Nitrogen-Doped Sulfide Solid Electrolyte for Low H2S Emission

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Solution Overview

Problem

Sulfide electrolytes in all-solid-state batteries are susceptible to hydrogen sulfide generation due to their reaction with moisture, posing safety and durability concerns.

Innovation Solution

A solid electrolyte comprising lithium, phosphorous, sulfur, halogen, and nitrogen elements, with specific molar ratios and incorporating ammonium halides, is developed to suppress hydrogen sulfide generation by forming P-N bonds that preferentially react with moisture instead of P-S bonds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If sulfur is incorporated into the solid electrolyte to achieve high lithium-ion conductivity, then ionic conductivity is improved, but hydrogen sulfide generation increases when exposed to moisture

Engineering Contradiction:
Improvelithium-ion conductivityVSAvoidhydrogen sulfide generation
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by incorporating nitrogen elements (ammonium halides) into the solid electrolyte system. This modifies the bonding characteristics from P-S bonds to P-N bonds, which have different reactivity toward moisture, thereby reducing hydrogen sulfide generation while maintaining ionic conductivity through appropriate molar ratio adjustments

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite solid electrolyte system containing multiple elements (Li, P, S, halogen, and nitrogen). By combining ammonium halides with lithium phosphorus sulfide base materials, the invention achieves a composite structure where nitrogen-containing compounds modify the overall chemical behavior, suppressing hydrogen sulfide emission while preserving the conductive properties of the sulfide electrolyte matrix

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If the sulfur content is reduced to suppress hydrogen sulfide generation, then safety is improved, but lithium-ion conductivity may deteriorate

Engineering Contradiction:
Improvehydrogen sulfide emissionVSAvoidlithium-ion conductivity
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent adjusts the molar ratios of Li, P, S, halogen, and nitrogen elements to specific ranges. By controlling these compositional parameters, the invention achieves optimal balance between reducing hydrogen sulfide generation (through nitrogen incorporation) and maintaining sufficient lithium-ion conductivity (through appropriate sulfur content and stoichiometry)

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 electrolyte effectively reduces hydrogen sulfide emission while maintaining high lithium-ion conductivity, enhancing safety and durability of all-solid-state batteries.

Implementation Method 1

incorporated nitrogen exhibits suppression of hydrogen sulfide generation while retaining the performance properties of conventional solid electrolytes

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Implementation Method 2

a sulfide solid electrolyte with reduced sulfur and incorporated nitrogen exhibits suppression of hydrogen sulfide generation

Methodology Applied
Scientific EffectChemical Reaction: Reaction (physics)

Implementation Method 3

all-solid-state batteries using a sulfide solid electrolyte synthesized from, e.g., lithium sulfide

Methodology Applied
Scientific EffectIon Conduction: Conduction (electrical)

Data Source

PatentEP4693340A1Solid electrolyte and method for producing same
Publication Date: 2026.02.11 MITSUI MINING & SMELTING CO LTD
  • EP4693340A1 patent drawingFigure 1~2
  • EP4693340A1 patent drawingFigure 3~4
  • EP4693340A1 patent drawing

AI summary

A solid electrolyte containing a lithium (Li) element, a sulfur (S) element, a phosphorous (P) element, a halogen (X) element, and a nitrogen (N) element. The molar ratio of the difference between the Li and S elements to the P element is 1.5 to 2.2. The molar ratio of the sum of the Li and X elements to the P element is preferably 7.1 to 10.0. The solid electrolyte preferably exhibits diffraction peaks at 2θ = 25.5° ± 1.0°, 29.8° ± 0.5°, and 31.2° ± 1.0° in a diffraction pattern measured by an X-ray diffractometer.