Protective Layer for Solid Electrolyte Anode Interfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional lithium-ion batteries face limitations due to organic liquid electrolytes' safety issues and low ionic conductivity, while all-solid-state batteries (ASSBs) with solid electrolytes suffer from poor ionic conductivity and instability with lithium and environmental elements.
Innovation Solution
A protective layer with high ionic conductivity and electrochemical stability is introduced between the solid electrolyte and anode in ASSBs, comprising ion-conducting materials like Cs2Li3I5 and Li2La4O7, which provides a wide electrochemical stability window and inertness to environmental elements, reducing interfacial resistance and enhancing compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid electrolytes are used in ASSBs to address safety issues and increase energy density, then battery safety and energy density are improved, but ionic conductivity and electrochemical stability deteriorate
Solution Approach 1:
The patent introduces an intermediate protective layer between the solid electrolyte and lithium anode. This intermediary layer mediates the interaction between the two materials, preventing direct harmful reactions while maintaining ionic conductivity. The protective layer acts as a buffer that resolves the contradiction by allowing ion transport without direct contact between the solid electrolyte and lithium, thus preserving both safety and ionic conductivity.
Solution Approach 2:
The patent employs composite material structures, specifically combining the solid electrolyte with a protective layer made of materials like LiNbO3, Li2SiO3, or Li2SiO2. This composite approach allows the system to leverage the high energy density and safety benefits of solid electrolytes while the additional protective material compensates for their poor ionic conductivity and electrochemical stability issues.
2Object-affected harmful factors
If solid electrolytes are used to eliminate organic liquid electrolytes, then safety against flammability is improved, but electrochemical stability window and compatibility with lithium deteriorate
Solution Approach 1:
The protective layer serves as an intermediary that shields the solid electrolyte from direct exposure to lithium and environmental elements. This mediator prevents harmful electrochemical reactions and stabilizes the interface, resolving the contradiction between eliminating flammable liquids and maintaining electrochemical stability.
Solution Approach 2:
The protective layer creates an inert environment at the interface between the solid electrolyte and lithium anode. Materials like LiNbO3 and Li2SiO3 provide chemical inertness that protects the electrochemically unstable solid electrolyte from degradation, effectively creating a stable protective atmosphere without requiring organic liquids.
3Use of energy by moving object
If solid electrolytes with high energy density are used, then battery energy density is improved, but stability against environmental elements such as water and air deteriorates
Solution Approach 1:
The patent employs thin film protective layers that conformally coat the solid electrolyte surfaces. These thin films provide effective environmental protection against water and air while maintaining the high energy density benefits of the solid electrolyte. The flexible nature of thin films allows complete coverage without adding significant volume, preserving energy density while improving reliability.
Solution Approach 2:
The protective layer forms a composite structure with the solid electrolyte, where the outer layer provides environmental stability while the inner solid electrolyte maintains high energy density. This composite approach allows the system to simultaneously achieve both high energy density and environmental stability by combining materials with complementary properties.
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 protective layer improves the electrochemical performance of ASSBs by reducing interfacial resistance, increasing stability, and providing high ionic conductivity, thereby addressing the limitations of traditional lithium-ion batteries and ASSBs.
Implementation Method 1
The protective layer comprises an ion-conducting material having an electrochemical stability window against lithium of at least 1.0 V... possessing high ionic conductivity
Data Source
AI summary
An all-solid-state battery comprises a lithium anode, a cathode, solid electrolyte and a protective layer between the solid electrolyte and the lithium anode. The protective layer comprises an ion-conducting material having an electrochemical stability window against lithium of at least 1.0 V, a lowest electrochemical stability being 0.0 V and a highest electrochemical stability being greater than 1.0 V. More particularly, when the solid electrolyte is LiSiCON, the electrochemical stability window is at least 1.5 V, the lowest electrochemical stability is 0.0 V and the highest electrochemical stability is greater than 1.5 V. When the solid electrolyte is sulfide-based, the electrochemical stability window is at least 2.0 V, the lowest electrochemical stability is 0.0 V and the highest electrochemical stability is greater than 2.0 V.