Engineering low-cost multifunctional carbon interface layer with hydrophobic negative surface and oriented zinc deposition dynamics for dendrite-free zinc ion batteries

Aqueous zinc-ion batteries (AZIBs) are ideal for next-generation energy storage due to low cost, safety, and ecofriendliness, but Zn anode issues like dendrites, hydrogen evolution, and corrosion limit their lifespan. This study engineers a low-cost multifunctional nitrogen-doped porous carbon (NC) interface layer with a three-dimensional (3D) zincophilic structure and a hydrophobic, negatively charged surface for Zn anode. Its conductive 3D structure enables the uniform distribution of the electric field, suppressing dendrite formation and promoting even Zn2+ deposition. On the one hand, the hydrophobic surface minimizes water-zinc interactions, while on the other hand, the negative charge facilitates selective Zn2+ transport and repels sulfate anions, thereby significantly reducing hydrogen evolution and corrosion. Additionally, rich zincophilic sites not only lower the deposition overpotential but also induce (002) crystal-oriented growth, further stabilizing the interface and extending battery life. As a result, symmetric cells assembled with NC-coated Zn electrodes exhibit an impressive cycling life of over 2800 h at a current density of 2 mA cm-2. At higher current densities (10 and 20 mA cm-2), the cells maintain cycling lifetimes of over 1300 and 1000 h, respectively, demonstrating exceptional stability. This work is expected to provide a simple, practical and scalable strategy for developing efficient and stable AZIBs.