Complementary Anion-Cation Modulated Electrolyte with Balanced Conductivities for High-Performance All-Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• High specific energy all-solid-state batteries require solid-state electrolytes with superionic conductivity and excellent compatibility with lithium-metal anodes.
• Current electrolytes often face challenges with interfacial stability and ion transport limitations, hindering battery performance and lifespan.

Purpose of the Study:

• To design and develop a novel argyrodite-type solid-state electrolyte with enhanced lithium-ion transport and superior interfacial compatibility with lithium metal.
• To investigate the mechanism of interfacial stabilization through a cooperative anion-cation modulation strategy.
• To evaluate the electrochemical performance of the developed electrolyte in lithium-metal symmetric cells and full cells.

Main Methods:

• Synthesis of a tailored argyrodite-type solid-state electrolyte using a cooperative anion-cation modulation strategy.
• In situ interfacial analysis of the reaction between the electrolyte and lithium metal.
• Electrochemical characterization including cycling stability tests in Li//Li symmetric cells and Li//LiNi0.8Co0.1Mn0.1O2 full cells.

Main Results:

• A robust anodic interface spontaneously formed through in situ reaction of Li metal with the modulated electrolyte, involving Li-Mo alloy and Li3N formation.
• The modulated electrolyte demonstrated stable cycling for over 3100 hours in Li//Li symmetric cells at 0.5 mA cm-2.
• Li//LiNi0.8Co0.1Mn0.1O2 batteries exhibited 75% capacity retention over 1500 cycles at 4C with 99.99% average coulombic efficiency.

Conclusions:

• The cooperative anion-cation modulation strategy is effective in designing solid-state electrolytes with fast Li+ transport and excellent interfacial compatibility.
• The developed argyrodite electrolyte enables stable lithium metal anode operation, suppressing parasitic reactions and promoting uniform Li stripping/plating.
• This work provides a promising pathway for developing high-performance, long-life all-solid-state lithium-metal batteries.