Zhao Peiyu, Zhang Yanhua, Sun Baoyu, Qiao Rui, Li Chao, Hai Pengqi, Wang Yingche, Liu Feng, Song Jiangxuan
State Key Laboratory for Mechanical Behavior of Materials, Shaanxi International Research Center for Soft Matter, Xi'an Jiaotong University, 710049, Xi'an, China.
Instrumental Analysis Center, Xi'an Jiaotong University, 710049, Xi'an, China.
Angew Chem Int Ed Engl. 2024 Oct 7;63(41):e202317016. doi: 10.1002/anie.202317016. Epub 2024 Sep 6.
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 LiNiCoMnO|TP-COF@Li pouch cell with high energy density (473.4 Wh kg) and excellent cycling stability (97.4 %, 95 cycles) under lean electrolyte 1.39 g Ah, high areal capacity 5.7 mAh cm, and high current density 2.7 mA cm. Our selective catalysis strategy opens a promising avenue toward the practical applications of high energy-density rechargeable batteries.
调控固体电解质界面（SEI）的组成是构建高能量密度锂金属电池的关键。在此，我们报道一种选择性催化阴离子分解策略，以实现用于稳定锂金属电池的富含氟化锂（LiF）的SEI。为实现这一目标，采用三（4-氨基苯基）胺-吡咯二酐共价有机框架（TP-COF）作为锂金属负极的中间层。TP-COF强大的供体-受体单元结构诱导局部电荷分离，导致电子耗尽，从而增强其对FSI的亲和力。TP-COF与FSI之间的强相互作用降低了FSI的最低未占据分子轨道（LUMO）能级，加速了FSI的分解并生成稳定的富含LiF的SEI。这一特性有助于快速的Li传输并抑制锂枝晶生长。值得注意的是，我们展示了一款6.5 Ah的LiNiCoMnO|TP-COF@Li软包电池，在贫电解质1.39 g Ah、高面积容量5.7 mAh cm和高电流密度2.7 mA cm的条件下，具有高能量密度（473.4 Wh kg）和出色的循环稳定性（97.4%，95次循环）。我们的选择性催化策略为高能量密度可充电电池的实际应用开辟了一条有前景的途径。
