Kinetics regulation in yarn-shaped Zn-ammonium vanadate batteries by sodium-ion and polyaniline co-intercalation and carbon nanotube intermediate layer

Flexible yarn-shaped aqueous zinc ion batteries (AZIBs) show great promise for wearable and portable energy devices due to their low cost, small volume, flexibility, and compatibility with textiles. However, challenges such as low capacity and energy density due to sluggish Zn 2+ ion kinetics prevent their practical applications in wearable electronics. Herein, we develop a strategy involving Na + ions and polyaniline co-intercalation, along with coaxially wrapping, to fabricate yarn-shaped AZIBs containing core-sheath carbon nanotube/Na + ion and polyaniline co-intercalated NH 4 V 4 O 10 (NaNVO-PANI) yarn cathode and zinc wire anode. The NaNVO-PANI structure enhances electrochemical performance by enlarging interlayer spacing and improving electronic conductivity. The resulting yarn batteries exhibit high specific capacity (346.9 mA h g −1 ), energy density (255.2 Wh kg −1 ), and long cycling life, making them suitable for self-powered energy systems. Notably, the CNT sheet sheath enables tunable charge storage kinetics by accelerating ion mixing between the electrolyte fluid and electrode interface through turbulence effects. This work is of great significance for developing high-performance flexible yarn-shaped AZIBs for wearable electronics.