Highly reversible Zn electrodeposition enabled by glutathione-protected copper nanoclusters for aqueous Zn-ion batteries

Dendrite growth and side reactions occurring in Zn anodes hinder the development and practical application of aqueous Zn-ion batteries. Herein, for the first time, we demonstrated the use of ligand-protected Cu nanoclusters as Zn plating/stripping mediators to construct dendrite-free Zn anodes. The abundant polar functional groups (–COOH, –NH2, and –CO–NH–) on the peripheral ligands modulated the solvation structure and regulated the transport of Zn2+, whereas the zincophilic Cu cores functioned as nucleating agents to guide the uniform nucleation and plating of Zn. Using such bifunctional CuNCs, the asymmetric cell achieves a coulombic efficiency of 99.40% for over 1000 cycles, and the symmetric cell exhibits low voltage hysteresis and superior cycling over 400 h with a high depth of discharge of 40%. These findings may contribute to the design of multifunctional mediators at the atomic level.