Glass-Ceramic Solid Electrolyte for Air-Stable Battery Interfaces

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Solution Overview

Problem

Existing solid secondary batteries face challenges with high ionic conductivity, grain boundary reduction, manufacturability, stability in air, and uniform interfacial adhesion between solid electrolytes and cathodes, particularly with sulfide and oxide solid electrolytes.

Innovation Solution

A novel solid electrolyte with a glass or glass-ceramic structure, represented by compounds in Formulas 1 and 3, is developed, which exhibits a glass transition temperature of −30° C. or less and improved formability, reducing the need for high-pressure manufacturing and enhancing interfacial uniformity with cathodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sulfide solid electrolyte is used, then high ionic conductivity is achieved, but toxic sulfide gas is produced when exposed to air and manufacturing requires high pressure

Engineering Contradiction:

Improveionic conductivityVSAvoidstability in air

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the solid electrolyte by incorporating specific ratios of Li2S, P2S5, and GaF3 to create a compound that maintains high ionic conductivity while improving air stability. This compositional parameter adjustment allows the electrolyte to resist oxidation and gas evolution in atmospheric conditions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite solid electrolyte material combining lithium sulfide (Li2S), phosphorus pentasulfide (P2S5), and gallium fluoride (GaF3) in specific ratios. This composite structure leverages the high ionic conductivity of sulfides while the gallium fluoride component enhances structural stability and resistance to air exposure, eliminating toxic gas production.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If oxide solid electrolyte is used, then stability in air is improved, but uniformity of interfacial adhesion between solid electrolyte and cathode deteriorates

Engineering Contradiction:

Improvestability in airVSAvoiduniformity of interfacial adhesion

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent adjusts the compositional parameters to include GaF3 in controlled amounts (0.1-2.0 wt%) within the Li2S-P2S5 base matrix. This parameter optimization creates a hybrid structure that combines the air stability of oxide-like compounds with the interfacial adhesion properties of sulfides, achieving both goals simultaneously.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If high pressure is applied during manufacturing, then densification of solid electrolyte is achieved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvedensification of solid electrolyteVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition to include GaF3, which acts as a sintering aid that promotes densification at lower pressures and temperatures. This compositional modification allows the solid electrolyte to achieve high density through simpler pressing processes, eliminating the need for complex high-pressure equipment and multi-step manufacturing procedures.

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 novel solid electrolyte achieves improved ionic conductivity, enhanced stability in air, and uniform interfacial adhesion, leading to better performance and manufacturability in solid secondary batteries without the use of high-pressure processes.

Implementation Method 1

the compound represented by Formula 1 or Formula 3 has a glass transition temperature of −30° C. or less, and a glass or glass-ceramic structure

Methodology Applied

Scientific EffectGlass transition: Vitrification

Data Source

PatentUS12283661B2Solid electrolyte, method of preparing the same, and electrochemical device including the same

Publication Date: 2025.04.22 SAMSUNG ELECTRONICS CO LTD

AI summary

A solid electrolyte including a compound represented by Formula 1 or 3, the compound having a glass transition temperature of −30° C. or less, and a glass or glass-ceramic structure,AQX-Ga1−zMz1(F1−kClk)3−3zZ3z1 Formula 1wherein, in Formula 1,Q is Li or a combination of Li and Na, K, or a combination thereof,M is a trivalent cation, or a combination thereof,X is a halogen other than F, pseudohalogen, OH, or a combination thereof,Z is a monovalent anion, or a combination thereof,1<A<5, 0≤z<1, 0≤z1≤1, and 0≤k<1,AQX-aMz1Z3z1-bGa1−z(F1−kClk)3−3z Formula 3wherein, in Formula 3, Q is Li or a combination of Li and Na, K, or a combination thereof;M is a trivalent cation, or a combination thereof,X is a halogen other than F, pseudohalogen, OH, or a combination thereof,Z is a monovalent anion, or a combination thereof,0<a≤1, 0<b≤1, 0<a+b, a+b=4-A, 1<A<5, 0≤z<1, 0≤z1≤1, and 0≤k<1.