∼ 2.5 nm pores in carbon-based cathode promise better zinc-iodine batteries

The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I 2 batteries, but is unclear, retarding further advances. This work innovatively indicates a great contribution of similar to 2.5 nm pore structure of nanocarbons to efficient iodine adsorption, rapid I - <-> I 2 conversion, and polyiodide inhibition, via scrupulously designing catalysts with controllable pore sizes systematically. The I 2 -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 40 0 0 h at 5.0 C. Notably, these is no polyiodide such as I 3 - and I 5 - detected during the charge -discharge processes from comprehensive electrochemical cyclic voltammetry, X-ray photoelectron spectroscopy, and Raman technique. This work provides a novel knowledge -guided concept for rational pore design, promising better Zn-I 2 batteries, which is also hoped to benefit other advanced energy technologies, such as Li-S, Li -ion, and Al-I 2 batteries. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.