A two-dimensional porous conjugated porphyrin polymer for uniform lithium deposition

Uniform lithium deposition is a benefit to achieving high-energy-density lithium metal batteries. There are many effective methods to suppress the dendritic growth of metallic lithium and promote the application of the lithium anode. However, the designation of lithiophilic sites at the atomic level remains a huge challenge. Herein, a two-dimensional porous conjugated porphyrin polymer linked by two acetylenic linkages from an in situ coupling reaction has been prepared on copper foil and employed as the lithiophilic host. The four electron-rich pyrrolic nitrogen atoms in the porphyrin building block and the linkage electron-rich sp-hybridized carbon atoms were regarded as precise lithiophilic sites, resulting in a decreased nucleation overpotential and dendrite free morphology. With uniform lithium deposition, the electrochemical performance of the electrode was significantly improved in regard to the overpotential, coulombic efficiency and lifespan. This work expands the precise construction of lithiophilic sites at the atomic level and benefits to further development of high-energy density lithium metal batteries.