Surface wrinkle modulated pyridinic nitrogen-rich zincophilic sites for stable, fast and uniform zinc deposition

Aqueous zinc ion batteries attract much attention due to the advantages including low cost and intrinsic safety. However, uncontrolled dendrite growth and complex side reactions on Zn anodes significantly reduce the battery cycle life and hinder their practical application. Here, we designed a pyridinic nitrogen-rich carbon layer with a unique wrinkled structure (W-NC) as a protective layer for Zn anodes. Finite element simulations, theoretical calculations, and microstructure characterizations show that the wrinkled structure modulates the electric field strength on the Zn surface and guides the uniform Zn deposition. Moreover, the wrinkled structure leads to the exposure of more pyridinic-N zincophilic sites, which further suppress dendrites and other side reactions. Therefore, the W-NC@Zn electrode exhibits a low Zn nucleation overpotential, facilitates high reversible and dendrite-free Zn deposition. Consequently, excellent electrochemical performance is realized. The cycle life of the W-NC@Zn||W-NC@Zn symmetric cell reaches 2542 h at a current density of 1 mA cm⁻². After 1020 cycles operation, the average Coulombic efficiency of the W-NC@Zn||Cu asymmetric cell is 99.51 %. The practical applications of the W-NC@Zn electrodes are also demonstrated by evaluating the W-NC@Zn||VO₂ full cells. By integrating active sites modulation and surface roughness engineering, our studies provide an alternative way to optimize electrode performance for a wide range of applications.