Precise lithiophilicity regulation of atomically dispersed Zn_n-anchored C₂N matrix for uniform lithium deposition

Lithiophilic modification of Li hosts is regarded as an effective strategy to address the uncontrollable Li dendrite issue for stably cycling lithium metal anode (LMA). Precise construction of stable and lightweight Li hosts with homogeneously distributed lithiophilic sites is vital to promoting uniform Li deposition but remains highly challenging, and the lithiophilic mechanism is still unrevealed. Herein, atomically dispersed single-, double-, and triple- Zn_n-anchored C₂N matrixes (denoted as Zn_n@C₂N, n = 1, 2, and 3) are proposed as potential lithiophilic hosts with well-defined and homogeneously distributed multilithiophilic sites to regulate Li metal deposition by means of DFT calculations and ab initio molecular dynamics simulations. The results demonstrate that Zn₂ dimer-anchored C₂N (Zn₂@C₂N) exhibits the highest thermodynamic stability and excellent electronic conductivity among the three atomically dispersed Zn_n single-atom/clusters anchored C₂N hosts. The chemical essence of lithiophilic activity and the exact mechanism of Zn₂@C₂N as a promising Li host are systematically explored by in-depth analysis of the electron structure, local dipole, and chemical bonding at the atomical level. It is found that the lithiophilicity of Zn₂@C₂N is co-contributed by Zn₂-anchoring and N-containing functional groups, which facilitate the uniform Li deposition by inducing heterogeneous nucleation at uniform and multiple lithiophilic sites. The moderate adsorption strength, low diffusion energy barrier, and stable atomic structure of these lithiophilic sites endow Zn₂@C₂N with low Li nucleation overpotential, smooth Li deposition morphology, and thus a long cycle life. This work sheds new light on the precise design of ideal lithiophilic hosts for dendrite-free LMA.