Iodine doping accelerating ion kinetics and stabilizing flower-like NH4V4O10 cathodes for aqueous zinc-ion batteries

Iodine-doped flower-like NH 4 V 4 O 10 is fabricated via one-step hydrothermal route. • I - partially replaces O 2- , expanding interlayer spacing and creating O vacancies. • I-doped NH 4 V 4 O 10 delivers 482.9 mAh g −1 at 0.3 A g −1 with remarkable rate capability. • Maintains 219.1 mAh g −1 after 2000 cycles at 5 A g −1 with robust stability. • Boosted pseudocapacitance and Zn 2+ diffusion kinetics are confirmed by GITT/EIS. Layered NH 4 V 4 O 10 suffers from poor electronic conductivity, sluggish Zn 2 + transport and structural degradation when used as cathodes for aqueous zinc-ion batteries (AZIBs). Herein, flower-like iodine(I)-doped NH 4 V 4 O 10 (I-NVO) is synthesized through one-step hydrothermal route. I - partially substitution for lattice O 2- , simultaneously introduces oxygen vacancies and expanding interlayer spacing, which jointly improve pseudocapacitive behavior and facilitate and Zn 2+ transport. The optimized I 0.05 -NVO exhibits a specific capacity of 482.91 mAh g −1 at 0.3 A g −1 and maintains 219.18 mAh g −1 after 2000 long-term cycles at 5 A g −1 . Combined electrochemical tests and ex-situ characterizations confirm enhanced redox kinetics and reversible Zn 2+ storage capability. This halogen-anion doping provides a feasible strategy for developing high-performance vanadium cathode materials toward AZIB applications. Download: Download high-res image (200KB) Download: Download full-size image