LGPS Solid Electrolyte Production via Crystalline Mixing
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Solution Overview
Problem
Conventional methods for producing LGPS-based solid electrolytes face challenges such as limited scalability and instability due to the use of volatile and decomposable materials, making it difficult to achieve stable performance and high productivity.
Innovation Solution
A method involving the mixing of Li3PS4 crystals with Li2S and MS2 crystals (M being Ge, Si, or Sn) followed by heat treatment between 300 to 700°C, eliminating the need for an amorphous step and reducing impurities, while maintaining the desired crystal structure and ion conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional methods use P2S5 as raw material, then synthesis can be performed, but the process requires amorphous step with complex treatment and cannot be scaled up due to high volatility and decomposability
Solution Approach 1:
The patent changes the physical state parameter of the raw materials from amorphous (conventional) to crystalline (invention). Specifically, it uses crystalline Li2S, crystalline P2S5, and crystalline GeS2 instead of amorphous materials, which eliminates the need for the amorphous step and enables direct sintering to form LGPS solid electrolyte with high density and stability.
Solution Approach 2:
The patent extracts and removes the problematic amorphous step from the conventional synthesis process. By using crystalline raw materials that can be directly sintered, the complex amorphization treatment is completely eliminated, simplifying the process to only mixing and sintering steps while improving scalability.
2Reliability
If P2S5 is used as raw material, then LGPS can be synthesized, but stable performance cannot be easily obtained due to high volatility and decomposability
Solution Approach 1:
The patent changes the crystallinity parameter of P2S5 from amorphous to crystalline state. Crystalline P2S5 has lower volatility and better thermal stability compared to amorphous form, enabling stable LGPS synthesis at elevated temperatures without decomposition, thus improving performance reliability.
Solution Approach 2:
The patent performs preliminary crystallization of all raw materials (Li2S, P2S5, GeS2) before the main synthesis process. This preliminary action ensures that the raw materials are in a stable crystalline state, preventing decomposition during sintering and ensuring consistent LGPS formation with stable performance.
3Productivity
If amorphous step is used in conventional production, then synthesis can proceed, but complex treatment is required and scalability is limited
Solution Approach 1:
The patent completely extracts and eliminates the amorphous step from the synthesis process by using crystalline raw materials. This removal simplifies the操作流程 to only two steps: mixing crystalline materials and sintering, making the process suitable for mass production while maintaining ease of operation.
Solution Approach 2:
The patent changes the physical state parameter of the final product from amorphous or partially crystalline (conventional) to fully crystalline (invention). The sintering process transforms the mixed crystalline raw materials directly into crystalline LGPS, eliminating the need for subsequent amorphization treatment and enabling scalable production.
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
This method enables the production of a stable LGPS-based solid electrolyte with improved scalability and performance, suitable for mass production and application in all-solid-state batteries, ensuring high ion conductivity across a wide temperature range.
Implementation Method 1
Li3PS4 crystals having a peak at 420 ± 10 cm−1 in a Raman spectrum, Li2S crystals and MS2 crystals (M is selected from the group consisting of Ge, Si and Sn) are used as raw materials
Implementation Method 2
a heat treatment step, thereby obtaining an LGPS-based solid electrolyte
Data Source
Figure 1~2
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AI summary
The present invention provides an LGPS-based solid electrolyte production method characterized by having a step in which a mixture of Li3PS4 crystals having a peak at 420 ± 10 cm-1 in a Raman measurement and Li4MS4 crystals (M being selected from the group consisting of Ge, Si, and Sn) is heat treated at 300-700°C. In addition, the present invention can provide an LGPS-based solid electrolyte production method characterized by having: a step in which Li3PS4 crystals having a peak at 420 ± 10 cm-1 in a Raman measurement, Li2S crystals, and sulfide crystals indicated by MS2 (M being selected from the group consisting of Ge, Si, and Sn) are mixed while still having crystals present and a precursor is synthesized; and a step in which the precursor is heat treated at 300-700°C.