All-Solid-State Battery Electrode Infiltration for Low-Pressure Bonding

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Solution Overview

Problem

Current methods for producing all-solid-state batteries face challenges such as high pressure requirements, limited productivity, and instability of sulfide and complex hydride solid electrolytes, particularly in forming interfaces and handling organic solvents, which restrict the scalability and safety of these batteries.

Innovation Solution

A method involving impregnation of electrode layers with a solid electrolyte solution containing boron hydride compounds, followed by solvent removal to precipitate the solid electrolyte, allowing for bonding of electrode layers at low pressure, thereby eliminating the need for high-pressure forming and enabling mass production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high pressing pressure is used to form interfaces between solid electrolyte and electrodes, then interface bonding quality is improved, but production complexity and difficulty increase

Engineering Contradiction:
Improveinterface bonding qualityVSAvoidproduction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the physical state of the electrolyte from solid to liquid, allowing interface formation at atmospheric pressure through liquid infiltration, eliminating the need for high-pressure pressing equipment and complex production processes while maintaining reliable interface bonding

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses liquid electrolyte as an intermediary substance that infiltrates the interface between solid electrodes and solid electrolyte layer, forming a reliable bond without requiring high-pressure mechanical contact

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If sulfide solid electrolyte is dissolved with alcohol solvent for coating, then interface bonding is improved, but hydrogen sulfide generation occurs causing safety issues

Engineering Contradiction:
Improveinterface bondingVSAvoidhydrogen sulfide generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention replaces the harmful alcohol solvent with water as the dissolution medium, converting a potentially harmful chemical process into a safe one while maintaining the ability to form good interface bonding through liquid electrolyte infiltration

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

Solution Approach 2:

The invention uses water, a safe and inexpensive solvent, instead of alcohol, eliminating the need for special handling facilities and reducing safety risks associated with flammable and toxic substances

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If positive electrode layer and negative electrode layer are formed with high pressing pressure, then electrode density is improved, but productivity decreases

Engineering Contradiction:
Improveelectrode densityVSAvoidproduction speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention changes the electrolyte state to liquid, allowing electrode assembly at atmospheric pressure, which eliminates time-consuming high-pressure pressing steps and significantly increases production speed while maintaining adequate electrode density through liquid infiltration

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

This approach results in high productivity and scalable production of all-solid-state batteries with improved safety and energy density, as it avoids the use of flammable organic solvents and reduces the risk of hydrogen sulfide generation, facilitating their application in large energy storage devices and vehicles.

Implementation Method 1

a step of removing the solvent from the solid electrolyte solution and causing the solid electrolyte to precipitate on at least one of the positive electrode layer and the negative electrode layer

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP3699996B1Production method for all-solid-state battery
Publication Date: 2024.02.14 MITSUBISHI GAS CHEM CO INC
  • EP3699996B1 patent drawingFigure 1~2
  • EP3699996B1 patent drawingFigure 3

AI summary

The present invention makes it possible to provide a production method for an all-solid-state battery having a solid electrolyte layer between a positive electrode layer and a negative electrode layer, the production method being characterized by including: a step for coating or impregnating the positive electrode layer and/or the negative electrode layer with a solid electrolyte solution in which a boron hydride compound serving as the solid electrolyte has been dissolved in a solvent; and a step for removing the solvent from the coated or impregnated solid electrolyte solution and causing the solid electrolyte to precipitate on the positive electrode layer and/or the negative electrode layer.