Composite Separator Coating for Thermal Stability and Electrode Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing separators in electrochemical devices suffer from inadequate thermal stability and adhesive strength to electrodes, leading to potential short circuits and safety risks due to heat shrinkage and lifting phenomena during charging and discharging.
Innovation Solution
A separator design featuring a porous substrate with an inorganic particle layer and a heat fusion layer, where the heat fusion layer has a surface gloss value of 10 GU or more, is developed. This includes a hydrolytic condensate of a silane compound as a binder, applied in a weakly acidic atmosphere, to enhance adhesion and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If an organic-inorganic composite porous separator with an inorganic particle layer is used, then thermal stability is improved, but adhesive strength to electrode deteriorates
Solution Approach 1:
The separator is divided into three functional layers: a porous substrate layer providing mechanical support, an inorganic particle layer providing thermal stability, and a heat fusion layer providing adhesive strength. This segmentation allows each layer to optimize its specific function without compromising the others, resolving the contradiction between thermal stability and adhesion.
Solution Approach 2:
The separator uses a composite structure combining organic porous substrate, inorganic particles (such as alumina, silica), and heat-fusible polymer particles. This composite material approach integrates the thermal stability of inorganic materials with the adhesive properties of organic polymers, simultaneously achieving both thermal stability and strong electrode adhesion.
2Ease of manufacture
If separator structure is simplified, then manufacturing ease is improved, but thermal stability deteriorates
Solution Approach 1:
The inorganic particles and heat-fusible polymer particles are pre-mixed to form a slurry before application. This preliminary preparation simplifies the manufacturing process by combining multiple functions into a single coating step, while still achieving the desired thermal stability through the included inorganic particles.
Solution Approach 2:
The manufacturing process utilizes temperature parameter changes during battery assembly and charging cycles. The heat fusion layer softens at specific temperatures (above 80°C) to enable electrode adhesion, then solidifies to provide structural integrity. This temperature-dependent behavior allows simple manufacturing with enhanced thermal stability.
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 separator exhibits improved thermal stability with a heat shrinkage rate of 3% or less and adhesive strength of over 5 gf, maintaining integrity and safety by preventing electrode separation and short circuits.
Implementation Method 1
a heat fusion layer provided on at least one surface of the inorganic particle layer
Implementation Method 2
improves the thermal stability such as a heat shrinkage rate
Data Source
AI summary
The present invention relates to a separator, a method of manufacturing the separator, and an electrochemical device including the separator. An embodiment of the present invention may provide a separator including: a porous substrate; an inorganic particle layer provided on at least one surface of the porous substrate; and a heat fusion layer provided on at least one surface of the inorganic particle layer, wherein a surface gloss value at 60° of a surface of the heat fusion layer is 10 GU or more.