Ion Hopping: Design Principles for Strategies to Improve Ionic Conductivity for Inorganic Solid Electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Solid-state Chemistry

Background:

• Liquid electrolytes in rechargeable batteries pose safety risks due to volatilization, flammability, and explosion.
• Solid electrolytes are a safer alternative but face performance challenges, notably lower ionic conductivity.
• Ionic conductivity in solid electrolytes is critically dependent on material type and crystalline structure.

Purpose of the Study:

• To revisit the fundamental principles of ion hopping in crystalline solid electrolytes.
• To identify key factors influencing ion migration, specifically ion hopping pathways and skeleton-material interactions.
• To systematically summarize strategies for enhancing the ionic conductivity of inorganic solid electrolytes.

Main Methods:

• Review of existing literature on ion transport mechanisms in solid electrolytes.
• Analysis of the physical image of ion hopping, focusing on diffusion pathways and lattice interactions.
• Categorization of universal strategies to improve ionic conductivity based on fundamental principles.

Main Results:

• Identified ion hopping pathways and skeleton interactions as critical determinants of ion migration.
• Summarized two primary strategies for improving ionic conductivity: creating efficient diffusion pathways and minimizing potential field resistance.
• Provided a unified perspective on ion movement applicable across different ion species.

Conclusions:

• Understanding ion hopping mechanisms is crucial for designing high-performance solid electrolytes.
• Strategies focusing on diffusion pathways and lattice interactions offer a clear roadmap for enhancing ionic conductivity.
• This review provides a comprehensive guide for the development of advanced inorganic solid electrolytes for safer energy storage.