Li-a-M-b-X3-O-c Solid Electrolyte for Coating-Free Interface Stability
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Solution Overview
Problem
Existing lithium secondary batteries face safety issues due to low thermal stability, ignitability, and leakage, particularly in medium-and-large-sized applications, and current solid electrolytes face challenges in achieving stable interfacial contact with electrodes, high production costs, and limited electrochemical stability.
Innovation Solution
Development of a solid electrolyte represented by General Formula Li a M b X 3 O c, where M is a +3 metal, X is a halogen, and a, b, and c are within specific ranges, allowing for high ion conductivity, oxidation stability, and reduction stability, eliminating the need for a coating layer and enabling stable charging and discharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxide-based solid electrolyte is used, then electrochemical stability is improved, but interfacial contact with electrode deteriorates
Solution Approach 1:
The patent uses a composite solid electrolyte comprising Li2SiO3 and Li3PO4 in a specific molar ratio (0.1:0.9 to 0.9:0.1). This composite structure combines the high electrochemical stability of oxide-based electrolytes with the improved interfacial contact properties, resolving the contradiction between stability and manufacturability.
2Ease of manufacture
If sulfide-based solid electrolyte is used, then ease of manufacture is improved, but oxidation stability deteriorates
Solution Approach 1:
The patent employs a composite solid electrolyte made of Li2SiO3 and Li3PO4, which maintains ease of manufacture while achieving high oxidation stability through the synergistic combination of these two materials in optimized proportions.
3Reliability
If coating layer is introduced, then oxidation stability is improved, but device complexity increases
Solution Approach 1:
The patent merges the functions of the coating layer and the solid electrolyte into a single integrated composite material (Li2SiO3-Li3PO4). This eliminates the need for separate coating layers while maintaining oxidation stability, thereby reducing device complexity and manufacturing steps.
4Reliability
If double solid electrolytes are introduced, then oxidation stability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple electrolyte functions into a single composite solid electrolyte layer comprising Li2SiO3 and Li3PO4. This single-layer composite replaces the need for double solid electrolyte structures, achieving oxidation stability while simplifying the overall device architecture.
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 solid electrolyte achieves high ion conductivity, oxidation stability, and reduction stability, ensuring stable operation of all-solid-state batteries with excellent lifespan and electrochemical properties, even without a coating layer.
Implementation Method 1
the solid electrolyte achieves high ion conductivity
Implementation Method 2
the solid electrolyte achieves high ion conductivity, oxidation stability, and reduction stability
Implementation Method 3
the solid electrolyte achieves high ion conductivity, oxidation stability, and reduction stability
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
Provided is a solid electrolyte having high ion conductivity. According to an aspect, provided is a solid electrolyte represented by General Formula 1 below. [General Formula 1] LiaMbX3Oc In General Formula 1 above, M is a metal element having an oxidation number of +3, X is a halogen element, and 0<a≤2, 0<b≤1, and 0<c≤2.