Nickel Sulfide Doped Sulfide Solid Electrolyte
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium secondary batteries using liquid organic electrolytes pose safety risks due to leakage, and sulfide-based solid electrolytes have limited lithium ion conductivity and restricted composition ratios, which hinder their performance.
Innovation Solution
A sulfide-based solid electrolyte comprising lithium sulfide (Li2S), diphosphorus pentasulfide (P2S5), and nickel sulfide (Ni3S2) in specific mole ratios, exhibiting a novel crystal structure and high lithium ion conductivity, is developed, along with a method of preparing this electrolyte through grinding and thermal treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid organic electrolyte is used in lithium secondary batteries, then high lithium ion conductivity is achieved, but safety risks increase due to leakage and fire hazards
Solution Approach 1:
The patent changes the physical state parameter of the electrolyte from liquid to solid, and the chemical composition from organic to inorganic sulfide-based material. This fundamental parameter change eliminates the harmful effects of liquid electrolyte leakage and fire risk while maintaining high lithium ion conductivity through the solid inorganic electrolyte composition Li2S-P2S5-Ni3S2
Solution Approach 2:
The patent creates a composite solid electrolyte material by combining multiple components (Li2S, P2S5, and Ni3S2) in specific ratios. This composite material approach achieves superior lithium ion conductivity (1 mS/cm or greater) that exceeds both liquid electrolytes and conventional sulfide-based solid electrolytes, while simultaneously providing the safety benefits of solid state operation
2Reliability
If elements (Al, Si, Fe, Ni, Zr) are added to sulfide-based solid electrolyte to increase lithium ion conductivity, then conductivity improves, but composition ratio ranges become limited and quantitative correlations are not established
Solution Approach 1:
The patent systematically varies the composition parameters of Li2S, P2S5, and Ni3S2 within broad ranges (Li2S: 60-80 mol%, P2S5: 10-40 mol%, Ni3S2: 10-30 mol%) to identify optimal composition ratios. By establishing quantitative correlations between composition ratios and lithium ion conductivity, the patent achieves high conductivity (1 mS/cm or greater) while maintaining flexibility in composition selection, overcoming the limitation of restricted composition ranges in previous studies
Solution Approach 2:
The patent employs a systematic approach where composition ratios are varied, lithium ion conductivity is measured, and feedback is used to optimize the composition. This iterative process establishes quantitative correlations between the amounts of Li2S, P2S5, and Ni3S2 and the resulting conductivity, enabling precise control over electrolyte performance while maintaining broad composition flexibility
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 electrolyte achieves lithium ion conductivity of 1 mS/cm or greater in a broad range of composition ratios, enhancing safety and performance by providing a stable and efficient ionic pathway for lithium ions, surpassing conventional sulfide-based solid electrolytes.
Implementation Method 1
a lithium ion-conductive sulfide-based solid electrolyte which may include nickel sulfide
Data Source
AI summary
Disclosed is a lithium ion-conductive sulfide-based solid electrolyte which includes nickel sulfide and, accordingly, the solid electrolyte can obtain a novel structure and performance.More particularly, the sulfide-based solid electrolyte includes lithium sulfide (Li2S), diphosphorus pentasulfide (P2S5), and nickel sulfide (Ni3S2) in a specific ratio by mol % and exhibits a novel crystal structure due to nickel (Ni). Accordingly, the sulfide-based solid electrolyte has greater lithium ion conductivity than an conventional sulfide-based solid electrolyte and a stable crystal structure.