High-Yield Carbon Dots Interlayer for Ultra-Stable Zinc Batteries

摘要

The practical implementation of Zn metal anodes with high volumetriccapacity is seriously plagued by the dendritic growth and accompanying interfacialparasitic reactions. Herein, high yield carbon dots (CDs) with abundantpolar functional groups (-CHO and -C≡N), as a functional artificial interfacelayer, are rationally designed to optimize electrolyte/Zn interfaces withlarge-scale viability. Of particular note, the quantum-sized CDs with strongZn affinity can effectively ameliorate the electric field distribution and ensurethat more Zn~(2+) is adsorbed onto the whole electrode, which are beneficialfor lowering the barrier of Zn~(2+) nucleation and inducing homogeneous Zndeposition, thus rendering a dendrite-free Zn anode, as extensively confirmedby in situ optical microscope observation and finite element simulation.Meanwhile, the dense and insoluble coating layer with abundant polarfunctional groups is conducive to arousing the repulsion effect, which is goodfor shielding the active water and SO_4~(2?), thus eliminating the water-mediatedparasitic reactions and improving Zn~(2+) reaction kinetics. More importantly,the electrochemically stable CDs layer endows the Zn anode with a prolongedlifespan of 3000 h at 1 mA cm~(?2). This feasible and efficient fabrication of functionalCDs layer opens a new avenue for stable dendrite-free metal anodes.