Liu Tiancun, Lu Xiao-Meng, Lu Song, Jiang Ronghan, Guo Min, Guo Chaofei, Yu Zhixin, Wang Yong
Institute of New Energy, School of Chemistry and Chemical Engineering, Shaoxing University Shaoxing 312000 Zhejiang China
Department of Chemical Engineering, School of Environmental and Chemical Engineering, Shanghai University 99 Shangda Road Shanghai 200444 China
Chem Sci. 2025 Sep 3. doi: 10.1039/d5sc03645c.
Lithium metal is deemed to be the ultimate anode material for high-energy-density and fast-charging lithium batteries. However, issues of dendritic deposition and frangible solid electrolyte interphases must be resolved for lithium metal anodes. Herein, a hybrid interfacial layer, hierarchical hollow nanospheres assembled from lithiophilic imine-based covalent organic frameworks and built-in Ag sites (Ag@ICOFs), has been applied to regulate the interfacial lithium ion flux and enhance the anode stability for effectively inhibiting dendrite formation. The hollow ICOFs play important roles in enhancing electrolyte infiltration caused by ordered porous channels and promoting uniform lithium distribution due to the superior lithiophilic ability of binding sites (C[double bond, length as m-dash]N groups and benzene rings). Moreover, the filling of Ag can induce internal deposition in hollow Ag@ICOFs nanospheres when lithium metal tends to grow vertically. The dendrite-free lithium development is further verified by electrochemical electrode measurements and theoretical calculation. As a result, a synergistic enhancement in electrochemical performance is realized through stable long-term 1000 cycles and excellent capacity retention (87.3%) at a quick charge/discharge of 5C in a full cell paired with a LiFePO cathode. This work provides a fresh exploration of constructing functional nanomaterials with hierarchical structures for energy storage.
锂金属被认为是用于高能量密度和快速充电锂电池的终极负极材料。然而，锂金属负极必须解决枝晶沉积和易碎的固体电解质界面问题。在此，一种由亲锂的亚胺基共价有机框架和内置银位点组装而成的混合界面层（Ag@ICOFs），即分级中空纳米球，已被用于调节界面锂离子通量并增强负极稳定性，以有效抑制枝晶形成。中空的ICOFs在增强由有序多孔通道引起的电解质渗透以及由于结合位点（C=N基团和苯环）的优异亲锂能力促进锂均匀分布方面发挥着重要作用。此外，当锂金属倾向于垂直生长时，银的填充可诱导在中空Ag@ICOFs纳米球内部沉积。通过电化学电极测量和理论计算进一步验证了无枝晶锂的发展。结果，通过在与LiFePO正极配对的全电池中以5C的快速充放电进行稳定的长期1000次循环和优异的容量保持率（87.3%），实现了电化学性能的协同增强。这项工作为构建具有分级结构的功能纳米材料用于能量存储提供了新的探索。
