A Smart Non-Sacrificial Interphase for Improved Lithium Reversibility in Anode-Free Solid-State Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anode-free solid-state lithium metal batteries promise high energy density and safety.
• However, unstable interphase formation and uncontrolled lithium deposition limit their practical application.
• These issues lead to rapid capacity decay and hinder battery longevity.

Purpose of the Study:

• To develop a novel strategy for stabilizing lithium metal anodes in anode-free solid-state batteries.
• To introduce a smart non-sacrificial interphase (SNI) to prevent dendrite formation and improve cycling stability.
• To enhance the Coulombic efficiency and overall performance of these advanced battery systems.

Main Methods:

• Utilized 5-nitro-2-mercaptobenzimidazole (N-MBI) as an additive to form a self-assembled protective layer on copper current collectors.
• Investigated the in-situ lithiation of N-MBI to form a stable Li-NH₂-MBI interphase.
• Evaluated the performance of Li|Cu half-cells and Cu||LiFePO₄ pouch cells with the SNI.

Main Results:

• The N-MBI additive formed an ultrathin, self-healing interphase that guided uniform lithium deposition.
• Achieved an average Coulombic efficiency of 99.3% in Li|Cu half-cells.
• Cu||LiFePO₄ pouch cells with N-MBI retained 52.4% capacity at 0.2 C after 100 cycles, outperforming LiNO₃ additive.

Conclusions:

• The smart non-sacrificial interphase (SNI) effectively stabilizes lithium metal anodes in anode-free configurations.
• This molecular-level strategy significantly improves battery performance and cycle life.
• The N-MBI additive offers a promising solution for developing safer and more energy-dense solid-state batteries.