Li₄SiO₄ Doped-Li₇P₂S₈I solid electrolytes with high lithium stability synthesised using liquid-phase shaking

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Solid electrolytes are crucial for advanced battery technologies.
• Improving ionic conductivity and electrochemical stability is key for lithium-ion batteries.

Purpose of the Study:

• To synthesize and characterize novel Li₇P₂S₈I·xLi₄SiO₄ solid electrolytes.
• To investigate the effect of Li₄SiO₄ doping on ionic conductivity and stability.
• To explore synthesis methods for improved solid electrolyte performance.

Main Methods:

• Synthesis via mechanical milling and liquid-phase shaking.
• Ionic conductivity measurements at various temperatures.
• Cyclic voltammetry to determine electrochemical window.
• Galvanostatic cycling tests for long-term stability assessment.

Main Results:

• Liquid-phase shaking yielded Li₇P₂S₈I·10Li₄SiO₄ with 0.85 mS cm^-1 conductivity at 25 °C.
• Doping with 10 mol% Li₄SiO₄ enhanced ionic conductivity.
• Electrolytes exhibited a wide electrochemical window (-0.3 to +10 V).
• Excellent cycling stability over 680 cycles (1370 h) demonstrated compatibility with Li anodes.

Conclusions:

• Liquid-phase shaking is an effective method for synthesizing high-performance solid electrolytes.
• Li₄SiO₄ doping significantly improves ionic conductivity and stability of Li₇P₂S₈I electrolytes.
• These doped solid electrolytes show great promise for stable and efficient lithium-ion batteries.