Interfacial Electronic Nanoarchitectonics for Sustainable Zn─I ₂ Batteries

Abstract

Abstract Aqueous zinc‐iodine batteries (AZIBs) are intrinsically safe and cost‐effective, yet their performance is limited by sluggish iodine redox kinetics, poor conductivity, and severe polyiodide shuttling. Herein, we design a heterostructure cathode by depositing titanium nitride (TiN) onto biomass‐derived porous nitrogen‐doped carbon (PNC), forming a tailored PNC@TiN interface that markedly enhances electronic conductivity and regulates iodine electrochemistry. Density functional theory (DFT) calculations reveal pronounced interfacial charge redistribution with an upward shift of the Ti d ‐band centeri, enabling strong Ti─I bonding through orbital coupling among Ti 3 d , C/N 2 p , and I 5 p states, as well as improved iodine affinity with suppressed polyiodide shuttle. Accordingly, the AZIB with the PNC@TiN cathode exhibits a high reversible capacity of 166.9 mAh g −1 after 21,000 cycles at 2.0 A g −1 (95.4% retention), and exceptional durability over 66,000 cycles at 5.0 A g −1 with an ultralow capacity decay of 0.00028% per cycle. Furthermore, the as‐assembled pouch cells achieve 176.1 mAh g −1 with negligible degradation, highlighting their practical viability. This work underscores the crucial role of interfacial electronic nanoarchitectonics in modulating iodine chemistry, and presents a sustainable strategy to repurpose biomass into advanced energy‐storage materials.