Constructing dual ion–electron transport channels via Ti₃C₂T_x quantum-dot-embedded ZIF-8 for advanced Zn anodes

Uncontrolled dendrite growth and surface corrosion of Zn metal anodes severely hinder practical application of aqueous Zn-ion batteries (ZIBs). Herein, we propose a novel strategy to construct dual ion–electron transport channels by embedding Ti₃C₂T_x quantum-dots (QDs) into a metal–organic framework (MOF) protective layer in-situ grown on the Zn surface. The zeolitic imidazolate framework-8 (ZIF-8) matrix provides well-defined sub-nanopores to guide Zn²⁺ flux uniformly while selectively blocking larger solvated Zn clusters, thereby suppressing dendrite growth, the hydrogen evolution reaction (HER), and corrosion. Meanwhile, highly conductive QDs, which act as electron mediators within the insulating ZIF-8, create interconnected electron pathways to accelerate charge transfer across the interface. As a result, the MOF@QD layer on the Zn anode enables stable Zn plating/stripping over extended cycles (1200 cycles at 1 mA·cm⁻² and 2000 cycles at 5 mA·cm⁻²) with reduced overpotential, dendrite-free morphology, and suppressed anode HER/corrosion. Zn//MnO₂ full batteries with MOF@QDs/Zn deliver an impressive high initial specific capacity of 277 mAh·g⁻¹ at 0.2 A·g⁻¹, enhanced long-term capacity retention of 60% with ultra-high (99.5%) Coulombic efficiency (CE) after 500 cycles at 1 A·g⁻¹. This dual-channel design offers a generalizable approach for Zn-anode modification, paving the way for high-performance Zn-based energy storage systems.