Enhancing Anion‐Selective Catalysis for Stable Lithium Metal Pouch Cells through Charge Separated COF Interlayer
Peiyu Zhao, Yanhua Zhang, Baoyu Sun, Rui Qiao, Chao Li, Pengqi Hai, Yingche Wang, Feng Liu, Jiangxuan Song
Abstract
Abstract 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.