Ni3V2O8/CNFs composite electrodes for flexible supercapacitors with excellent cycling stability

The emergence of Internet of Things (IoT) and wearable devices has driven demand for flexible and miniaturized supercapacitors. Screen printing, as an emerging technology, demonstrates strong vitality and enormous potential in the manufacturing of supercapacitors. Herein, the Ni 3 V 2 O 8 /carbon nanofibers (CNFs) composite electrode materials are prepared via hydrothermal pyrolysis, and its morphology, composition, oxidation states, and bonding information are carefully characterized. Electrochemical characterizations revealed that the Ni 3 V 2 O 8 /CNFs electrode exhibited outstanding performance, with a significant specific capacitance of 1645 F g −1 (1 A g −1 ). Furthermore, the electrode demonstrated remarkable cycling stability, with a capacitance retention of 80.4 % after 20,000 cycles, highlighting its excellent rate capability and robust pseudocapacitive properties. Subsequently, the screen-printing inks are formulated using as-prepared Ni 3 V 2 O 8 /CNFs, acetylene black, and ethyl cellulose. The flexible printed Ni 3 V 2 O 8 /CNFs//AC asymmetric supercapacitor exhibited an areal capacitance of 234.18 mF cm −2 (1 mA cm −2 ). After 15,000 charge-discharge cycles, it retained 76.73 % of its capacitance. The individual supercapacitor achieved a charging voltage of up to 1.60 V, and could power an LED bouquet for over 35 s. We anticipate that the printed supercapacitor will become a promising candidate for next-generation wearable and portable energy, storage systems.