Excellent Deformable Oxide Glass Electrolytes and Oxide-Type All-Solid-State Li₂S-Si Batteries Employing These...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Oxide-type all-solid-state lithium-ion batteries offer enhanced safety but suffer from low energy and rate performance due to poor ion/electron transport.
• Existing oxide systems face challenges in creating efficient charge transfer pathways between particles, limiting their practical application.
• Developing new solid electrolytes is crucial for advancing next-generation battery technologies.

Purpose of the Study:

• To investigate novel Li₂SO₄-Li₂CO₃-LiX (X = Cl, Br, I) glass systems as highly deformable and ionic-conductive oxide electrolytes.
• To evaluate the suitability of these electrolytes for different battery components (anode, cathode, separator).
• To demonstrate a functional all-solid-state lithium-ion battery utilizing these advanced oxide electrolytes.

Main Methods:

• Synthesis and characterization of Li₂SO₄-Li₂CO₃-LiX glass systems.
• Evaluation of ionic conductivity, deformability, and electrochemical stability of the synthesized electrolytes.
• Fabrication and testing of composite electrodes (Li₂S cathode, Si anode) and a full battery cell using the developed electrolytes.

Main Results:

• Li₂SO₄-Li₂CO₃-LiX glass electrolytes exhibit excellent deformability and high ionic conductivity.
• LiI-based electrolyte is suitable for negative electrodes (stable up to 2.8 V), while LiCl/LiBr are suitable for positive electrodes and separators (stable up to 3.2 V).
• A Li₂S-Si full-cell using LiBr and LiI electrolytes achieved a discharge capacity of 740 mA h g⁻¹(Li₂S) and area capacity of 2.8 mA h cm⁻².

Conclusions:

• The developed deformable oxide glass electrolytes are promising for solid-state lithium-ion batteries, enhancing performance and safety.
• Mechanical milling processes do not negatively impact the ionic conductivity of these deformable electrolytes.
• The successful demonstration of a Li₂S-Si full-cell validates the potential of these novel oxide electrolytes for practical applications.