Metal oxide ultrafine fiber-based composite separator with heat resistance and secondary battery using same

摘要

An ultrafine fiber-based composite separator comprising a fibrous porous body which comprises ultrafine metal oxide/polymer composite fibers, or ultrafine metal oxide fibers and a polymer resin coating layer formed on the surface thereof, the ultrafine fibers being continuously randomly arranged and layered, and obtained by electrospinning a metal oxide precursor sol-gel solution or a mixture of a metal oxide precursor sol-gel solution and a polymer resin solution, wherein the surface of the metal oxide/polymer composite fibers has a uniform mixing composition of the metal oxide and the polymer resin, in which the separator has a heat shrinkage rate at 150˜250° C. of 10% or less and does not break down due to melting at a temperature of 200° C. or lower, has low heat shrinkage rate, and superior heat resistance and ionic conductivity, being capable of providing improved cycle and power properties when used in manufacturing a battery.

主权项

1. An ultrafine fiber-based composite separator comprising a fibrous porous body which comprises ultrafine metal oxide/polymer composite fibers, or ultrafine metal oxide fibers and a polymer resin coating layer formed on the surface thereof, the ultrafine fibers being continuously randomly arranged and layered, and obtained by electrospinning a homogenous mixture of a metal oxide precursor sol-gel solution and a polymer resin solution, wherein the surface of the metal oxide/polymer composite fibers has a uniform mixing composition of the metal oxide and the polymer resin, in which the separator has a heat shrinkage rate at 150˜250° C. of 10% or less and does not break down due to melting at a temperature of 200° C. or lower, and wherein the polymer resin solution comprises a polymer resin that swells in an electrolyte solution and/or a polymer resin that has a melting point of 180° C. or higher or is amorphous, or is a mixture thereof.