Lithium-Ion Conducting Composite Material for Solid-State Electrolytes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid-state inorganic electrolytes face issues such as the generation of H2S gas during decomposition and formability challenges due to the hardness of oxides, which affect their mechanical stability and ease of construction in secondary battery design.
Innovation Solution
A lithium-ion conducting composite material is developed, comprising a Li binary salt, a Li-ion conductor with a specific chemical composition, and at least two inorganic compounds, including a first inorganic compound with a mixed iron oxychloride composition and a defected doped inorganic compound, which enhances thermal stability and ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sulfide solid-state inorganic electrolytes are used, then ionic conductivity can be achieved, but H2S gas is generated during decomposition
Solution Approach 1:
The patent employs composite materials by combining Li3OCl with FeOCl and additional inorganic compounds (such as Al2O3, SiO2, TiO2, or Nb2O5) to create a multi-component solid-state electrolyte system. This composite approach maintains the high ionic conductivity of Li3OCl while the FeOCl component suppresses H2S generation through chemical interaction with sulfur species, and the oxide components provide structural stability and further reduce harmful gas evolution.
2Strength
If traditional oxide solid-state inorganic electrolytes are used, then mechanical stability is improved, but formability deteriorates due to hardness
Solution Approach 1:
The patent changes the physical and chemical parameters of the electrolyte system by incorporating chloride components (Li3OCl, FeOCl) alongside oxides. The chloride phases have lower melting points and softer mechanical properties compared to traditional oxides, enabling better formability and ease of processing while the oxide components (Al2O3, SiO2, etc.) provide the necessary mechanical strength and stability. This parameter balancing allows the material to be formed into desired shapes without excessive hardness.
3Reliability
If Li3OCl is used as solid-state electrolyte, then ionic conductivity is enhanced, but thermal stability deteriorates
Solution Approach 1:
The patent creates a composite material system where Li3OCl (providing high ionic conductivity) is combined with FeOCl and thermally stable oxide components (Al2O3, SiO2, TiO2, Nb2O5). The FeOCl component contributes to thermal stability through its high decomposition temperature, while the oxide additives form a thermally robust matrix that constrains Li3OCl, preventing excessive thermal degradation. This composite structure achieves synergistic enhancement of both ionic conductivity and thermal stability.
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 composite material exhibits improved thermal stability and ionic conductivity, with ionic conductivity equal to or greater than 3×10−4 S/cm, addressing the limitations of traditional solid-state inorganic electrolytes.
Implementation Method 1
a Li-ion conductor with a chemical composition of Li2−3x+y−zFexOy(OH)1−yCl1−z
Implementation Method 2
at least two of a first inorganic compound with a chemical composition of (Fe1−xM1x)O1−y(OH)yCl1−x, a second inorganic compound with a chemical composition of M2OX, and a defected doped inorganic compound comprising a chemical composition of (M3OX)′
Data Source
AI summary
A lithium-ion conducting composite material includes a Li binary salt, a Li-ion conductor with a chemical composition of Li2−3x+y−zFexOy(OH)1−yCl1−z, and at least two of: a first inorganic compound with a chemical composition of (Fe1−xM1x)O1−y(OH)yCl1−x; a second inorganic compound with a chemical composition of M2OX; and a defected doped inorganic compound with a chemical composition of (M3OX)′. The value of n is 1 or 2, x is greater than 0 and less than or equal to 0.25, and y is greater than or equal to 0 and less than or equal to 0.25. Also, M1 is at least one of Mg and Ca, M2 and M3 are each at least one of Fe, Al, Sc, La, and Y, and X is at least one of F, Cl, Br, and I.