Dry-Mixed Electrode Assembly With Porous Separator Adhesion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional electrode assemblies for secondary batteries manufactured in a wet manner require high-temperature heat treatment, which can damage metal oxides, and the use of binders like PTFE limits electron movement and reduces productivity due to the need for additional adhesive layers.

Innovation Solution

An electrode assembly is developed with a dry-mixing method using a separator with adhesive layers that have a porous structure, minimizing binder content and eliminating separate adhesive layers between active material layers and current collectors, allowing direct contact and improved conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a wet manufacturing method is used for electrodes, then adhesive force between active material and current collector is improved, but high-temperature heat treatment is required which can damage metal oxides

Engineering Contradiction:

Improveadhesive forceVSAvoidheat treatment temperature

Core Design Contradiction:

StrengthVSTemperature

Solution Approach 1:

The invention changes the manufacturing method from wet to dry, eliminating the need for high-temperature heat treatment while maintaining adhesive force through mechanical bonding and fiberization of PTFE binder during mixing and pressing operations

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the chemical bonding method (wet manufacturing requiring heat treatment) with a mechanical bonding method (dry manufacturing using shear force and compression during mixing and pressing)

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If PTFE binder is used in electrode composition, then adhesive force is improved, but electron movement is limited and discharge capacity is lowered

Engineering Contradiction:

Improveadhesive forceVSAvoiddischarge capacity

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The invention uses PTFE binder selectively and in minimized amounts only where mechanical bonding is required, rather than as a comprehensive adhesive layer, thereby reducing its harmful effect on electron movement while maintaining necessary adhesion

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention uses a porous nonwoven fabric substrate that provides mechanical support and adhesion without requiring excessive binder, allowing electron and ion transport through the porous structure

Inventive Principle:

Principle #31Porous materials

3Strength

If separate adhesive layers are applied between freestanding film and current collectors, then adhesive force is enhanced, but device complexity and manufacturing steps are increased

Engineering Contradiction:

Improveadhesive forceVSAvoidmanufacturing process complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The invention merges the adhesive function into the electrode composition itself and the nonwoven fabric substrate, eliminating the need for separate adhesive layers and reducing manufacturing complexity

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The nonwoven fabric substrate serves multiple functions: mechanical support, adhesion to current collectors, and structural framework for the electrode, replacing the need for separate adhesive layers

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Strength

If adhesive binder is coated onto current collectors using slurry coating method, then adhesive force is improved, but productivity is reduced due to additional coating steps

Engineering Contradiction:

Improveadhesive forceVSAvoidmanufacturing efficiency

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The invention combines the adhesive function with the electrode composition and substrate, eliminating separate coating steps and improving manufacturing efficiency

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts the adhesive function from separate coating operations and integrates it into the electrode structure itself, removing unnecessary manufacturing steps

Inventive Principle:

Principle #2Taking out (Extraction)

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

This approach enhances productivity and reduces resistance, maintaining high discharge capacity even in high-rate regions by minimizing binder content and ensuring stable adhesion without disrupting ion movement.

Implementation Method 1

a separator (300), wherein a positive electrode active material layer (110) is adhered to a first surface of the separator (300), and a negative electrode active material layer (210) is adhered to a second surface of the separator (300)

Methodology Applied

Scientific EffectPorosity: Porosity

Data Source

PatentUS20230369655A1Electrode Assembly and Battery Cell Including the Same

Publication Date: 2023.11.16 LG ENERGY SOLUTION LTD

AI summary

An electrode assembly including a separator; a positive active material layer adhered to a first surface of the separator; and a negative electrode active material layer adhered to a second surface of the separator, wherein the positive electrode active material layer is formed of a first electrode composition in which a positive electrode active material, a binder, and a conductive material are dry-mixed, and wherein the negative electrode active material layer is formed of a second electrode composition in which a negative electrode active material, a binder, and a conductive material are dry-mixed.