Ultrastable Zinc Anode by Simultaneously Manipulating Solvation Sheath and Inducing Oriented Deposition with PEG
Ziyi Cao1,2, Xiaodong Zhu1,3, Shangpeng Gao3
1Institute of Special Materials and Technology, Fudan University, Shanghai, 200433, P. R. China.
Abstract:
Aqueous zinc-ion batteries are a low-cost and safe energy storage system, but suffer from detrimental side reactions and Zn dendrites due to the strong interactions between Zn2+ and water molecules in the electrolytes, and random Zn2+ deposition on the anode surface. Here, an electrolyte involving a dual-functional additive of polyethylene glycol (PEG) to bypass these issues is reported. The electrolyte can not only tailor the solvation sheath of Zn2+ but also enable favorably oriented deposition of Zn2+ on the anode surface. The dendrite-free Zn anode in Zn//Zn cells is obtained with high Columbic efficiency (98.8%) and long cycling lifespan (1500 h), six times longer than that of electrolyte without PEG at 0.25 mA cm-2 . What is more, the excellent cycling stability of the prepared batteries (Zn//V2 O5 ·1.6 H2 O) suggests that the developed tailoring strategy may propel a promising pathway for stabilizing Zn metal anodes.
