Designing lithium halide solid electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Solid-state Chemistry

Background:

• All-solid-state lithium batteries offer enhanced safety and cycling stability for next-generation energy storage.
• Solid electrolyte performance is crucial, driving research into complex compositional structures.
• Lithium halides are promising solid electrolytes due to their ionic conductivity and cathode compatibility.

Purpose of the Study:

• To establish effective guidelines for designing complex halide solid electrolyte compositions beyond ab-initio modeling.
• To demonstrate the utility of ionic potential in predicting and guiding the development of solid electrolyte materials.
• To synthesize novel complex halide materials with improved electrochemical properties.

Main Methods:

• Utilized ionic potential (charge number/ion radius) to analyze interactions within halide materials.
• Developed a methodology for guiding the design of representative crystal structures.
• Synthesized a family of complex layered halides.

Main Results:

• Ionic potential effectively captures key interactions in halide materials, enabling structure design.
• A new family of complex layered halides was prepared.
• These materials exhibit enhanced ionic conductivity and favorable isometric morphology.
• High configurational entropy was identified as a factor inducing favorable morphology.

Conclusions:

• Ionic potential serves as a valuable tool for designing complex halide solid electrolytes.
• The developed methodology facilitates the creation of solid materials with tailored properties.
• This research provides critical insights into complex halide phases for advanced energy storage applications.