Improving Zn metal anode performance with powdery graphene as a deposition modulator

Abstract

The inadequate cycling stability of Zn anodes, caused by dendritic growth and side reactions, impedes the practical advancement of aqueous Zn metal batteries. Graphene (Gr) has garnered considerable attention in recent years owing to the high degree of lattice constant match to Zn(002). However, the inherent zincophobicity of Gr and its hindrance to Zn2+ transport have necessitated intricate optimization strategies. In this work, we propose a straightforward solution by fabricating a protective layer for Zn anodes using Gr powder (p-Gr), which could effectively modulate Zn deposition behavior. The homogenized interfacial electric field and abundant edges of p-Gr nanosheets facilitate the planar deposition of Zn while concurrently exhibiting excellent capabilities in restricting side reactions. As a result, symmetric cells demonstrate long-lasting lifespan over 2500 h under 5.0 mA cm−2. Furthermore, when paired with a ZnxV2O5 cathode, full cells showcase outstanding capacity retention and cycling stability. Our research imparts valuable insight into the design of high-performance Zn metal anode based on graphene materials.