【摘要】 水系锌离子电池因其高安全性、环境友好性和低成本等优势，被视为一种富有前景的新型储能器件。然而，不可控的锌枝晶生长以及有害的副反应严重限制了水系锌电池的电化学性能。在众多改善策略中，电解液添加剂因其成本低廉和操作简便的优势，相较于人工界面涂层和电极结构设计更具应用潜力。本研究采用一种新型零维纳米材料——硫掺杂的碳点，作为电解液添加剂，通过多种表征手段对其结构和性质进行了系统分析，并组装成电池以评估这种碳点对电池性能的影响。实验结果表明，碳点通过其表面磺酸基团诱导锌电极表面择优形成稳定的（002）晶面，并重构水合Zn²⁺的溶剂化壳层，显著提升了电池的循环稳定性。在碳点添加剂的作用下，对称电池在10 mA·cm^-2的高电流密度下实现了近2000 h的稳定循环，Zn||NH₄V₄O₁₀和Zn||MnO₂全电池也表现出优异的电化学性能和显著提升的循环稳定性。本研究为开发高性能水系锌离子电池提供了新的思路和理论依据。更多还原

【Abstract】 Aqueous zinc-ion batteries（AZIBs） have gained considerable attention as next-generation energy storage devices due to their inherent safety, environmental friendliness, and costeffectiveness. However, their widespread application is severely hampered by uncontrolled zinc dendrite growth and detrimental side reactions（e.g., hydrogen evolution, corrosion, and passivation）, which lead to reduced Coulombic efficiency and shortened cycle life. Current strategies to improve zinc anode stability mainly focus on artificial interface coatings, electrode structure design, and electrolyte optimization. Among these approaches, electrolyte additive engineering is considered the most promising for practical applications due to its simplicity, low cost, and excellent scalability. Nevertheless, conventional additives（including metal ions, polymers, and surfactants） typically address only single issues（either dendrite suppression or side reaction mitigation）, failing to achieve synergistic effects. In this work, we developed sulfur-doped carbon dots（SCDs） as a novel bifunctional electrolyte additive to significantly enhance AZIB performance. The carbon dot additive was synthesized via a facile calcination method, followed by systematic characterization of its structure and properties using methods such as Fourier transform infrared spectroscopy（FT-IR）, X-ray photoelectron spectroscopy（XPS）, X-ray diffraction（XRD）, and density functional theory（DFT） calculations. Comprehensive electrochemical evaluations were conducted to investigate the influence of S-CDs on zinc deposition behavior and overall battery performance. Experimental results demonstrate the successful synthesis of sulfur-doped carbon dots with abundant surface functional groups. During battery operation, the strong binding affinity between S-CDs and Zn²⁺ effectively reconstructs the Zn²⁺ solvation shell, reducing water molecule content and thereby minimizing electrode corrosion and side reactions caused by interfacial active water molecules. Moreover, the S-CDs induce the formation of stable（002） crystallographic planes that continuously renew during plating/stripping cycles, with particularly pronounced effects under high current densities, significantly enhancing the structural stability of the electrode. The synergistic effect of these dual functions leads to remarkable improvement in zinc electrode performance and ultimately endows the battery with ultra-long cycling life. Benefiting from the positive effects of the carbon dot additive, the symmetric cell achieves exceptional stability for nearly 2000 h at a high current density of 10 m A·cm^-2, far outperforming conventional electrolyte systems. Furthermore, both Zn||NH₄V₄O₁₀ and Zn||MnO₂ full cells exhibit superior electrochemical performance and significantly enhanced cycling stability, confirming the excellent compatibility of the carbon dot additive with various cathode materials. This study provides novel insights and fundamental theoretical guidance for developing high-performance AZIBs, representing a significant advancement in sustainable energy storage technologies.更多还原