Porous Coated Polyolefin Separator for Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium secondary battery separators face challenges with thermal stability and ion conductivity, leading to potential short circuits and reduced power output due to thermal shrinkage and low ion conductivity.
Innovation Solution
A separator with a monolayer-type polyolefin-based micro-porous film and a porous coating layer made of inorganic particles and a binder polymer, optimizing porosity, air permeability, and ion conductivity to enhance thermal stability and minimize leak current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a polyolefin-based micro-porous film is used as a separator, then thermal stability is improved, but ion conductivity deteriorates due to controlled porosity and pore size
Solution Approach 1:
The patent applies composite materials by forming a porous coating layer made of binder polymer and inorganic particles on the polyolefin-based micro-porous film substrate. This composite structure combines the thermal stability of polyolefin with the ion conductivity enhancement from the porous coating layer, resolving the contradiction between thermal stability and ion conductivity.
Solution Approach 2:
The patent utilizes porous materials by creating a porous coating layer with controlled porosity on the separator surface. This porous structure increases ion conductivity by providing additional pathways for ion transport while the underlying polyolefin film maintains thermal stability through its shrinkage behavior at elevated temperatures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively controls thermal shrinkage and increases ion conductivity, enabling high-power battery performance while reducing the occurrence of leak current and improving overall battery output.
Implementation Method 1
a porous coating layer made of a mixture of a binder polymer and inorganic particles is formed on at least one surface of a micro-porous film
Implementation Method 2
A polyolefin-based micro-porous film commonly used as a separator of an electrochemical device is extremely thermally shrunken at a temperature of 100° C. or above due to its material characteristics
Data Source
AI summary
A separator includes a monolayer-type polyolefin-based micro-porous film having a porosity of 40 to 60%, an average pore diameter of 60 nm or less, and an air permeability of 350 s/100 mL or less; and a porous coating layer formed on at least one surface of the micro-porous film and made of a mixture of a plurality of inorganic particles and a binder polymer. An electrochemical device having the above separator has excellent thermal stability and allows a high power while minimizing the occurrence of leak current.