Sulfide Solid Electrolyte Air Stability via Antimony Substitution
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Solution Overview
Problem
Current inorganic sulfide electrolytes are not stable under air conditions, reacting with oxygen, water vapor, and carbon dioxide, which reduces their ion conductivity and restricts their application in all-solid-state lithium batteries.
Innovation Solution
Replacing some or all phosphorus (P) elements in sulfide electrolytes with antimony (Sb) to form a solid solution phase structure, enhancing air stability and ion mobility, and adjusting the ratio of P and Sb to regulate ion conductivity and chemical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inorganic sulfide electrolytes are used to achieve high ion conductivity, then ion conductivity is improved, but air stability deteriorates due to irreversible reactions with oxygen, water vapor, and carbon dioxide
Solution Approach 1:
A protective coating layer is introduced as an intermediary between the sulfide electrolyte and the air environment. This coating acts as a barrier that prevents direct contact and irreversible reactions between the electrolyte and harmful atmospheric components (oxygen, water vapor, carbon dioxide), thereby maintaining both high ion conductivity and air stability.
Solution Approach 2:
The invention creates a composite structure combining the sulfide electrolyte material with a protective coating layer. This composite approach allows the inner sulfide electrolyte to provide high ion conductivity while the outer protective layer provides air stability, resolving the contradiction between these two properties.
2Stability of the object's composition
If protective layers and additives are introduced to improve air stability, then air stability is improved, but device complexity increases
Solution Approach 1:
The protective coating is applied as a thin film layer on the surface of the sulfide electrolyte. This thin film approach provides effective protection against air degradation while minimizing the increase in device complexity and maintaining the overall simplicity of the battery structure.
3Stability of the object's composition
If oxide solid electrolytes are used to achieve high stability, then stability is improved, but ion conductivity deteriorates due to low ion conductance
Solution Approach 1:
The invention changes the chemical composition parameters by using sulfide-based electrolytes instead of oxide-based electrolytes. Sulfide electrolytes have different bonding characteristics (lower electronegativity of sulfide ions) and larger ionic radii, which fundamentally alter the ion conduction mechanism to achieve higher ion conductivity while maintaining stability through protective coatings.
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 resulting sulfide electrolyte materials exhibit improved air stability, higher ion conductivity, and reduced reaction activity with lithium metal and other battery materials, enabling their use in high-performance all-solid-state lithium secondary batteries without protective coatings or additives.
Implementation Method 1
the obtained inorganic sulfide solid electrolyte material has controllable ion conductivity and shows excellent performance as an inorganic electrolyte
Data Source
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AI summary
An inorganic sulfide solid electrolyte having high air stability, and a preparation method and use thereof. In the invention, some or all of P elements in a sulfide electrolyte are replaced with Sb elements, thereby providing an electrolyte having high air stability and ion mobility and applicable to an all-solid lithium secondary battery. The resulting inorganic sulfide electrolyte comprises the following materials: Li10M(P1-aSba)2S12, Li6(P1-aSba)S5X and Li3(P1-aSba)S4, where M is one or more of Ge, Si or Sn, X is one or more of F, Cl, Br or I, and 0.01≤a≤1.