Scalable Construction of Multifunctional Protection Layer with Low‐Cost Water Glass for Robust and High‐Performance Zinc Anode

Abstract Zinc ion batteries (ZIBs) have recently attracted tremendous interest for being low‐cost, environmentally benign, and high energy density. However, the large‐scale practical application of ZIBs is hampered by well‐known undesirable dendrite growth and serious side reactions of the Zn anode during the long‐term cycling process. Herein, a multifunctional water‐glass artificial protection layer with enormous Si─O functional groups is constructed on Zn anode through a simple spin‐coating method. The theoretical and experimental investigation suggests that the as‐constructed interface with rich Si─O hydrophilic functional groups on Zn anode could facilitate the even distribution of electric field distribution and homogeneous wettability, navigate uniform zinc deposition/stripping along the (002) plane, and subsequently lead to well‐suppressed dendrite growth and effective prohibition of oxygen‐involved corrosion. Consequently, the water glass‐modified anode achieves highly reversible Zn plating/stripping over 1500 h at a high current density of 10 mA cm −2 in symmetrical cells, and a high capacity retention ratio of 79.4% at the current density of 5 A g −1 in full cells paired with V 2 O 5 cathode. This proposed water glass coating layer design is cheap, up‐scalable, and facile, which could substantially accelerate the rapid commercialization of zinc anodes and unleash the full potential of renewable ZIBs for next‐generation large‐scale energy storage.