylene diaphragm as well as a preparation method and application thereof. The polypropylene diaphragm is prepared from a mixture of a polypropylene raw material and an additive through melt extrusion, annealing and stretching, the additive is at least one of the following three groups: the first group is at least one of polyoxyethylene, polyvinylidene fluoride and polytetrafluoroethylene; the second group is a binary or terpolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene; and the third group is a copolymer of at least one of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene and ethylene and/or propylene. According to the polypropylene diaphragm disclosed by the invention, friction between a melt and metal equipment is reduced by utilizing the additive, so that the surface of the diaphragm is smoother; the additive is used for reducing the friction coefficient of the diaphragm; under the condition that the safety performance and the ele