Highly stable Zn anodes realized by 3D zincophilic and hydrophobic interphase buffer layer

Abstract

Aqueous zinc-ion batteries (AZIBs) are promising contenders for energy storage systems owing to their low cost and high safety. However, their practical application is hindered by uncontrolled Zn dendrites and other side reactions. Here, the three-dimensional (3D) TiO2/Cu2Se/C heterostructure layer derived from MXene/Cu-MOF is constructed on the Zn anode to control the deposition/dissolution behavior, which has numerous active sites, better electrical conductivity and excellent structural stability. Based on DFT calculation, the built-in electric field (BIEF) formed of TiO2/Cu2Se/C can enhance charge transfer and ionic diffusion to inhibit the dendrites. Furthermore, hydrophobic coating has the ability to impede the corrosion and hydrogen evolution reaction (HER) of zinc anode. Thus, TiO2/Cu2Se/C@Zn enable the stable and reversible Zn plating/stripping process with the outstanding lifetime of 1100 h at 2 mA·cm–2 and even 650 h at 10 mA·cm–2. The batteries constructed with commercial MnO2 cathodes demonstrate the remarkable capacity (248.7 mAh·g−1 at 0.1 A·g−1) and impressive cycle stability (with 71.3% capacity retention after 300 cycles). As well as extending the life of AZIBs, this study is also motivating for other metal anode based secondary batteries.

Keywords

• zinc anode
• heterostructure
• built-in electric field
• zincophilic
• hydrophobic