PI-SiO2-PTFE ternary nano composite multi-curvature pore membrane material as well as preparation method and application thereof

The invention discloses a nano composite multi-curvature pore membrane material. According to the nano composite multi-curvature pore membrane material, a polyimide (PI) nano fiber non-woven fabric serves as a base material, and pores of the base material are filled with composite nano particles. The nano composite multi-curvature pore membrane material is characterized by being formed by mixing polytetrafluoroethylene nano-particles (PTFE-NP) and silicon dioxide nano-particles (SiO2-NP) in a weight ratio of (7-12):(8-13). The nano composite multi-curvature pore membrane material provided by the invention has high-temperature resistance, moderate porosity, moderate surface density, excellent ion transportation property and excellent mechanical property, and when the material is used in a lithium ion battery, the problem of micro short circuit of the battery caused by over-high porosity of a pure PI nano fiber membrane can be solved; the serious problem of thermal runaway of a power lithium ion battery caused by mechanical collision can be solved.