Sulfide Solid Electrolyte Glass Ceramics for High Conductivity
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Solution Overview
Problem
Current lithium batteries face challenges with safety due to the use of inflammable organic solvents and require improvements in structure and materials to prevent short-circuiting, while all-solid-state lithium batteries with solid electrolytes offer better safety but need sulfide solid electrolyte materials with high Li ion conductivity to enhance battery performance.
Innovation Solution
Development of sulfide solid electrolyte materials with glass ceramics containing Li, A (P, Si, Ge, Al, or B), and X (a halogen) that exhibit high Li ion conductivity, achieved by heat-treating LiX-doped sulfide glass within specific ranges of LiX addition and temperature, resulting in novel crystalline phases with improved chemical stability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sulfide solid electrolyte materials are used to replace inflammable organic solvents, then battery safety is improved, but Li ion conductivity needs to be enhanced to maintain battery performance
Solution Approach 1:
The patent applies parameter changes by precisely controlling the LiX addition amount (14-30 mol%) and heat treatment temperature (100-200°C) to transform sulfide glass into glass ceramics with optimal Li ion conductivity. This parameter optimization resolves the contradiction by achieving high conductivity (≥10⁻⁴ S/cm) while maintaining the safety benefits of solid electrolytes.
Solution Approach 2:
The patent creates composite glass ceramic materials by combining sulfide glass with LiX dopants and controlling crystallization to form specific crystalline phases. This composite approach achieves both high Li ion conductivity and chemical stability, resolving the contradiction between safety and performance.
2Power
If LiX is added to sulfide glass to improve Li ion conductivity, then conductivity is enhanced, but chemical stability may deteriorate
Solution Approach 1:
The patent optimizes the LiX addition amount within 14-30 mol% and controls heat treatment temperature (100-200°C) to achieve the right balance between conductivity enhancement and chemical stability preservation. This parameter control prevents excessive LiX from degrading stability while maintaining high conductivity.
Solution Approach 2:
The patent utilizes phase transition by heat-treating sulfide glass to form crystalline phases within the glass matrix. This glass ceramic transformation creates a stable crystalline structure that accommodates LiX dopants while maintaining overall chemical stability and high Li ion conductivity.
3Power
If glass ceramics are produced by heat-treating LiX-doped sulfide glass, then Li ion conductivity is improved, but production process complexity increases
Solution Approach 1:
The patent simplifies the production process by optimizing heat treatment parameters (100-200°C for 1-48 hours) that achieve desired glass ceramic transformation without requiring complex multi-step processing. This parameter optimization reduces production complexity while maintaining high Li ion conductivity.
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 sulfide solid electrolyte materials demonstrate high Li ion conductivity and chemical stability, enhancing the output power of lithium solid-state batteries and simplifying safety mechanisms by inhibiting heat generation and improving battery safety.
Implementation Method 1
heat-treating LiX-doped sulfide glass within specific ranges of LiX addition and temperature, resulting in novel crystalline phases
Implementation Method 2
heat-treating LiX-doped sulfide glass within specific ranges of LiX addition and temperature
Implementation Method 3
peaks at 2θ=20.2° and 23.6° in X-ray diffraction measurement with CuKα line
Data Source
AI summary
A sulfide solid electrolyte material contains glass ceramics that contains Li, A, X, and S, and has peaks at 2θ=20.2° and 23.6° in X-ray diffraction measurement with CuKα line. A is at least one kind of P, Si, Ge, Al, and B, and X is a halogen. A method for producing a sulfide solid electrolyte material includes amorphizing a raw material composition containing Li2S, a sulfide of A, and LiX to synthesize sulfide glass, and heating the sulfide glass at a heat treatment temperature equal to or more than a crystallization temperature thereof to synthesize glass ceramics having peaks at 2θ=20.2° and 23.6° in X-ray diffraction measurement with CuKα line, in which a ratio of the LiX contained in the raw material composition and the heat treatment temperature are controlled to obtain the glass ceramics.