What dictates soft clay-like lithium superionic conductor formation from rigid salts mixture

Area of Science:

• Materials Science
• Solid-State Chemistry
• Battery Technology

Background:

• Soft clay-like materials are crucial for developing advanced all-solid-state batteries.
• Current synthesis methods involve mixing rigid salts, but the underlying mechanism remains unclear.

Purpose of the Study:

• To elucidate the microscopic mechanisms behind soft clay-like material formation from rigid salt mixtures.
• To identify key factors enabling plasticity in these ionic solid mixtures.

Main Methods:

• Utilized molecular dynamics simulations with a deep learning-based interatomic potential energy model.
• Employed extended X-ray absorption fine structure (EXAFS) spectroscopy for experimental validation.

Main Results:

• Identified the formation of molecular solid units via anion exchange as critical for soft clay formation.
• Demonstrated that slow reaction kinetics and the presence of these units facilitate shear transformation zones.
• Confirmed that molecular solid units contribute to material plasticity under low stress.

Conclusions:

• Soft clay-like materials can be engineered from rigid ionic solids by controlling molecular solid unit formation and reaction kinetics.
• This provides a generalizable strategy for synthesizing advanced materials for solid-state batteries.