Polyimide Electrode Insulating Layer for Battery Thermal Stability
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Solution Overview
Problem
High-temperature heat-treatment of electrodes with polyimide insulating layers can lead to oxidation of current collectors and thermal deterioration of binders, resulting in reduced bonding strength and pore blockage, which decreases battery performance and lifespan.
Innovation Solution
Incorporating an aromatic compound with an electron donating group and an organic acid group into the polyimide insulating layer to promote imidization at lower temperatures, reducing the heat-treatment temperature and preventing oxidation and thermal deterioration of the current collector and binder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high-temperature heat-treatment (300°C or higher) is applied to convert polyamic acid to polyimide, then heat resistance and strength of the insulating layer are improved, but oxidation of current collector and thermal deterioration of binder occur, resulting in decreased bonding strength and pore blockage
Solution Approach 1:
The invention changes the chemical structure parameters of the polyimide by introducing specific aromatic diamine components with electron-donating groups and organic acid groups. This structural modification enables the polyimide to achieve high heat resistance through molecular design rather than high-temperature processing, thus avoiding the thermal deterioration that occurs with conventional high-temperature heat-treatment methods.
2Temperature
If high-temperature heat-treatment (300°C or higher) is applied to convert polyamic acid to polyimide, then the insulating layer achieves sufficient heat resistance, but the binder undergoes melting and thermal deterioration, causing pore blockage and decreased adhesiveness
Solution Approach 1:
The invention modifies the chemical composition parameters of the polyimide by incorporating specific aromatic diamines with electron-donating groups and organic acid groups. This compositional change allows the polyimide to achieve high heat resistance at the molecular level, eliminating the need for high-temperature heat-treatment that would otherwise cause binder melting and thermal deterioration.
3Strength
If high-temperature heat-treatment (300°C or higher) is applied to convert polyamic acid to polyimide, then the insulating layer achieves sufficient strength, but oxidation of current collector occurs, resulting in decreased bonding strength between electrode mixture layer and current collector
Solution Approach 1:
The invention changes the chemical structure parameters of the polyimide by introducing specific aromatic diamine components with electron-donating groups and organic acid groups. This structural modification enables the polyimide to achieve high strength through molecular design rather than high-temperature processing, thus preventing oxidation of the current collector that would otherwise occur during conventional high-temperature heat-treatment.
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 use of aromatic compounds with electron donating and organic acid groups in polyimide insulating layers allows for effective imidization at lower temperatures, minimizing thermal deterioration and maintaining battery performance and extending lifespan.
Implementation Method 1
a polyimide is a high heat resistant resin. Since a polyimide is poor in terms of plasticity due to its high heat resistance, a polyimide resin product excellent in heat resistance and strength is generally obtained by shaping a polyamic acid varnish that is a precursor into a film or a coating film, and then subjecting it to a high temperature more than 300° C. to convert the polyamic acid to a polyimide (imidization)
Data Source
AI summary
The purpose of the present invention is to provide an electrode with reduced thermal deterioration even though the electrode has an insulating layer comprising a polyimide. The present invention relates to an electrode comprising a current collector and an electrode mixture layer, wherein the electrode comprises an insulating layer comprising a polyimide and an aromatic compound having an electron donating group and an organic acid group.