Polyimide Silicone Binder Electrode for Capacitors
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Solution Overview
Problem
Existing electrochemical capacitors face challenges in achieving both low internal resistance and high capacity due to the trade-off between binder amount and adhesion, with current binders offering either poor heat and electrolyte resistance or inadequate adhesion to conductive materials.
Innovation Solution
The development of an electrode using a polyimide silicone binder with a specific molecular weight range and composition, combined with a conductive material, to provide superior adhesion, heat resistance, and electrolyte resistance, along with a method of manufacturing that involves a polyamic acid precursor and heat treatment to ensure strong bonding to the collector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the amount of binder is increased to improve adhesion between electrode and collector, then adhesion is improved, but internal resistance of the electrode increases
Solution Approach 1:
The patent changes the molecular weight parameter of the binder from conventional ranges to a specific range of 5,000-150,000. This parameter change enables the binder to achieve both sufficient adhesion strength and low internal resistance, resolving the contradiction between adhesion improvement and resistance increase.
Solution Approach 2:
The patent uses a composite binder system comprising polyimide silicone with specific molecular weight characteristics. This composite material combines the advantages of strong adhesion with low electrical resistance, overcoming the limitations of conventional single-material binders that must compromise between these two properties.
2Strength
If polyimide silicone resin is used as binder to improve adhesion and heat resistance, then adhesion and heat resistance are improved, but the binder swells when immersed in electrolyte solution
Solution Approach 1:
The patent modifies the molecular weight parameter of polyimide silicone resin to fall within 5,000-150,000. This specific parameter range changes the physical and chemical properties of the binder, reducing its tendency to swell in electrolyte solutions while maintaining strong adhesion and heat resistance.
Solution Approach 2:
The patent applies local quality by creating a binder with specific molecular weight distribution that exhibits different properties in different contexts: strong adhesion to conductive materials, resistance to swelling in electrolyte, and maintenance of heat resistance. The binder's molecular structure is optimized to provide these localized properties where needed.
3Quantity of substance
If pores in conductive material are made smaller to increase surface area, then capacity increases, but mobility of electrolyte solution decreases and internal resistance increases
Solution Approach 1:
The patent changes the molecular weight parameter of the binder to optimize the electrode's interaction with the conductive material. This parameter change enables the binder to effectively hold small-pore conductive materials while maintaining electrolyte mobility, resolving the contradiction between increased capacity and increased internal resistance.
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
This approach results in an electrochemical capacitor with enhanced heat resistance, electrolyte resistance, and high capacity, maintaining stability and adhesion over extended cycles, thereby addressing the limitations of previous technologies.
Implementation Method 1
a polyimide silicone expressed by the following general formula (1) having an average molecular weight of 5,000-150,000... having superior adhesive properties
Implementation Method 2
an electrode for an electrochemical capacitor having superior heat resistance and electrolyte resistance
Implementation Method 3
the binder which is the other component of the electrode must be a material which has resistance to electrolyte solutions, electrochemical stability and heat resistance
Data Source
AI summary
An electrode for an electrochemical capacitor which contains an electrode, a collector, an electrolyte solution and a separator, wherein the electrode contains at least a conductive material and a polyimide silicone of formula (1)having an average molecular weight of 5,000-150,000.