Modifying the Zn Anode with Nano-Silica: A Strategy to Realize Dendrite-Free Zinc-Ion Hybrid Supercapacitors

• Published in: Journal of the Electrochemical Society Vol. 170; no. 2; pp. 20508 - 20515
• Main Authors: Yu, Juan, Peng, Jiaxin, Jia, Xuefeng, Wang, Lejie, Yang, Kai, Zhao, JunKai, Yang, Naixing
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2023
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/acb614

In recent years, zinc-ion hybrid supercapacitors have been widely studied due to many advantages, but zinc dendrite and anodic corrosion limit its cycle stability and safety performances. A hybrid coating composed of nano-silica and polyvinylidene fluoride was prepared on the surface of metal zinc by coating method. Insulating nano-silica is conducive to the directional migration of Zn 2+ , and hydrophobic coating can effectively reduce anodic corrosion. The Zn@SiO 2 //Zn@SiO 2 symmetrical cell exhibits stable cycling for over 500 cycles at 1 mA cm −2 , while the bare Zn symmetrical cell shows high overpotential and short cycle life. The specific capacity of the assembled zinc ion hybrid supercapacitor under different current densities is higher than that of bare zinc cell. When the current density is 0.2 A g −1 , the specific capacity reaches 263.1 mAh g −1 . This study reveals a simple and effective strategy to achieve dendrite-free zinc anode. Highlights A hybrid coating composed of nano-silica and polyvinylidene fluoride was prepared on the surface of metal zinc by coating method. Insulating coating is conducive to the directional migration of Zn 2+ , and guided uniform electrolyte flux and Zn plating rate over the entire Zn foil surface, resulting in a uniform, bottom-up Zn plating process. Hydrophobic coating can effectively inhibit the form of byproducts and reduce anode corrosion. The Zn@SiO 2 anode shows good cycling stability in the aqueous electrolyte