Binder for Electricity Storage Electrodes with Thixotropic Resin
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electricity storage device electrodes face challenges in achieving high energy density with reduced binder amounts while maintaining peel strength and minimizing internal resistance for rapid charging, which leads to capacity loss.
Innovation Solution
A binder comprising a polyvinyl alcohol resin with specific viscosity and thixotropic properties, combined with an electrolyte solution-swellable resin, is used to enhance peel strength and reduce resistance, allowing for increased active material content without binder flaking and maintaining capacity during rapid charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the amount of binder is reduced to increase energy density, then the energy density is improved, but the peel strength decreases causing flaking
Solution Approach 1:
The patent changes the physical and chemical parameters of the binder by specifying viscosity (4-30 Pa·s at 25°C and 10 s⁻¹ shear rate) and thixotropic index (1.8-5) to achieve optimal adhesion properties that maintain peel strength with reduced binder content
Solution Approach 2:
The patent creates a composite binder system combining polyvinyl alcohol resin with specific viscosity characteristics and thixotropic properties, along with electrolyte solution-swellable resin, to achieve both high adhesion and low binder content requirements
2Quantity of substance
If the amount of binder is reduced to increase energy density, then the energy density is improved, but the electrode structure stability deteriorates
Solution Approach 1:
The patent optimizes the binder's thixotropic index (1.8-5) and viscosity to provide structural stability while minimizing binder content, allowing the electrode to maintain its composition stability during operation
Solution Approach 2:
The patent uses a small amount of binder that is optimized for maximum efficiency, accepting that the binder layer is thin and relies on its enhanced adhesive properties rather than thickness to maintain structural integrity
3Speed
If rapid charging is performed to reduce charging time, then the charging speed is improved, but the capacity decreases due to internal resistance
Solution Approach 1:
The patent modifies the binder's viscosity and thixotropic properties to create a low-resistance electrode structure that allows rapid ion transport during fast charging while maintaining capacity
4Strength
If the viscosity of polyvinyl alcohol resin is increased to improve peel strength, then the adhesion is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent specifies a precise viscosity range (4-30 Pa·s) and thixotropic index (1.8-5) for the polyvinyl alcohol resin to achieve optimal peel strength while maintaining manufacturability through standardized material specifications
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 binder solution achieves a high peel strength and low resistance, enabling electrodes with reduced binder content to maintain capacity and prevent flaking, even during rapid charging and discharging.
Implementation Method 1
an electrolyte solution-swellable resin having an electrolyte solution swelling rate, which is represented by the following equation (1), of 10% by mass or more
Implementation Method 2
a polyvinyl alcohol resin in the state of an aqueous solution having a solid content concentration of 10% by mass has a viscosity of 4 Pa·s or higher at 25° C. and a shear rate of 10 s−1
Data Source
AI summary
The present disclosure provides a binder for electricity storage device electrodes, said binder containing a polyvinyl alcohol resin and an electrolyte solution-swellable resin.