Styrene-Acrylate Binder for Lithium Battery Rapid Charging
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Solution Overview
Problem
Rechargeable lithium batteries face challenges in rapid charging, which leads to decreased cycle-life and capacity fading due to high internal resistance, necessitating the development of a low-resistance binder for electrodes.
Innovation Solution
A binder composed of a copolymer of styrene-based and acrylate-based monomers with a specific mole ratio of 1:1 to 1:3, which exhibits high energy density and excellent cycle-life characteristics by optimizing electrolyte impregnation and adhesion to the current collector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If rapid charging is conducted to improve charging speed, then charging time is reduced, but internal resistance increases and cycle-life decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the binder by using a copolymer of styrene and butadiene with specific weight ratios (styrene: 10-40 parts, butadiene: 60-90 parts by weight). This parameter optimization reduces internal resistance and improves electrolyte impregnation, enabling rapid charging while maintaining cycle-life through balanced polymer composition that provides both conductivity and structural stability.
Solution Approach 2:
The patent employs a composite binder material combining styrene and butadiene polymers in specific proportions, creating a composite structure that leverages the electrical conductivity and adhesion properties of styrene with the flexibility and ion transport properties of butadiene. This composite approach reduces internal resistance and improves overall battery performance for rapid charging applications.
2Stability of the object's composition
If conventional binders are used to maintain adhesion, then structural stability is maintained, but internal resistance remains high and electrolyte impregnation is insufficient
Solution Approach 1:
The patent optimizes the compositional parameters of the binder by controlling the weight ratio of styrene (10-40 parts) to butadiene (60-90 parts). This parameter adjustment creates optimal balance between adhesion strength and electrical conductivity, reducing internal resistance while maintaining structural stability through the synergistic combination of aromatic styrene groups and conjugated diene butadiene groups.
Solution Approach 2:
The patent introduces local quality differentiation within the binder structure by distributing styrene and butadiene segments in specific proportions throughout the polymer matrix. The styrene-rich regions provide adhesion and structural framework, while butadiene-rich regions provide flexibility and ion transport pathways, creating localized functional zones that collectively reduce internal resistance while maintaining overall adhesion.
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 effectively reduces battery resistance, maintains adhesion at low temperatures, and enhances cycle-life characteristics, ensuring improved performance and capacity retention.
Implementation Method 1
The binder may have a swelling degree to an electrolyte of 50 wt% or more and 70 wt% or less
Implementation Method 2
a copolymer of a styrene-based monomer and an acrylate-based monomer
Data Source
Figure 1
AI summary
Disclosed is that a binder for a negative electrode of a rechargeable lithium battery, a negative electrode for a rechargeable lithium battery, and a rechargeable lithium battery including the same, and the binder including a copolymer of a styrene-based monomer and an acrylate-based monomer, wherein a mole ratio of the styrene-based monomer and the acrylate-based monomer is about 1:1 to about 1:3.