Interfacial reconstruction via electronegative sulfonated carbon dots in hybrid electrolyte for ultra-durable zinc battery

Water-induced side reactions and the growth of zinc dendrites are generally considered as the key problems hindering the development of zinc batteries. Herein, robust electrode/electrolyte interface is successfully constructed via introducing carbon dots (CDs) additive into hybrid electrolyte to enhance the stability of Zn anode. The CDs with -SO3− groups deliver strong binding energy toward Zn, which can reduce the nucleation barrier, thus favoring the homogeneous Zn deposition, as successfully evidenced by theoretical DFT calculation and intuitive in-situ optical microscope observation. Meanwhile, the zincophilic CDs can be preferentially adsorbed on the surface of Zn electrode, further diminishing water-induced adverse reaction by virtue of the electrostatic repulsion between SO42− and negative charge of CDs. Accordingly, benefiting from the synergetic effect, the hybrid electrolyte with CDs endows Zn||Zn symmetric cell a prolonged lifespan over 4000 h with steady voltage fluctuation at 1 mA cm−2.