Constructing defect-free zincophilic organic layer via ultrasonic coating for anticorrosive and dendrite-free zinc anode

Due to their exceptional safety profile and cost-effectiveness, aqueous zinc-ion batteries have garnered considerable interest as promising energy storage systems. Nonetheless, issues such as dendrites and interfacial side reactions limit their practical applications. Constructing anticorrosive interface is one of the effective strategies to achieve a stable Zn anode. However, it remains challenge to construct a uniform interface on Zn anode. Herein, we proposed an ultrasonic coating method to construct a thin, zincophilic and uniform layer (∼ 0.98 µm) of zinc tartrate on the zinc anode (Tar-Zn). This method can effectively remove the adsorbed H2 and weakly adhered layers generated during the processing, thereby forming a defect-free and thin protective layer on the zinc anode. This Tar-Zn layer has the ability to inhibit corrosion of the zinc anode and induce uniform deposition of zinc. As a result, the lifespan of Zn anode is prolonged from 42 h to over 1300 h at 2 mA cm−2. Full cells assembled with MnO2 cathode and Tar-Zn anode provide an initial capacity of 139.9 mAh g−1 and an improved capacity retention of 82.7 % after 500 cycles at 1 A g−1, whereas the cells with bare Zn can only retain 65.9 % of capacity. This work provides a coating method to construct uniform layers for suppressing dendrites and side reactions.