Hydroxyl/Amino-Co-Functionalized Carbon Dots Regulate Zn Deposition Texture for Stable Aqueous Zinc Metal Anodes

Abstract

Hydroxyl/amino-functionalized carbon dots (OH/NH2-CDs) are introduced as nanoscopic electrolyte additives to regulate Zn deposition texture in aqueous zinc metal batteries. Spectroscopic characterization and simplified calculations suggest interactions between Zn species and the O/N-containing CD surface, together with altered sulfate-associated ion pairing. Compared with OH-CDs, NH2-CDs, and physically mixed OH + NH2-CDs, OH/NH2-CDs exhibit the lowest Zn nucleation overpotential of 45 mV and a distinct Zn(002)/(101) texture distribution. These changes are accompanied by compact Zn deposition, stable Zn||Zn cycling for 1400 h, improved Zn||Cu reversibility, and enhanced Zn||MnO2 full-cell cycling. This work highlights surface-functionalized CDs as texture-regulating nanoadditives for aqueous zinc metal anodes.