Deposition of Horizontally Stacked Zn Crystals on Single Layer 1T-VSe2 for Dendrite-Free Zn Metal Anodes
YY Li and HL Wong and J Wang and WL Peng and YD Shen and MY Xu and Q An and JK Kim and B Yuan and WA Goddard and ZT Luo, ADVANCED ENERGY MATERIALS, 12 (2022).
Owing to the moderate redox potential and high safety, Zn metal anodes have been garnering great attention. However, the poor reversibility and limited-service period caused by side reactions and dendrites hinder their applications. Here, a novel anode material consisting of a hexagonal 1T-Vanadium diselenide (1T-VSe2) film on graphene is developed as a zincophilic template to epitaxially electrodeposit hexagonal closest packed Zn to replace the conventional metal substrates in Zn batteries. The 1T-VSe2/Zn anode induces a horizontally (002)-oriented plate-like Zn crystal deposition morphology instead of randomly oriented grains that prompts the compact Zn deposition. According to density functional theory calculations, the VSe2 substrate exhibits a higher Zn adsorption (-0.54 eV) than the graphene (-0.38 eV) or neat Zn (-0.48 eV) counterparts, leading to the enhanced zincophilicity and a lower nucleation overpotential, in agreement with the experimental results. The force field-based molecular dynamics simulations visualize Zn nucleation and morphological evolution at the atomistic level. The rapid adatom diffusion on VSe2 leads to layer-by-layer Zn electrodeposits with higher fraction of the (002) facets to effectively prohibit dendrite formation. The symmetric cell with 1T-VSe2/Zn delivers an ultra-stable cyclic life of 2500 h with 50 mV overpotential at 1 mA cm(-2) and 1 mAh cm(-2).
Return to Publications page