Multi-Cation Solid Electrolytes for Faster Lithium-Ion Conduction
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Solution Overview
Problem
There is an ongoing need for solid lithium-ion conductors with suitable ionic conductivity for use as solid electrolytes in solid-state lithium batteries, as existing materials do not adequately meet the requirements for high conductivity.
Innovation Solution
The development of a solid material with a composition derived from Li6PY5X, where 10 to 90 atom % of phosphorus is substituted by cations such as Zn2+, Ga3+, Si4+, Ge4+, Sn4+, Sb5+, and W6+, resulting in an increase in configurational and vibrational entropy, thereby enhancing lithium-ion migration and ionic conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphorus is substituted by multiple cations in the solid material, then ionic conductivity increases, but compositional complexity increases
Solution Approach 1:
The patent applies composite materials by substituting phosphorus with multiple cations (Zn2+, Ga3+, Si4+, Ge4+, Sn4+, Sb5+, W6+) to create a composite solid electrolyte material. This multi-cation substitution creates a composite structure that achieves high ionic conductivity (up to 10.7 mS/cm at 25°C) while maintaining a manageable compositional complexity through systematic selection from a defined cation group.
Solution Approach 2:
The patent employs parameter changes by systematically varying the cation substitution level (10 to 90 atom %) and selecting from cations with different valences (2+ to 6+). This allows optimization of ionic conductivity through controlled compositional parameters while managing complexity through defined substitution ranges and selection criteria.
2Reliability
If configurational entropy is increased through cation substitution, then lithium-ion migration is enhanced, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses parameter changes by controlling the substitution level (10-90 atom %) and selecting cations with specific valences to achieve desired configurational entropy. This systematic parameter control enhances lithium-ion migration while managing manufacturing precision through defined compositional ranges and selection criteria.
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 substitution of phosphorus with multiple cations in the solid material significantly increases its ionic conductivity, making it suitable for use as a solid electrolyte in solid-state lithium batteries, with some compositions achieving ionic conductivities of up to 10.7 mS/cm at 25°C.
Implementation Method 1
the configurational entropy (i.e. the compositional disorder) within the argyrodite structure, due to the introduction of foreign cations
Implementation Method 2
the configurational entropy and/or the vibrational entropy of the argyrodite material are assumed to be increased
Implementation Method 3
results in an increase of the lithium-ion migration, resulting in an increased ionic conductivity
Data Source
AI summary
Described are a solid material which has ionic conductivity for lithium ions, a process for preparing said solid material, a use of said solid material as a solid electrolyte for an electrochemical cell, a solid structure selected from the group consisting of a cathode, an anode and a separator for an electrochemical cell comprising the solid material, and an electrochemical cell comprising such solid structure.