Sulfide Solid Electrolyte Gas-Phase Synthesis With Air-Stable Precursors

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Solution Overview

Problem

Current methods for synthesizing sulfide solid-electrolyte materials are complex, energy-intensive, and require expensive raw materials and strict environmental controls, limiting their scalability and compatibility with existing lithium battery production processes.

Innovation Solution

A gas phase synthesis method using air-stable and low-cost raw materials, which simplifies the process by eliminating the need for vacuum or inert atmospheres, allowing synthesis in an air environment and enabling large-scale production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solid phase methods or liquid phase methods are used to synthesize sulfide electrolyte, then the sulfide electrolyte can be produced, but the synthesis process requires vacuum sealed tube or inert atmosphere protection and long-term sintering at high temperature

Engineering Contradiction:
Improveproduct qualityVSAvoidsynthesis process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a tube furnace equipped with a gas inlet and outlet system to create a controlled inert atmosphere environment during synthesis. This allows the reaction to proceed without requiring vacuum sealing while protecting air-sensitive materials, thus simplifying the device complexity while maintaining product quality.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent performs preliminary mixing of raw materials (Li2CO3, SnO2, P2O5, and sulfur source) before synthesis. This pre-mixing ensures uniform distribution of components, which facilitates complete reaction and reduces the required sintering time, thereby simplifying the overall process while ensuring reliable product quality.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If ball milling method is used to mix raw materials, then the mixing can be performed, but raw materials and abrasives need to be placed in a sealed container free of water and oxygen

Engineering Contradiction:
Improvemixing capabilityVSAvoidenvironmental control requirements
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical ball milling system with a chemical reaction system conducted in a tube furnace. Instead of mechanically mixing materials in a sealed container, the patent uses gas-phase sulfurization reaction to synthesize the sulfide electrolyte directly from mixed oxides, eliminating the need for sealed containers and complex environmental controls during mixing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the reaction parameters from solid-state mechanical mixing to gas-phase chemical reaction. By introducing a sulfur source gas and heating the mixed oxides in a controlled atmosphere, the synthesis proceeds through chemical transformation rather than mechanical processing, thereby eliminating environmental control requirements.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If expensive sulfides like Li2S and SiS2 are used as starting materials, then the sulfide electrolyte can be synthesized, but the cost increases and vacuum tube sealing and multi-step heat treatment are still needed

Engineering Contradiction:
Improvesynthesis successVSAvoidraw material cost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent uses inexpensive, stable oxide materials (Li2CO3, SnO2, P2O5) as starting materials instead of expensive air-sensitive sulfides. These oxides are readily available, stable in air, and can be handled without special precautions. The sulfur is introduced as a gas phase reagent, eliminating the need for expensive solid sulfur sources and reducing overall material costs.

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

Solution Approach 2:

The patent inverts the conventional synthesis approach by starting with oxides instead of sulfides. Rather than converting sulfides to the desired sulfide electrolyte composition, the method directly synthesizes the target material from oxides through gas-phase sulfurization, thereby avoiding the use of expensive sulfide starting materials entirely.

Inventive Principle:
Principle #13The other way round (Inversion)

4Reliability

If long-term ball milling and high-pressure sheeting are performed, then the sulfide electrolyte can be prepared, but the time consumption and energy consumption increase

Engineering Contradiction:
Improveproduct formationVSAvoidsynthesis time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces mechanical ball milling and high-pressure sheeting processes with a thermal-chemical synthesis approach. By conducting the sulfurization reaction in a tube furnace at elevated temperatures with gas-phase sulfur, the method achieves complete reaction and product formation without requiring prolonged mechanical processing or high-pressure consolidation steps, significantly reducing synthesis time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes phase transitions during the thermal-chemical synthesis process. The gas-phase sulfur undergoes phase change to react with the oxide materials, and the product formation involves crystalline phase development during heating. These phase transitions drive the reaction to completion efficiently, eliminating the need for long-term mechanical processing.

Inventive Principle:
Principle #36Phase transitions

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 method produces sulfide solid-electrolyte materials with good air stability, reducing production costs and environmental constraints, and enhances compatibility with existing lithium battery production lines, facilitating their application in lithium batteries.

Implementation Method 1

heating the heating furnace to 200° C.-800° C. at a set heating rate

Methodology Applied
Scientific EffectThermal energy: Heating

Implementation Method 2

synthesizing a sulfide solid-electrolyte material by using a gas phase method

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS20240030485A1Sulfide solid electrolyte material, gas-phase synthesis method for materials thereof and application thereof
Publication Date: 2024.01.25 TIANMU LAKE INST OF ADVANCED ENERGY STORAGE TECH CO LTD

AI summary

A sulfide solid electrolyte material, a gas-phase synthesis method for materials thereof and an application thereof are disclosed. The gas-phase synthesis method comprises: weighing a Li source and an M source according to a defined ratio, the M source being an oxide or sulfide of at least one of group 4, 5, 6, 13, 14 and 15 elements from the third period to the sixth period in the periodic table of elements; mixing and placing the mixed raw materials into a furnace; adding an S source into a sulfur source gas generation device; using a carrier gas, and performing gas washing on the furnace for a certain duration at a set ventilation rate; heating the furnace to 200-800° C. at a set heating rate in an environment in which the gas containing the S source is introduced at the set ventilation rate, keeping warm for a set duration, and then cooling to room temperature; and removing a sulfide solid electrolyte from the furnace.