VO2-Polymorph-Dependent Energy-Storage Performance of Laser-Scribed Flexible Microsupercapacitors

With the rapid advancement of portable electronic devices, the demand for miniaturized and integrated energy-storage systems has grown significantly. Among these, microbatteries and microsupercapacitors (MSCs) play a crucial role in powering next-generation wearable and flexible electronics. In this study, we report high-performance MSCs based on various polymorphs of vanadium dioxide (VO 2 ), including VO 2 (A), VO 2 (B), VO 2 (D), and VO 2 (M) on laser-induced graphene (LIG) polyimide (PI) films. Through comprehensive electrochemical characterization, we found that the flexible VO 2 (M)-based MSC exhibited a superior energy-storage performance, delivering a high specific energy of 0.66 mWh cm –2 and a power density of 858 W cm –2, outperforming other VO 2 polymorphs. Furthermore, the device demonstrated remarkable mechanical flexibility, maintaining a stable electrochemical performance even at bending angles of 0°, 120°, and 180°. These findings highlight the potential of VO 2 (M)-based MSCs as promising candidates for all-solid-state, flexible, miniaturized energy-storage devices, paving the way for their integration into next-generation portable and wearable electronic devices.