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

Regulating the composition of solid-electrolyte-interphase (SEI) is the key to construct high-energy density lithium metal batteries. Here we report a selective catalysis anionic decomposition strategy to achieve a lithium fluoride (LiF)-rich SEI for stable lithium metal batteries. To accomplish this, the tris(4-aminophenyl) amine-pyromeletic dianhydride covalent organic frameworks (TP-COF) was adopted as an interlayer on lithium metal anode. The strong donor-acceptor unit structure of TP-COF induces local charge separation, resulting in electron depletion and thus boosting its affinity to FSI - . The strong interaction between TP-COF and FSI - lowers the lowest unoccupied molecular orbital (LUMO) energy level of FSI - , accelerating the decomposition of FSI - and generating a stable LiF-rich SEI. This feature facilitates rapid Li + transfer and suppresses dendritic Li growth. Notably, we demonstrate a 6.5 Ah LiNi 0.8 Co 0.1 Mn 0.1 O 2 |TP-COF@Li pouch cell with high energy density (473.4 Wh kg -1 ) and excellent cycling stability (97.4 %, 95 cycles) under lean electrolyte 1.39 g Ah -1 , high areal capacity 5.7 mAh cm -2 , and high current density 2.7 mA cm -2 . Our selective catalysis strategy opens a promising avenue toward the practical applications of high energy-density rechargeable batteries.