An All-Solid-State Li-Cu Battery via Cuprous/Lithium-Ion Halide Solid Electrolyte.

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Copper cathodes offer low cost and high capacity for batteries.
• Limited copper-ion conductivity and solubility in electrolytes hinder Li-Cu battery development.

Purpose of the Study:

• To synthesize a novel solid electrolyte for enhanced copper-ion transport.
• To develop the first all-solid-state lithium-copper battery (ASSLCB) with improved performance.
• To investigate synergistic ion migration and exchange mechanisms.

Main Methods:

• Synthesis of copper(I) halide solid electrolyte (Cu2ZrCl6, CZC) via mechanochemical method.
• Fabrication and testing of Cu||CZC||Cu symmetric batteries.
• Modeling of synergistic Cu+ and Li+ migration and ion exchange.
• Assembly and electrochemical evaluation of the first ASSLCB.

Main Results:

• CZC exhibited high room-temperature Cu+ conductivity (14 mS cm-1) and high solubility of Cu species.
• Cu||CZC||Cu symmetric batteries showed stable Cu+ plating/stripping over 1000 hours.
• The ASSLCB delivered a high reversible specific capacity of 360 mAh g-1 and outstanding cycling performance.
• A cathode-free ASSLCB demonstrated pure copper metal deposition and dissolution.

Conclusions:

• The developed CZC solid electrolyte offers a new design concept for efficient Cu+ conductors.
• This work lays a foundation for future research and development of ASSLCBs.
• The study highlights the potential of solid-state electrolytes in advancing battery technology.