Enabling High-Rate and High-Areal-Capacity Zn Deposition via an Interfacial Preferentially Adsorbed Molecular Layer

Abstract

The poor electrochemical performance of Zn anodes at high current densities and large areal capacities is a tough challenge due to the accelerated dendrite growth and worsened reaction irreversibility. Herein, an ester-based organic, γ-butyrolactone (GBL), is utilized to regulate the deposition behaviors and performance of the Zn anode. Through DFT calculations, the strong interactions of GBL molecules with Zn2+ and Zn slab were confirmed. In addition, improved interfacial properties were achieved, including the reduced potential of hydrogen evolution and enhanced wetting ability. Significantly, the concentration distribution difference of GBL between the Zn/electrolyte interface and the electrolyte was investigated by Raman spectra, and the interfacial preferential adsorption of GBL was highlighted. Electrochemical tests indicated that the supporting current density and the cycle life of the Zn anode using GBL could reach 30 mA cm–2 and 5000 h, respectively, proving the effectiveness of this strategy.