N, O Co-doped porous carbon host with interconnected reaction microenvironments for long-life zinc-iodine batteries

High energy density, intrinsic safety, and eco-friendliness of aqueous zinc‑iodine (Zn I 2 ) batteries are hindered by the shuttle effect and sluggish iodine redox kinetics. These limitations result in the formation of highly soluble triiodide ( I 3 − ) intermediates, which adversely affect energy density and cycle life. To address these issues, we designed N, O co-doped porous carbon with interconnected microchannels (N/O-PC) to create abundant catalytic sites and a locally strong adsorption microenvironment for the iodine reduction reaction (IRR). The unique structure of N/O-PC facilitates electrolyte penetration and enhances iodine fixation and loading, effectively inhibiting the formation and shuttling of I 3 − . Leveraging this favorable microenvironment, the battery exhibits exceptional cycling stability with a high capacitance retention rate after 65,000 cycles at 10 A g −1 . In situ characterization and theoretical calculations confirm that N/O dopants serve as active centers promoting the chemical immobilization and catalytic conversion of polyiodides. This work integrates physical adsorption and catalytic conversion to construct a host material, offering a novel strategy for developing a powerful Zn I 2 batteries.