Bottom Deposition Enables Stable All-Solid-State Batteries with Ultrathin Lithium Metal Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state batteries (ASSBs) are crucial for safer energy storage, utilizing solid electrolytes and lithium (Li) metal anodes.
• Non-uniform Li deposition in ASSBs causes performance degradation, internal short circuits, and hindered charge transfer.

Purpose of the Study:

• To introduce and validate a
• bottom deposition
• strategy for stabilizing Li metal anodes in ASSBs.
• To enhance the safety and electrochemical performance of ASSBs by controlling Li deposition.

Main Methods:

• Development of a lithiophilic current collector with a protective layer (polymeric binder and carbon black).
• Implementation of the "bottom deposition" concept for Li plating between the protective layer and current collector.
• Electrochemical cycling, scanning electron microscopy (SEM) analysis, and performance assessment under high current density (6 mA·cm^-2).

Main Results:

• The "bottom deposition" method effectively stabilizes Li metal anodes, preventing internal short circuits.
• The functional binder provides mechanical robustness and adhesion, accommodating Li volume changes.
• Uniform Li plating/stripping morphology and excellent ion transfer properties were observed, even at high current densities.
• Enhanced electrochemical performance with a high Li utilization rate was achieved in the ASSB framework.

Conclusions:

• The "bottom deposition" strategy using a lithiophilic current collector and protective layer significantly improves Li metal anode stability in ASSBs.
• This approach addresses key challenges in ASSB performance, paving the way for safer and more efficient energy storage solutions.