Nonpolar Soluble Binder for All-Solid-State Battery Adhesion

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Solution Overview

Problem

Current binder compositions for all-solid-state batteries face challenges in achieving excellent adhesion to solid electrolyte materials and current collectors while maintaining the integrity and performance of electrode active materials, particularly due to the use of highly-polar organic solvents that degrade the active materials and hinder uniform electrode layer formation.

Innovation Solution

A binder composition featuring a polymer with specific structural units and functional groups, such as amino, hydroxyl, or alkoxysilyl groups, that is soluble in nonpolar organic solvents, enhancing adhesion and reducing the amount of binder needed, thereby improving electrode durability and electrical conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a highly-polar organic liquid medium is used to dissolve the polymer binder, then adhesion to solid electrolyte material is improved, but electrode active material is degraded

Engineering Contradiction:

Improveadhesion to solid electrolyte materialVSAvoiddegradation of electrode active material

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention changes the polarity parameter of the organic liquid medium from highly-polar to nonpolar or low-polar, while simultaneously modifying the polymer binder structure to include specific functional groups that provide adhesion capability without requiring high solvent polarity, thus preventing active material degradation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite approach by combining a nonpolar or low-polar organic liquid medium with a polymer binder that has specific structural units and functional groups, creating a binder composition that achieves both adhesion and compatibility with active materials

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If a nonpolar organic liquid medium is used to dissolve the polymer binder, then degradation of electrode active material is suppressed, but uniform electrode layer formation becomes difficult

Engineering Contradiction:

Improvedegradation of electrode active materialVSAvoiduniformity of electrode layer

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The invention modifies the polymer binder structure by introducing specific structural units and functional groups that enhance solubility and uniform distribution in nonpolar or low-polar organic liquid mediums, enabling uniform electrode layer formation without degrading active materials

Inventive Principle:

Principle #35Parameter changes

3Strength

If the amount of binder is increased to improve adhesion to solid electrolyte material, then adhesion is improved, but electrical conductivity of solid electrolyte layer decreases

Engineering Contradiction:

Improveadhesion to solid electrolyte materialVSAvoidelectrical conductivity of solid electrolyte layer

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The invention changes the chemical structure parameters of the polymer binder to include specific structural units and functional groups that enhance adhesion efficiency, allowing lower binder content to achieve the same or better adhesion performance, thus preserving electrical conductivity

Inventive Principle:

Principle #35Parameter changes

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 achieves high adhesion to both solid electrolyte materials and current collectors, suppresses degradation of electrode active materials, and enhances the workability and electrical performance of electrodes in all-solid-state batteries.

Implementation Method 1

a polymer that has at least one structural unit selected from structural units represented by the following formulae (a1) to (a5), respectively, and (f) a functional group containing a nitrogen atom, an oxygen atom, a silicon atom, a germanium atom, a tin atom or a combination thereof; and (B) a liquid medium, the polymer (A) having a solubility of no less than 5 g in 100 g of cyclohexane at 25° C.

Methodology Applied

Scientific EffectSolvation: Solvation

Data Source

PatentUS9172092B2Binder composition for batteries, slurry for battery electrodes, solid electrolyte composition, electrode, and all-solid-state battery

Publication Date: 2015.10.27 ENEOS MATERIALS CORP

AI summary

A binder composition for batteries, including (A) a polymer that has at least one structural unit selected from the group consisting of structural units represented by the following formulae (a1) to (a5), respectively, and (f) a functional group containing a nitrogen atom, an oxygen atom, a silicon atom, a germanium atom, a tin atom or a combination thereof; and (B) a liquid medium, the polymer (A) having a solubility of no less than 5 g in 100 g of cyclohexane at 25° C. and 1 atom.