Sulfide Solid Electrolyte Material for High Conductivity
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Solution Overview
Problem
Current lithium batteries with liquid electrolytes pose safety risks due to flammable organic solvents, and there is a need for solid electrolyte materials with high Li ion conductivity to reduce internal resistance and enhance battery performance.
Innovation Solution
A sulfide solid electrolyte material with a low molecular weight organic compound (0.2 wt % to 0.8 wt %) is used, which is synthesized through mechanical milling and drying to achieve high Li ion conductivity, and is incorporated into a lithium solid battery structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid electrolyte containing flammable organic solvent is used in lithium battery, then high Li ion conductivity is achieved, but safety risk increases due to flammability
Solution Approach 1:
The invention changes the physical state parameter of the electrolyte from liquid to solid by using sulfide solid electrolyte material. This phase transition eliminates the flammability issue inherent in liquid organic electrolytes while maintaining high Li ion conductivity, directly resolving the safety contradiction.
Solution Approach 2:
The invention uses a composite sulfide solid electrolyte material composed of multiple components (Li2S, P2S5, and other sulfides) to achieve both high ionic conductivity and inherent safety. The composite structure provides synergistic effects that maintain performance while eliminating flammability risks.
2Reliability
If sulfide solid electrolyte material is used to achieve high Li ion conductivity, then internal resistance decreases, but manufacturing complexity increases
Solution Approach 1:
The invention performs preliminary mixing of raw materials (Li2S, P2S5, and other sulfides) in specific ratios before sintering. This pre-mixing step ensures homogeneous composition and facilitates the sintering process, reducing manufacturing complexity while achieving the desired high Li ion conductivity in the final product.
Solution Approach 2:
The invention optimizes sintering parameters (temperature, time, atmosphere) to achieve high Li ion conductivity. By carefully controlling these parameters, the material achieves optimal ionic conductivity without requiring excessively complex manufacturing processes, resolving the contradiction between performance and manufacturing simplicity.
3Reliability
If organic compound is added to sulfide solid electrolyte material, then Li ion conductivity is enhanced, but content must be kept very low to maintain performance
Solution Approach 1:
The invention precisely controls the concentration parameter of organic compound additives in the sulfide solid electrolyte. By optimizing this composition parameter, the material achieves enhanced Li ion conductivity while maintaining very low organic compound content (0.1-5 wt%), resolving the contradiction between conductivity enhancement and material purity.
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 material exhibits high Li ion conductivity, reducing internal resistance and enabling high-performance lithium solid batteries with improved safety and cost-effectiveness.
Implementation Method 1
sulfide solid electrolyte material exhibiting high Li ion conductivity
Implementation Method 2
performing mechanical milling to a mixture of a raw material composition and the above organic compound to convert the raw material composition to an amorphous state
Implementation Method 3
a drying step of drying the sulfide glass with the organic compound remaining
Data Source
AI summary
A method for preparing a sulfide solid electrolyte material exhibiting Li ion conductivity. The sulfide solid electrolyte material contains an organic compound having a molecular weight within a range of 30 to 300, and the organic compound is present in an amount of 0.8 wt % or less. The method includes: (i) performing mechanical milling to a mixture of a raw material composition and the organic compound to convert the raw material composition to an amorphous state, thereby synthesizing a sulfide glass; and (ii) drying the sulfide glass such that at least some of the organic compound remains in the sulfide solid electrolyte material.