Enhancing Anion-Selective Catalysis for Stable Lithium Metal Pouch Cells through Charge Separated COF Interlayer

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-electrolyte-interphase (SEI) composition is critical for high-energy density lithium metal batteries.
• Achieving a stable and uniform SEI layer remains a significant challenge in battery development.

Purpose of the Study:

• To develop a novel strategy for regulating SEI composition.
• To engineer a lithium fluoride (LiF)-rich SEI for enhanced lithium metal battery stability and performance.

Main Methods:

• Utilized tris(4-aminophenyl) amine-pyromeletic dianhydride covalent organic frameworks (TP-COF) as an interlayer on lithium metal anodes.
• Investigated the catalytic effect of TP-COF on the anionic decomposition of FSI-based electrolytes.
• Analyzed the electronic structure and interactions between TP-COF and FSI- using computational methods.

Main Results:

• TP-COF selectively catalyzes FSI- decomposition, leading to a LiF-rich SEI.
• The engineered SEI layer facilitates rapid Li+ transfer and suppresses lithium dendrite growth.
• Demonstrated a high-energy density pouch cell (473.4 Wh/kg) with excellent cycling stability (97.4% over 95 cycles) under lean electrolyte conditions.

Conclusions:

• The selective catalysis strategy effectively regulates SEI composition for stable lithium metal batteries.
• TP-COF interlayers offer a promising approach for advancing high-energy density rechargeable battery technology.