Construction of a multifunctional Ti3C2Tx MXene/g-C3N4 artificial protective layer for dendrite-free aqueous Zn-ion batteries

The electrochemical utilization of Zn anodes in aqueous batteries is hampered by the intricate and interconnected issues of Zn dendrite growth, H 2 evolution and Zn corrosion reactions. In this study, a multifunctional protective layer comprising MXene and graphitic carbon nitride (g-C 3 N 4 ) was constructed using a self-assembly strategy. The MXene/g-C 3 N 4 protective layer exhibited robust zincophilic characteristics, which facilitated a uniform distribution of the electric field and ensured a sufficient influx of Zn 2+ . This reduces the Zn 2+ nucleation barrier and prevents dendrite growth. In addition, the hydrophobic nature of the protective layer, coupled with its negative charge, can repel SO 4 2− and select water molecules from the electrolyte, which aids in mitigating corrosion and H 2 evolution. The symmetric Zn cell coated with the MXene/g-C 3 N 4 protective layer showed remarkable stability, achieving over 2000 h of reversible cycling at 1 mA·cm −2 . Furthermore, the MXene/g-C 3 N 4 -coated Zn anode paired with a sodium-doped V 2 O 5 cathode (NVO) exhibited enhanced cycling capability over 1500 cycles. Graphical Abstract