Mosaic Nanocrystalline Graphene Skin Empowers Highly Reversible Zn Metal Anodes

Constructing a conductive carbon-based artificial interphase layer (AIL) to inhibit dendritic formation and side reaction plays a pivotal role in achieving longevous Zn anodes. Distinct from the previously reported carbonaceous overlayers with singular dopants and thick foreign coatings, a new type of N/O co-doped carbon skin with ultrathin feature (i.e., 20 nm thickness) is developed via the direct chemical vapor deposition growth over Zn foil. Throughout fine-tuning the growth conditions, mosaic nanocrystalline graphene can be obtained, which is proven crucial to enable the orientational deposition along Zn (002), thereby inducing a planar Zn texture. Moreover, the abundant heteroatoms help reduce the solvation energy and accelerate the reaction kinetics. As a result, dendrite growth, hydrogen evolution, and side reactions are concurrently mitigated. Symmetric cell harvests durable electrochemical cycling of 3040 h at 1.0 mA cm(-2)/1.0 mAh cm(-2) and 136 h at 30.0 mA cm(-2)/30.0 mAh cm(-2). Assembled full battery further realizes elongated lifespans under stringent conditions of fast charging, bending operation, and low N/P ratio. This strategy opens up a new avenue for the in situ construction of conductive AIL toward pragmatic Zn anode.

Automated summary

Constructing a conductive carbon-based artificial interphase layer (AIL) with ultrathin N/O co-doped carbon skin is developed to inhibit dendritic formation and side reactions in Zn anodes, achieving long cycling lifespans. This new approach allows for the orientational deposition along Zn (002), resulting in a planar Zn texture, and the abundant heteroatoms reduce solvation energy and accelerate reaction kinetics. Symmetric cell testing shows durable electrochemical cycling and assembled full battery exhibits elongated lifespans under various stringent conditions. This strategy opens up new possibilities for real-world applications of Zn anodes.