Robust All-Solid-State Lithium Metal Batteries Enabled by a Composite Lithium Anode with Improved Bulk Li Diffusion...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state batteries (ASSBs) with lithium metal anodes promise high energy density.
• Interfacial instability between lithium metal anodes and solid-state electrolytes (SSEs) hinders ASSB performance.
• Void formation and lithium dendrites at the Li/SSE interface limit rate capability and cycling stability.

Purpose of the Study:

• To develop a stable lithium anode for ASSBs.
• To overcome interfacial challenges in lithium metal-based ASSBs.
• To enhance the performance of all-solid-state batteries.

Main Methods:

• Constructed a composite lithium anode (LAO) using Li-Ag alloy and Li₂O.
• Mixed stoichiometric lithium and silver oxide (Ag₂O) to create the LAO.
• Tested ASSBs with LAO anode, Li₆PS₅Cl SSE, and LiCoO₂ cathode.

Main Results:

• LAO improved bulk lithium diffusion kinetics and inhibited interfacial void formation.
• Achieved high critical current density (>1.5 mA cm⁻²).
• Demonstrated stable cycling over 1000 hours at 1 mA cm⁻² and over 4000 cycles at 5 C in ASSBs.
• Maintained stable operation with high LiCoO₂ loading (17.8 mg cm⁻²) for over 100 cycles at 0.2 C.

Conclusions:

• The composite lithium anode effectively addresses interfacial instability in ASSBs.
• LAO enables superior rate capability and long-term cycling stability.
• This composite anode is a promising strategy for high-performance ASSBs.