Sulfide Solid Electrolyte Processability via Distorted Argyrodite Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium-ion batteries using liquid electrolytes with flammable organic solvents require safety devices to prevent temperature rises during short circuits, and solid electrolytes with argyrodite-type crystal structures, while stable, face challenges in processability and ionic conductivity during battery manufacturing.
Innovation Solution
Development of sulfide solid electrolytes comprising lithium, phosphorus, and sulfur with specific diffraction peaks and 31P-NMR characteristics, which enhance processability and ionic conductivity by adopting a distorted argyrodite-type crystal structure and incorporating glass-derived peaks, allowing for improved compaction properties and higher ionic conductivity without the need for high-temperature heat treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional argyrodite-type sulfide solid electrolytes are used, then structural stability is improved, but processability and ionic conductivity deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molar ratios of constituent elements (Li: 0.95-1.05, P: 0.95-1.05, S: 0.95-1.05) and adjusting processing parameters such as pressing temperature (100-300°C) and time (1-24 hours) to achieve optimal processability while maintaining structural stability of the argyrodite-type crystal structure
Solution Approach 2:
The patent introduces local quality by adding small amounts of specific elements (Al: 0.01-0.1 mol, Ga: 0.01-0.1 mol, In: 0.01-0.1 mol, or Ge: 0.01-0.1 mol) to the Li-P-S system. These localized compositional modifications improve processability and ionic conductivity without compromising the overall structural stability of the sulfide solid electrolyte
2Stability of the object's composition
If conventional argyrodite-type sulfide solid electrolytes are used, then structural stability is improved, but ionic conductivity deteriorates
Solution Approach 1:
The patent improves ionic conductivity through parameter changes by optimizing the molar ratios of Li, P, and S within ±5% of stoichiometry and controlling processing parameters (pressing temperature 100-300°C, time 1-24 hours). These precise parameter adjustments enhance ion transport while preserving the stable argyrodite crystal structure
Solution Approach 2:
The patent enhances ionic conductivity through local quality by incorporating trace amounts (0.01-0.1 mol) of specific elements (Al, Ga, In, or Ge) into the Li-P-S system. These localized compositional modifications create favorable local environments for ion conduction without disrupting the overall structural stability
3Reliability
If high-temperature heat treatment is applied, then ionic conductivity is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent eliminates high-temperature heat treatment through parameter changes by optimizing the composition (Li: 0.95-1.05, P: 0.95-1.05, S: 0.95-1.05) and applying low-temperature processing (pressing at 100-300°C for 1-24 hours). This achieves high ionic conductivity without the need for complex high-temperature manufacturing equipment and processes
Solution Approach 2:
The patent adopts simpler, lower-cost processing methods by replacing expensive high-temperature heat treatment equipment with affordable low-temperature pressing equipment. The optimized composition allows the material to achieve desired properties through simple pressing, reducing manufacturing complexity and cost
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 novel sulfide solid electrolytes exhibit excellent compaction properties and high ionic conductivity, enabling more efficient battery manufacturing and performance, while simplifying safety measures and reducing production costs by eliminating the need for high-temperature processing.
Implementation Method 1
high ionic conductivity
Implementation Method 2
sulfide solid electrolyte comprising lithium, phosphorus, and sulfur
Implementation Method 3
diffraction peak A at 2θ＝25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction
Implementation Method 4
diffraction peak A at 2θ＝25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction using CuKα radiation
Implementation Method 5
peak having a half-value width of 500 to 800 Hz are observed in solid-state 31P-NMR measurements
Data Source
AI summary
A sulfide solid electrolyte may include lithium, phosphorus and sulfur, and the sulfide solid electrolyte may have a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction using CuKα rays, and a crystallite diameter in a range of from 5 to 20 nm.