Halogen Sulfide Solid Electrolyte for High-Temperature Phase Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid electrolytes lack sufficient thermal stability at high temperatures, with the high Li ion conductive crystal phase being metastable and unstable above 200°C, necessitating the development of a material with enhanced thermal stability and ionic conductivity.
Innovation Solution
A solid electrolyte composition containing lithium, phosphorus, sulfur, halogen, and elements such as magnesium, calcium, or barium, with a specific crystal structure, which maintains high ionic conductivity and thermal stability even at temperatures above 200°C, achieved through a method involving the reaction and heating of a composition containing these elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solid electrolyte composition is used, then high ionic conductivity can be achieved through heat treatment, but thermal stability deteriorates at temperatures of 200°C or higher
Solution Approach 1:
The invention changes the compositional parameters by introducing element A (Mg, Ca, Sr, or Ba) at specific concentration ranges (0.01-0.5 mol ratio relative to P). This compositional modification enables the solid electrolyte to maintain phase stability and high ionic conductivity at elevated temperatures up to 400°C, resolving the contradiction between achieving high ionic conductivity and maintaining thermal stability.
Solution Approach 2:
The invention creates a composite solid electrolyte material by combining traditional sulfide-based electrolyte components (Li, P, S, halogen) with element A (Mg, Ca, Sr, or Ba). This composite approach leverages the beneficial properties of both systems: the high ionic conductivity of sulfide electrolytes and the thermal stability contributed by element A, thereby achieving both high reliability and compositional stability simultaneously.
2Reliability
If heat treatment is performed to obtain high Li ion conductive crystal phase, then ionic conductivity is improved, but thermal stability worsens due to metastable phase formation
Solution Approach 1:
The invention modifies the heat treatment parameters and compositional parameters simultaneously. By adjusting the composition to include element A within specific ranges and optimizing heat treatment conditions, the material forms a stable crystal phase that maintains high ionic conductivity without being metastable. This resolves the contradiction by achieving both high ionic conductivity and phase stability through coordinated parameter optimization.
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 proposed solid electrolyte exhibits high thermal stability and sufficient ionic conductivity at elevated temperatures, enabling the creation of energy storage devices with increased operating temperature limits and improved performance in electronic and automotive applications.
Implementation Method 1
a nonaqueous electrolyte interposed between the electrodes, and is configured to allow lithium ions to be transferred between the two electrodes for charge-discharge
Implementation Method 2
a solid electrolyte having the high Li ion conductive crystal phase is obtained by heat treatment at lower than 200° C.
Implementation Method 3
the solid electrolyte has a crystal structure
Data Source
AI summary
One aspect of the present invention is a solid electrolyte containing lithium, phosphorus, sulfur, halogen, and an element A, in which the element A is at least one selected from the group consisting of magnesium, calcium, strontium, and barium, and the solid electrolyte has a crystal structure.