Anchoring Iodine to N‑Doped Hollow Carbon Fold-Hemisphere: Toward a Fast and Stable Cathode for Rechargeable Lithium–Iodine Batteries

Rechargeable lithium–iodine batteries with abundant raw materials and low cost are promising electrochemical energy storage systems. Herein, we demonstrate that anchoring iodine to N-doped hollow carbon fold-hemisphere (N-FHS) is highly efficient to overcome slow kinetics and low stability of iodine cathode in lithium–iodine batteries. For the first time, significant effects of carbon framework architecture on the lithium storage performance of iodine cathode are studied in detail. Notably, the fold-hemisphere (N-FHS) is more effective than the similar architectures, such as hollow sphere (N-S) or hemisphere (N-HS), in modifying slow ion transport capability and fast structure deterioration. The superior property of iodine@N-FHS is associated with its highly porous structure and strong interconnection to iodine. The iodine deterioration mechanism in lithium–iodine battery is analyzed, and the deterioration processes of iodine in different carbon frameworks during cycling are investigated. This work opens a new avenue to solve the key problems in lithium–iodine batteries, allowing it an important candidate for energy storage.