Abstract
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 nextgeneration
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.