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

Abstract

Rechargeable lithium–iodine\nbatteries with abundant raw\nmaterials and low cost are promising electrochemical energy storage\nsystems. Herein, we demonstrate that anchoring iodine to N-doped hollow\ncarbon fold-hemisphere (N-FHS) is highly efficient to overcome slow\nkinetics and low stability of iodine cathode in lithium–iodine\nbatteries. For the first time, significant effects of carbon framework\narchitecture on the lithium storage performance of iodine cathode\nare studied in detail. Notably, the fold-hemisphere (N-FHS) is more\neffective than the similar architectures, such as hollow sphere (N-S)\nor hemisphere (N-HS), in modifying slow ion transport capability and\nfast structure deterioration. The superior property of iodine@N-FHS\nis associated with its highly porous structure and strong interconnection\nto iodine. The iodine deterioration mechanism in lithium–iodine\nbattery is analyzed, and the deterioration processes of iodine in\ndifferent carbon frameworks during cycling are investigated. This\nwork opens a new avenue to solve the key problems in lithium–iodine\nbatteries, allowing it an important candidate for energy storage.