Lithium metal anode is widely studied owing to its feature of ultrahigh theoretical specific capacity with lowest electrochemical potential. Nevertheless, the inhomogeneous deposition of Li⁺ ions is apt to accelerate the emergence of dendritic Li, which is a brake on the practical application of lithium metal batteries. To solve this issue, herein, we propose nitrogen, sulfur-codoped carbon dots (N,S-CDs) as the deposition regulating additives of electrolyte to guide lithium ion homogeneous deposition. Within the electrolyte, N,S-CDs additives can absorb the surrounding Li⁺ ions and deposit homogeneously on the current collector, resulting in a uniform lithium deposition layer. As expected, at the presence of 0.3 mg/mL N,S-CDs, the long-term cycling stability over 1200 h and 300 h with low polarization are achieved both in the Li|Li symmetric cell at current density of 1.0 and 3.0 mA cm⁻², respectively. Meanwhile, there is an obvious contrast between the capacity retention in the Li-S full cell between the cell with and without N,S-CDs. In addition, it is worth noting that the beneficial effect of N,S-CDs for stable lithium metal anode is firstly demonstrated by means of confocal laser scanning microscope as well.

锂金属负极因其具有超高理论比容量和最低电化学电位的特点而被广泛研究。然而，Li ⁺离子的不均匀沉积容易加速树枝状锂的出现，这对锂金属电池的实际应用是一个刹车。为了解决这个问题，在本文中，我们提出氮、硫共掺杂的碳点（N,S-CDs）作为电解质的沉积调节添加剂，以引导锂离子均匀沉积。在电解液中，N,S-CDs 添加剂可以吸收周围的 Li ⁺离子并均匀地沉积在集电器上，从而形成均匀的锂沉积层。正如预期的那样，在 0.3 mg/mL N,S-CD 的存在下，Li|Li 对称电池在 1.0 和 3.0 mA 的电流密度下均实现了 1200 小时和 300 小时的低极化长期循环稳定性cm ^-2，分别。同时，含和不含 N,S-CDs 的电池在 Li-S 全电池中的容量保持率存在明显差异。此外，值得注意的是，N,S-CDs 对稳定锂金属负极的有益作用也首次通过共聚焦激光扫描显微镜得到证实。