Electrochemically-Matched and Nonflammable Janus Solid Electrolyte for Lithium-Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state batteries offer enhanced safety and energy density over conventional lithium-ion batteries.
• Ceramic electrolytes like Li7La3Zr2O12 (LLZO) provide stability but suffer from poor cathode contact due to rigidity.
• Organic phosphates offer good contact but exhibit instability with lithium metal anodes.

Purpose of the Study:

• To design a quasi-solid Janus electrolyte combining the benefits of ceramic and organic electrolytes.
• To improve interfacial contact with cathodes and stability with lithium metal anodes.
• To develop a safer, high-performance solid-state battery technology.

Main Methods:

• Fabrication of a quasi-solid Janus electrolyte using garnet-type LLZO and trimethyl phosphate (TMP) gel.
• Electrochemical characterization of the Janus electrolyte's stability and performance.
• Assembly and cycling of lithium-metal batteries utilizing the Janus electrolyte.

Main Results:

• The Janus electrolyte demonstrated an extended electrochemical window, accommodating lithium metal anodes.
• The semifluid TMP gel component ensured good cathode-electrolyte contact.
• Lithium-metal batteries with the Janus electrolyte achieved stable cycling at room temperature (1C) for over 100 cycles with 115 mAh g-1 capacity.

Conclusions:

• The quasi-solid Janus electrolyte effectively combines ceramic stability with organic electrolyte's contact properties.
• This hybrid electrolyte enables safe, high-energy solid-state lithium-metal batteries.
• The developed strategy offers a promising approach for next-generation energy storage solutions.