Conjugated Diene Binder for All-Solid-State Battery Adhesion

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Solution Overview

Problem

Existing all-solid-state batteries face challenges with electrode adhesive strength and solvent selection due to the limitations of acrylonitrile butadiene rubber (NBR) binders, leading to reduced ion and electron transfer efficiency and battery stability issues.

Innovation Solution

A binder composition using a conjugated diene-based rubber polymer with a cis bond content of 90% or more, produced with neodymium or nickel-based catalysts, and dissolved in solvents like benzene or butyl butyrate, which provides excellent adhesive properties and solubility, enhancing electrode stability and ion transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If acrylonitrile butadiene rubber (NBR) is used as a binder, then the binder provides basic adhesive function, but the electrode adhesive strength is insufficient

Engineering Contradiction:
Improveelectrode adhesive strengthVSAvoidbattery performance stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the binder by using butadiene-based rubber with specific cis-bond content (80-95%) and molecular weight (100,000-2,000,000), replacing the conventional NBR binder. This parameter change achieves both high electrode adhesive strength and good stability without the limitations of NBR.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite binder system by combining butadiene-based rubber polymer with specific solvents (aliphatic hydrocarbons, cyclic hydrocarbons, or esters) and additives, forming a composite material that achieves superior adhesive properties and stability compared to pure NBR.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If conventional binders are used, then the manufacturing process is simple, but the solubility problem limits solvent selection and causes stability issues

Engineering Contradiction:
Improvesolvent selection rangeVSAvoidbattery stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the chemical structure parameters of the binder polymer to be compatible with various solvent types. The butadiene-based rubber with controlled molecular weight and cis-bond content exhibits excellent solubility in aliphatic hydrocarbons, cyclic hydrocarbons, and esters, expanding solvent selection while maintaining stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses specific solvents as intermediaries that bridge the binder and electrode components. The selected solvents (n-hexane, cyclohexane, butyl butyrate, etc.) serve as mediators that provide good dispersion and adhesion without reacting adversely with battery components, ensuring both versatility and stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If the binder provides strong adhesion, then electrode stability improves, but the ion and electron transfer path may be hindered

Engineering Contradiction:
Improveelectrode stabilityVSAvoidion and electron transfer efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies local quality by creating a binder with specific molecular characteristics (cis-bond content and molecular weight) that provides strong adhesion at the electrode-binder interface while maintaining appropriate flexibility and porosity in the bulk structure. This allows simultaneous achievement of electrode stability and efficient ion/electron transfer paths.

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 new binder composition improves electrode adhesive strength, solubility, and processability, leading to enhanced long-term stability and capacity of all-solid-state batteries by facilitating a balanced ion and electron transfer path.

Implementation Method 1

a binder composition for an all-solid-state battery including a conjugated diene-based rubber polymer and a solvent

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

dissolved in solvents like benzene or butyl butyrate, which provides excellent adhesive properties and solubility

Methodology Applied
Scientific EffectSolvation: Solvation

Data Source

PatentUS20230231140A1Binder composition for all-solid-state battery, slurry composition comprising the same and all-solid-state battery
Publication Date: 2023.07.20 KOREA KUMHO PETROCHEMICAL CO LTD

AI summary

Disclosed is a binder composition for an all-solid-state battery including a conjugated diene-based rubber polymer and a solvent, wherein a content of a cis bond in the conjugated diene-based rubber polymer is 90% by weight or more.