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Electrochemical nucleation and deposition of Li2S/Li2S2 is among the major problems hindering the application of lithium‐sulfur batteries. Adsorption behavior of Li2Sx (x=1, 2, 4, 8) with nitrogen‐doped, boron‐doped graphene and reduced graphene oxides (r‐GOs) are investigated in this study by DFT method. It is discovered that graphene with pyridinic N doping (PD−N) and pyrrolic N doping (PL−N) are able to benefit the nucleation for short‐chain lithium‐polysulfides (Li2S/Li2S2) through Li−N interaction. r‐GOs can also enhance the nucleation to some extent through Li−O interaction, which is not as good as Li−N interaction. At the same time, pristine graphene, graphene with graphitic N (GRN) and B‐doped graphene can only provide Li−C interaction, which is weaker than Li−O and Li−N. This makes the sequence of adsorption strength to be PD−N≈PL−D>r‐GO>B>GRN≈pristine graphene. The unique mechanism of B‐doped graphene adsorbed with Li2S/Li2S2 is also discovered.

Lithium-dendrite growth is one of the most challenging problems affecting the safety performance of Li-ion batteries. Understanding the evolution process of Li-dendrite growth at the atomic scale is critical for solving this problem. In this paper, the adsorption processes, geometrical configurations, and electronic structures of Li clusters on double-layered graphene with two types of defects were investigated by first-principles calculations. It was found that single vacancy (SV) defects tend to promote the nucleation of Li dendrites, and the adsorption energy of Li clusters near the SV defect decreases with increasing number of Li atoms. Meanwhile, the Li atoms accumulated on the surface of SV-defect graphene with distances between the Li atoms similar to those in bulk metallic Li. However, in the case of double vacancy (DV) defects, the Li atoms could diffuse freely in the direction perpendicular to the graphene sheets through DV defects at the top-layer graphene, thus hindering nucleation and dendrite growth. Density of states analyses suggested that the Li atoms on SV-defect graphene transform from the fully ionized state to the metallic state with continuously increasing number, while the ionic properties of the Li atoms remain and even increase on DVdefect graphene. Our conclusions can help to understand the Li-graphite interaction from an atomistic point of view and provide theoretical hints for the development of graphite anodes with high charge-rate properties.