Constructing robust and fast desolvation interfacial layer with halloysite nanotubes/polydopamine for dendrite-free and durable zinc metal anode

Metallic zinc is recognized as a promising anode candidate for aqueous zinc-based batteries (AZBs), however, issues such as dendrite formation and parasitic side reactions severely deteriorate its reversibility and practical lifespan. In this study, we construct a robust and fast desolvation interfacial layer composed of halloysite nanotubes and polydopamine (HNTs/PDA) on the surface of Zn foil to achieve dendrite-free and durable Zn anodes. The amino and hydroxyl groups in PDA promote the desolvation process of Zn(H₂O)₆²⁺, resulting in a uniform dispersion of Zn²⁺ flux, while the negatively charged siloxane groups on the outer surface of HNTs function as an ion sieve, homogenizing the Zn²⁺ flux distribution and alleviating concentration polarization. Additionally, the positively charged aluminum hydroxyl groups and hollow tubular structure of HNTs effectively trap SO₄²⁻ and OH⁻ through electrostatic adsorption, thereby suppressing side reactions. Consequently, the symmetric cell based on HNTs/PDA@Zn can be stably cycled for over 2000 h at 1 mA cm⁻² with a capacity of 1 mAh cm⁻², demonstrating excellent cycling performance. When paired with a V₂O₅ cathode, the HNTs/PDA@Zn||V₂O₅ full cell delivers high discharge capacity and long cycle stability without significant performance deterioration over 1800 cycles at 5.0 A g⁻¹.