Electrode Isolation Layer Composition for Separator Adhesion

Solution Overview

Problem

The existing method for manufacturing electric double layer capacitor separators results in a porous structure, leading to poor adhesion between the separator and electrodes, causing non-aqueous electrolyte penetration and reduced electrochemical device performance.

Innovation Solution

A liquid composition for electrodes comprising inorganic particles, resins with an ethylene oxide chain, and a dispersion medium, which forms an isolation layer with excellent adhesion to the electrode composite material layer, using a non-polar solvent or mixed solvent for better solubility and adhesion properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a porous separator structure is used to allow electrolyte flow, then ion transport is improved, but adhesion between separator and electrodes deteriorates

Engineering Contradiction:

Improveion transportVSAvoidadhesion between separator and electrodes

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The separator is designed with different local properties: the bulk remains porous for ion transport, while the surface forms a dense isolation layer with the electrode for strong adhesion. This local differentiation resolves the contradiction between porosity needed for ion flow and surface density needed for bonding.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The separator comprises a composite structure combining a porous base material with a surface isolation layer containing inorganic particles and resin. This composite design enables simultaneous achievement of ion permeability in the bulk and strong adhesion at the interface with electrodes.

Inventive Principle:

Principle #40Composite materials

2Productivity

If the separator is made porous to facilitate electrolyte penetration, then electrochemical activity is improved, but adhesion to electrodes deteriorates

Engineering Contradiction:

Improveelectrochemical activityVSAvoidadhesion to electrodes

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The separator is designed with different local properties: the bulk remains porous for ion transport, while the surface forms a dense isolation layer with the electrode for strong adhesion. This local differentiation resolves the contradiction between porosity needed for ion flow and surface density needed for bonding.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The separator comprises a composite structure combining a porous base material with a surface isolation layer containing inorganic particles and resin. This composite design enables simultaneous achievement of ion permeability in the bulk and strong adhesion at the interface with electrodes.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If a conventional liquid composition is used for electrode manufacturing, then production simplicity is maintained, but isolation layer adhesion is insufficient

Engineering Contradiction:

Improveproduction simplicityVSAvoidisolation layer adhesion

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The liquid composition uses resins soluble in non-aqueous solvents (such as dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate) rather than water-soluble resins. This parameter change in solvent compatibility enables the formation of an isolation layer with significantly improved adhesion to the electrode while maintaining the simplicity of the coating process.

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 solution enhances the adhesion between the separator and electrodes, maintaining electrochemical device characteristics and improving the performance of lithium-ion secondary batteries by preventing electrolyte penetration and ensuring reliable adhesion.

Implementation Method 1

the resin is soluble in a non-polar solvent or in a mixed solvent containing a non-polar solvent

Methodology Applied

Scientific EffectSolubility: Solvation

Implementation Method 2

forming an isolation layer having an excellent adhesion to the electrode composite material layer

Methodology Applied

Scientific EffectDeposition: Deposition (physical)

Implementation Method 3

including inorganic particles, resins, and a dispersion medium

Methodology Applied

Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentUS20240021825A1Liquid composition for electrode, storage container, electrode manufacturing device, method of manufacturing electrode, electrode, and electrochemical device

Publication Date: 2024.01.18 RICOH CO LTD

AI summary

A liquid composition for electrodes is capable of forming an isolation layer having an excellent adhesion to the electrode composite material layer when used as an electrode for an electrochemical device. A corresponding electrochemical device has excellent electrochemical device characteristics. The liquid composition for an electrode contains inorganic particles, a resin, and a dispersant. The resin is soluble in a non-polar solvent or in a mixed solvent containing a non-polar solvent, and the resin has an ethylene oxide chain in a main chain.