摘要
An organic small molecule additive fluorouracil (FUC) is introduced to regulate the solvated structure and the electrical double layer and reduced interfacial tension at electrode–electrolyte to construct of a stable Zn anode interface.
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•Fluorouracil (FUC) as an electrolyte additive reduces the interfacial tension to promote uniform Zn2+ deposition.•FUC participates the formation of SEIs enriched with ZnF2 and Zn3N2, which improves the kinetic properties of Zn anodes.•Employing FUC containing electrolyte, Zn||V2O5 full cell exhibits excellent electrochemical performance.
Aqueous zinc-metal batteries (AZMBs) have received extensive research interest due to its advantages of high safety, environmental friendliness, and cost effectiveness. However, dendrite growth, hydrogen evolution reaction, and water-induced corrosion still challenge commercialization of AZMBs. Herein, an all-purpose electrolyte additive, fluorouracil (FUC), is introduced to address these challenges by controlling Zn deposition and reducing interfacial tension at the electrolyte–electrode interface with addition of FUC. Both theoretical computations and experimental results show that FUC preferentially adsorbs onto Zn anode surfaces over H2O molecules, reducing the electrolyte–electrode interfacial tension, regulating the diffusion pathway and deposition sites of Zn2+, and promoting uniform Zn2+ deposition and suppressing dendrite formation. It also mitigates water-induced corrosion on Zn anode surfaces and generation of insulating by-products (Zn4SO4(OH)6-xH2O), by reconfiguring the Zn2+ solvation structure and the electric double layer, thus improving the deposition/stripping of Zn. As a result, FUC based Zn||Zn symmetric cells stably cycle for over 760 h at an ultra-high current density of 40 mA cm−2 and 1.0 mAh cm−2. FUC based Zn||V2O5 pouch full cells are capable of cycling 400 cycles at a current density of 1 A/g, with a 88 % capacity retention. This study paves a new avenue for the stabilization of the metal-electrolyte interfacial layer, which narrows the gap toward practical applications of metal-based rechargeable batteries.