Stress Release of Zincophilic N-Doped Carbon@Sn Composite on High-Curvature Surface of Zinc Foam for Dendrite-Free 3D Zinc Anode.

Abstract

Commercial 3D zinc foam anodes with high deposition space and ion permeation have shown great potential in aqueous ion batteries. However, the local accumulated stress from its high-curvature surface exacerbates the Zn dendrite issue, leading to poor reversibility. Herein, we have employed zincophilic N-doped carbon@Sn composites (N-C@Sn) as nano-fillings to effectively release the local stress of high curvature surface of 3D Zn foams toward dendrite-free anode in aqueous zinc ion battery (AZIB). These electronegative and conductive N-C@Sn nano-fillings as supporters can provide a highly zincophilic channel for initial Zn nucleation and reduce local current density for regulating Zn deposition. Uniform Zn deposition further assists homogenous stress distribution on the platting surface, which gives a positive feedback loop to improve anode reversibility. As a result, zinc foam with N-C@Sn composite (ZCSn Foam) symmetric cell achieves a long cycle lifespan of 1100h at 0.5 mA cm^-2, much more than that of Zn Foam (∼80 h lifespan). The full cell ZCSn Foam||MnO₂ exhibits remarkable reversibility with 67% retention after 1000 cycles at 0.8 A g^-1 and 76% after 1600 cycles at 2 Ag^-1. This 3D-constructing strategy may offer a promising and practical pathway for metal anode application.