SEPARATOR FOR ELECTROCHEMICAL DEVICE

摘要

Disclosed is a separator for an electrochemical device including a porous polymer film, and a porous coating layer including at least one type of particles of inorganic particles and organic particles and binder polymer, the porous coating layer formed on one surface or both surfaces of the porous polymer film, wherein the porous polymer film has a structure in which multiple fibrils arranged parallel to the surface of the film are stacked in layers, and the fibrils are bound to each other to form a lamellar structure with a size from 130 to 200 nm and tortuosity of the porous polymer film is from 1.60 to 1.90, and an electrochemical device comprising the same.

主权项

1. A separator for an electrochemical device, comprising:
a porous polymer film; and a porous coating layer including at least one type of particles of inorganic particles and organic particles and binder polymer, the porous coating layer formed on one surface or both surfaces of the porous polymer film, wherein the porous polymer film has a structure in which multiple fibrils arranged parallel to the surface of the porous polymer film are stacked in layers, and the fibrils are bound to each other to form a lamellar structure with a size from 130 to 200 nm and tortuosity of the porous polymer film is from 1.60 to 1.90, in which the tortuosity is calculated by the following equation:
(Tortuosity (τ))2=NM×∈  [Equation] where NM denotes the MacMullin number and is a value obtained by dividing σ0 by σeff, σ0 denotes a conductivity value of a pure liquid electrolyte, σoff denotes a conductivity value when combining the separator with the liquid electrolyte, and ∈ denotes porosity of the separator.