Lattice-matched antiperovskite-perovskite system toward all-solid-state batteries

Area of Science:

• Materials Science
• Electrochemistry
• Computational Materials Science

Background:

• Inorganic solid electrolytes offer enhanced safety and cycle life for all-solid-state batteries by replacing flammable liquid electrolytes.
• Antiperovskite and perovskite materials show promise individually, but challenges remain in their integration and performance.

Purpose of the Study:

• To develop a highly lattice-matched composite solid electrolyte combining antiperovskite and perovskite properties.
• To enhance lithium-ion diffusion and enable room-temperature operation for solid-state batteries.
• To demonstrate the practical application of this composite electrolyte in conventional lithium-ion battery electrodes.

Main Methods:

• Atomistic simulations were used to predict lithium-ion diffusion at the interface of cubic Li2OHCl and Li0.31La0.56TiO3.
• Fluorine incorporation stabilized the cubic phase of Li2OHCl1-xFx, reducing lattice mismatch.
• Pressure-assisted melt infiltration was employed to synthesize the composite solid electrolyte.

Main Results:

• A composite solid electrolyte with a 0.8% lattice mismatch ratio was successfully synthesized.
• The electrolyte demonstrated effective infiltration into conventional lithium-ion battery electrodes, maintaining interface stability.
• Electrochemical testing revealed promising charge-discharge characteristics, including extended cycle life and good rate performance.

Conclusions:

• The developed antiperovskite-perovskite composite solid electrolyte significantly improves lithium-ion battery safety and performance.
• Effective infiltration and interface stability mitigate degradation, enabling stable operation in complex electrode structures.
• This material represents a significant advancement towards practical and high-performance all-solid-state batteries.