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 (VO2), including VO2(A), VO2(B), VO2(D), and VO2(M) on laser-induced graphene (LIG) polyimide (PI) films. Through comprehensive electrochemical characterization, we found that the flexible VO2(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 VO2 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 VO2(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.