Positive Electrode Adhesive Layer for Battery Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Batteries face challenges in achieving lower resistance and higher durability due to the excessive use of electrically conductive material in positive electrode layers, which increases internal resistance and reduces durability through side reactions with the solid electrolyte.

Innovation Solution

A positive electrode configuration that includes a current collector, an adhesive layer with spherical and fibrous carbon as electrically conductive materials, and an acrylic binder, optimizing the volume and mass fractions of these components to reduce foil contact resistance while maintaining battery durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the proportion of electrically conductive material in the positive electrode layer is increased to reduce foil contact resistance, then the contact resistance between the positive electrode layer and current collector is reduced, but the internal resistance of the battery increases due to blocking of ion conduction paths

Engineering Contradiction:

Improvefoil contact resistanceVSAvoidinternal resistance

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The patent introduces an adhesive layer as an intermediary between the current collector and the positive electrode layer. This adhesive layer contains electrically conductive particles that provide electrical conductivity without requiring excessive conductive material in the positive electrode layer itself, thus maintaining ion conduction paths while reducing contact resistance

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the electrical conductivity function by placing conductive particles specifically in the adhesive layer rather than uniformly distributing them throughout the positive electrode layer. This segmentation allows the conductive material to serve its purpose at the interface without interfering with ion transport in the electrode layer

Inventive Principle:

Principle #1Segmentation

2Shape

If the proportion of electrically conductive material in the positive electrode layer is increased to reduce foil contact resistance, then the contact resistance is reduced, but the durability of the battery decreases due to side reactions with the solid electrolyte

Engineering Contradiction:

Improvefoil contact resistanceVSAvoiddurability

Core Design Contradiction:

ShapeVSDuration of action of stationary object

Solution Approach 1:

The adhesive layer acts as a mediator that contains the electrically conductive particles, isolating them from direct contact with the solid electrolyte. This prevents harmful side reactions between the conductive material and electrolyte while still achieving the desired electrical conductivity at the current collector interface

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potential harm of electrically conductive material contacting the solid electrolyte into a benefit by strategically positioning the conductive particles in the adhesive layer. This positioning prevents side reactions that would reduce durability while maintaining the electrical conductivity function

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Shape

If carbon-coated foil is used as a positive electrode current collector to reduce contact resistance, then the foil contact resistance is reduced, but an excessive amount of electrically conductive material is added to the positive electrode layer

Engineering Contradiction:

Improvefoil contact resistanceVSAvoidamount of electrically conductive material

Core Design Contradiction:

ShapeVSQuantity of substance

Solution Approach 1:

The patent extracts the electrical conductivity function from the positive electrode layer and relocates it to the adhesive layer. This extraction allows the positive electrode layer to contain minimal conductive material while the adhesive layer provides the necessary conductivity at the current collector interface

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The adhesive layer serves as an intermediary that carries the electrically conductive particles, providing the needed conductivity without requiring the positive electrode layer itself to contain excessive conductive material

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration reduces foil contact resistance and overall battery resistance while enhancing durability by minimizing the amount of electrically conductive material in the positive electrode layer, leading to improved electron conductivity and prolonged battery life.

Implementation Method 1

The adhesive layer contains spherical carbon and fibrous carbon as an electrically conductive material... reduces foil contact resistance

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

contains an acrylic binder as an adhesive

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS20230238515A1Positive electrode

Publication Date: 2023.07.27 TOYOTA JIDOSHA KK

AI summary

A positive electrode includes a positive electrode current collector, an adhesive layer, and a positive electrode layer. The positive electrode current collector, the adhesive layer, and the positive electrode layer are stacked in this order. The adhesive layer contains spherical carbon and fibrous carbon as an electrically conductive material, and contains an acrylic binder as an adhesive.