Long-life and dendrite-free zinc metal anode enabled by a flexible, green and self-assembled zincophilic biomass engineered MXene based interface

Abstract

• Green zincophilic biomass engineered MXene based interface is designed for dendrite-free Zn anode. • The MX/CS layer enhances the hydrophilicity and promotes uniform Zn nucleation. • The MX/CS layer significantly suppress the Zn dendrites growth and side reactions. • The MX/CS layer buffers the volume change of Zn metal anode during cycling. • MX/CS@Zn anode exhibits extended cycling life and high reversibility. As a promising candidate of safety, low-cost and eco-friendliness, Zn metal batteries still suffer from poor stability and irreversibility, which attribute to dendrite growth and accompanied side reactions. To enable highly reversible Zn anode, a flexible and self-assembled biomass engineered MXene film, functioning as an artificial protective interface, is firmly adhered on the Zn foil surface by facile blade-casting. This amine-rich ultrathin protective film not only effectively protects fresh Zn against water corrosion, but also promotes Zn nucleation and triggers homogeneous Zn plating/stripping underneath the film attributing to its excellent adhesion, flexibility, hydrophilicity and strong coordination of amine groups to Zn 2+ . Meanwhile, the conductive MXene component can terminate the accidental Zn dendrites by ionizing the contacted Zn and dispersing the tip electric field. Consequently, the protected Zn electrode delivers prolonged cycling life and improved coulombic efficiency, which also conduces to improving the full cell performance when it is matched with MnO 2 cathodes. This work brings a new insight into the practical design of highly reversible Zn metal anodes.