Stable interphase chemistry of textured Zn anode for rechargeable aqueous batteries

Despite the advances of aqueous zinc (Zn) batteries as sustainable energy storage systems, their practical application remains challenging due to the issues of spontaneous corrosion and dendritic deposits at the Zn metal anode. In this work, conformal growth of zinc hydroxide sulfate (ZHS) with dominating (001) facet was realized on (002) plane-dominated Zn metal foil fabricated through a facile thermal annealing process. The ZHS possessed high Zn2+ conductivity (16.9 mS cm(-1)) and low electronic conductivity (1.28 x 10(4) Omega cm), and acted as a heterogeneous and robust solid electrolyte interface (SEI) layer on metallic Zn electrode, which regulated the electrochemical Zn plating behavior and suppressed side reactions simultaneously. Moreover, low self-diffusion barrier along the (002) plane promoted the 2D diffusion and horizontal electrochemical plating of metallic Zn for (002)-textured Zn electrode. Consequently, the as-achieved Zn electrode exhibited remarkable cycling stability over 7000 cycles at 2 mA cm(-2) and 0.5 mAh cm(-2) with a low overpotential of 25 mV in symmetric cells. Pairing with a MnO2 cathode, the as-achieved Zn electrode achieved stable cell cycling with 92.7% capacity retention after 1000 cycles at 10 C with a remarkable average Coulombic efficiency of 99.9%. (C) 2022 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.

Automated summary

In this work, conformal growth of zinc hydroxide sulfate (ZHS) was achieved on Zn metal foil through a thermal annealing process, improving Zn2+ conductivity and forming a beneficial SEI layer on the Zn electrode. The achieved Zn electrode exhibited remarkable cycling stability and high efficiency, showcasing potential for practical application in energy storage systems.