Indium Selenide Doped Sulfide Solid Electrolyte for Battery Stability
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Solution Overview
Problem
Existing secondary batteries, particularly those using lithium-phosphorus-sulfur (Li—P—S) based solid electrolytes, face limitations in lithium ion conductivity, atmospheric stability, and energy density, making them unsuitable for high-performance applications like electric vehicles and electronic devices.
Innovation Solution
A lithium-ion-conductive sulfide-based solid electrolyte containing lithium (Li), sulfur (S), phosphorus (P), indium (In), and selenium (Se) with a specific crystal structure, represented by Chemical Formula (Li2S)a.(P2S5)b.(In2Se3)c, which is synthesized through mixing and heat-treating lithium sulfide, phosphorus pentasulfide, and indium selenide, enhancing ion conductivity and atmospheric stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium-phosphorus-sulfur (Li-P-S) based solid electrolyte is used, then atmospheric stability is improved compared to organic liquid electrolytes, but lithium ion conductivity at room temperature becomes low
Solution Approach 1:
The patent uses composite materials by combining Li-P-S base electrolyte with metal selenides (CdSe, ZnSe, HgSe, or their oxides/sulfides) to create a new composite solid electrolyte. This composite structure allows the material to simultaneously achieve high lithium ion conductivity and good atmospheric stability, resolving the contradiction between the two properties that plagued conventional Li-P-S electrolytes alone.
Solution Approach 2:
The patent changes the compositional parameters of the solid electrolyte by introducing metal selenides in specific weight ratios (0.1-10 parts by weight per 100 parts Li-P-S electrolyte). By optimizing these compositional parameters, the electrolyte achieves peak lithium ion conductivity while maintaining atmospheric stability, thus resolving the performance trade-off.
2Quantity of substance
If existing sulfide-based solid electrolyte is used, then energy density can be increased compared to organic liquid electrolytes, but charge-discharge performance and energy efficiency remain insufficient
Solution Approach 1:
The patent creates a composite solid electrolyte system combining Li-P-S base material with metal selenide additives. This composite structure optimizes both energy density and charge-discharge performance by leveraging the high theoretical energy density of sulfide-based electrolytes while the metal selenide components enhance ionic conductivity and electrochemical stability, thereby improving overall charge-discharge performance and energy efficiency.
Solution Approach 2:
The patent optimizes compositional parameters including the weight ratio of metal selenide to Li-P-S electrolyte (0.1-10:100), heat treatment temperature (200-1200°C), and treatment time (1-3 hours). These parameter optimizations enable the electrolyte to achieve simultaneous improvement in energy density and charge-discharge performance, overcoming the limitations of conventional sulfide-based electrolytes.
3Stability of the object's composition
If crystal phase stability is improved in Li-P-S electrolyte, then atmospheric stability increases, but processability and large-scale producibility are limited
Solution Approach 1:
The patent develops a composite solid electrolyte where metal selenides are dispersed within the Li-P-S matrix. This composite approach allows the base Li-P-S phase to maintain its crystal structure stability for atmospheric resistance, while the dispersed metal selenide particles enhance overall stability without significantly complicating the manufacturing process. The composite structure can be produced through conventional mixing and heat treatment methods.
Solution Approach 2:
The patent optimizes processing parameters including heat treatment temperature (200-1200°C) and time (1-3 hours) to achieve the desired crystal phase stability while maintaining manufacturability. By carefully controlling these parameters, the electrolyte attains stable crystal structure for atmospheric resistance without requiring overly complex or expensive manufacturing processes, thus balancing stability and ease of manufacture.
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 proposed electrolyte exhibits superior charge-discharge performance, high energy efficiency, and extended battery life span by maintaining ion conductivity and stability even after exposure to atmospheric conditions, outperforming conventional sulfide-based solid electrolytes.
Implementation Method 1
The lithium-ion-conductive sulfide-based solid electrolyte may have a crystal structure of InSe
Implementation Method 2
a step of mixing lithium sulfide (Li2S), a sulfide-based raw material and indium selenide (In2Se3) and a step of milling the resulting mixture
Data Source
AI summary
The present invention relates to a lithium-ion-conductive sulfide-based solid electrolyte which contains lithium (Li), sulfur (S), phosphorus (P), indium (In) and selenium (Se) and has a crystal structure of InSe and a method for preparing the same.