Abstract
The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I2 batteries,but is unclear,retarding further advances.This work innovatively indicates a great contribution of～2.5nm pore structure of nanocarbons to efficient iodine adsorption,rapid I-↔ I2 conversion,and polyiodide inhibition,via scrupulously designing catalysts with controllable pore sizes systematically.The I2-loading within the designed nitrogen-doped nanocarbons can reach up to as high as 60.8 wt％.The batteries based on the cathode deliver impressive performances with a large capacity of 178.8 mAh/g and long-term cycling stability more than 4000 h at 5.0 C.Notably,these is no polyiodide such as I3-and I5-detected during the charge-discharge processes from comprehensive elec-trochemical cyclic voltammetry,X-ray photoelectron spectroscopy,and Raman technique.This work pro-vides a novel knowledge-guided concept for rational pore design,promising better Zn-I2 batteries,which is also hoped to benefit other advanced energy technologies,such as Li-S,Li-ion,and Al-I2 batteries.
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