In Situ-Constructed Lithiophobic-Lithiophilic Gradient Interlayer Enabling Ultrahigh Critical Current Density for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium batteries promise high energy density but face challenges with lithium dendrite growth and interfacial reactions.
• These issues hinder the practical application and safety of next-generation batteries.

Purpose of the Study:

• To engineer a novel lithiophilic-lithiophobic gradient interlayer for lithium anodes.
• To mitigate lithium dendrite formation and improve the stability of solid-state electrolytes.

Main Methods:

• In situ construction of a gradient interlayer using metal trifluoromethanesulfonate (OTf-) salt modification on a lithium anode.
• Formation of a lithiophobic LiF-rich top layer and a lithiophilic lithium-metal alloy (Ag, In, Al) bottom layer.
• Electrochemical characterization of symmetric and full cells incorporating the gradient interlayer.

Main Results:

• The gradient interlayer effectively regulated uniform lithium deposition and suppressed dendrite formation.
• Silver (Ag) demonstrated superior performance in forming a Li-Ag alloy with tunable composition for controlled lithium deposition.
• Symmetric batteries with the gradient interlayer achieved a high critical current density of 8.0 mA cm⁻².
• A full cell (NCM/LPSC/AgOTf@Li) demonstrated a high areal capacity of 0.345 mA h cm⁻² at 1.2 mA cm⁻² with high mass loading.

Conclusions:

• The developed lithiophilic-lithiophobic gradient interlayer is a promising strategy for enhancing the performance and safety of all-solid-state lithium batteries.
• The Li-Ag alloy interlayer shows significant potential for enabling high-energy-density solid-state energy storage devices.