Multifunctional fullerene protective layer for dendrite-free Zn metal anode

Although the aqueous zinc batteries are deemed as the most competitive alternatives in the next-generation batteries, there are still annoying issues, including obdurate dendrites formation and side reactions, limiting practical applications. Hence, a uniform artificial C60 layer via an ex-situ approach is successfully assembled to construct robust Zn anode (denoted as Zn@C60). The functional C60 layer allows the formation of the ohmic contact interface between the C60 layer and Zn anode, inducing a low nucleation barrier and restraining 2D diffusion of Zn ions. More importantly, density functional theory calculations and simulation of the electric field contribution demonstrate that the C60 layer can facilitate the deposition of Zn on the Zn(0 0 2) plane and homogenize the electric field distribution. Consequently, the Zn@C60 electrode is obtained with a cycling stability over 3800 h at 0.25 mA cm-2 in symmetric cells, excellent coulombic efficiency for 1400 h in half cells, and together with better cycling stability and enhanced rate performance in full cells. Significantly, the C60 layer protection strategy provides a new view for an excellent dendrite-free Zn metal anode.

Automated summary

Although the aqueous zinc batteries are considered as competitive alternatives for next-generation batteries, they still face challenges such as dendrites formation and side reactions. In this study, a uniform artificial C60 layer is successfully assembled onto the Zn anode (Zn@C60) to address these issues. The C60 layer enables an ohmic contact interface and lowers the nucleation barrier, resulting in improved cycling stability and enhanced rate performance.