Solid-State Battery Intermediate Layer for Interface Bondability

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Solution Overview

Problem

Existing solid-state batteries face challenges in achieving favorable interfacial bondability between the negative electrode layer and the solid electrolyte layer due to differences in density or porosity, leading to suboptimal performance.

Innovation Solution

Incorporating an intermediate layer with a porosity of 46% or less and specific particle sizes and binder content, along with controlled pressing pressures, to enhance bondability between the negative electrode layer and the solid electrolyte layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If another layer is interposed between the negative electrode layer and the solid electrolyte layer, then the interfacial bondability between these layers deteriorates due to density differences

Engineering Contradiction:

Improveinterfacial bondabilityVSAvoidlayer structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

An intermediate layer is introduced between the negative electrode layer and the solid electrolyte layer to improve interfacial bondability. This intermediate layer acts as a mediator that bridges the density difference between the electrode and electrolyte layers, enabling favorable bonding without direct contact between incompatible layers.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The porosity of the intermediate layer is precisely controlled within the range of 30% to 46% to optimize its density. This parameter adjustment allows the intermediate layer to serve as an effective bridge between layers of different densities, resolving the bonding issue caused by density mismatch.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If an intermediate layer is added to improve bondability, then the device complexity increases

Engineering Contradiction:

Improveinterface bondabilityVSAvoidnumber of layers

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The intermediate layer is designed with a porous structure having a porosity of 30% to 46%. This porous configuration allows the layer to maintain appropriate density for bonding while using minimal material, thus improving interface bondability without proportionally increasing device complexity.

Inventive Principle:

Principle #31Porous materials

3Reliability

If layers with high density are bonded to each other, then favorable interface bondability cannot be achieved due to density mismatch

Engineering Contradiction:

Improveinterface bondabilityVSAvoiddensity uniformity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The intermediate layer serves as a transitional medium between layers of different densities. By having its own optimized density (controlled through porosity), it creates gradual density transitions that enable favorable bonding between high-density layers that would otherwise be incompatible.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250309361A1Solid-state battery and method of manufacturing solid-state battery

Publication Date: 2025.10.02 HONDA MOTOR CO LTD

AI summary

Provided is a solid-state battery capable of allowing an intermediate layer interposed between a negative electrode layer and a solid electrolyte layer to improve in bondability with another layer. A solid-state battery having a structure in which a negative electrode layer, a solid electrolyte layer, and a positive electrode layer are laminated in this order, includes an intermediate layer interposed between the negative electrode layer and the solid electrolyte layer, and the intermediate layer has a porosity of 46% or less.