Synergistic Manipulation of Zn²⁺ Ion Flux and Nucleation Induction Effect Enabled by 3D Hollow SiO₂/TiO₂/Carbon Fiber for Long-Lifespan and Dendrite-Free Zn–Metal Composite Anodes

Aqueous rechargeable zinc–metal batteries are a promising candidate for next-generation energy storage devices due to their intrinsic high capacity, low cost, and high safety. However, uncontrollable dendrite formation is a serious problem, resulting in limited lifespan and poor coulombic efficiency of zinc–metal anodes. To address these issues, a 3D porous hollow fiber scaffold with well-dispersed TiO₂, SiO₂, and carbon is used as superzincophilic host materials for zinc anodes. The amorphous TiO₂ and SiO₂ allow for controllable nucleation and deposition of metal Zn inside the porous hollow fiber even at ultrahigh current densities. Furthermore, the as-fabricated interconnected conductive hollow SiO₂ and TiO₂ fiber (HSTF) possess high porosity, high conductivity, and fast ion transport. Meanwhile, the HSTF exhibits remarkable mechanical strength to sustain massive Zn loading during repeated cycles of plating/stripping. The HSTF with interconnected conductive network can build a uniform electric field, redistributing the Zn²⁺ ion flux and resulting in smooth and stable Zn deposition. As a result, in symmetrical cells, the Zn@HSTF electrode delivers a long cycle life of over 2000 cycles at 20 mA cm⁻² with low overpotential (≈160 mV). The excellent cycling lifespan and low polarization are also realized in Zn@HSTF//MnO₂ full cells.