Iodine-functionalized Ti 3 C 2 T x MXene interfacial layers drive ultrastable iron–iodine batteries to achieve high iodine loading and cycling durability

I 2 /Ti 3 C 2 T x MXene composite cathode (high iodine loading) enables Fe–I 2 batteries to show strong stability, good capacity retention, and robust coulombic efficiency over extended cycles, ideal for advanced energy storage.