NiV2O6·H2O Nanosheets as Electrode Materials for Asymmetric Supercapacitors

Asymmetric supercapacitors (ASCs) have garnered significant attention as efficient and practical energy storage devices due to their high energy density and ultralong lifespan. The performance of the ASC is largely dependent on the composition and structure of electrode materials. This study introduces the synthesis of a hydrated nickel vanadate (NiV₂O₆·H₂O) nanosheet electrode material and evaluates its electrochemical performance in supercapacitors. Notably, the NiV₂O₆·H₂O nanosheets demonstrated a high specific capacitance of 1053.3 F g^–1 at 1 A g^–1 and 113.0% capacitance retention after 10000 cycles at 5 A g^–1. Furthermore, an ASC assembled with NiV₂O₆·H₂O nanosheets and activated carbon (AC) achieved a high energy density of 27.6 Wh kg^–1 at a power density of 725.3 W kg^–1, demonstrating its promising potential in ASC applications. Additionally, the obtained NiV₂O₆·H₂O nanosheets were examined as an anode for lithium-ion batteries (LIBs), achieving a specific capacity of 472.4 mA h g^–1 after 1000 cycles at 500 mA g^–1. This work presents an approach to the design and development of electrode materials for high-performance energy storage devices.