Argyrodite Solid Electrolyte Composition for Lithium-Metal Stability
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Solution Overview
Problem
Current solid electrolytes in all-solid lithium batteries suffer from low lithium-ion conductivity and instability when in contact with lithium metal, leading to degraded performance and lifespan.
Innovation Solution
A solid ion conductor compound with an argyrodite crystal structure, represented by Formula 1 (LiaMxTyPbScClaXe), is developed, incorporating elements like Na, Sc, Br, and I, which enhances lithium-ion conductivity and stability by increasing the crystal lattice volume and improving contact with active material layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solid electrolyte materials are used, then the battery structure is simplified and stability is improved, but lithium-ion conductivity is lower than liquid substituents
Solution Approach 1:
The patent changes the chemical composition parameters of the solid electrolyte by incorporating halogen elements (Cl, Br, I) into the argyrodite structure, achieving optimal ionic conductivity of 3.4 mS/cm at room temperature while maintaining stability against lithium metal
Solution Approach 2:
The patent creates a composite solid electrolyte material combining argyrodite base structure with halogen elements (Li-M-T-P-S-Cl-X system), achieving synergistic effects that simultaneously improve ionic conductivity and stability properties
2Device complexity
If conventional solid electrolyte materials are used, then the battery is simpler and more stable, but they are not sufficiently stable to lithium metal
Solution Approach 1:
The patent modifies the chemical composition parameters by introducing halogen elements into the argyrodite structure, achieving enhanced electrochemical stability window of up to 4.0 V vs. Li/Li+ and stability against lithium metal while maintaining structural simplicity
3Object-generated harmful factors
If crystal lattice volume is increased, then lithium-ion conductivity is improved, but density may be reduced
Solution Approach 1:
The patent optimizes the crystal lattice parameters by incorporating halogen elements with different ionic radii, expanding the lattice volume to facilitate ion transport while controlling the density through compositional adjustment in the Li-M-T-P-S-Cl-X system
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 compound significantly improves lithium-ion conductivity, stability, and cycle characteristics, resulting in higher density and longer-lasting all-solid batteries with improved ionic conductivity and reduced harmful gas emissions.
Implementation Method 1
the ionic conductivity of solid electrolytes in the art is lower than that of liquid substituents
Implementation Method 2
performing heat treatment on the mixture in an inert atmosphere to provide a solid ion conductor compound
Data Source
AI summary
The present invention relates to a solid ion conductor compound represented by LiaMxTyPbScCldXe and having an argyrodite crystal structure, a solid electrolyte including the same, and an electrochemical cell including the same.