Customizing Helmholtz Plane with N, F, P Tri-Doped rGO/CNT Aerogel Protective Layer for Long-Life Zinc-Ion Batteries

The practical application of aqueous zinc-ion batteries (AZIBs) is impeded by dendrite formation and water-induced parasitic reactions at the anodes. In this article, a relatively hydrophobic inner Helmholtz plane (IHP) and an outer Helmholtz plane (OHP) with abundant nucleation sites are engineered through coating a N, F, and P heteroatom doped reduced graphene oxide/carbon nanotube (NFP-rGO-CNT) multifunctional aerogel protective layer. The rGO with certain hydrophobicity construct a lean-water environment at IHP, effectively blocking adverse parasitic reactions between water and metallic Zn, while zincophilic and uniformly distributed N, F, and P heteroatoms facilitate Zn²⁺ migration and homogenize Zn²⁺ flux at the OHP, thereby promoting the directional deposition of Zn²⁺ along the (002) crystal plane. Consequently, the fabricated NFP-rGO-CNT/Zn//Cu asymmetric cell exhibits a high Coulombic efficiency close to 100% for 3200 cycles. In addition, the symmetric cell assembled with NFP-rGO-CNT/Zn electrodes presents an impressive lifespan of 1990 h at 5 mA cm⁻² and 2 mAh cm⁻², significantly outperforming the control group (about 27 h). More remarkably, a NFP-rGO-CNT/Zn//V₂O₃ pseudo-pouch cell is capable of powering a small fan to rotate steadily. This aerogel protective layer strategy offers a novel perspective for HP regulation, enabling textured and reversible Zn anodes.