Engineering Sb/Zn4(OH)6SO4·5H2O interfacial layer by in situ chemically reacting for stable Zn anode.

ABSTRACT

Rechargeable aqueous zinc ion batteries with abundant resources and high safety have gained extensive attention in energy storage technology. However, the cycle stability is largely limited by notorious Zn dendrite growth and water-induced interfacial side reactions. Here, a uniform and robust protection layer consisting of metal antimony (Sb) nanoparticles and micrometer-size sheets Zn4(OH)6SO4·5H2O (ZHS) is purposely designed to stabilize Zn anode via an in situ chemical reaction strategy. The two-phase protection layers (Sb/ZHS) induce a reinforcement effect on the Zn anode (Zn@Sb/ZHS). Specifically, Sb nanoparticles play the part of nucleation sites to facilitate uniform Zn plating and homogenize the electric field around the Zn surface. ZHS micrometer-size sheets possess sufficient electrolyte wettability, fast ion transfer kinetics, and anti-corrosion, thus guaranteeing uniform ion flux and inhibiting H2O decomposition. As expected, the symmetric Zn@Sb/ZHS//Zn@Sb/ZHS cells achieve a minimal voltage hysteresis and a reversible cycle of over 2000 h at 1 mA cm-2. By pairing with the MnO2 cathode, the full cell exhibits a significantly improved stability (∼94.17 % initial capacity after 1500 cycles). This study provides a new strategy to design artificial protection layers.