Gu Yu, Li Chunhua, Wang Yingbin, Lu Wenxin, Shang Hong, Sun Bing
School of Science, China University of Geosciences (Beijing), Beijing 100084, P. R. China.
College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
Dalton Trans. 2022 Apr 12;51(15):5828-5833. doi: 10.1039/d2dt00406b.
Uncontrolled growth of lithium dendrite is the key challenge that impedes the practical application of Li anodes in high-energy-density Li-metal batteries. Precisely constructing lithiophilic active sites on the anode surface is expected to be an effective strategy for promoting the anode interfacial properties and alleviating the dendrite growth of lithium. Herein, a diyne-linked phthalocyanine polymer (PcEP) with precise lithiophilic active sites is designed and constructed in a bottom-up manner on the surface of the copper foil the coupling reaction of tetraethynylphthalocyanine. The lithiophilic electron-rich pyrrolic nitrogen and aza nitrogen in the Pc structure, and the sp-hybridized carbon in the diyne linkage (-CC-CC-) in PcEP can conduct the homogeneous nucleation and deposition processes of lithium, and thus suppress the dendrite growth. This dendrite-free metallic lithium anode exhibits reduced overpotential, high coulombic efficiency (98.6%), and prolonged lifespan (200% longer than that of a Cu anode). These impressive achievements demonstrate that the advanced phthalocyanine polymer might be a promising material for addressing the critical interfacial issues related to the next-generation high-energy-density Li-metal-based storage devices.
锂枝晶的无控制生长是阻碍锂阳极在高能量密度锂金属电池中实际应用的关键挑战。在阳极表面精确构建亲锂活性位点有望成为促进阳极界面性能和缓解锂枝晶生长的有效策略。在此，通过四乙炔基酞菁的偶联反应，以自下而上的方式在铜箔表面设计并构建了具有精确亲锂活性位点的二炔连接酞菁聚合物（PcEP）。Pc结构中富电子的亲锂吡咯氮和氮杂氮，以及PcEP中二炔键（-CC-CC-）中的sp杂化碳可以引导锂的均匀成核和沉积过程，从而抑制枝晶生长。这种无枝晶金属锂阳极表现出降低的过电位、高库仑效率（98.6%）和延长的寿命（比铜阳极长200%）。这些令人瞩目的成果表明，先进的酞菁聚合物可能是解决与下一代高能量密度锂金属基存储设备相关的关键界面问题的有前途的材料。
