High-performance wide-temperature zinc-ion batteries with K⁺/C₃N₄ co-intercalated ammonium vanadate cathodes

Abstract

NH4V4O10 (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 C3N4 co-intercalated NVO (KNVO-C3N4) 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 C3N4 content to achieve higher reaction kinetics. The synergistic effect of K+ and C3N4 co-intercalation significantly reduces the electrostatic interaction between Zn2+ and the [VOn] layer, improves the specific capacity and cycling stability. Consequently, the KNVO-C3N4 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.