In situ engineering of a hydrophobic–zincophilic interface toward long‐cycle stability of Zn metal anodes

Abstract Aqueous zinc‐ion batteries (AZIBs) are widely used in energy storage devices due to their low cost and environmental sustainability. Nevertheless, the growth of Zn dendrites and the occurrence of side reactions remain significant barriers to the practical application of AZIBs. Here, a hydrophobic and zinc‐compatible solid–electrolyte interface layer of poly(dimethylsiloxane) (PDMS) is in situ grafted on the Zn anode surface via spontaneous hydrolytic condensation reactions. The high viscoelasticity of PDMS and the chemically formed Si–O–Zn bonds synergistically ensure the adaptability and stability of PDMS on Zn anodes. Moreover, the strong hydrophobicity of PDMS shields the direct contact between the Zn anode and the aqueous electrolyte and further optimizes the reversible plating/stripping of Zn. The symmetrical cell assembled with PDMS@Zn anode displays a long lifespan of over 3000 h at 1 mA cm −2 for 1 mAh cm −2 . The PDMS@Zn||NH 4 V 4 O 10 full cell maintains the specific capacity of 284.8 mAh g −1 after 1200 cycles at 1 A g −1 . Overall, our work sheds new light on the Zn electrodeposition process under the mediation of anode interface, offers sustainability considerations in designing stable Zn metal anodes, as well as provides a facile and viable path for stabilizing Zn anodes to achieve dendrite‐free and long lifespan.