Ultra‐stable Electrolytic Zn‐I2 Batteries Based on Nanocarbon Wrapped by Highly Efficient Single‐Atom Fe‐NC Iodine Catalysts

Abstract Aqueous Zn‐iodine (Zn‐I 2 ) conversion batteries with iodine redox chemistry suffers the severe polyiodide shuttling and sluggish redox kinetics, which impede the battery lifespan and rate capability. Herein, we introduce an ultrastable Zn‐I 2 battery based on single‐atom Fe‐N‐C encapsulated high‐surface‐area carbon (HC@FeNC) as the core‐shell cathode materials, which accelerate the I − /I 3 − /I° conversion significantly. The robust chemical‐physical interaction between polyiodides and Fe‐N 4 sites tightly binds the polyiodide ions and suppresses the polyiodide shuttling, thereby significantly enhancing the coulombic efficiency. As a result, the core‐shell HC@FeNC cathode endows the electrolytic Zn–I 2 battery with an excellent capacity, remarkable rate capability, and an ultra‐long lifespan over 60000 cycles. More importantly, a practical 253 Wh kg −1 pouch cell shows good capacity retention of 84% after 100 cycles, underscoring its considerable potential for commercial Zn‐I 2 batteries. This article is protected by copyright. All rights reserved