Polyvinyl Alcohol Binder Adhesion and Stability in Non-Aqueous Batteries

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current binder compositions for non-aqueous electrolyte batteries face challenges such as low adhesion properties, high electrical resistance, poor flexibility, and instability, which affect the performance and longevity of portable terminals.

Innovation Solution

A binder composition comprising polyvinyl alcohol, a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid, and a neutralized salt, along with an amino acid, carboxylic acid-containing polymer, or polyamine, is used to enhance adhesion, stability, and charge/discharge efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If diene-based rubber (SBR) is used as binder with CMC-Na thickener, then adhesion to current collector can be improved, but the binder system becomes complex and storage stability decreases

Engineering Contradiction:
Improveadhesion to current collectorVSAvoidbinder system complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the CMC-Na thickener component from the binder system, using only polyvinyl alcohol as the binder. This simplifies the binder system from a two-component system (SBR+CMC-Na) to a single-component system (polyvinyl alcohol), while maintaining adhesion performance through the specific molecular structure and functional groups of polyvinyl alcohol.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses polyvinyl alcohol as a composite material that inherently provides both binding and thickening functions. The polymer's molecular structure, containing hydroxyl groups and carbonyl groups, allows it to form strong interactions with both the current collector and active material particles, replacing the need for separate binder and thickener components.

Inventive Principle:
Principle #40Composite materials

2Strength

If diene-based rubber (SBR) is used as binder, then adhesion property can be enhanced, but heat resistance and capacity retention ratio deteriorate

Engineering Contradiction:
Improveadhesion propertyVSAvoidheat resistance and capacity retention
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the binder from diene-based rubber to polyvinyl alcohol. This parameter change fundamentally alters the thermal stability and electrochemical compatibility of the binder system. Polyvinyl alcohol's molecular structure provides superior heat resistance and maintains capacity retention ratio at high temperatures, while still achieving adequate adhesion through its functional groups.

Inventive Principle:
Principle #35Parameter changes

3Strength

If acrylic binder or polyamide/imide-based binder is used, then adhesion property is improved, but electrical resistance increases and flexibility deteriorates

Engineering Contradiction:
Improveadhesion propertyVSAvoidelectrical resistance
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using polyvinyl alcohol's specific functional groups (hydroxyl and carbonyl groups) at the interface with the current collector and active material to provide adhesion, while the bulk polymer structure maintains electrical conductivity and flexibility. This localized functional group interaction allows strong adhesion without compromising the overall electrical properties of the electrode.

Inventive Principle:
Principle #3Local quality

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 proposed binder composition improves adhesion to current collectors, enhances slurry stability, and achieves high charge/discharge efficiency, addressing the limitations of existing binders by providing better mechanical strength and flexibility.

Implementation Method 1

The proposed binder composition improves adhesion to current collectors

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

a neutralized salt of the copolymer, and (C) at least one selected from an amino acid, a carboxylic acid-containing polymer, and a polyamine

Methodology Applied
Scientific EffectNeutralization reaction: Chemical Bonding

Data Source

PatentUS11581543B2Binder composition for non-aqueous electrolyte batteries, and binder aqueous solution for non-aqueous electrolyte batteries, slurry composition for non-aqueous electrolyte batteries, electrode for non-aqueous electrolyte batteries and non aqueous electrolyte battery each utilizing same
Publication Date: 2023.02.14 KURARAY CO LTD

AI summary

The present invention relates to a binder composition for a non-aqueous electrolyte battery, which is characterized by containing (A) polyvinyl alcohol, (B) at least one selected from a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid and a neutralized salt of the copolymer and (C) at least one selected from an amino acid, a carboxylic acid-containing polymer and a polyamine; and a binder aqueous solution for a non-aqueous electrolyte battery, a slurry composition for a non-aqueous electrolyte battery, an electrode for a non-aqueous electrolyte battery, and a non-aqueous electrolyte battery, each containing the binder composition; and others.