Descriptor and Scaling Relations for Ion Mobility in Crystalline Solids

Area of Science:

• Materials Science
• Electrochemistry
• Computational Materials Science

Background:

• Ion mobility is crucial for electrochemical energy storage and conversion devices.
• Predicting and optimizing ion mobility in solid-state materials remains a challenge.

Purpose of the Study:

• To derive a descriptor for ion mobility based on fundamental properties.
• To establish scaling relations connecting migration barriers to this descriptor.
• To accelerate the discovery of novel materials with enhanced ion mobility.

Main Methods:

• Utilized first-principles electronic structure calculations.
• Derived a descriptor based on ionic radii, oxidation states, and Pauling electronegativities.
• Investigated linear scaling relations for migration barriers.

Main Results:

• A novel descriptor for ion mobility was successfully derived.
• Linear scaling relations were identified between migration barriers and the descriptor.
• These relations hold for variations in cation and anion chemistry.

Conclusions:

• The derived descriptor, based on observable properties, simplifies ion mobility prediction.
• Scaling relations reveal limitations of purely ionic models for ion transport in solids.
• This approach significantly accelerates the discovery of materials for electrochemical applications.