Manipulating underpotential deposition nucleation of zinc deposition towards high-stable zinc metal battery

Abstract

The uneven Zn deposition severely hinders the commercial application of zinc anode and rechargeable aqueous zinc metal batteries (AZMBs). In this work, the underpotential deposition (UPD) behavior of zinc is unveiled and a stable zinc anode host with underpotential deposition nucleation site of copper (3DH-Cu) is fabricated to guide homogeneous zinc deposition and enable long cycling stable rechargeable AZMBs. The uniformly distributed Cu UPD nucleation sites can avoid the electron concentration, reduce the nucleation barrier, and accelerate the deposition kinetics, which is attributed to the narrow band gap of Cu UPD nucleation sites, thus achieving a low nucleation overpotential of ~20 mV and a low activation energy (Ea) of 24.3 kJ mol−1. The 3DH-Cu@Zn anode exhibited an extremely stable overpotential (37 mV), and a high average Coulombic Efficiency of 99.4 % in 1000 cycling under 10 mA cm−2/1mAh cm−2 condition. A full cell with 3DH-Cu@Zn anode and NaV3O8-1.5H2O cathode (NVO) provides long cycle life and a low capacity degradation at 1Ag−1(above 150mAh g−1 capacity after 1000 cycles). Hopefully, anode design based on UPD can be considered to improve the electrochemical performance of AZMBs.