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

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, an all‐around protection strategy is reported for achieving stable Zn metal anodes. First, a proton‐resistant Pb‐containing (Pb and Pb(OH)2) interface is constructed on a Zn anode (denoted as Zn@Pb), which in situ forms PbSO4 during H2SO4 corrosion and protects the Zn substrate from HEC. Second, to improve the plating/stripping reversibility of Zn@Pb, Pb(CH3COO)2 an additive (denoted as Zn@Pb‐Ad) is introduced, which triggers PbSO4 precipitation and releases trace Pb2+ that can dynamically deposit a Pb layer on the 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 795 h in 0.2 and 0.1 m H2SO4 electrolytes, respectively, which are >40 times better than that of bare Zn. The as‐prepared A h‐level battery achieves a one‐month calendar life, opening the door to the next generation of high‐durable grid‐scale Zn batteries. A Pb‐containing interface and Pb layer constructed in situ on a Zn substrate and Zn plating layer provide all‐around protection for stable Zn anodes. Benefiting from the low H+ affinity and strong bonding, they show high hydrogen evolution corrosion resistance. Based on this, an electrolytic Zn//MnO2 battery achieves long‐term cycling stability and ultra‐high energy density in an acidic electrolyte.