Achieving stable Zn anodes by reducing desolvation barrier and guiding homogeneous nucleation through zincophilic polymer layer

The real-world commercial application of aqueous zinc-ion batteries (AZIBs) is retarded by the poor stability of Zn anode in aqueous solutions, resulting in annoying dendrite growth and intricate side reactions. Herein, the KI-CHOP polymer with rich hydroxyl groups is decorated on the Zn anode surface to rationally construct a solid-state ion-regulating interface. Combing with elaborate experiments and theoretical calculations, the tremendous zincophilic nucleation sites exposed on the KI-CHOP layer could homogenize the Zn²⁺ flux passing through the interface and decrease the desolvation barrier of hydrated Zn²⁺, thus speeding up deposition kinetics. Furthermore, the KI-CHOP coating could serve as a hydrogen-bond breaker to construct a lean-water interface thereby suppressing the parasitic side reactions. As expected, as-obtained KI-CHOP@Zn symmetric cells could deliver ultra-long cyclability for over 2200 h at 1.0 mA cm⁻² with an area capacity of 1.0 mAh cm⁻² as well as excellent reversibility of repeated plating/stripping of Zn²⁺. Moreover, the KI-CHOP@Zn//MnO₂ full cells also exhibit exceptional long-term durability under 1.0 A g⁻¹ for 2000 cycles and rate performance. The KI-CHOP protective layer in this work paves an inspiration for multifunctional polymer coating and takes a step towards the real-world application for AZIBs.