Interface-centric strategies in Nb₂O₅/MoS₂ heterostructure: Leveraging synergistic potential for dual-function electrochromic energy storage

The advancement of multifunctional materials integrating electrochromic and energy storage functionalities represents a transformative approach to next-generation energy systems. This study reports the Nb₂O₅/MoS₂ heterostructure thin films, fabricated via a hydrothermal method, for dual electrochromic energy storage applications. The optimized heterostructure leverages the complementary properties of Nb₂O₅ and MoS₂, attaining unrivaled performance in both domains. The electrochemical determinations reveal that the Nb@Mo20 exhibits an areal capacitance of 176.74 mF/cm² at 0.8 mA/cm², alongside magnificent cycling stability. Owing to its favorable structural characteristics, the heterostructure unveiled striking optical modulation of 77.11 % at 600 nm, transitioning between 82.25 % (bleached) and 5.14 % (colored) states. It delivered rapid switching times, with a high coloration efficiency of 98.92 cm²/C. Long-term cycling stability conveyed minimal performance loss after 20,000 s, ensuring sustained efficiency. Additionally, a hybrid electrochromic supercapacitor is developed, demonstrating a notable optical contrast (73.60 % at 600 nm), acceptable capacitance with good cycling stability. The device maintains a wide voltage range, effectively powering LEDs, showcasing scalability for real-world applications. The design principles outlined in this study offer valuable insights into the development of high-performance electrochromic energy storage materials, highlighting their potential applications in energy efficiency and storage.