Atomic-scale Identification of Influence Factors of Sodium Dendrite Growth on Different Current Collectors
To design high-performance and safe Na metal anodes for rechargeable Na-metal batteries, the dendrite-growth mechanisms during Na electroplating process await to be fully understood. Here, we provided a density functional theory (DFT) insight into essential mechanisms associated with Na dendrite formation on different current collectors, such as Cu, Al, and single wall carbon nanotube (SWCNT). We investigated the adsorption behavior of Na atoms on SWCNT, Cu (111) surface, and Al (111) surface and further compared the stability of Na dimers. The “Sodiophilic” property and electronic configuration of Cu, Al, and SWCNTs were evaluated. Meanwhile, the electron transfer and the stability of Na dimers were estimated. For the adsorption of single Na atom, SWCNT, Cu and Al performed well with the adsorption energies of -2.15, -2.93 and -2.24 eV, respectively. However, the Na dimer was not energetically favorable to form on SWCNTs. Based on Hirshfeld atomic charges and electron density distribution, the stable electron configuration of SWCNT was found to play a critical role in dispersing Na adatoms. In addition, the vacancy defects in SWCNT induced better “Sodiophilic” property and inhibit dendrite growth. Our results unraveled the possible mechanisms underlying dendritic electrodeposition of Na on SWCNT, Cu and Al current collectors, indicating SWCNTs can be a promising current collector to develop dendrite-free Na metal anodes for safe Na-metal batteries.
- This article is part of the themed collection: Journal of Materials Chemistry A HOT Papers