Composite Solid Electrolyte for Lithium-Sulfur Battery Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-sulfur batteries face limitations due to low stability against liquid organic electrolyte solutions, insufficient stability against metallic lithium or high voltage cathode materials, extreme sensitivity to moisture and air, and intrinsically low ionic conductivity in existing lithium-ion conductive compounds.
Innovation Solution
Development of ionically conductive compounds with the composition Li2xSx+w+5zMyP2z, where M is selected from specific groups of atoms, and x, y, and z are within defined ranges, which are crystalline or amorphous, and used in electrochemical cells as protective layers or solid electrolytes, formed through heating a mixture of precursors and deposited on electrodes or separators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing lithium-ion conductive compounds (such as Li2Sx/P2S5 glasses, Li7P3S11, thio-LISICON) are used, then ionic conductivity is provided, but stability against liquid organic electrolyte solutions, metallic lithium, and high voltage cathode materials deteriorates
Solution Approach 1:
The patent employs composite materials by combining lithium sulfide (Li2S) with phosphorus-based compounds (P2S5, P4S3, or PSP) to create a composite solid electrolyte. This composite structure provides both ionic conductivity and chemical stability, resolving the contradiction between providing ionic conductivity and maintaining stability against electrolyte and electrode materials.
Solution Approach 2:
The patent changes the compositional parameters by defining specific ranges for Li2S content (60-95 wt%) and phosphorus-based compound content (5-40 wt%), along with specific molar ratio ranges (x:y:z). These parameter changes optimize both ionic conductivity and chemical stability, addressing the contradiction between conductivity and stability.
2Duration of action of moving object
If conventional secondary batteries (lead-based) are replaced with lithium-based batteries, then capacity and life-time are improved, but technical problems regarding stability and reactivity arise
Solution Approach 1:
The patent changes the chemical composition parameters by specifying precise weight percentages and molar ratios of Li2S and phosphorus-based compounds. This compositional optimization enables lithium-based batteries to achieve both high capacity/long life-time and improved stability against electrolyte and electrode materials.
Solution Approach 2:
The patent uses composite materials combining lithium sulfide with phosphorus-based compounds to create a solid electrolyte that maintains the high capacity and long life-time advantages of lithium-based batteries while resolving their stability and reactivity problems.
3Quantity of substance
If lithium-sulfur batteries are used to improve capacity, then high capacity is achieved, but stability against moisture and air deteriorates due to sensitivity of sulfide materials
Solution Approach 1:
The patent employs composite materials by combining lithium sulfide with phosphorus-based compounds (P2S5, P4S3, or PSP). This composite structure maintains the high capacity of lithium-sulfur batteries while improving stability against moisture and air through the protective effect of the phosphorus-based compound matrix.
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 compounds enhance the stability and ionic conductivity of lithium-sulfur batteries, reducing lithium consumption during charge/discharge, inhibiting chemical reactions, and improving the durability of electrodes, thereby increasing the performance and lifespan of lithium-sulfur batteries.
Implementation Method 1
improving the durability of electrodes, thereby increasing the performance and lifespan of lithium-sulfur batteries
Data Source
AI summary
Articles, compositions, and methods involving ionically conductive compounds are provided. The disclosed ionically conductive compounds may be incorporated into an electrochemical cell (e.g., a lithium-sulfur electrochemical cell, a lithium-ion electrochemical cell, an intercalated-cathode based electrochemical cell) as, for example, a protective layer for an electrode, a solid electrolyte layer, and/or any other appropriate component within the electrochemical cell. In certain embodiments, electrode structures and/or methods for making electrode structures including a layer comprising an ionically conductive compound described herein are provided.