High-Performance Wide-Temperature Zinc-Ion Batteries with K+/C3N4 Co-Intercalated Ammonium Vanadate Cathodes

Abstract NH 4 V 4 O 10 (NVO) is considered a promising cathode material for aqueous zinc-ion batteries due to its high theoretical capacity. However, its practical application is limited by irreversible deamination, structural collapse, and sluggish reaction kinetics during cycling. Herein, K + and C 3 N 4 co-intercalated NVO (KNVO-C 3 N 4 ) nanosheets with expanded interlayer spacing are synthesized for the first time to achieve high-rate, stable, and wide-temperature cathodes. Molecular dynamics and experimental results confirm that there is an optimal C 3 N 4 content to achieve higher reaction kinetics. The synergistic effect of K + and C 3 N 4 co-intercalation significantly reduces the electrostatic interaction between Zn 2+ and the [VO n ] layer, improves the specific capacity and cycling stability. Consequently, the KNVO-C 3 N 4 electrode displays outstanding electrochemical performance at room temperature and under extreme environments. It exhibits excellent rate performance (228.4 mAh g −1 at 20 A g −1 ), long-term cycling stability (174.2 mAh g −1 after 10,000 cycles at 20 A g −1 ), and power/energy density (210.0 Wh kg −1 at 14,200 W kg −1 ) at room temperature. Notably, it shows remarkable storage performance at − 20 °C (111.3 mAh g −1 at 20 A g −1 ) and 60 °C (208.6 mAh g −1 at 20 A g −1 ). This strategy offers a novel approach to developing high-performance cathodes capable of operating under extreme temperatures.