Preparation method of fiber membrane for lithium ion battery

The invention relates to a preparation method of a fiber membrane for a lithium ion battery. The preparation method comprises the following steps: preparing a fiber material and dispersion liquid through hydraulic defirbering equipment into a sizing agent; feeding the sizing agent to a fourdrinier film-forming machine by adopting a multi-pipe sizing agent distribution method to form a wet membrane using a wet method, so that fibers in the wet membrane are of a space net structure with directional arrangement; conveying the wet membrane to a glue applying section by adopting a vacuum conversion transfer method to carry out atomizing glue application; conveying the wet membrane in a tunnel-type drying oven with a progressively decreased temperature to dry until the thickness is 30-150 microns; warming the membrane after being dried by using nitrogen, and removing gas impurities absorbed inside and on the surface of the membrane. The preparation method can guarantee uniform longitudinal thickness and transverse thickness of the fiber membrane, the thermal safety performance of the battery can be greatly promoted, and particularly the problems such as explosions and fire breakout generated by short circuits between an anode and a cathode inside the battery are avoided.