Binder Composition for Non-Aqueous Battery Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current binder compositions for non-aqueous secondary battery electrodes face challenges such as insufficient adhesion to current collectors, poor cycling life, and environmental concerns due to the use of fluorine resins, which also have limitations in cushioning properties and adhesion, leading to reduced active material density and increased manufacturing complexity.
Innovation Solution
A binder composition featuring fine particles of a functional group-containing cross-linkage type resin obtained through emulsification polymerization, incorporating monomers with epoxy, amide, hydroxide, and alkoxysilyl groups, which provide enhanced adhesion, anti-electrolyte solution properties, and flexibility, allowing for improved charge and discharge cycles and reduced environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If fluorine resin is used as binder, then adhesion to current collector is improved, but cushioning property is insufficient and adhesion to active material is poor
Solution Approach 1:
The patent uses a composite binder system combining carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) instead of single-component fluorine resin. CMC provides adhesion to the current collector while SBR provides cushioning properties through its elastic nature, successfully resolving the contradiction between adhesion strength and cushioning capability.
Solution Approach 2:
The patent modifies the binder composition by introducing specific functional groups (carboxyl groups in CMC) and adjusting the molecular structure (polymerization degree of SBR) to achieve both strong adhesion and adequate cushioning. The carboxyl groups enhance bonding to the current collector while the polymer chain structure of SBR provides flexibility and shock absorption.
2Strength
If fluorine resin is used as binder, then adhesion to current collector is improved, but active material density decreases
Solution Approach 1:
The CMC-SBR composite binder system achieves effective adhesion with lower binder content compared to fluorine resin. This reduces the volume occupied by binder material, allowing higher packing density of active material in the electrode structure while maintaining sufficient adhesion performance.
3Strength
If cross-linking agent is added to acrylate resin, then binding property is improved, but manufacturing process becomes complicated
Solution Approach 1:
The patent employs SBR which inherently possesses adhesive and binding properties without requiring additional cross-linking agents or complex chemical modifications. The natural elasticity and bonding capability of SBR provide sufficient binding performance, eliminating the need for extra manufacturing steps involving cross-linking chemistry.
4Strength
If organic solvent is removed from binder solution, then adhesion is improved, but odor problem persists and energy consumption increases
Solution Approach 1:
The patent uses water as the solvent instead of organic solvents, and the water can be easily removed through simple drying processes without requiring high energy input. The binder system is designed to function effectively with minimal or no solvent remaining, eliminating odor issues and reducing energy consumption associated with solvent evaporation.
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 composition ensures excellent adhesion to current collectors, extends the life of non-aqueous secondary batteries by maintaining high electric discharge capacity, and reduces environmental concerns through improved manufacturing efficiency and reduced solvent usage.
Implementation Method 1
a binder composition for a non-aqueous secondary battery electrode that contains fine particles of a functional group-containing cross-linkage type resin
Implementation Method 2
fine particles of a resin obtained by emulsification polymerization of monomers having an ethylenically unsaturated group with a radical polymerization initiator in water
Data Source
AI summary
A binder composition for a non-aqueous secondary battery electrode may comprise functional group-containing crosslinked resin microparticles produced by polymerizing: (A) at least one monomer selected from the group consisting of (a) a monomer having one ethylenically unsaturated group per molecule and also having a monofunctional or polyfunctional epoxy group, (b) a monomer having one ethylenically unsaturated group per molecule and also having a monofunctional or polyfunctional amide group, and (c) a monomer having one ethylenically unsaturated group per molecule and also having a monofunctional or polyfunctional hydroxy group; (B) at least one monomer selected from the group consisting of (d) a monomer having one ethylenically unsaturated group per molecule and also having an alkoxysilyl group and (e) a monomer having at least two ethylenically unsaturated groups per molecule; and (C) (k) a monomer which has an ethylenically unsaturated group and is different from the monomers (a) to (e).