Secondary Battery Electrode Binder for Uniform Conductive Dispersion
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Solution Overview
Problem
Conductive materials in secondary battery electrodes often aggregate, leading to uneven distribution and reduced performance due to inadequate dispersion in conventional binder compositions, resulting in suboptimal electrode mixed material layers and secondary battery characteristics.
Innovation Solution
A binder composition containing a copolymer with an alkylene structural unit and a nitrile group-containing monomer unit, having a specific Mooney viscosity, is used to enhance conductive material dispersion in the slurry composition, along with a conductive material paste composition and another polymer, ensuring uniform distribution and improved battery characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional binder compositions are used, then the electrode mixed material layer can be formed, but the conductive material aggregates and distributes unevenly, reducing battery performance
Solution Approach 1:
The patent changes the chemical composition parameters of the binder by incorporating specific polymers with carboxyl groups (such as polyacrylic acid and carboxymethyl cellulose) at controlled ratios. This compositional parameter change enables the binder to effectively disperse conductive materials like acetylene black, preventing aggregation and achieving uniform distribution in the electrode mixed material layer, thereby resolving the contradiction between formability and uniformity.
2Strength
If the binder composition is optimized for strong adherence, then electrode active material adheres well to current collector, but conductive material dispersion deteriorates
Solution Approach 1:
The patent creates a composite binder system by combining polymers with carboxyl groups (providing strong adhesion through chemical bonding) with polymers containing hydrophilic groups (providing excellent dispersion capability). This composite material approach allows the binder composition to simultaneously achieve strong adherence between electrode active material and current collector while maintaining uniform dispersion of conductive materials, thus resolving the contradiction between strength and dispersion precision.
Data Source
AI summary
Provided are a binder composition for a secondary battery electrode that enables favorable dispersion of a conductive material when used in production of a slurry composition for a secondary battery electrode, and a slurry composition for a secondary battery electrode in which a conductive material is favorably dispersed. The binder composition for a secondary battery electrode contains a solvent and a copolymer including an alkylene structural unit and a nitrile group-containing monomer unit. The copolymer has a Mooney viscosity (ML1+4, 100°C) of 40 or less. The slurry composition for a secondary battery electrode contains an electrode active material, a conductive material, the aforementioned binder composition for a secondary battery electrode, and a polymer other than the aforementioned copolymer.