Submicrometer Lithiophilic Interphase Layer Engineering toward Inorganic-Rich Solid Electrolyte Interphase for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anode-free lithium metal batteries (AFLMBs) offer high energy density but face challenges with bare copper current collectors due to poor lithium deposition.
• Non-lithiophilic copper hinders cycling stability and limits practical AFLMB applications.

Purpose of the Study:

• To develop a thin, lithiophilic interphase layer for copper current collectors to improve lithium deposition/stripping behavior in AFLMBs.
• To enhance the cycling stability and energy density of AFLMBs through surface modification of the current collector.

Main Methods:

• Constructed a submicrometer (∼0.55 μm) lithiophilic interphase layer using silica nanospheres decorated with silver nanoparticles (Ag NPs) and a polyacrylonitrile binder.
• Engineered the interphase layer to enhance lithiophilicity and Li+ transportation on the copper substrate.
• Analyzed the formation of a robust solid electrolyte interphase (SEI) layer.

Main Results:

• Achieved highly reversible lithium deposition and stripping with the modified copper current collector.
• Demonstrated high Coulombic efficiency (CE) of 98.5% over 650 cycles in half cells.
• Attained improved cycling stability with average CEs over 99.3% for 100 cycles in anode-free pouch-type full cells using LiFePO4 cathodes.

Conclusions:

• The submicrometer lithiophilic interphase layer effectively addresses Li deposition issues in AFLMBs.
• This approach offers a simple, scalable method for engineering high-performance AFLMBs.
• The modified current collector enhances battery safety and energy density, paving the way for practical applications.