Li-P-S Sulfide Solid Electrolyte for High Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium batteries with liquid electrolytes face safety concerns due to flammable organic solvents, while all-solid-state batteries with sulfide solid electrolytes have lower energy densities and inadequate electrochemical stability.
Innovation Solution
A Li—P—S-based sulfide solid electrolyte material with specific crystal structure and composition, characterized by peaks in powder X-ray diffraction measurements, and a production method involving fragmentation and heating to achieve high ion conductivity and electrochemical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Li-Ge-P-S-based sulfide solid electrolytes such as Li10GeP2S12 (LGPS) are used, then ion conductivity is improved to 12×10−3 Scm−1 comparable to electrolytic solution, but electrochemical stability deteriorates due to reductive decomposition at around 0.25 V based on lithium
Solution Approach 1:
The patent changes the compositional parameters of the sulfide solid electrolyte by replacing Ge with P to create Li-P-S-based systems (such as Li3PS4, Li2.5PS3, Li4P2S7) that maintain high ion conductivity while achieving electrochemical stability up to 3.0 V or higher versus Li/Li+, thereby resolving the contradiction between conductivity and stability
Solution Approach 2:
The patent creates composite sulfide solid electrolyte materials by combining multiple Li-P-S compounds or doping elements into the Li-P-S system, achieving both high ion conductivity and enhanced electrochemical stability through synergistic material composition
2Reliability
If all-solid-state lithium batteries with solid electrolyte layers are used, then safety is improved by eliminating flammable organic solvents, but energy density deteriorates compared to liquid-based batteries
Solution Approach 1:
The patent changes the physical and chemical parameters of the solid electrolyte by developing Li-P-S-based sulfide electrolytes with ultra-high ion conductivity (comparable to liquid electrolytes) and appropriate electrochemical stability windows, enabling all-solid-state batteries to achieve energy densities comparable to or exceeding liquid-based batteries while maintaining safety advantages
Solution Approach 2:
The patent optimizes the local properties of the solid electrolyte material by controlling crystal structure, particle size, and phase composition of Li-P-S-based sulfides to maximize ion conductivity in the electrolyte layer, compensating for the inherently lower energy density of solid-state systems
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 new sulfide solid electrolyte material enhances lithium ion conductivity and electrochemical stability, enabling the development of high-output lithium batteries with improved safety and energy density.
Implementation Method 1
a sulfide solid electrolyte material including a Li element, a P element, and a S element and having peaks at positions of 2θ＝17.90±0.20, 29.0±0.50, and 29.75±0.25° in powder X-ray diffraction measurement
Implementation Method 2
having peaks at positions of 2θ＝17.90±0.20, 29.0±0.50, and 29.75±0.25° in powder X-ray diffraction measurement using a Cu-Kα ray having an X-ray wavelength of 1.5418 Å
Data Source
AI summary
(Problem to be Solved) The present invention was made in view of the above-described problems, with an object of providing a Li—P—S-based sulfide solid electrolyte material with both excellent electrochemical stability and a high lithium ion conductivity, providing a method of producing the Li—P—S-based sulfide solid electrolyte material, and providing a lithium battery including the sulfide solid electrolyte material.(Solution) There is provided a sulfide solid electrolyte material including a Li element, a P element, and a S element and having peaks at positions of 2θ=17.90±0.20, 29.0±0.50, and 29.75±0.25′ in powder X-ray diffraction measurement using a Cu-Kα ray having an X-ray wavelength of 1.5418 Å, in which assuming that the diffraction intensity of the peak at 2θ=17.90±0.20 is IA and the diffraction intensity of the peak at 2θ=18.50±0.20 is IB, a value of IB/IA is less than 0.50.