Zincophilic Ti3C2Cl2 MXene and anti-corrosive Cu NPs for synergistically regulated deposition of dendrite-free Zn metal anode

Abstract

Dendrites growth, chemical corrosion, and hydrogen evolution reaction (HER) on zinc anodes are the main barriers for the development of aqueous zinc-ion batteries (AZIBs). Constructing interfacial protective layer is an effective way to alleviate the side reactions on the anodes. Herein, Cu/Ti3C2Cl2 MXene (CMX) with high zincophilic and hydrophobic property is prepared by the lewis molten salts etching method, and the CMX interface protection layer is constructed by a simple spin coating. The CMX coating layer can provide abundant nucleation sites and uniformize the charge distribution through the zincophilic Ti3C2Cl2 MXene matrix, leading to homogenous Zn deposition. In addition, the hydrophobic coating contained anti-corrosive Cu nanoparticles can prevent the Zn anode from the electrolyte, beneficial for suppressing the chemical corrosion and HER. Therefore, the stable and reversible Zn plating/stripping is achieved for the Zn anode coated by the CMX, which exhibits the lifespan of over 1400 h at 0.5 mA cm−2, and even can steadily run for 700 h with 65 mV at 10 mA cm−2. Furthermore, CMX@Zn shows a high coulombic efficiency of over 100% for 3800 cycles, which indicates that the CMX@Zn electrode has excellent stability and reversibility of Zn stripping/plating. The full batteries assembled with ZnCoMnO/C (ZCM) cathodes also exhibits higher capacity (450.6 mAh g−1 at 0.1 A g−1) and cycle stability (capacity retention of 70% after 1500 cycles). This work enhanced the lifespan of AZIBs and broaden the research of multifunctional coating layer to other secondary batteries based on metal anodes.