Achieving Highly Proton-Resistant Zn-Pb Anode through Low Hydrogen Affinity and Strong Bonding for Long-Life Electrolytic Zn//MnO2 Battery.

Abstract

High-energy electrolytic Zn//MnO2 batteries show potential for grid-scale energy storage, but the severe hydrogen evolution corrosion (HEC) caused by acidic electrolytes results in subdued durability. Here, we report an all-around protection strategy for achieving stable metal Zn anode. Firstly, a proton-resistant Pb-containing (Pb and Pb(OH)2) interface is constructed on Zn anode (denoted as Zn@Pb), which will in-situ form PbSO4 during H2SO4 corrosion and protect the Zn substrate from HEC. Secondly, to improve the plating/stripping reversibility of Zn@Pb, Pb(CH3COO)2 additive (denoted as Zn@Pb-Ad) is introduced, which will convert to PbSO4 precipitation and release trace Pb2+ that can dynamically deposit Pb layer on Zn plating layer to suppress HEC. The superior HEC resistance stems from the low affinity of PbSO4 and Pb for H+ as well as strong bonding between Pb-Zn or Pb-Pb, which increase the hydrogen evolution reaction overpotential and the H+ corrosion energy barrier. Consequently, the Zn@Pb-Ad//MnO2 battery runs stably for 630 and 795h in 0.2 and 0.1M H2SO4 electrolytes, respectively, which are >40 times than that of bare Zn. The as-prepared A h-level battery achieves the one-month calendar life, opening the door to the next generation of high-durable grid-scale Zn batteries. This article is protected by copyright. All rights reserved.