Work

Oxygen‐Rich Carbon Quantum Dots Enable Multiscale Synergistic Regulation for Ultralong‐Life Aqueous Zinc‐Ion Batteries

Year: 2026

Type: article

Abstract: ABSTRACT The practical application of aqueous zinc‐ion batteries (AZIBs) is now threatened by irreversible parasitic processes at the Zn anode. Here we report a molecular‐scale interfacial engineering strategy using oxygen‐rich carbon quantum dots (o‐CQDs, 38.83 wt% oxygen) that spontaneously self‐assemble into a 2D ion‐transport network in ZnSO 4 electrolyte. This architecture enables multiscale synergistic regulation. First, o‐CQDs induce reconstitution of the primary solvation sheath into a stable [Zn(H 2 O) 4 (o‐CQDs)] 2+ complex, reducing the desolvation barrier from 23.6 to 17.8 kJ mol −1 . Furthermore, the continuous 2D network elevates the Zn 2+ transference number from 0.51 to 0.85 and ionic conductivity enhanced from 40 to 93 mS cm −1 . At the electrode interface, a protective electric double layer promotes preferential Zn(002) deposition while effectively excluding reactive water species. Thus, the Zn//Zn symmetric cells achieve a long cycling life (>10 000 h) and high average Coulombic efficiency (99.6%). Full cells employing the commercial activated carbon as cathode retain >96.1% capacity after 100 000 cycles. More importantly, it can work in a wide temperature range from −10°C to 60°C, with obvious self‐healing capability. This work establishes a synergistic regulation method by using a functional carbonic additive to optimize interfacial engineering to achieve durable zinc‐based energy storage devices.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.79505