Sulfide Solid Electrolyte Solvent Control for Hydrogen Sulfide Reduction

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Solution Overview

Problem

Conventional methods for producing sulfide solid electrolytes often result in the formation of hydrogen sulfide due to residual solvents, which is difficult to eliminate completely, especially in large-scale production, prolonging drying times and affecting the ease of handling and lithium ionic conductivity.

Innovation Solution

A sulfide solid electrolyte with a controlled amount of organic solvent, within the range of 0.01 to 0.95 mass%, is formulated to minimize hydrogen sulfide production while maintaining high lithium ionic conductivity, using wet grinding and vacuum drying techniques to adjust particle size and composition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the amount of organic solvent in the sulfide solid electrolyte is reduced to minimize hydrogen sulfide production, then hydrogen sulfide formation is reduced, but the drying time is prolonged

Engineering Contradiction:
Improvehydrogen sulfide formationVSAvoiddrying time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent applies parameter changes by precisely controlling the organic solvent content within the range of 0.01 to 0.95 mass%. This optimization allows the material to maintain sufficient solvent for processing while minimizing excess solvent that would require prolonged drying, thereby reducing both hydrogen sulfide formation and drying time through parameter optimization.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If the amount of organic solvent is minimized to reduce hydrogen sulfide, then hydrogen sulfide production is reduced, but the ease of handling and flow characteristics deteriorate

Engineering Contradiction:
Improvehydrogen sulfide productionVSAvoidhandling and flow characteristics
Core Design Contradiction:
Object-generated harmful factorsVSEase of operation

Solution Approach 1:

The patent optimizes the organic solvent content parameter within the specific range of 0.01 to 0.95 mass%, which balances the reduction of hydrogen sulfide production with the maintenance of adequate flow characteristics and handling properties. This parameter optimization ensures sufficient lubrication and flowability while minimizing harmful gas generation.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If wet grinding is used to improve particle size and composition, then manufacturing precision is improved, but the amount of organic solvent increases leading to more hydrogen sulfide formation

Engineering Contradiction:
Improveparticle size and composition controlVSAvoidhydrogen sulfide formation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by precisely controlling the organic solvent content to 0.01 to 0.95 mass% after wet grinding. This optimization allows the process to benefit from improved particle size and composition control achieved through wet grinding, while minimizing the organic solvent content to reduce hydrogen sulfide formation during subsequent processing.

Inventive Principle:
Principle #35Parameter changes

4Object-generated harmful factors

If vacuum drying is used to remove organic solvent, then hydrogen sulfide formation is reduced, but the drying time is prolonged especially in mass production

Engineering Contradiction:
Improvehydrogen sulfide formationVSAvoidproduction efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent applies partial action by controlling the organic solvent content to 0.01 to 0.95 mass%, which is sufficient to enable wet grinding and achieve desired particle characteristics, but limited enough to minimize drying time requirements. This partial optimization allows efficient mass production while still reducing hydrogen sulfide formation compared to conventional methods.

Inventive Principle:
Principle #16Partial or excessive action

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 effectively reduces hydrogen sulfide formation while preserving high lithium ionic conductivity, improving handling and flow characteristics, and enabling efficient production for solid-state batteries.

Implementation Method 1

a sulfide solid electrolyte having ionic conductivity

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

from the viewpoint of reducing the amount of hydrogen sulfide to be produced, it is desirable to minimize the amount of solvent remaining in the sulfide solid electrolyte

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3951962B1Solid electrolyte
Publication Date: 2025.09.10 MITSUI MINING & SMELTING CO LTD
  • EP3951962B1 patent drawingFigure 1

AI summary

Provided is a sulfide solid electrolyte having ionic conductivity. The sulfide solid electrolyte contains an organic solvent. The amount of organic solvent contained in the sulfide solid electrolyte is 0.95 mass% or less. It is preferable that the amount of organic solvent contained in the sulfide solid electrolyte is 0.01 mass% or more. It is preferable that the sulfide solid electrolyte has an argyrodite-type crystal structure. Also provided are an electrode mixture including the sulfide solid electrolyte and a positive electrode active material or a negative electrode active material, as well as a solid-state battery including the electrode mixture.